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Sample records for include biosorption diminished

  1. Biosorption of 239Pu by immobilized sargassum fusiforme

    International Nuclear Information System (INIS)

    Liang Zhirong; Chen Qi; Wu Yusheng

    2009-01-01

    Sargassum fusiforme was immobilized with calcium alginates and its biosorption property to 239 Pu was studied by batch and column methods. Biosorption equilibrium time of immobilized Sargassum fusiforme biosorbent to 239 Pu is 120 min and biosorption efficiency is over 99.2% when the initial concentration of 239 Pu is 21.5 kBq/L and pH is 2.5-5.0. After five times repetition biosorption-desorption cycles biosorption efficiency is still over 98.0% when the velocity of flow is 2 ml/min in column experiment. Immobilized Sargassum fusiforme biosorbent is better to 239 Pu due to its better chemical stability, mechanical strength, lower cost, high biosorption efficiency and repeated biosorption-desorption cycles. (authors)

  2. Assessment of cationic dye biosorption characteristics of untreated and non-conventional biomass: Pyracantha coccinea berries

    Energy Technology Data Exchange (ETDEWEB)

    Akar, Tamer, E-mail: takar@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Science, Eskisehir Osmangazi University, 26480, Eskisehir (Turkey); Anilan, Burcu; Gorgulu, Asli [Department of Cemistry Education, Faculty of Education, Eskisehir Osmangazi University, 26480, Eskisehir (Turkey); Akar, Sibel Tunali [Department of Chemistry, Faculty of Arts and Science, Eskisehir Osmangazi University, 26480, Eskisehir (Turkey)

    2009-09-15

    This work reports on the assessment of the dye methylene blue biosorption properties of Pyracantha coccinea berries under different experimental conditions. Equilibrium and kinetic studies were carried out to determine the biosorption capacity and rate constants. The highest biosorption yield was observed at about pH 6.0, while the biosorption capacity of the biomass decreased with decreasing initial pH values. Batch equilibrium data obtained at different temperatures (15, 25, 35 and 45 deg. C) were modeled by Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherms. Langmuir isotherm model fitted the equilibrium data, at the all studied temperatures, better than the other isotherm models indicating monolayer dye biosorption process. The highest monolayer biosorption capacity was found to be 127.50 mg/g dry biomass at 45 deg. C. Kinetic studies indicate that the biosorption process followed the pseudo-second-order model, rather than the pseudo-first-order model. {Delta}G{sup o}, {Delta}H{sup o} and {Delta}S{sup o} parameters of biosorption show that the process is spontaneous and endothermic in nature. The biosorbent-dye interaction mechanisms were investigated using a combination of Fourier transform infrared spectroscopy and scanning electron microscopy. The biosorption procedure was applied to simulated wastewater including several pollutants. The results obtained indicated that the suggested inexpensive and readily available biomaterial has a good potential for the biosorptive removal of basic dye.

  3. Assessment of cationic dye biosorption characteristics of untreated and non-conventional biomass: Pyracantha coccinea berries

    International Nuclear Information System (INIS)

    Akar, Tamer; Anilan, Burcu; Gorgulu, Asli; Akar, Sibel Tunali

    2009-01-01

    This work reports on the assessment of the dye methylene blue biosorption properties of Pyracantha coccinea berries under different experimental conditions. Equilibrium and kinetic studies were carried out to determine the biosorption capacity and rate constants. The highest biosorption yield was observed at about pH 6.0, while the biosorption capacity of the biomass decreased with decreasing initial pH values. Batch equilibrium data obtained at different temperatures (15, 25, 35 and 45 deg. C) were modeled by Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherms. Langmuir isotherm model fitted the equilibrium data, at the all studied temperatures, better than the other isotherm models indicating monolayer dye biosorption process. The highest monolayer biosorption capacity was found to be 127.50 mg/g dry biomass at 45 deg. C. Kinetic studies indicate that the biosorption process followed the pseudo-second-order model, rather than the pseudo-first-order model. ΔG o , ΔH o and ΔS o parameters of biosorption show that the process is spontaneous and endothermic in nature. The biosorbent-dye interaction mechanisms were investigated using a combination of Fourier transform infrared spectroscopy and scanning electron microscopy. The biosorption procedure was applied to simulated wastewater including several pollutants. The results obtained indicated that the suggested inexpensive and readily available biomaterial has a good potential for the biosorptive removal of basic dye.

  4. Effect of pH on cadmium biosorption by coconut copra meal

    International Nuclear Information System (INIS)

    Ofomaja, Augustine E.; Ho, Y.-S.

    2007-01-01

    Biosorption of cadmium ion by coconut copra meal, an agricultural waste product was investigated as a function of initial solution pH and initial cadmium concentration. Pseudo-second-order kinetic analyses were performed to determine the rate constant of biosorption, the equilibrium capacity, and initial biosorption rate. Cadmium biosorption by copra meal was found to be dependent on the initial solution pH and initial cadmium concentration. Ion exchange occurred in the initial biosorption period. In addition, mathematical relationships were drawn to relate the change in the solution hydrogen ion concentration with equilibrium biosorption capacity, initial cadmium concentration, and equilibrium biosorption capacity

  5. Lead (II) biosorption equilibrium and characterization through FT-IR and SEM-EDAX crosslinked pectin from orange peels

    International Nuclear Information System (INIS)

    Garcia Villegas, Victor R.; Ale Borja, Neptali; Guzman Lezama, Enrique G.; Maldonado Garcia, Holger J.; Yipmantin Ojeda, Andrea G.

    2013-01-01

    Pectic material extracted from orange peels was previously cross-linked to diminish hydration and swelling capacity when pectin is found in aqueous solution medium. Degree of metoxilation (DM), galacturonic acid anhydrous (% AGA) and pKa determination allowed characterizing biosorbent. Maximum sorption capacity was obtained at pH between 4.5 and 5.5. For data processing and statistical treatment informatics Orign 6.0 version program was used. Data from biosorption equilibrium had a better fit on Langmuir sorption equation model, obtaining q max = 186 mg/g as a maximum adsorption capacity. Fourier transform infrared spectroscopy analysis (FT-IR) allowed recognizing characteristic functional groups presents as well as biomass modifications. Biosorbent surface morphologic was studied by scanning electron microscope (SEM) and elemental composition biomass before biosorption process was obtained through Energy-dispersive X-ray spectroscopy (EDAX). (author)

  6. Biosorption of Sr(II) from aqueous solutions using aerobic granules. Equilibrium and mechanisms

    International Nuclear Information System (INIS)

    Li Wang; Xiang Liu; Xiao-feng Chen; Duu-Jong Lee; Joo-Hwa Tay; Yi Zhang; Chun-li Wan

    2015-01-01

    Aqueous strontium biosorption using aerobic granules was investigated. Parameters affecting the biosorption were optimized, including initial pH, biomass dosage, temperature, and rotation speed. The equilibrium data were fitted using Langmuir and Freundlich models, and both could well describe the process (R 2 = 0.987 and 0.989, respectively). Ion exchange and water-desorption experiments were conducted, and ion exchange together with physical adsorption were found to be the main mechanisms. The aerobic granules were characterized with methods including scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The results showed that surface complexation could also be involved in the Sr(II) biosorption. (author)

  7. Biosorption of gold from computer microprocessor leachate solutions using chitin.

    Science.gov (United States)

    Côrtes, Letícia N; Tanabe, Eduardo H; Bertuol, Daniel A; Dotto, Guilherme L

    2015-11-01

    The biosorption of gold from discarded computer microprocessor (DCM) leachate solutions was studied using chitin as a biosorbent. The DCM components were leached with thiourea solutions, and two procedures were tested for recovery of gold from the leachates: (1) biosorption and (2) precipitation followed by biosorption. For each procedure, the biosorption was evaluated considering kinetic, equilibrium, and thermodynamic aspects. The general order model was able to represent the kinetic behavior, and the equilibrium was well represented by the BET model. The maximum biosorption capacities were around 35 mg g(-1) for both procedures. The biosorption of gold on chitin was a spontaneous, favorable, and exothermic process. It was found that precipitation followed by biosorption resulted in the best gold recovery, because other species were removed from the leachate solution in the precipitation step. This method enabled about 80% of the gold to be recovered, using 20 g L(-1) of chitin at 298 K for 4 h. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Biosorption of heavy metals from wastewater by biosolids

    Energy Technology Data Exchange (ETDEWEB)

    Orhan, Y.; Bueyuekguengoer, H. [Ondokuz Mayis University, Engineering Faculty, Environmental Engineering Department, 55139 Samsun (Turkey); Hrenovic, J. [University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb (Croatia)

    2006-08-15

    In a study where the removal of heavy metals from wastewater is the primary aim, the biosorption of heavy metals onto biosolids prepared as Pseudomonas aeruginosa immobilized onto granular activated carbon was investigated in batch and column systems. In the batch system, adsorption equilibriums of heavy metals were reached between 20 and 50 min, and the optimal dosage of biosolids was 0.3 g/L. The biosorption efficiencies were 84, 80, 79, 59 and 42 % for Cr(VI), Ni(II), Cu(II), Zn(II) and Cd(II) ions, respectively. The rate constants of biosorption and pore diffusion of heavy metals were 0.013-0.089 min{sup -1} and 0.026-0.690 min{sup -0.5}. In the column systems, the biosorption efficiencies for all heavy metals increased up to 81-100 %. The affinity of biosorption for various metal ions towards biosolids was decreased in the order: Cr = Ni > Cu > Zn > Cd. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  9. Competitive biosorption of thorium and uranium by actinomycetes

    International Nuclear Information System (INIS)

    Nakajima, Akira; Tsuruta, Takehiko

    2002-01-01

    The competitive biosorption of thorium and uranium by actinomycetes was examined. Of the actinomycetes tested, Streptomyces levoris showed the highest ability to sorb both thorium and uranium from aqueous systems. Thorium sorption was not affected by co-existed uranium, while uranium sorption was strongly hindered by co-existed thorium. The amounts of both thorium and uranium sorbed by Streptomyces levoris cells increased with an increase of the solution pH. Although the equilibrium isotherm of uranium biosorption is in similar manner as that of thorium biosorption, uranium was sorbed much faster than thorium. Biosorption isotherm of each metal ion could be well fitted by Langmuir isotherm taking the ionic charge of metal ions into account. The Langmuir isotherm for binary system did not explain completely the competitive biosorption of thorium and uranium by Streptomyces levoris. However, the results suggested that the ion species of both metals in the cells should be Th(OH) 2 2+ and UO 2 2+ , respectively. (author)

  10. Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

    Directory of Open Access Journals (Sweden)

    G. L. Dotto

    2013-03-01

    Full Text Available The equilibrium and thermodynamics of azo dye (tartrazine and allura red biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0% and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

  11. [Biosorption of heavy metals in fluoritum decoction by fungal mycelium].

    Science.gov (United States)

    Cui, Pei-wu; Hu, Wei; Hu, Ya-qiang; Tan, Zhao-yang

    2014-09-01

    To explore the biosorption technology of heavy metals in Fluoritum decoction by fungal mycelium. Four factors including fungal mycelium amount, adsorption time, pH value and temperature were employed to estimate the fungal biomass adsorption conditions for removing the heavy metals in Fluoritum decoction. Then an orthogonal experimental design was taken to optimize the biosorption process, and the removal efficiency was also evaluated. Under the optimized conditions of 1.0 g/50 mL Fluoritum decoction, 3 hours adsorption time, pH 5.0 and 40 degrees C, a result of 70.12% heavy metals removal rate was accomplished with 35.99% calcium ion loss. The study indicates that removing of heavy metals in Fluoritum decoction through fungal mycelium is feasible, and the experiment results can also provide a basis for further research on biosorption of heavy metals in traditional Chinese medicine

  12. Biosorption of americium by alginate beads

    International Nuclear Information System (INIS)

    Borba, Tania Regina de; Marumo, Julio Takehiro; Goes, Marcos Maciel de; Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi

    2009-01-01

    The use of biotechnology to remove heavy metals from wastes plays great potential in treatment of radioactive wastes and therefore the aim of this study was to evaluate the biosorption of americium by alginate beads. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. The calcium alginate beads as biosorbent were prepared and analyzed for americium uptaking. The experiments were performed in different solution activity concentrations, pH and exposure time. The results suggest that biosorption process is more efficient at pH 4 and for 75, 150, 300 Bq/mL and 120 minutes were necessary to remove almost 100% of the americium-241 from the solution. (author)

  13. Biosorption of heavy metals by immobilized microalgae; Biosorption von Schwermetallen durch immobilisierte Mikroalgen

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, A.; Bunke, G.; Goetz, P.; Buchholz, R. [Technische Univ. Berlin (Germany). Fachgebiet Bioverfahrenstechnik

    1999-07-01

    Some microalgae stand out by the fact that they are highly capable of adsorbing heavy metals (biosorption). In contrast to bioaccumulation, where heavy metals are actively integrated into living cells, biosorption is a process of chemical-physical deposition to functional groups of the cell wall components. For a process-technological application, different reactor configurations may be used. Owing to different advantages such as a continuous mode of operation, attainable low effluent concentrations, low operating cost, ease of scaling up, modular design, modest space demand and a high degree of automation, packed-bed adsorption is the process-technological solution to be preferred. Mathematical modelling of adsorption kinetics as a basis for scaling up requires knowledge of resistances to suspended matter transport for the adsorbents used. By appropriate experiments the different resistances (film resistance, diffusion resistance inside particles) need to be decoupled from each other prior to their determination. (orig.) [German] Einige Mikroalgen zeichnen sich dadurch aus, im hohen Masse Schwermetalle zu adsorbieren (Biosorption). Im Gegensatz zur Bioakkumulation, bei der die Schwermetalle aktiv in die lebende Zelle aufgenommen werden, handelt es sich bei der Biosorption um einen chemischen/physikalischen Anlagerungsprozess an funktionelle Gruppen der Zellwandkomponenten. Fuer eine verfahrenstechnische Umsetzung koennen unterschiedliche Reaktorkonfigurationen verwendet werden. Aufgrund verschiedener Vorteile wie kontinuierliche Betriebsweise, niedrige erreichbare Ablaufkonzentration, geringe Betriebskosten, einfache Scale-up-Faehigkeit, modulare Bauweise, geringer Platzbedarf sowie hoher Automatisierungsgrad ist eine Festbettadsorption als verfahrenstechnische Loesung vorzuziehen. Eine mathematische Modellierung der Adsorptionskinetik, als Basis einer Massstabsvergroesserung, erfordert die Kenntnis der Stofftransportwiderstaende bei den verwendeten Adsorbentien

  14. Biodecolorization of Textile Dye Effluent by Biosorption on Fungal Biomass Materials

    Science.gov (United States)

    Kabbout, Rana; Taha, Samir

    Colored industrial effluents have become a vital source of water pollution, and because water is the most important natural source; its treatment is a responsibility. Usually colored wastewater is treated by physical and chemical processes. But these technologies are ineffective in removing dyes, expensive and not adaptable to a wide range of colored water. Biosorption was identified as the preferred technique for bleaching colored wastewater by giving the best results. This treatment was based on the use of dead fungal biomass as new material for treating industrial colored effluents by biosorption. We studied the ability of biosorption of methylene blue (MB) by Aspergillus fumigatus and optimize the conditions for better absorption. Biosorption reaches 68% at 120 min. Similarly, the biosorbed amount increases up to 65% with pH from 4 to 6, and it's similar and around 90% for pH from 7 to 13. At ambient temperature 20-22 °C, the percentage of biosorption of methylene blue was optimal. The kinetic of biosorption is directly related to the surface of biosorbent when the particle size is also an important factor affecting the ability of biosorption. Also the biosorption of methylene blue increases with the dose of biosorbent due to an augmentation of the adsorption surface. In this study, for an initial concentration of 12 mg/L of MB (biosorbent/solution ratio=2g/L) buffered to alkaline pH, and a contact time of 120 min, biosorption takes place at an ambient temperature and reaches 93.5% under these conditions.

  15. Biosorption of copper (II) from aqueous solution by mycelial pellets ...

    African Journals Online (AJOL)

    The optimum diameter and pH for biosorption of copper (II) was found to be 1.0 to 1.2 mm and 4.0. Evaluation of the experimental data in terms of biosorption dynamics showed that the biosorption of copper (II) onto MPRO followed the pseudo-second-order kinetic model. The equilibrium data fitted very well to the Langmuir ...

  16. Mechanism of biosorption of Heavy metals by mucor rouxii

    Energy Technology Data Exchange (ETDEWEB)

    Yan, G. [Alberta Capital Region Wastewater Commission, Fort Saskatchewan, Alberta (Canada); Viraraghavan, T. [Faculty of Engineering, University of Regina, Regina, Saskatchewan (Canada)

    2008-08-15

    Fungi such as Aspergillus niger and Mucor rouxii are capable of removing heavy metals from aqueous solutions. The role various functional groups play in the cell wall of M. rouxii in metal biosorption of lead, cadmium, nickel and zinc was investigated in this paper. The biomass was chemically treated to modify the functional carboxyl, amino and phosphate groups. These modifications were examined by means of infrared spectroscopy. It was found that an esterification of the carboxyl groups and phosphate and a methylation of the amine groups significantly decreased the biosorption of the heavy metals studied. Thus, the carboxylate, amine and phosphate groups were recognized as important in the biosorption of metal ions by M. rouxii biomass. The role the lipids fraction play was not significant. The study showed that Na, K, Ca and Mg ions were released from the biomass after biosorption of Pb,Cd,Ni and Zn, indicating that ion exchange was a key mechanism in the biosorption of metal ions by M. rouxii biomass. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  17. Investigation on batch biosorption of lead using Lactobacillius ...

    African Journals Online (AJOL)

    In this research, the biosorption of lead by Lactobacillus bulgaricus was investigated. The mechanism for the biosorption was similar to ionic exchanger. The media pH, weight of dried biomass and initial lead concentration were investigated at ambient temperature. At high acidic solution (pH<1.5) and also in alkaline ...

  18. Statistical analysis and optimization of copper biosorption capability ...

    African Journals Online (AJOL)

    These three variables were further adopted by the three-level Box– Behnken design to correlate between the three variables and to estimate the optimal conditions required for Cu2+ biosorption. Although the maximum value for Cu2+ biosorption was 85%, the calculated optimum percentage was 72%, which was a 2.57-fold ...

  19. Biosorption of Cadmium from Aqueous Solutions Using A local ...

    African Journals Online (AJOL)

    Yomi

    2012-01-31

    Jan 31, 2012 ... Through the study period, the organism was routinely maintained at. 4°C on the ..... Isotherm and Thermodynamic Studies of the Biosorption of Cadmium. (II) by Snail ... An innovative matrix to enhance the biosorption of Cd (II) ...

  20. Biosorption of heavy metal ions from aqueous solution by red macroalgae.

    Science.gov (United States)

    Ibrahim, Wael M

    2011-09-15

    Biosorption is an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine algae has been reported to have high biosorption capacities for a number of heavy metal ions. In this study, four species of red seaweeds Corallina mediterranea, Galaxaura oblongata, Jania rubens and Pterocladia capillacea were examined to remove Co(II), Cd(II), Cr(III) and Pb(II) ions from aqueous solution. The experimental parameters that affect the biosorption process such as pH, contact time and biomass dosage were studied. The maximum biosorption capacity of metal ions was 105.2mg/g at biomass dosage 10 g/L, pH 5 and contact time 60 min. The biosorption efficiency of algal biomass for the removal of heavy metal ions from industrial wastewater was evaluated for two successive cycles. Galaxaura oblongata biomass was relatively more efficient to remove metal ions with mean biosorption efficiency of 84%. This study demonstrated that these seaweeds constitute a promising, efficient, cheap and biodegradable sorbent biomaterial for lowering the heavy metal pollution in the environment. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements-A Review.

    Science.gov (United States)

    Bilal, Muhammad; Rasheed, Tahir; Sosa-Hernández, Juan Eduardo; Raza, Ali; Nabeel, Faran; Iqbal, Hafiz M N

    2018-02-19

    In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed.

  2. Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

    Science.gov (United States)

    Bilal, Muhammad; Rasheed, Tahir; Raza, Ali; Nabeel, Faran

    2018-01-01

    In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed. PMID:29463058

  3. Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

    Directory of Open Access Journals (Sweden)

    Muhammad Bilal

    2018-02-01

    Full Text Available In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed.

  4. Biosorption of mercury by capsulated and slime layerforming Gram ...

    African Journals Online (AJOL)

    The biosorption of mercury by two locally isolated Gram-ve bacilli: Klebsiella pneumoniae ssp. pneumonia (capsulated) and slime layer forming Pseudomonas aeruginosa, was characterized. Mercury adsorption was found to be influenced by the pH value of the biosorption solution, initial metal concentration, amount of the ...

  5. Biosorption of the strontium ion by irradiated Saccharomyces cerevisiae under culture conditions.

    Science.gov (United States)

    Qiu, Liang; Feng, Jundong; Dai, Yaodong; Chang, Shuquan

    2017-06-01

    As a new-emerging method for strontium disposal, biosorption has shown advantages such as high sorption capacity; low cost. In this study, we investigated the potential of Saccharomyces cerevisiae (S. cerevisiae) in strontium disposal under culture conditions and the effects of irradiation on their biosorption capabilities. We found that S. cerevisiae can survive irradiation and grow. Pre-exposure to irradiation rendered S. cerevisiae resistant to further irradiation. Surprisingly, the pre-exposure to irradiation can increase the biosorption capability of S. cerevisiae. We further investigated the factors that influenced the biosorption efficiency, which were (strongest to weakest): pH > strontium concentration > time > temperature. In our orthogonal experiment, the optimal conditions for strontium biosorption by irradiated S. cerevisiae were: pH 7, 150 mg L -1 strontium at the temperature of 32 °C with 30 h. The equilibrium of strontium biosorption was analyzed by Langmuir and Freundlich models, from which the formal model is found to provide a better fit for the experimental results. The kinetics of strontium biosorption by living irradiated S. cerevisiae was found to be comprised of three phases: dramatically increased during 0-9 h, decreased during 12-24 h, and increased during 30-50 h. These results provide a systematic understanding of the biosorption capabilities of irradiated S. cerevisiae, which can contribute to the development of remediating nuclear waste water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Characterization of biosorption process of As(III) on green algae Ulothrix cylindricum

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Sari, Ahmet; Mendil, Durali; Uluozlu, Ozgur Dogan; Soylak, Mustafa; Dogan, Mehmet

    2009-01-01

    Arsenic (As) is generally found as As(III) and As(V) in environmental samples. Toxicity of As(III) is higher than As(V). This paper presents the characteristics of As(III) biosorption from aqueous solution using the green algae (Ulothrix cylindricum) biomass as a function of pH, biomass dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of As(III) by U. cylindricum biomass. The biosorption capacity of U. cylindricum biomass was found as 67.2 mg/g. The metal ions were desorbed from U. cylindricum using 1 M HCl. The high stability of U. cylindricum permitted 10 times of adsorption-elution process along the studies with a slightly decrease about 16% in recovery of As(III) ions. The mean free energy value evaluated from the D-R model indicated that the biosorption of As(III) onto U. cylindricum biomass was taken place by chemical ion-exchange. The calculated thermodynamic parameters, ΔG o , ΔH o and ΔS o showed that the biosorption of As(III) onto U. cylindricum biomass was feasible, spontaneous and exothermic under examined conditions. Experimental data were also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of As(III) followed well pseudo-second-order kinetics.

  7. Potentiality of uranium biosorption from nitric acid solutions using shrimp shells.

    Science.gov (United States)

    Ahmed, S H; El Sheikh, E M; Morsy, A M A

    2014-08-01

    Biosorption has gained important credibility during recent years because of its good performance and low cost. This work is concerned with studying the potentiality of the chitin component of the shrimp shells for uranium biosorption from nitric acid liquid solutions. The structural characteristics of the working chitin have been determined via Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was examined using Scanning Electron Microscopy (SEM). The adsorption capacity of biomass was investigated experimentally. The influence of contact time, pH, metal ion concentration, solution volume to mass ratio and temperature were evaluated and the results were fitted using adsorption isotherm models. The kinetic of uranium biosorption was also investigated as well as biosorption thermodynamic. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Reuse of waste beer yeast sludge for biosorptive decolorization of reactive blue 49 from aqueous solution.

    Science.gov (United States)

    Wang, Baoe; Guo, Xiu

    2011-06-01

    Reactive blue 49 was removed from aqueous solution by biosorption using powder waste sludge composed of Saccharomyces cerevisiae from the beer-brewing industry. The effect of initial pH, temperature and the biosorption thermodynamics, equilibrium, kinetics was investigated in this study. It was found that the biosorption capacity was at maximum at initial pH 3, that the effect of temperature on biosorption of reactive blue 49 was only slight in relation to the large biosorption capacity (25°C, 361 mg g(-1)) according as the biosorption capacity decreased only 43 mg g(-1) at the temperature increased from 25 to 50°C. The biosorption was spontaneous, exothermic in nature and the dye molecules movements decreased slightly in random at the solid/liquid interface during the biosorption of dye on biosorbents. The biosorption equilibrium data could be described by Freundich isotherm model. The biosorption rates were found to be consistent with a pseudo-second-order kinetics model. The functional group interaction analysis between waste beer yeast sludge and reactive blue 49 by the aid of Fourier transform infrared (abbr. FTIR) spectroscopy indicated that amino components involved in protein participated in the biosorption process, which may be achieved by the mutual electrostatic adsorption process between the positively charged amino groups in waste beer yeast sludge with negatively charged sulfonic groups in reactive blue 49.

  9. Biosorption of 241Am by Candida sp

    International Nuclear Information System (INIS)

    Luo Shunzhong; Zhang Taiming; Liu Ning; Yang Yuanyou; Jin Jiannan; Hua Xinfeng

    2003-01-01

    The biosorption of radionuclide 241 Am from solutions by Candida sp., and the influences of experimental conditions on the adsorption were studied. The results showed that the adsorption equilibrium was achieved within 4h and the optimum pH=2. No significant differences on 241 Am biosorption were observed at 10-45 degree C, or challenged with Au 3+ or Ag + , even 1500 times or 4500 times over 241 Am, respectively. The adsorption rate could reach 97.8% by dry Candida sp. of 0.82 g/L in 241 Am solutions (pH=2) of 5.6-111 MBq/L (44.04-873.0 μg/L) (C 0 ), with maximum adsorption capacity (W) of 63.5 MBq/g (501.8 μg/g), implying that the removal of 241 Am by Candida sp. from solutions was feasible. The relationship between activities (C 0 ) and adsorption capacities (W) of 241 Am indicated that the biosorption process could be described by Langmuir adsorption isotherm

  10. Development of engineering parameters for the design of metal biosorption waste treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Graham, W.S.

    1991-12-03

    Untreated landfill leachates and wastes from metal plating and mining operations are sources of environmental contamination by heavy metals. Because of their toxicity and potential for accumulation, the discharge of heavy metals must be controlled. Standard physical and chemical treatments used to remove metals from wastes such as concentration by electro-precipitation, ion exchange, solvent extraction, evaporative recovery, and conventional precipitation, are usually expensive and produce high quantities of sludge. Biosorption is the removal of metals from aqueous solutions by microorganisms. It is called biosorption rather than bioadsorption or bioaccumulation because the mechanisms of removal are not restricted to adsorption or metabolic uptake and so the more general term is preferable and has come to be accepted. In this thesis the focus is one two microorganisms and two metals. However, the possible combinations of conditions such as pH, relative metal molarities, time of contact, and organism are numerous. These experiments are designed to provide optimized parameters to facilitate the design of a functioning biosorption system. The two metals chosen for study are copper and lead in aqueous solution. The two types of microorganisms chosen for testing include an actinomycete and a fungus. The purpose of this research is to identify the significant engineering parameters to be evaluated include reaction rates, equilibrium partitioning of metal ions between those in solution and those removed to the cells, optimum pH for achieving the removal or recovery goal, and biosorption selectivity for one metal over another.

  11. The biosorption of cadmium and lead ions from aqueous Solution ...

    African Journals Online (AJOL)

    The biosorption potentiality of Musa paradisiaca stalk at removing cadmium and lead ions from aqueous solution was investigated. The biosorption experiment was carried out as a function of contact time, initial pH, initial metal ion concentration and biosorbent dose. Adsorption equilibria were obtained from batch ...

  12. Potentiality of uranium biosorption from nitric acid solutions using shrimp shells

    International Nuclear Information System (INIS)

    Ahmed, S.H.; El Sheikh, E.M.; Morsy, A.M.A.

    2014-01-01

    Biosorption has gained important credibility during recent years because of its good performance and low cost. This work is concerned with studying the potentiality of the chitin component of the shrimp shells for uranium biosorption from nitric acid liquid solutions. The structural characteristics of the working chitin have been determined via Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was examined using Scanning Electron Microscopy (SEM). The adsorption capacity of biomass was investigated experimentally. The influence of contact time, pH, metal ion concentration, solution volume to mass ratio and temperature were evaluated and the results were fitted using adsorption isotherm models. The kinetic of uranium biosorption was also investigated as well as biosorption thermodynamic. - Graphical abstract: Physicochemical process of biosorption is known to be promising technique due to the ease of operation and comparable low cost of biosorbant application. Chitin flakes extracted from shrimp shells show potentiality in uranium adsorption reached 7.48 mg uranium at the following conditions: 60 min contact time, pH 3.66, 50:1 V/m ration and at room temperature. The theoretical sorption capacity was 25.31 mg g −1 , according to Langmuir isotherm model. The rate of sorption follows pseudo second-order. The nature of biosorption process is spontaneous and exothermic. - Highlights: • This study shows the potentially for shrimp shell beads for uranium adsorption. • The max. biosorption was achieved at pH 3.6, contact time 60 min, S/L ratio 1:50. • Uranium sorption follows Langmuir isotherm with theoretical capacity of 25.31 g/kg. • The nature of sorption process of the sorbents is spontaneous and exothermic. • The rate of sorption follows pseudo second-order

  13. Biosorption of malachite green from aqueous solutions by Pleurotus ostreatus using Taguchi method

    Science.gov (United States)

    2014-01-01

    Dyes released into the environment have been posing a serious threat to natural ecosystems and aquatic life due to presence of heat, light, chemical and other exposures stable. In this study, the Pleurotus ostreatus (a macro-fungus) was used as a new biosorbent to study the biosorption of hazardous malachite green (MG) from aqueous solutions. The effective disposal of P. ostreatus is a meaningful work for environmental protection and maximum utilization of agricultural residues. The operational parameters such as biosorbent dose, pH, and ionic strength were investigated in a series of batch studies at 25°C. Freundlich isotherm model was described well for the biosorption equilibrium data. The biosorption process followed the pseudo-second-order kinetic model. Taguchi method was used to simplify the experimental number for determining the significance of factors and the optimum levels of experimental factors for MG biosorption. Biosorbent dose and initial MG concentration had significant influences on the percent removal and biosorption capacity. The highest percent removal reached 89.58% and the largest biosorption capacity reached 32.33 mg/g. The Fourier transform infrared spectroscopy (FTIR) showed that the functional groups such as, carboxyl, hydroxyl, amino and phosphonate groups on the biosorbent surface could be the potential adsorption sites for MG biosorption. P. ostreatus can be considered as an alternative biosorbent for the removal of dyes from aqueous solutions. PMID:24620852

  14. Biosorption of fluoride ion from water using the seeds of the ...

    African Journals Online (AJOL)

    Biosorption of fluoride ion from water using the seeds of the cabbage tree ( Moringa ... The maximum fluoride sorption capacity was found to be 1.32 mg.g-1 of dry weight ... Key words: Biosorption, chemisorption, desorption, fluoride, isotherm, ...

  15. Column studies for biosorption of dyes from aqueous solutions on ...

    African Journals Online (AJOL)

    Biosorption is becoming a promising alternative to replace or supplement the present dye removal processes from dye wastewaters. Based on the results of batch studies on biosorption of the dyes on powdered fungal biomass, Aspergillus niger, an immobilised fungal biomass was used in column studies for removal of four ...

  16. Use of Aspergillus wentii for biosorption of methylene blue from ...

    African Journals Online (AJOL)

    In this study, Aspergillus wentii was used as a biosorbent for the adsorption of methylene blue from aqueous solution. The effects of contact time, initial dye concentration, solution pH and temperature on biosorption were investigated. The contact time required (that is, the equilibrium time) for maximum dye biosorption was ...

  17. Selection of Biosorbents for Biosorption of Three Heavy Metals in a ...

    African Journals Online (AJOL)

    Initial ion concentrations of heavy metals and mass of biosorbents increase with biosorption capacity. Furthermore, Langmuir isotherm better described equilibrium biosorption of copper by Pseudomonas aeruginosa, Staphylococcus xylosus and Saccharomyces sp. (Yeast) with linear regression coefficient of correlation, R2 ...

  18. Biosorption treatment of brackish water

    International Nuclear Information System (INIS)

    Rizwan, M.; Ali, M.; Tariq, M.I.; Rehman, F.U.; Karim, A.; Makshoof, M.; Farooq, R.

    2010-01-01

    Biosorptivity of different agricultural wastes have been evaluated for the treatment of brackish water and a new method, based on the principle of bio-sorption has been described. Wastes of the Saccharum officinarum, Moringa oleifera, Triticum aestivcum and Oryza sativa have been used in raw forms as well as after converting them into ash and activated carbon as biosorbents for treatment of brackish water in this study. Samples of brackish water have been analyzed before and after treatment for quality control parameters of water. A significant Improvement has been observed in quality control parameters of water after treatment. pH of the water samples slightly increased from 7.68 to 7.97 with different treatments. A substantial decrease in conductivity,. TDS, TH, concentrations of cations and anions was observed in the samples of brackish water after treatment with different biosorbents. (author)

  19. Biosorption of Am-241 and Cs-137 by radioactive liquid waste by coffee husk

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi; Bellini, Maria Helena; Marumo, Julio Takehiro, E-mail: jtmarumo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Radioactive Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP, has stored many types of radioactive liquid wastes, including liquid scintillators, mixed wastes from chemical analysis and spent decontamination solutions. These wastes need special attention, because the available treatment processes are often expensive and difficult to manage. Biosorption using biomass of vegetable using agricultural waste has become a very attractive technique because it involves the removal of heavy metals ions by low cost biossorbents. The aim of this study is to evaluate the potential of the coffee husk to remove Am-241 and Cs-137 from radioactive liquid waste. The coffee husk was tested in two forms, treated and untreated. The chemical treatment of the coffee husk was performed with HNO{sub 3} and NaOH diluted solutions. The results showed that the coffee husk did not showed significant differences in behavior and capacity for biosorption for Am-241 and Cs-137 over time. Coffee husk showed low biosorption capacity for Cs-137, removing only 7.2 {+-} 1.0% in 4 hours of contact time. For Am-241, the maximum biosorption was 57,5 {+-} 0.6% in 1 hours. These results suggest that coffee husk in untreated form can be used in the treatment of radioactive waste liquid containing Am-241. (author)

  20. Biosorption of copper and zinc by immobilised and free algal biomass, and the effects of metal biosorption on the growth and cellular structure of Chlorella sp.and Chlamydomonas sp.isolated from rivers in Penang, Malaysia

    Institute of Scientific and Technical Information of China (English)

    W.O.Wan Maznah; A.T. Al-Fawwaz; Misni Surif

    2012-01-01

    In this study,the biosorption of copper and zinc ions by Chlorella sp.and Chlamydomonas sp.isolated from local environments in Malaysia was investigated in a batch system and by microscopic analyses.Under optimal biosorption conditions,the biosorption capacity of Chlorella sp.for copper and zinc ions was 33.4 and 28.5 mg/g,respectively,after 6 hr of biosorption in an immobilised system.Batch experiments showed that the biosorption capacity of algal biomass immobilised in the form of sodium alginate beads was higher than that of the free biomass.Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed that copper and zinc were mainly sorbed at the cell surface during biosorption.Exposure to 5 mg/L of copper and zinc affected both the chlorophyll content and cell count of the algal cells after the first 12 hr of contact time.

  1. Biosorption of nickel (II) ions from aqueous solutions by tapioca peel ...

    African Journals Online (AJOL)

    Tapioca peel, waste from native tapioca starch industry in Thailand, was used for the biosorption of nickel from aqueous solution. The experimental parameter focuses on the influence of contact time, solution pH, initial concentration and temperature using batch experiments. The results indicated that the biosorption ...

  2. Biosorption characteristics of Spirulina and Chlorella cells to accumulate heavy metals

    Directory of Open Access Journals (Sweden)

    Kőnig-Péter Anikó

    2015-01-01

    Full Text Available The heavy metal biosorption of dried Chlorella vulgaris and Spirulina platensis-Spirulina maxima cells was studied under various experimental conditions. The effect of biosorbent dosage, pH, adsorption time, temperature, initial metal concentration on biosorption was studied. Biosorption process can be divided into two parts: the first part follows zero-order, the second part pseudo second-order kinetics. Characterization of biosorption equilibrium was evaluated with Langmuir and Dubinin-Radushkevich models using non-linear regression. The optimum pH range was found to be 5.0 − 6.0 for Pb(II and 4.0 − 6.0 for Cu(II and Cd(II adsorption. The maximum adsorption capacities for Pb(II, Cd(II and Cu(II were 144, 161 and 138 mg g-1 by Chlorella cells and 370, 201 and 165 by Spirulina cells, based on the experimental data. The same values for activated carbon were 86, 134 and 43 mg g-1, respectively.

  3. Biosorption of Cd(II) and Zn(II) by nostoc commune: isotherm and kinetics studies

    Energy Technology Data Exchange (ETDEWEB)

    Morsy, Fatthy M. [Faculty of Science, Botany Department, Assiut University, Assiut (Egypt); Hassan, Sedky H.A. [Department of Biological Environment, Kangwon National University, Kangwon-do (Korea, Republic of); Koutb, Mostafa [Faculty of Science, Botany Department, Assiut University, Assiut (Egypt); Umm Al-Qura University, Faculty of Applied Science, Biology Department, Mecca (Saudi Arabia)

    2011-07-15

    In this study, Nostoc commune (cyanobacterium) was used as an inexpensive and efficient biosorbent for Cd(II) and Zn(II) removal from aqueous solutions. The effect of various physicochemical factors on Cd(II) and Zn(II) biosorption such as pH 2.0-7.0, initial metal concentration 0.0-300 mg/L and contact time 0-120 min were studied. Optimum pH for removal of Cd(II) and Zn(II) was 6.0, while the contact time was 30 min at room temperature. The nature of biosorbent and metal ion interaction was evaluated by infrared (IR) technique. IR analysis of bacterial biomass revealed the presence of amino, carboxyl, hydroxyl, and carbonyl groups, which are responsible for biosorption of Cd(II) and Zn (II). The maximum biosorption capacities for Cd(II) and Zn(II) biosorption by N. commune calculated from Langmuir biosorption isotherm were 126.32 and 115.41 mg/g, respectively. The biosorption isotherm for two biosorbents fitted well with Freundlich isotherm than Langmuir model with correlation coefficient (r{sup 2} < 0.99). The biosorption kinetic data were fitted well with the pseudo-second-order kinetic model. Thus, this study indicated that the N. commune is an efficient biosorbent for the removal of Cd(II) and Zn(II) from aqueous solutions. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Biosorption of uranium on Bacillus sp. dwc-2: preliminary investigation on mechanism

    International Nuclear Information System (INIS)

    Li, Xiaolong; Ding, Congcong; Liao, Jiali; Lan, Tu; Li, Feize; Zhang, Dong; Yang, Jijun; Yang, Yuanyou; Luo, Shunzhong; Tang, Jun; Liu, Ning

    2014-01-01

    In this paper, the biosorption mechanisms of uranium on an aerobic Bacillus sp. dwc-2, isolated from a potential disposal site for (ultra-) low uraniferous radioactive waste in Southwest China, was explored by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, FT-IR spectroscopy, proton induced X-ray emission (PIXE) and enhanced proton backscattering spectrometry (EPBS). The biosorption experiments for uranium were carried out at a low pH (pH 3.0), where the uranium solution speciation is dominated by highly mobile uranyl ions. The bioaccumulation was found to be the potential mechanism involved in uranium biosorption by Bacillus sp. dwc-2, and the bioaccumulated uranium was deposited in the cell interior as needle shaped particles at pH 3.0, as revealed by TEM analysis as well as EDX spectra. FTIR analysis further suggested that the absorbed uranium was bound to amino, phosphate and carboxyl groups of bacterial cells. Additionally, PIXE and EPBS results confirmed that ion-exchange also contributed to the adsorption process of uranium. All the results implied that the biosorption mechanism of uranium on Bacillus sp. is complicated and at least involves bioaccumulation, ion exchange and complexation process. - Highlights: • We examined U (VI) biosorption by a bacterial strain isolated from Southwest China. • We studied the involved mechanisms between uranium and this bacterium. • U (VI) was intracellularly bioaccumulated as needlelike granules by this bacterium. • The biosorption mechanisms involved ion exchange, complexation and bioccumulation

  5. Biosorption of uranium by Azolla, SP, Brazil

    International Nuclear Information System (INIS)

    Vieira, Ludmila C.; Alves, Eliakim G.; Marumo, Julio T.; Ferreira, Rafael V. de P.; Canevesi, Rafael L.S.; Silva, Edson A.

    2015-01-01

    Radioactive liquid waste needs special attention and requires suitable treatment before deposition. Among the potential technologies under development for the treatment of liquid radioactive wastes the biosorption has been highlighted by being an efficient and low cost technique. Biosorption process involves the exchange of ions contained in the biomass matrix by others present in solution. There are many biomasses that could be applied in treatment of radioactive wastes, for example, agricultural residues and macrophyte. The aim of this study is evaluate the ability of the Azolla sp., a floating aquatic plant, to absorb uranium in solution. Azolla sp. is a macrophyte that has been used to treat effluents containing heavy metals. The biosorption capacity of uranium by Azolla sp. was experimentally determined and modeled by isotherms. Experiments were performed to determine metal uptake, and then the solutions were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). The isotherms applied to model the data was Langmuir, Freundlich, Sips Toth, Redlich Peternson, Two-Site-Langmuir, Radke Prausnitz to develop a technique for the treatment of radioactive liquid waste generated at the Nuclear and Energy Research Institute (IPEN-CNEN/SP), Brazil. (author)

  6. Biosorption of uranium by Azolla, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Ludmila C.; Alves, Eliakim G.; Marumo, Julio T., E-mail: lcvieira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ferreira, Rafael V. de P., E-mail: rafael@itatijuca.com [Itatijuca Biotech, Sao Paulo, SP (Brazil); Canevesi, Rafael L.S.; Silva, Edson A., E-mail: edson.silva2@unioeste.br [Universidade Estadual do Oeste Parana (UNIOESTE), Toledo, PR (Brazil)

    2015-07-01

    Radioactive liquid waste needs special attention and requires suitable treatment before deposition. Among the potential technologies under development for the treatment of liquid radioactive wastes the biosorption has been highlighted by being an efficient and low cost technique. Biosorption process involves the exchange of ions contained in the biomass matrix by others present in solution. There are many biomasses that could be applied in treatment of radioactive wastes, for example, agricultural residues and macrophyte. The aim of this study is evaluate the ability of the Azolla sp., a floating aquatic plant, to absorb uranium in solution. Azolla sp. is a macrophyte that has been used to treat effluents containing heavy metals. The biosorption capacity of uranium by Azolla sp. was experimentally determined and modeled by isotherms. Experiments were performed to determine metal uptake, and then the solutions were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). The isotherms applied to model the data was Langmuir, Freundlich, Sips Toth, Redlich Peternson, Two-Site-Langmuir, Radke Prausnitz to develop a technique for the treatment of radioactive liquid waste generated at the Nuclear and Energy Research Institute (IPEN-CNEN/SP), Brazil. (author)

  7. [Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

    Science.gov (United States)

    Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming

    2011-12-01

    With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

  8. Studies on biosorption of heavy metals

    African Journals Online (AJOL)

    Gulnaz

    2012-10-18

    Oct 18, 2012 ... 1Department of Chemical Engineering, Faculty of Engineering and Science, ... The results show that the introduction of microbial biomass into the palm ..... equilibrium, kinetic and thermodynamic parameters of biosorption of.

  9. Biosorption of Pb2+ using Trichoderma viride as Alternative Solution for Heavy Metal Pollution in the Waters

    Directory of Open Access Journals (Sweden)

    Rensani Taloin

    2018-01-01

    Full Text Available Lead(II is considered as the main cause of pollutant that is toxic, corrosive, and irritant. One method that can be applied for reducing Pb(II in the environment is by using microorganisms. In this work, the study of biosorption of Pb(II in the water samples was conducted using Trichoderma viride. The research is focused on determination of optimum conditions including pH, biosorption time, and initial concentration of Pb(II used. The profiles in functional groups contained in the T. viride have been monitored using FT-IR spectrophotometry. Results showed that the maximum biosorption of Pb(II achieved at pH 4.5, with equilibrium of contact time of 20 h, optimum concentration of 50 mg/L, and adsorption capacity of 85 mg/1x106 T. viride colonies. The FTIR results indicated that biosorption process changed the functional groups in the T. viride. These have shown in the absorption bands at ~3200 cm-1, ~2850 cm-1, ~2260 cm-1, ~1650 cm-1, ~1450 cm-1, 1180 cm-1, and in the finger printing regions. The biosorption mechanism was proposed through the adsorption process between positively charged metal ions and the negative charge on the functional groups, such as -COO-, -OPO32-, and –NH2-, on the cell surface.

  10. Chromium removal through biosorption and bioaccumulation by bacteria from tannery effluents contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Mohammad Zubair [Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh (India); Ahmad, Shamim [Microbiology Division, Institute of Ophthalmology, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh (India)

    2011-03-15

    Four bacterial isolates (two resistant and two sensitive to chromium) were isolated from soil contaminated with tannery effluents at Jajmau (Kanpur), India, and were identified by 16S rDNA gene sequencing as Stenotrophomonas maltophilia, Exiguobacterium sp., Pantoea sp., and Aeromonas sp. Biosorption of chromium by dried and living biomasses was determined in the resistant and sensitive isolates. The effect of pH, initial metal concentration, and contact time on biosorption was studied. At pH 2.5 the living biomass of chromium resistant isolate Exiguobacterium sp. ZM-2 biosorbed maximum amount of Cr{sup 6+} (29.8 mg/g) whereas the dried biomass of this isolate biosorbed 20.1 mg/g at an initial concentration of 100 mg/L. In case of chromate sensitive isolates, much difference was not observed in biosorption capacities between their dried and living biomasses. The maximum biosorption of Cr{sup 3+} was observed at pH 4.5. However, biosorption was identical in resistant and sensitive isolates. The data on chromium biosorption were analyzed using Langmuir and Freundlich isotherm model. The biosorption data of Cr{sup 6+} and Cr{sup 3+} from aqueous solution were better fitted in Langmuir isotherm model compared to Freundlich isotherm model. Metal recovery through desorption was observed better with dried biomasses compared to the living biomasses for both types of chromium ions. Bioaccumulation of chromate was found higher in chromate resistant isolates compared to the chromate sensitive isolates. Transmission electron microscopy confirmed the accumulation of chromium in cytoplasm in the resistant isolates. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Biosorption of Am-241 and Cs-137 by radioactive liquid waste by coffee husk

    International Nuclear Information System (INIS)

    Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi; Bellini, Maria Helena; Marumo, Julio Takehiro

    2011-01-01

    Radioactive Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP, has stored many types of radioactive liquid wastes, including liquid scintillators, mixed wastes from chemical analysis and spent decontamination solutions. These wastes need special attention, because the available treatment processes are often expensive and difficult to manage. Biosorption using biomass of vegetable using agricultural waste has become a very attractive technique because it involves the removal of heavy metals ions by low cost biossorbents. The aim of this study is to evaluate the potential of the coffee husk to remove Am-241 and Cs-137 from radioactive liquid waste. The coffee husk was tested in two forms, treated and untreated. The chemical treatment of the coffee husk was performed with HNO 3 and NaOH diluted solutions. The results showed that the coffee husk did not showed significant differences in behavior and capacity for biosorption for Am-241 and Cs-137 over time. Coffee husk showed low biosorption capacity for Cs-137, removing only 7.2 ± 1.0% in 4 hours of contact time. For Am-241, the maximum biosorption was 57,5 ± 0.6% in 1 hours. These results suggest that coffee husk in untreated form can be used in the treatment of radioactive waste liquid containing Am-241. (author)

  12. Biosorption and desorption of Cd2+ from wastewater by dehydrated shreds of Cladophora fascicularis

    Science.gov (United States)

    Deng, Liping; Zhu, Xiaobin; Su, Yingying; Su, Hua; Wang, Xinting

    2008-02-01

    The adsorption and desorption of algae Cladophora fascicularis and their relation with initial Cd2+ concentration, initial pH, and co-existing ions were studied. Adsorption equilibrium and biosorption kinetics were established from batch experiments. The adsorption equilibrium was adequately described by the Langmuir isotherm, and biosorption kinetics was in pseudo-second order model. The experiment on co-existing ions showed that the biosorption capacity of biomass decreased with an increasing concentration of competing ions. Desorption experiments indicated that EDTA was efficient desorbent for recovery from Cd2+. With high capacities of metal biosorption and desorption, the biomass of Cladophora fascicularis is promising as a cost-effective biosorbent for the removal of Cd2+ from wastewater.

  13. Biosorption of Acid Yellow 17 from aqueous solution by non-living aerobic granular sludge

    International Nuclear Information System (INIS)

    Gao Jingfeng; Zhang Qian; Su Kai; Chen Ranni; Peng Yongzhen

    2010-01-01

    Batch biosorption experiments were carried out for the removal of Acid Yellow 17 from aqueous solution using non-living aerobic granular sludge as an effective biosorbent. The effects of solution pH value, biosorbent dosage, initial Acid Yellow 17 concentration, NaCl concentration and temperature on the biosorption were investigated. The experimental results indicate that this process was highly dependent on pH value and the pH value of 2.0 was favorable. The Temkin isotherm was more applicable for describing the biosorption equilibrium at the whole concentration range than the Freundlich and Langmuir isotherm. The results of kinetics study show that the pseudo-second-order model fitted to the experimental data well. Both intraparticle diffusion and boundary layer diffusion might affect the biosorption rate. Thermodynamic studies demonstrate that the biosorption process was spontaneous and exothermic. The FTIR analysis before and after Acid Yellow 17 binding indicated that functional groups such as amine, hydroxyl, carboxyl and either on the non-living aerobic granular sludge would be the active binding sites for the biosorption of the studied dye. These results show that non-living aerobic granular sludge could be effectively used as a low-cost and alternative biosorbent for the removal of Acid Yellow 17 dye from wastewater.

  14. Biosorption of americium-241 by Candida sp

    International Nuclear Information System (INIS)

    Luo Shunzhong; Zhang Taiming; Liu Ning; Yang Yuanyou; Jin Jiannan; Liao Jiali

    2003-01-01

    As an important radioisotope in nuclear industry and other fields, americium-241 is one of the most serious contamination concerns duo to its high toxicity and long half-life. In this experiment, the biosorption of 241 Am from solution by Candida sp., and the effects of various experimental conditions on the adsorption were investigated. The preliminary results showed that the adsorption of 241 Am by Candida sp. was efficient. 241 Am could be removed by Candida sp. of 0.82 g/L (dry weight) from 241 Am solutions of 5.6-111 MBq/L (44.3-877.2 μg/L)(C 0 ), with maximum adsorption rate (R) of 98% and maximum adsorption capacities (W) of 63.5 MBq/g biomass (dry weight) (501.8 μg/g). The biosorption equilibrium was achieved within 4 hour and the optimum pH was pH = 2. No significant differences on 241 Am adsorption were observed at 10 C-45 C, or in solutions containing Au 3+ or Ag + , even 1500 times or 4500 times above the 241 Am concentration, respectively. The relationship between concentrations and adsorption capacities of 241 Am indicated the biosorption process should be described by a Langmuir adsorption isotherm. (orig.)

  15. Biosorption of C.I. Direct Blue 199 from aqueous solution by nonviable Aspergillus niger

    International Nuclear Information System (INIS)

    Xiong Xiaojing; Meng Xuejiao; Zheng Tianling

    2010-01-01

    The capacity and mechanism with which nonviable Aspergillus niger removed the textile dye, C.I. Direct Blue 199, from aqueous solution was investigated using different parameters, such as initial dye concentration, pH and temperature. In batch experiments, the biosorption capacity increased with decrease in pH, and the maximum dye uptake capacity of the biosorbent was 29.96 mg g -1 at 400 mg L -1 dye concentration and 45 deg. C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of C.I. Direct Blue 199 onto the fungal biomass. Biosorption followed a pseudo-second order kinetic model with high correlation coefficients (r 2 > 0.99). Thermodynamic studies revealed that the biosorption process was successful, spontaneous and endothermic in nature.

  16. Study on biosorption of uranium by alginate immobilized saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Wang Baoe; Xu Weichang; Xie Shuibo; Guo Yangbin

    2005-01-01

    Saccharomyces cerevisiae has great capability of biosorption of uranium. The maxium uptake is 172.4 mg/g according to this study. To adapt to the application of the biomass in the field, the biosorption of uranium by cross-linked and alginate calcium immobilized Saccharomyces cerevisiae is studied. Results indicate the maxium uptake is 185.2 mg/g by formaldehyde cross-linked biomass, and it is 769.2 mg/g by alginate calcium immobilized biomass. (authors)

  17. Kinetic and Thermodynamic Studies on Biosorption of Direct Red 81 from Aqueous Solutions by Chamomilla Plant

    Directory of Open Access Journals (Sweden)

    M. Momen Heravi

    2013-01-01

    Full Text Available In this study, Chamomilla plant biomass used as a sorbent for biosorption of a textile dye, direct red 81, from an aqueous solution. The batch sorption was studied with respect to dye concentration, adsorbent dose and temperature. Also, kinetic and isotherm parameters were determined for biosorption of Direct red 81 by Chamomilla plant. The maximum biosorption capacity (qm of Direct red 81 10 mg g-1 was obtained at 25oC. The kinetic and isotherm studies indicated that the biosorption process obeys a pseudo-second order and Langmuir isotherm models. In addition, various thermodynamic parameters, such as changes in Gibbs free energy (ΔG, enthalpy (ΔH and entropy (ΔS have been calculated. The biosorption process of Direct Red 81 dye onto activated carbon prepared from Chamomilla plant was found to be spontaneous and exothermic. The findings of this investigation suggest that this procces is a physical biosorption. The experimental studies indicated that Chamomilla plant had the potential to act as an alternative biosorbent to remove the Direct Red 81 dye from an aqueous solution.

  18. Heavy metal biosorption by bacterial cells

    NARCIS (Netherlands)

    Vecchio, A; Finoli, C; Di Simine, D; Andreoni, [No Value

    Microbial biomass provides available ligand groups on which metal ions bind by different mechanisms. Biosorption of these elements from aqueous solutions represents a remediation technology suitable for the treatment of metal-contaminated effluents. The purpose of the present investigation was the

  19. The effect of pulse voltage and capacitance on biosorption of uranium by biomass derived from whiskey distillery spent wash

    Energy Technology Data Exchange (ETDEWEB)

    Bustard, M.; Rollan, A.; McHale, A.P. [Biotechnology Research Group, School of Applied Biological and Chemical Sciences, University of Ulster (United Kingdom)

    1999-01-01

    Biosorption of uranium by residual biomass from The Old Bushmill`s Distillery Co. Ltd., Bushmills, Co. Antrim, Northern Ireland, following exposure to short and intense electric pulses has been examined. The biomass was prepared from the distillery spent wash and consisted of non-viable yeast and bacterial cells. As shown previously, untreated biomass had a maximum biosorption capacity of 170 mg uranium/g dry weight biomass. When biosorption reactions were placed between two electrodes and exposed to electric pulses with field strengths ranging from 1.25-3.25 kV/cm at a capacitance of 25 {mu}F, biosorption increased from 170 mg of uranium to 275 mg uranium/g dry weight biomass. The data were obtained from biosorption isotherm analyses and taken as the degree of biosorption at residual uranium concentrations of 3 mM. In addition, when the capacitance of the electric pulses increased from 0.25 {mu}F to 25 {mu}F at a fixed pulse field strength the degree of biosorption increased from 210 mg uranium to 240 mg uranium/g dry weight biomass. The results suggest that application of short and intense electric pulses to biosorption reactions may play an important role in enhancing microbial biosorption of toxic metals/radionuclides from waste water streams. (orig.) With 2 tabs., 10 refs.

  20. Cadmium biosorption by Aspergillus niger; Biossorcao de cadmio pelo Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.P.; Barros Junior, L.M.; Duarte, M.M.L.; Macedo, G.R. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)]. E-mail: edmilson@eq.ufrn.br

    2003-07-01

    Biosorption is a property of certain types of inactive, dead, microbial biomass to bind and concentrate heavy metals from even very dilute aqueous solutions. Biomass exhibits this property, acting just as a chemical substance, as an ion exchanger of biological origin. It is particularly the cell wall structure of certain algae, fungi and bacteria which was found responsible for this phenomenon. Some of the biomass types come as a waste by-product of large-scale industrial fermentations (the mold Rhizopus or the bacterium Bacillus subtilis). Other metal-binding biomass types, certain abundant seaweeds (particularly brown algae e.g. Sargassum, Ecklonia), can be readily collected from the oceans. These biomass types, serving as a basis for metal biosorption processes, can accumulate in excess of 25% of their dry weight in deposited heavy metals: Pb, Cd, U, Cu, Zn, even Cr and others. Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. (author)

  1. Biosorption of radionuclide Americium-241 by A. niger spore and hyphae

    International Nuclear Information System (INIS)

    Yang Yuanyou; Liu Ning; Jin Jiannan; Hua Xinfeng; Zhang Taiming; Luo Shunzhong; Sun Qiling

    2002-01-01

    The biosorption of radionuclide 241 Am from solution was studied by a. niger spore and hyphae, and the effects of the operational conditions on the treatment were investigated. The results showed the treatment by A. niger spore and hyphae were very efficient. An average of 96% of the total 241 Am was removed from 241 Am solutions of 5.6-111 MBq/L (C 0 ), with adsorption capacities (W) of 7.2-142.4 MBq/g biomass, 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 h and the optimum pH value ranged 3-0.1 mol/L HNO 3 and 3-2 for spore and hyphae of A. niger, respectively. No significant effects on 241 Am biosorption were observed at 15 degree C-45 degree C, or challenged with containing Au 3+ or Ag + , even 2000 times above 241 Am amount. the index relationship between concentrations and adsorption capacities of 241 Am indicated that the 241 Am biosorption by A. niger spore and hyphae obey to Freundlich adsorption equation. The adsorption behavior of A. niger spore and hyphae were basically coincident

  2. Biosorption of copper(II) and lead(II) onto potassium hydroxide treated pine cone powder.

    Science.gov (United States)

    Ofomaja, A E; Naidoo, E B; Modise, S J

    2010-08-01

    Pine cone powder surface was treated with potassium hydroxide and applied for copper(II) and lead(II) removal from solution. Isotherm experiments and desorption tests were conducted and kinetic analysis was performed with increasing temperatures. As solution pH increased, the biosorption capacity and the change in hydrogen ion concentration in solution increased. The change in hydrogen ion concentration for lead(II) biosorption was slightly higher than for copper(II) biosorption. The results revealed that ion-exchange is the main mechanism for biosorption for both metal ions. The pseudo-first order kinetic model was unable to describe the biosorption process throughout the effective biosorption period while the modified pseudo-first order kinetics gave a better fit but could not predict the experimentally observed equilibrium capacities. The pseudo-second order kinetics gave a better fit to the experimental data over the temperature range from 291 to 347 K and the equilibrium capacity increased from 15.73 to 19.22 mg g(-1) for copper(II) and from 23.74 to 26.27 for lead(II). Activation energy was higher for lead(II) (22.40 kJ mol(-1)) than for copper(II) (20.36 kJ mol(-1)). The free energy of activation was higher for lead(II) than for copper(II) and the values of DeltaH* and DeltaS* indicate that the contribution of reorientation to the activation stage is higher for lead(II) than copper(II). This implies that lead(II) biosorption is more spontaneous than copper(II) biosorption. Equilibrium studies showed that the Langmuir isotherm gave a better fit for the equilibrium data indicating monolayer coverage of the biosorbent surface. There was only a small interaction between metal ions when simultaneously biosorbed and cation competition was higher for the Cu-Pb system than for the Pb-Cu system. Desorption studies and the Dubinin-Radushkevich isotherm and energy parameter, E, also support the ion-exchange mechanism. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. Biosorption of C.I. Direct Blue 199 from aqueous solution by nonviable Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Xiong Xiaojing, E-mail: xiongxj@xmu.edu.cn [Environmental Science Research Center, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005 (China); Meng Xuejiao [Environmental Science Research Center, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005 (China); Zheng Tianling [Environmental Science Research Center, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005 (China); Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005 (China)

    2010-03-15

    The capacity and mechanism with which nonviable Aspergillus niger removed the textile dye, C.I. Direct Blue 199, from aqueous solution was investigated using different parameters, such as initial dye concentration, pH and temperature. In batch experiments, the biosorption capacity increased with decrease in pH, and the maximum dye uptake capacity of the biosorbent was 29.96 mg g{sup -1} at 400 mg L{sup -1} dye concentration and 45 deg. C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of C.I. Direct Blue 199 onto the fungal biomass. Biosorption followed a pseudo-second order kinetic model with high correlation coefficients (r{sup 2} > 0.99). Thermodynamic studies revealed that the biosorption process was successful, spontaneous and endothermic in nature.

  4. Batch and continuous (fixed-bed column) biosorption of crystal violet by Artocarpus heterophyllus (jackfruit) leaf powder.

    Science.gov (United States)

    Saha, Papita Das; Chakraborty, Sagnik; Chowdhury, Shamik

    2012-04-01

    In this study, batch and fixed-bed column experiments were performed to investigate the biosorption potential of Artocarpus heterophyllus (jackfruit) leaf powder (JLP) to remove crystal violet (CV) from aqueous solutions. Batch biosorption studies were carried out as a function of solution pH, contact time, initial dye concentration and temperature. The biosorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer biosorption capacity of 43.39 mg g(-1) at pH 7.0, initial dye concentration=50 mg L(-1), temperature=293 K and contact time=120 min. According to Dubinin-Radushkevich (D-R) isotherm model, biosorption of CV by JLP was chemisorption. The biosorption kinetics followed the pseudo-second-order kinetic model. Thermodynamic analysis revealed that biosorption of CV from aqueous solution by JLP was a spontaneous and exothermic process. In order to ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the BDST model showed good agreement with the experimental results at all the process parameters studied. It can be concluded that JLP is a promising biosorbent for removal of CV from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Biosorption of nickel with barley straw.

    Science.gov (United States)

    Thevannan, Ayyasamy; Mungroo, Rubeena; Niu, Catherine Hui

    2010-03-01

    Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23+/-0.5 degrees C) was very sensitive to solution pH, showing a better uptake value at a pH of 4.85+/-0.10 among the tested values. The nickel biosorption isotherm fitted well the Langmuir equation. When the ionic strength (IS) of the solution was increased from less than 0.02-0.6M, nickel uptake was reduced to 12% of that obtained at IS of less than 0.02 M. Barley straw showed a higher nickel uptake (0.61 mmol/g) than acid washed crab shells (0.04 mmol/g), demonstrating its potential as an adsorbent for removal of nickel. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  6. Biosorption of copper(II) from aqueous solutions by green alga Cladophora fascicularis.

    Science.gov (United States)

    Deng, Liping; Zhu, Xiaobin; Wang, Xinting; Su, Yingying; Su, Hua

    2007-08-01

    Biosorption is an effective means of removal of heavy metals from wastewater. In this work the biosorption behavior of Cladophora fascicularis was investigated as a function of pH, amount of biosorbent, initial Cu2+ concentration, temperature, and co-existing ions. Adsorption equilibria were well described by Langmuir isotherm models. The enthalpy change for the biosorption process was found to be 6.86 kJ mol(-1) by use of the Langmuir constant b. The biosorption process was found to be rapid in the first 30 min. The presence of co-existing cations such as Na+, K+, Mg2+, and Ca2+ and anions such as chloride, nitrate, sulfate, and acetate did not significantly affect uptake of Cu2+ whereas EDTA substantially affected adsorption of the metal. When experiments were performed with different desorbents the results indicated that EDTA was an efficient desorbent for the recovery of Cu2+ from biomass. IR spectral analysis suggested amido or hydroxy, C=O, and C-O could combine strongly with Cu2+.

  7. Insight into biosorption equilibrium, kinetics and thermodynamics of crystal violet onto Ananas comosus (pineapple) leaf powder

    Science.gov (United States)

    Chakraborty, Sagnik; Chowdhury, Shamik; Saha, Papita Das

    2012-06-01

    Biosorption performance of pineapple leaf powder (PLP) for removal of crystal violet (CV) from its aqueous solutions was investigated. To this end, the influence of operational parameters such as pH, biosorbent dose, initial dye concentration and temperature were studied employing a batch experimental setup. The biosorption process followed the Langmuir isotherm model with high correlation coefficients ( R 2 > 0.99) at different temperatures. The maximum monolayer biosorption capacity was found to be 78.22 mg g-1 at 293 K. The kinetic data conformed to the pseudo-second-order kinetic model. The activation energy of the system was calculated as 58.96 kJ mol- 1 , indicating chemisorption nature of the ongoing biosorption process. A thermodynamic study showed spontaneous and exothermic nature of the biosorption process. Owing to its low cost and high dye uptake capacity, PLP has potential for application as biosorbent for removal of CV from aqueous solutions.

  8. Biosorption of heavy metals in polluted water, using different waste fruit cortex

    Science.gov (United States)

    Kelly-Vargas, Kevin; Cerro-Lopez, Monica; Reyna-Tellez, Silvia; Bandala, Erick R.; Sanchez-Salas, Jose Luis

    The biosorption capacity of different cortex fruit wastes including banana (Musa paradisiaca), lemon (Citrus limonum) and orange (Citrus sinensis) peel were evaluated. In order to perform these experiments, grinded dried cortexes were used as package in 100 mm high, 10 mm i.d. columns. The grinded material was powdered in a mortar and passed through a screen in order to get two different particle sizes, 2 and 1 mm, for all powders. To estimate the biosorption capabilities of the tested materials, different heavy metals were passed through the columns and the elution filtrate reloaded different times to increase the retention of metals. The heavy metals used were prepared as synthetic samples at 10 mg/L of Pb(NO3)2, Cd(NO3)2, and Cu(NO3)2·6H2O using primary standards. In preliminary experiments using banana cortex, it was found that material with 1 mm of particle size showed higher retention capability (up to12%) than the material with 2 mm of particle size. Considering these results, 1 mm particle size material was used in further experiments with the other waste materials. It was found that for Pb and Cu removal, lemon and orange cortex showed better biosorption capability when compared with banana cortex (up to 15% less for Pb and 48% less for Cu). For Cd, banana cortex showed better biosorption capability 57% (67.2 mg/g of cortex) more than orange (28.8 mg/g of cortex), and 82% more than lemon (12 mg/g of cortex). Reload of the columns with the filtrate after passing through the column improved the removal capability of all the materials tested from 10% to 50% depending on the cortex and metal tested.

  9. Biosorption of nonylphenol by pure algae, field-collected planktons and their fractions

    International Nuclear Information System (INIS)

    Zhang, Dainan; Ran, Yong; Cao, Xiaoyan; Mao, Jingdong; Cui, Jinfang; Schmidt-Rohr, Klaus

    2015-01-01

    Algal samples were fractionated into lipid (LP), lipid free (LF), alkaline nonhydrolyzable carbon (ANHC), and acid nonhydrolyzable carbon (NHC) fractions, and were characterized by the quantitative 13 C multiCP NMR technique. The biosorption isotherms for nonylphenol (NP) were established and compared with previously published data for phenanthrene (Phen). The log K OC values are significantly higher for the field-collected plankton samples than for the commercial algae and cultured algae samples, correlating with their lipid contents and aliphatic carbon structure. As the NHC fraction contains more poly(methylene) carbon, it exhibits a higher biosorption capacity. The sorption capacities are negatively related to the polarity index, COO/N–C=O, polar C and O-alkyl C concentrations, but are positively related to the H/O atomic ratios and poly(methylene) carbon. The higher sorption capacities observed for NP than for Phen on the investigated samples are explained by specific interactions such as hydrogen bonding and π–π interaction. - Highlights: • Quantitative 13 C NMR technique was applied to algae and their fraction samples. • The biosorption isotherms for the ANHC and NHC fractions are nonlinear. • Polarity and lipid affect the biosorption capacity of NP. • The sorption capacity is positively related to polymethylene carbon. • The hydrogen and π–π interactions between NP and algae could be important. - The NHC fractions are chemically and structurally different from other fractions, and their biosorption for NP is much higher than that of the bulk algae

  10. Biosorption of uranium by chemically modified Rhodotorula glutinis

    International Nuclear Information System (INIS)

    Bai Jing; Yao Huijun; Fan Fangli; Lin Maosheng; Zhang Lina; Ding Huajie; Lei Fuan; Wu Xiaolei; Li, Xiaofei; Guo Junsheng; Qin Zhi

    2010-01-01

    The present paper reports the biosorption of uranium onto chemically modified yeast cells, Rhodotorula glutinis, in order to study the role played by various functional groups in the cell wall. Esterification of the carboxyl groups and methylation of the amino groups present in the cells were carried out by methanol and formaldehyde treatment, respectively. The uranium sorption capacity increased 31% for the methanol-treated biomass and 11% for the formaldehyde-treated biomass at an initial uranium concentration of 140 mg/L. The enhancement of uranium sorption capacity was investigated by Fourier transform infrared (FTIR) spectroscopy analysis, with amino and carboxyl groups were determined to be the important functional groups involved in uranium binding. The biosorption isotherms of uranium onto the raw and chemically modified biomass were also investigated with varying uranium concentrations. Langmuir and Freundlich models were well able to explain the sorption equilibrium data with satisfactory correlation coefficients higher than 0.9. -- Research highlights: → Uranium biosorption on to chemically modified yeast cells → Cells before and after uranium sorption were investigate by FTIR spectroscopy → Amino and carboxyl groups were important functional groups involved in uranium binding → The sorption equilibrium date of raw and chemically modified biomass fitted well with Langmuir and Freundlich models

  11. Biosorption of uranium by chemically modified Rhodotorula glutinis

    Energy Technology Data Exchange (ETDEWEB)

    Bai Jing, E-mail: baijing@impcas.ac.c [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yao Huijun [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fan Fangli; Lin Maosheng [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang Lina; Ding Huajie; Lei Fuan; Wu Xiaolei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Li, Xiaofei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Guo Junsheng; Qin Zhi [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2010-11-15

    The present paper reports the biosorption of uranium onto chemically modified yeast cells, Rhodotorula glutinis, in order to study the role played by various functional groups in the cell wall. Esterification of the carboxyl groups and methylation of the amino groups present in the cells were carried out by methanol and formaldehyde treatment, respectively. The uranium sorption capacity increased 31% for the methanol-treated biomass and 11% for the formaldehyde-treated biomass at an initial uranium concentration of 140 mg/L. The enhancement of uranium sorption capacity was investigated by Fourier transform infrared (FTIR) spectroscopy analysis, with amino and carboxyl groups were determined to be the important functional groups involved in uranium binding. The biosorption isotherms of uranium onto the raw and chemically modified biomass were also investigated with varying uranium concentrations. Langmuir and Freundlich models were well able to explain the sorption equilibrium data with satisfactory correlation coefficients higher than 0.9. -- Research highlights: {yields} Uranium biosorption on to chemically modified yeast cells {yields} Cells before and after uranium sorption were investigate by FTIR spectroscopy {yields} Amino and carboxyl groups were important functional groups involved in uranium binding {yields} The sorption equilibrium date of raw and chemically modified biomass fitted well with Langmuir and Freundlich models

  12. Biosorption of strontium ions from aqueous solution using Ca-alginate biopolymer beads

    International Nuclear Information System (INIS)

    Goek, C.; Aytas, S.; Gerstmann, U.

    2009-01-01

    Biosorption of strontium ions from aqueous solution onto calcium alginate biopolymer beads was investigated in a batch system. Ca-alginate biopolymer beads were prepared from Na-alginate via cross-linking with divalent calcium ions according to the egg box model. Optimum biosorption conditions were determined as a function of initial solution pH, initial Sr concentration, contact time, biomass dosage and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of Sr ions by Ca-alginate biopolymer beads. The thermodynamic parameters (ΔH, ΔS, ΔG) for Sr sorption onto biosorbent were also determined from the temperature dependence. The results indicate that this biosorbent has a good potential for removal of Sr ions from dilute aqueous solution.

  13. Biosorption of bovine serum albumin by Ulva lactuca biomass from industrial wastewater: Equilibrium, kinetic and thermodynamic study

    International Nuclear Information System (INIS)

    Rathinam, Aravindhan; Zou, Linda

    2010-01-01

    Batch biosorption experiments have been carried out for the removal of bovine serum albumin (BSA) from simulated industrial wastewater onto Ulva lactuca seaweed. Various vital parameters influencing the biosorption process such as initial concentration of BSA, pH of the solution, adsorbent dosage and temperature have been determined. The biosorption kinetics follows a pseudo-second order kinetic model. Equilibrium isotherm studies demonstrate that the biosorption followed the Freundlich isotherm model, which implies a heterogeneous sorption phenomenon. Various thermodynamic parameters such as changes in enthalpy, free energy and entropy have been calculated. The positive value of ΔH o and the negative value of ΔG o show that the sorption process is endothermic and spontaneous. The positive value of change in entropy ΔS o shows increased randomness at the solid-liquid interface during the biosorption of BSA onto U. lactuca seaweed.

  14. Iron oxide impregnated Morus alba L. fruit peel for biosorption of Co(II): biosorption properties and mechanism.

    Science.gov (United States)

    Koduru, Janardhan Reddy; Chang, Yoon-Young; Yang, Jae-Kyu; Kim, Im-Soon

    2013-01-01

    Biosorption is an ecofriendly wastewater treatment technique with high efficiency and low operating cost involving simple process for the removal of heavy metal ions from aqueous solution. In the present investigation, Morus alba L. fruit peel powder (MAFP) and iron oxide impregnated Morus alba L. fruit peel powder (IO-MAFP) were prepared and used for treating Co(II) contaminated aqueous solutions. Further the materials were characterized by using FTIR and SEM-EDX analysis. From FT-IR analysis it was found that hydroxyl, methoxy, and carbonyl groups are responsible for Co(II) biosorption. The kinetic data obtained for both biosorbents was well fitted with pseudo-second-order kinetic model. The equilibrium data was in tune with the Langmuir and Freundlich isotherm models. The thermodynamic studies were also carried and it was observed that sorption process was endothermic at 298-328 K. These studies demonstrated that both biosorbents were promising, efficient, economic, and biodegradable sorbents.

  15. Potentiality of Neopestalotiopsis clavispora ASU1 in biosorption of cadmium and zinc.

    Science.gov (United States)

    Hassan, Sedky H A; Koutb, Mostafa; Nafady, Nivien Allam; Hassan, Elhagag Ahmed

    2018-07-01

    In this study, a fungal isolate was isolated from avocado fruit collected from a market in Makkah city, Saudi Arabia, and identified as Neopestalotiopsis clavispora ASU1. The biomass of Neopestalotiopsis clavispora ASU1 was used as a natural bio-sorbent for removal of Cd(II) and Zn(II) from aqueous solutions. Characterization of fungal biomass was performed using Fourier transform infrared spectroscopy, X-ray Diffractometer, and BET surface area. Different factors on Cd(II) and Zn(II) biosorption were studied to evaluate the maximum conditions for metals biosorption. The (q max ) for Cd(II) and Zn (II) by N. clavispora ASU1 calculated from the Langmuir adsorption isotherm was 185.3 ± 0.25 and 153.8 ± 0.21 mg/g, respectively. Based on r 2 , the equilibrium biosorption isotherms fitted well with Langmuir model than Freundlich isotherm. The adsorption kinetics was studied, and the biosorption followed to the pseudo-second-order model. Thus, the current study indicated that the biomass of N. clavispora ASU1 is an effective adsorbent for the removal of heavy metals from aqueous solutions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Biosorption of Phenolic Compounds from Aqueous Solutions using Pine (Pinus densiflora Sieb Bark Powder

    Directory of Open Access Journals (Sweden)

    Siva Kumar Nadavala

    2014-07-01

    Full Text Available The present study describes the development of a new bioadsorbent from lignocellulosic wastes of agricultural origin. The biosorption capacity of an agricultural solid waste, pine bark (Pinus densiflora Sieb., to remove phenolic compounds (phenol, 2-chlorophenol (2-CPh, and 4- chlorophenol (4-CPh from aqueous solutions under batch equilibrium conditions was investigated. The morphological characteristics of the biosorbent were evaluated by BET surface area analysis, Fourier transform infrared spectroscopy (FTIR, elemental analysis, an X-ray diffractometer (XRD, and a scanning electron microscope (SEM. Batch experiments were conducted to investigate the effect of initial pH (2 to 10, contact time, initial concentration of adsorbate (50 to 200 mg/L, and biosorbent dosage. The biosorption of phenolic compounds decreased with increasing pH, and the highest biosorption capacity was achieved at a pH of 6.0. Biosorption equilibrium was established in 120 min. The biosorption equilibrium data were fitted and analyzed with Langmuir, Freundlich, and Dubinin-Radushkevich isotherm equations, as well as four adsorption kinetic models. The kinetics data fitted well into the pseudo-second-order kinetic model, with a correlation coefficient greater than 0.993. The maximum monolayer biosorption capacity of pine bark for phenol, 2-CPh, and 4-CPh was found to be 142.85, 204.08, and 263.15 mg/g, respectively, as calculated by the Langmuir model at 30 ± 1 °C. Pine bark could be used as a new effective, low-cost biosorbent material with good uptake capacity and rapid kinetics for the removal of phenolic compounds from aqueous media.

  17. Biosorption of Basic Green 4 from aqueous solution by Ananas comosus (pineapple) leaf powder.

    Science.gov (United States)

    Chowdhury, Shamik; Chakraborty, Sagnik; Saha, Papita

    2011-06-01

    Biosorption characteristics of Ananas comosus (pineapple) leaf powder was investigated for decolorization of Basic Green 4 (BG 4), a cationic dye from its aqueous solutions employing a batch experimental set-up. Parameters that influence the sorption process such as pH, biosorbent dosage, contact time, initial dye concentration and temperature were systematically studied. The optimum conditions for removal of BG 4 were found to be pH 9.0, contact time=150 min, biosorbent dosage=5.0 g L(-1), initial dye concentration=50 mg L(-1). The temperature had a strong influence on the biosorption process. Further, the biosorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer, Emmett, Teller (BET) surface area and pore size analysis. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The biosorption process followed the Langmuir isotherm model with high coefficients of correlation (R(2)>0.99) at different temperatures. The pseudo second order kinetic model fitted well in correlation to the experimental results. Activation energy of the biosorption process (E(a)) was found to be 45.79 kJ mol(-1) by using the Arrhenius equation, indicating chemisorption nature of BG 4 sorption onto pineapple leaf powder. Thermodynamic parameters suggest that the biosorption process is spontaneous and exothermic in nature. Overall, the present findings suggest that this environmentally friendly, efficient and low-cost biosorbent may be useful for the removal of BG 4 from aqueous media. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Biosorption of Cu2+ and Pb2+ using sophora alopecuroides residue

    Science.gov (United States)

    Feng, N.; Fan, W.; Zhu, M.; Zhang, Y.

    2016-08-01

    Sophora alopecuroides residue (SAP), a kind of traditional Chinese herbal medicine residue, was developed in an alternative biosorbent for the removal Cu2+ and Pb2+ in simulated wastewater. The morphology and surface texture of SAP were characterized by scanning electron microscopy, which showed a loose and porous structure. The biosorption experiments of Cu2+ and Pb2+ onto SAP were investigated by using batch techniques. High biosorption percentage appeared at pH values of 4.5-6.0. The experimental data followed the second-order kinetic model well. Equilibrium fit with the Langmuir isotherm model well. The maximum biosorption capacity of an adsorbent at 25 °C was respectively 60.6 mg/g Cu2+ and 128.1 mg/g Pb2+. The findings of the present study show that SAP is an attractive and effective biosorbent for Cu2+ and Pb2+.

  19. Biosorption of bovine serum albumin by Ulva lactuca biomass from industrial wastewater: Equilibrium, kinetic and thermodynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Rathinam, Aravindhan [Chemical Laboratory, Central Leather Research Institute, Adyar, Chennai 600020 (India); Zou, Linda, E-mail: linda.zou@unisa.edu.au [SA Water Centre for Water Management and Reuse, University of South Australia, Mawson Lakes Campus, Adelaide, SA 5095 (Australia)

    2010-12-15

    Batch biosorption experiments have been carried out for the removal of bovine serum albumin (BSA) from simulated industrial wastewater onto Ulva lactuca seaweed. Various vital parameters influencing the biosorption process such as initial concentration of BSA, pH of the solution, adsorbent dosage and temperature have been determined. The biosorption kinetics follows a pseudo-second order kinetic model. Equilibrium isotherm studies demonstrate that the biosorption followed the Freundlich isotherm model, which implies a heterogeneous sorption phenomenon. Various thermodynamic parameters such as changes in enthalpy, free energy and entropy have been calculated. The positive value of {Delta}H{sup o} and the negative value of {Delta}G{sup o} show that the sorption process is endothermic and spontaneous. The positive value of change in entropy {Delta}S{sup o} shows increased randomness at the solid-liquid interface during the biosorption of BSA onto U. lactuca seaweed.

  20. Biosorption of bovine serum albumin by Ulva lactuca biomass from industrial wastewater: equilibrium, kinetic and thermodynamic study.

    Science.gov (United States)

    Rathinam, Aravindhan; Zou, Linda

    2010-12-15

    Batch biosorption experiments have been carried out for the removal of bovine serum albumin (BSA) from simulated industrial wastewater onto Ulva lactuca seaweed. Various vital parameters influencing the biosorption process such as initial concentration of BSA, pH of the solution, adsorbent dosage and temperature have been determined. The biosorption kinetics follows a pseudo-second order kinetic model. Equilibrium isotherm studies demonstrate that the biosorption followed the Freundlich isotherm model, which implies a heterogeneous sorption phenomenon. Various thermodynamic parameters such as changes in enthalpy, free energy and entropy have been calculated. The positive value of ΔH° and the negative value of ΔG° show that the sorption process is endothermic and spontaneous. The positive value of change in entropy ΔS° shows increased randomness at the solid-liquid interface during the biosorption of BSA onto U. lactuca seaweed. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Biosorption of Cr(VI from AqueousSolution Using New Adsorbent: Equilibrium and Thermodynamic Study

    Directory of Open Access Journals (Sweden)

    Israa G. Zainal

    2010-01-01

    Full Text Available Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from polluted water. In the present study cinnamon was utilized for Cr(VI removal from aqueous solutions.It was found that a time of two hours was sufficient for sorption to attain equilibrium. The optimum pH was 2 for Cr(VI removal. Temprature has little influence on the biosorption process. The Cr(VI removal decreased with increase in temperature. The biosorption data was well fitted to Dubinin - Radushkevich (D-R, Freundlich and Tempkin adsorption isotherm models, although the correlation coefficient of Langmuir model was high but the calculated adsorption capacity did not agree with the experimental. The thermodynamic study reveals that the biosorption process is spontaneous and the spontaneity decreased with temperature increase and the process is exothermic accompanied by highly ordered adsorbate at the solid liquid interface. ΔH° values were negative and lie in the range of physical adsorption.

  2. Biosorption studies on powder of stem of Acacia nilotica: Removal of arsenic from surface water

    International Nuclear Information System (INIS)

    Baig, Jameel A.; Kazi, Tasneem G.; Shah, Abdul Q.; Kandhro, Ghulam A.; Afridi, Hassan I.; Khan, Sumaira; Kolachi, Nida F.

    2010-01-01

    In present study a biomass derived from the stem of Acacia nilotica has been investigated to remove As ions from surface water samples of different origins (lake, canal and river). The effects of various parameters viz. pH, biosorbent dosage, contact time and temperature on the biosorption processes were systematically studied. Experimental data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. It was observed that As biosorption best fitted to the Langmuir and Freundlich isotherms. The mean sorption energy (E) calculated from D-R model, indicated physico-chemical biosorption. Study of thermodynamic parameters revealed the endothermic, spontaneous and feasible nature of biosorption process. The pseudo-second-order rate equation described better the kinetics of As biosorption with good correlation coefficients than pseudo-first-order equation. The biomass of A. nilotica was found to be effective for the removal of As with 95% sorption efficiency at a concentration of <200 μg/L of As solution, and thus uptake capacity is 50.8 mg As/g of biomass. The A. nilotica biomass could be used as a low-cost biosorbent for As ion removal.

  3. Biosorption of styrene from synthetic wastewater by sugar cane waste(Bagass

    Directory of Open Access Journals (Sweden)

    Mehdi Hassanzadeh

    2015-04-01

    Full Text Available In this work, styrene removal from wastewater by using sugarcane waste (bagasse as an adsorbent was studied. Equilibrium isotherms and kinetics were determined; the effects of bagasse particle size and concentration, solutions pH, and temperature on the biosorption of styrene were studied in batch experiments. Adsorption equilibrium data was successfully fitted to Langmuir isotherms (R2=0.986 and Freundlich isotherms (R2=0.96. Also, the kinetics of biosorption was fitted to pseudo-second order equations (K2=0.00146 g mg-1 min-1, qe=24.5 mg g-1 for particle size range of 88-105 μm. According to the obtained results, an empirical equation was presented that could be used to calculate the percentage of styrene adsorption. The results showed that an increase in temperature caused a decrease in styrene removal. Moreover, maximum uptake was observed with NaOH-treated bagasse. It was found that an increase in average particle size decreased the biosorption rate. According to the calculated heat of adsorption, this sorption can be classified as a chemical biosorption. The optimum uptake was determined to be 88% at a pH equal to 12.1, a temperature of 35 oC, a particle size of 420-500 μm, and a bagasse concentration of 1 g L-1.

  4. Heavy Metal Biosorption sites in Penicillium cyclopium *a ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    ABSTRACT: The biomass of Penicillium cyclopium was subjected to chemical treatment to study the role of the functional groups ... fermentation industries to produce varied metabolites ..... biosorption potential of Aspergillus and Rhizopus sp.

  5. Predictive approach for simultaneous biosorption of hexavalent ...

    African Journals Online (AJOL)

    Chromium and pentachlorophenol are the major environmental pollutants emanating from tannery effluent. Indigenous Bacillus cereus isolate was employed for biosorption and PCP degradation studies under varied environmental conditions such as pH, temperature, contact time, presence of other heavy metals, initial ...

  6. Remediation of radionuclide pollutants through biosorption - an overview

    Energy Technology Data Exchange (ETDEWEB)

    Das, Nilanjana [Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore (India)

    2012-01-15

    The development of nuclear science and technology has led to the increase of nuclear wastes containing radionuclides to be released and disposed in the environment. Pollution caused by radionuclides is a serious problem throughout the world. To solve the problem, substantial research efforts have been directed worldwide to adopt sustainable technologies for the treatment of radionuclide containing wastes. Biosorption represents a technological innovation as well as a cost effective excellent remediation technology for cleaning up radionuclides from aqueous environment. A variety of biomaterials viz. algae, fungi, bacteria, plant biomass, etc. have been reported for radionuclide remediation with encouraging results. This paper reviews the achievements and current status of radionuclide remediation through biosorption which will provide insights into this research frontier. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Batch study of uranium biosorption by Elodea canadensis biomass

    International Nuclear Information System (INIS)

    Zheng-ji Yi; University of Science and Technology Beijing, Haidian District, Beijing; Jun Yao; Chinese University of Geosciences, Beijing; Mi-jia Zhu; Hui-lun Chen; Fei Wang; Zhi-min Yuan; Xing Liu

    2016-01-01

    The adsorption of U(VI) onto Elodea canadensis was studied via a batch equilibrium method. Kinetic investigation indicated that the U(VI) adsorption by E. canadensis reached an equilibrium in 120 min and followed pseudo-second-order kinetics. The solution pH was the most important parameter controlling adsorption of U(VI) and the optimum pH for U(VI) removal is 6.0. The U(VI) biosorption can be well described by Langmuir model. IR spectrum analysis revealed that -NH 2 , -OH, C=O and C-O could bind strongly with U(VI). XPS spectrum analysis implied that ion exchange and coordination mechanism could be involved in the U(VI) biosorption process. (author)

  8. Metal biosorption-flotation. Application to cadmium removal.

    Science.gov (United States)

    Matis, K A; Zouboulis, A I; Grigoriadou, A A; Lazaridis, N K; Ekateriniadou, L V

    1996-05-01

    Biosorption using suspended non-living biomass, and flotation (for consequent solid/liquid separation of the metal-loaded biomass) have been studied in the laboratory as a possible combined process, for the removal of toxic metals (i.e., cadmium) from dilute aqueous solutions. The various parameters of the process were investigated in depth, including re-use of biosorbent. A filter aid (contained in the biomass industrial waste used) was found not really to interfere. Zeta-potential measurements of the aforementioned system were also carried out. Promising results were obtained during continuous-flow experiments. A flotation residence time of 4 min was achieved. Metal removal and suspended biomass recovery were generally over 95%.

  9. Utilization of unconventional lignocellulosic waste biomass for the biosorption of toxic triphenylmethane dye malachite green from aqueous solution.

    Science.gov (United States)

    Selvasembian, Rangabhashiyam; P, Balasubramanian

    2018-05-12

    Biosorption potential of novel lignocellulosic biosorbents Musa sp. peel (MSP) and Aegle marmelos shell (AMS) was investigated for the removal of toxic triphenylmethane dye malachite green (MG), from aqueous solution. Batch experiments were performed to study the biosorption characteristics of malachite green onto lignocellulosic biosorbents as a function of initial solution pH, initial malachite green concentration, biosorbents dosage, and temperature. Biosorption equilibrium data were fitted to two and three parameters isotherm models. Three-parameter isotherm models better described the equilibrium data. The maximum monolayer biosorption capacities obtained using the Langmuir model for MG removal using MSP and AMS was 47.61 and 18.86 mg/g, respectively. The biosorption kinetic data were analyzed using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models. The pseudo-second-order kinetic model best fitted the experimental data, indicated the MG biosorption using MSP and AMS as chemisorption process. The removal of MG using AMS was found as highly dependent on the process temperature. The removal efficiency of MG showed declined effect at the higher concentrations of NaCl and CaCl 2 . The regeneration test of the biosorbents toward MG removal was successful up to three cycles.

  10. Biosorptive removal of Pb 2+ , Cd 2+ and Zn 2+ ions from water by ...

    African Journals Online (AJOL)

    Biosorption was highly pH-dependent, and the optimal pH for investigated metals was in the range of 4.5 to 6.0. The effects of temperature demonstrated that biosorption of the metals is a chemical process. SEM analysis revealed interesting morphological changes after acid refinement of the raw biosorbent and metal ...

  11. A REVIEW OF BIOSORPTION OF CHROMIUM IONS BY MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Inga Zinicovscaia

    2012-12-01

    Full Text Available Due to its widespread industrial use, chromium has become a serious pollutant in diverse environmental settings. The main source of chromium pollution including the Republic o Moldova is industry. It is a great need to develop new eco-friendly methods of chromium removal. Biosorption of heavy metals is a most promising technology involved in the removal of toxic metals from industrial waste streams and natural waters. This article is an extended abstract of a communication presented at the Conference Ecological Chemistry 2012

  12. Biosorption of Cd+2 by green plant biomass, Araucaria heterophylla: characterization, kinetic, isotherm and thermodynamic studies

    Science.gov (United States)

    Sarada, B.; Krishna Prasad, M.; Kishore Kumar, K.; Murthy, Ch V. R.

    2017-11-01

    The present study attempted to analyze the biosorption behavior of novel biosorbent, Araucaria heterophylla (green plant) biomass, to remove Cd+2 from solutions against various parameters, i.e., initial metal ion concentration, pH, temperature, sorbent dosage and biomass particle size. The maximum biosorption was found to be 90.02% at pH 5.5 and biosorption capacity ( q e) of Cd+2 is 9.2506 mg g-1. The Langmuir and Freundlich equilibrium adsorption isotherms were studied and it was observed that Freundlich model is the best fit than the Langmuir model with correlation co-efficient of 0.999. Kinetic studies indicated that the biosorption process of Cd+2 well followed the pseudo-second-order model with R 2 0.999. Thermodynamic studies observed that the process is exothermic (Δ H ° negative). Free energy change (Δ G °) with negative sign reflected the feasibility and spontaneous nature of the process. The chemical functional -OH groups, CH2 stretching vibrations, C=O carbonyl group of alcohol, C=O carbonyl group of amide, P=O stretching vibrations and -CH groups were involved in the biosorption process. The XRD pattern of the A. heterophylla was found to be mostly amorphous in nature. The SEM studies showed Cd+2 biosorption on selective grains of the biosorbent. It was concluded that A. heterophylla leaf powder can be used as an effective, low-cost, and environmentally friendly biosorbent for the removal of Cd+2 from aqueous solution.

  13. Exploring multi-metal biosorption by indigenous metal-hyperresistant Enterobacter sp. J1 using experimental design methodologies

    International Nuclear Information System (INIS)

    Lu, W.-B.; Kao, W.-C.; Shi, J.-J.; Chang, J.-S.

    2008-01-01

    A novel experimental design, combining mixture design and response surface methodology (RSM), was developed to investigate the competitive adsorption behavior of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 able to tolerate high concentrations of a variety of heavy metals. Using the proposed combinative experimental design, two different experiment designs in a ternary metal biosorption system can be integrated to a succinct experiment and the number of experimental trials was markedly reduced from 38 to 26 by reusing the mutual experimental data. Triangular contour diagrams and triangular three-dimensional surface plots were generated to describe the ternary metal biosorption equilibrium data in mixture design systems. The results show that the preference of metal sorption of Enterobacter sp. J1 decreased in the order of Pb 2+ > Cu 2+ > Cd 2+ . The presence of other metals resulted in a competitive effect. The influence of the other two metals in ternary metal biosorption system can be easily determined by comparing the stray distance from the single metal biosorption. The behavior of competitive biosorption was successfully described and predicted using a combined Langmuir-Freundlich model along with new three-dimensional contour-surface plots

  14. Exploring multi-metal biosorption by indigenous metal-hyperresistant Enterobacter sp. J1 using experimental design methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W.-B. [Department of Cosmetic Science, Chung Hwa University of Medical Technology, Tainan, Taiwan (China); Kao, W.-C.; Shi, J.-J. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Chang, J.-S. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China)], E-mail: changjs@mail.ncku.edu.tw

    2008-05-01

    A novel experimental design, combining mixture design and response surface methodology (RSM), was developed to investigate the competitive adsorption behavior of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 able to tolerate high concentrations of a variety of heavy metals. Using the proposed combinative experimental design, two different experiment designs in a ternary metal biosorption system can be integrated to a succinct experiment and the number of experimental trials was markedly reduced from 38 to 26 by reusing the mutual experimental data. Triangular contour diagrams and triangular three-dimensional surface plots were generated to describe the ternary metal biosorption equilibrium data in mixture design systems. The results show that the preference of metal sorption of Enterobacter sp. J1 decreased in the order of Pb{sup 2+} > Cu{sup 2+} > Cd{sup 2+}. The presence of other metals resulted in a competitive effect. The influence of the other two metals in ternary metal biosorption system can be easily determined by comparing the stray distance from the single metal biosorption. The behavior of competitive biosorption was successfully described and predicted using a combined Langmuir-Freundlich model along with new three-dimensional contour-surface plots.

  15. Equilibrium, kinetic and thermodynamic studies of the biosorption of textile dye (Reactive Red 195) onto Pinus sylvestris L

    International Nuclear Information System (INIS)

    Aksakal, Ozkan; Ucun, Handan

    2010-01-01

    This study investigated the biosorption of Reactive Red 195 (RR 195), an azo dye, from aqueous solution by using cone biomass of Pinus sylvestris Linneo. To this end, pH, initial dye concentration, biomass dosage and contact time were studied in a batch biosorption system. Maximum pH for efficient RR 195 biosorption was found to be 1.0 and the initial RR 195 concentration increased with decreasing percentage removal. Biosorption capacity increased from 6.69 mg/g at 20 deg. C to 7.38 mg/g at 50 deg. C for 200 mg/L dye concentration. Kinetics of the interactions was tested by pseudo-first-order and pseudo-second-order kinetics, the Elovich equation and intraparticle diffusion mechanism. Pseudo-second-order kinetic model provided a better correlation for the experimental data studied in comparison to the pseudo-first-order kinetic model and intraparticle diffusion mechanism. Moreover, the Elovich equation also showed a good fit to the experimental data. Freundlich and Langmuir adsorption isotherms were used for the mathematical description of the biosorption equilibrium data. The activation energy of biosorption (Ea) was found to be 8.904 kJ/mol by using the Arrhenius equation. Using the thermodynamic equilibrium coefficients obtained at different temperatures, the study also evaluated the thermodynamic constants of biosorption (ΔG o , ΔH o and ΔS). The results indicate that cone biomass can be used as an effective and low-cost biosorbent to remove reactive dyes from aqueous solution.

  16. Prospective role of indigenous Exiguobacterium profundum PT2 in arsenic biotransformation and biosorption by planktonic cultures and biofilms.

    Science.gov (United States)

    Saba; Andreasen, R; Li, Y; Rehman, Y; Ahmed, M; Meyer, R L; Sabri, A N

    2018-02-01

    The aim of this study was to analyse arsenic (As) transformation and biosorption by indigenous As-resistant bacteria both in planktonic and biofilm modes of growth. As-resistant bacteria were isolated from industrial waste water and strain PT2, and identified as Exiguobacterium profundum through 16S rRNA gene sequencing was selected for further study. As transformation and biosorption by E. profundumPT2 was determined by HPLC-ICP-MS analysis. Planktonic cultures reduced 3·73 mmol l -1 As 5+ into As 3+ from artificial waste water effluent after 48-h incubation. In case of biosorption, planktonic cultures and biofilms exhibited 25·2 and 29·4 mg g -1 biomass biosorption, respectively. As biosorption kinetics followed Freundlich isotherm and pseudo second-order model. Biofilm formation peaked after 3 days of incubation, and in the presence of As stress, biofilm formation was significantly affected in contrast to control (P biofilms with an increased demand of nutrients was revealed by minimum roughness and maximum surface to biovolume ratio measured through CLSM analysis. Indigenous As-resistant E. profundumPT2 was found capable of As transformation and biosorption both in the form of planktonic cultures and biofilms. Indigenous biofilm forming E. profundum PT2 revealing As biosorption and biotransformation potential is presented an eco-friendly and cost-effective source for As remediation that can be implemented for waste water treatment. © 2017 The Society for Applied Microbiology.

  17. Kinetic and isotherm studies of Cu(II) biosorption onto valonia tannin resin

    Energy Technology Data Exchange (ETDEWEB)

    Sengil, I. Ayhan [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54100 Sakarya (Turkey)], E-mail: asengil@sakarya.edu.tr; Ozacar, Mahmut [Department of Chemistry, Science and Arts Faculty, Sakarya University, 54100 Sakarya (Turkey); Tuerkmenler, Harun [Institute of Sciences and Technology, Sakarya University, 54040 Sakarya (Turkey)

    2009-03-15

    The biosorption of Cu(II) from aqueous solutions by valonia tannin resin was investigated as a function of particle size, initial pH, contact time and initial metal ion concentration. The aim of this study was to understand the mechanisms that govern copper removal and find a suitable equilibrium isotherm and kinetic model for the copper removal in a batch reactor. The experimental isotherm data were analysed using the Langmuir, Freundlich and Temkin equations. The equilibrium data fit well in the Langmuir isotherm. The experimental data were analysed using four sorption kinetic models - the pseudo-first- and second-order equations, the Elovich and the intraparticle diffusion model equation - to determine the best fit equation for the biosorption of copper ions onto valonia tannin resin. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process, whereas the Elovich equation also fits the experimental data well.

  18. Biosorption of nickel by Lysinibacillus sp. BA2 native to bauxite mine.

    Science.gov (United States)

    Prithviraj, Desale; Deboleena, Kashyap; Neelu, Nawani; Noor, Nahar; Aminur, Rahman; Balasaheb, Kapadnis; Abul, Mandal

    2014-09-01

    The current scenario of environmental pollution urges the need for an effective solution for toxic heavy metal removal from industrial wastewater. Bioremediation is the most cost effective process employed by the use of microbes especially bacteria resistant to toxic metals. In this study, Lysinibacillus sp. BA2, a nickel tolerant strain isolated from bauxite mine was used for the biosorption of Ni(II). Lysinibacillus sp. BA2 biomass had isoelectric point (pI) of 3.3. The maximum negative zeta potential value (-39.45) was obtained at pH 6.0 which was highly favourable for Ni(II) biosorption. 238.04mg of Ni(II) adsorbed on one gram of dead biomass and 196.32mg adsorbed on one gram of live biomass. The adsorption of Ni(II) on biomass increased with time and attained saturation after 180min with rapid biosorption in initial 30min. The Langmuir and Freundlich isotherms could fit well for biosorption of Ni(II) by dead biomass while Langmuir isotherm provided a better fit for live biomass based on correlation coefficient values. The kinetic studies of Ni(II) removal, using dead and live biomass was well explained by second-order kinetic model. Ni(II) adsorption on live biomass was confirmed by SEM-EDX where cell aggregation and increasing irregularity of cell morphology was observed even though cells were in non-growing state. The FTIR analysis of biomass revealed the presence of carboxyl, hydroxyl and amino groups, which seem responsible for biosorption of Ni(II). The beads made using dead biomass of Lysinibacillus sp. BA2 could efficiently remove Ni(II) from effluent solutions. These microbial cells can substitute expensive methods for treating nickel contaminated industrial wastewaters. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Biosorption of uranium in radioactive liquid organic waste by coconut fiber

    International Nuclear Information System (INIS)

    Marumo, Julio Takehiro; Ferreira, Eduardo Gurzoni Alvares; Vieira, Ludmila Cabreira; Ferreira, Rafael Vicente de Padua; Silva, Edson Antonio da

    2013-01-01

    Radioactive liquid organic waste needs special attention because the available treatment processes are often expensive and difficult to be managed. Biosorption is a potential technique since it allies low cost with relatively high efficiency. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. Biosorption using vegetable biomass from agricultural waste has become a very attractive technique because it involves the removal of heavy metal ions by low cost biosorbent. This technique could be employed in the treatment of radioactive liquid wastes. Among the biosorbent reported in the literature, coconut fiber (Cocos nucifera L.) is highlighted due to the large number of functional groups in its composition. The aim of this study was to assess the potential of coconut fiber to remove uranium from radioactive liquid organic waste. This work was divided into three stages: 1) Preparation and activation of the coconut fiber; 2) Physical characterization of the biomass, 3) Batch biosorption experiments. Two forms of coconut fiber were tested, raw and activated. The activation was performed with dilute HNO3 and NaOH solutions. The parameters evaluated for physical characterization of biomass were morphological characteristics of coconut fiber, real and apparent density and surface area. The biomass was suspended in 10 ml of solutions prepared with distillate water and radioactive liquid waste for 2 hours in the proportion of 0.2% w/v. After the contact time, the coconut fiber was removed by filtration and the supernatant, analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES).The results were evaluated using Langmuir and Freundlich isotherms. The maximum capacity for the raw coconut fiber was lower than the activated one, removing only 1.14mg/g against 2.61mg/g. These results suggest that biosorption with coconut fiber in activated form can be applied in the

  20. Biosorption of uranium in radioactive liquid organic waste by coconut fiber

    Energy Technology Data Exchange (ETDEWEB)

    Marumo, Julio Takehiro; Ferreira, Eduardo Gurzoni Alvares; Vieira, Ludmila Cabreira; Ferreira, Rafael Vicente de Padua, E-mail: jtmarumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Silva, Edson Antonio da, E-mail: edson.silva2@unioeste.br [Universidade Estadual do Oeste do Parana (UNIOESTE), Toledo, PR (Brazil)

    2013-07-01

    Radioactive liquid organic waste needs special attention because the available treatment processes are often expensive and difficult to be managed. Biosorption is a potential technique since it allies low cost with relatively high efficiency. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. Biosorption using vegetable biomass from agricultural waste has become a very attractive technique because it involves the removal of heavy metal ions by low cost biosorbent. This technique could be employed in the treatment of radioactive liquid wastes. Among the biosorbent reported in the literature, coconut fiber (Cocos nucifera L.) is highlighted due to the large number of functional groups in its composition. The aim of this study was to assess the potential of coconut fiber to remove uranium from radioactive liquid organic waste. This work was divided into three stages: 1) Preparation and activation of the coconut fiber; 2) Physical characterization of the biomass, 3) Batch biosorption experiments. Two forms of coconut fiber were tested, raw and activated. The activation was performed with dilute HNO3 and NaOH solutions. The parameters evaluated for physical characterization of biomass were morphological characteristics of coconut fiber, real and apparent density and surface area. The biomass was suspended in 10 ml of solutions prepared with distillate water and radioactive liquid waste for 2 hours in the proportion of 0.2% w/v. After the contact time, the coconut fiber was removed by filtration and the supernatant, analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES).The results were evaluated using Langmuir and Freundlich isotherms. The maximum capacity for the raw coconut fiber was lower than the activated one, removing only 1.14mg/g against 2.61mg/g. These results suggest that biosorption with coconut fiber in activated form can be applied in the

  1. Utilization of fermentation waste (Corynebacterium glutamicum) for biosorption of Reactive Black 5 from aqueous solution

    International Nuclear Information System (INIS)

    Vijayaraghavan, K.; Yun, Yeoung-Sang

    2007-01-01

    A fermentation waste, Corynebacterium glutamicum, was successfully employed as a biosorbent for Reactive Black 5 (RB5) from aqueous solution. This paper initially studied the effect of pretreatment on the biosorption capacity of C. glutamicum toward RB5, using several chemical agents, such as HCl, H 2 SO 4 , HNO 3 , NaOH, Na 2 CO 3 , CaCl 2 and NaCl. Among these reagents, 0.1 M HNO 3 gave the maximum enhancement of the RB5 uptake, exhibiting 195 mg/g at pH 1 with an initial RB5 concentration of 500 mg/l. The solution pH and temperature were found to affect the biosorption capacity, and the biosorption isotherms derived at different pHs and temperatures revealed that a low pH (pH 1) and high temperature (35 deg. C) favored biosorption. The biosorption isotherm was well represented using three-parameter models (Redlich-Peterson and Sips) compared to two-parameter models (Langmuir and Freundlich models). As a result, high correlation coefficients and low average percentage error values were observed for three-parameter models. A maximum RB5 uptake of 419 mg/g was obtained at pH 1 and a temperature of 35 deg. C, according to the Langmuir model. The kinetics of the biosorption process with different initial concentrations (500-2000 mg/l) was also monitored, and the data were analyzed using pseudo-first and pseudo-second order models, with the latter describing the data well. Various thermodynamic parameters, such as ΔG o , ΔH o and ΔS o , were calculated, indicating that the present system was a spontaneous and endothermic process. The use of a 0.1 M NaOH solution successfully desorbed almost all the dye molecules from dye-loaded C. glutamicum biomass at different solid-to-liquid ratios examined

  2. Biosorption of Uranium by Magnetically Modified Wheat Bran

    Czech Academy of Sciences Publication Activity Database

    Wang, H.; Yanqin, J.; Tian, Q.; Horská, Kateřina; Shao, X.; Maděrová, Zdeňka; Miao, X.; Šafaříková, Miroslava; Šafařík, Ivo

    2014-01-01

    Roč. 49, č. 16 (2014), s. 2534-2539 ISSN 0149-6395 R&D Projects: GA MŠk LH12190 Institutional support: RVO:67179843 Keywords : magnetic separation * biosorption * magnetic wheat bran * uranium Subject RIV: CE - Biochemistry Impact factor: 1.171, year: 2014

  3. Equilibrium, thermodynamic and kinetic investigations for biosorption of uranium with green algae (Cladophora hutchinsiae).

    Science.gov (United States)

    Bağda, Esra; Tuzen, Mustafa; Sarı, Ahmet

    2017-09-01

    Removal of toxic chemicals from environmental samples with low-cost methods and materials are very useful approach for especially large-scale applications. Green algae are highly abundant biomaterials which are employed as useful biosorbents in many studies. In the present study, an interesting type of green algae, Cladophora hutchinsiae (C. hutchinsiae) was used for removal of highly toxic chemical such as uranium. The pH, biosorbent concentration, contact time and temperature were optimized as 5.0, 12 g/L, 60 min and 20 °C, respectively. For the equilibrium calculations, three well known isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich) were employed. The maximum biosorption capacity of the biosorbent was calculated as about 152 mg/g under the optimum batch conditions. The mean energy of biosorption was calculated as 8.39 kJ/mol from the D-R biosorption isotherm. The thermodynamic and kinetic characteristics of biosorption were also investigated to explain the nature of the process. The kinetic data best fits the pseudo-second-order kinetic model with a regression coefficient of >0.99 for all studied temperatures. The calculated ΔH° and ΔG° values showed that the biosorption process is exothermic and spontaneous for temperatures between 293 and 333 K. Furthermore, after seven cycling process, the sorption and desorption efficiencies of the biosorbent were found to be 70, and 58%, respectively meaning that the biosorbent had sufficiently high reusability performance as a clean-up tool. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Characterization of Pb2+ biosorption by psychrotrophic strain Pseudomonas sp. I3 isolated from permafrost soil of Mohe wetland in Northeast China.

    Science.gov (United States)

    Li, Dandan; Xu, Xingjian; Yu, Hongwen; Han, Xuerong

    2017-07-01

    Due to the long and severe winter in Northeast China, wastewater containing lead (Pb) is treated inefficiently, resulting in irregular disposal. In order to solve this problem, a Pb-resistant psychrotrophic bacterium, Pseudomonas sp. I3, was isolated from permafrost soil of Mohe wetland and served as biosorbent for Pb 2+ removal under 15 °C. The minimum inhibitory concentration of strain I3 for Pb 2+ was 7.5 mM, which was higher than that of Escherichia coli DH5α (1.5 mM). However, acid digestion results showed that these two bacteria had a comparable biosorption capacity for Pb 2+ , suggesting no direct relationship between biosorption ability of bacteria and their metal-resistance. Acid digestion results also proved that intracellular Pb accumulation was mainly contributed to the distinct performance between living and non-living biosorbents, which was further confirmed by the analyses of TEM-EDS. Results of FTIR revealed that functional groups including CH 2 , CO, CN, NH, COO and SO 3 were participated in the biosorption process of the tested biosorbents no matter bacteria were living or not. The effects of environmental factors including pH, temperature, biomass dose, operation time and initial Pb 2+ concentration were investigated through a batch of biosorption experiments. The equilibrium data for living and non-living biosorbent were well fitted to Langmuir model with their maximum Pb 2+ biosorption capacities of 49.48 and 42.37 mg/g, respectively. The kinetic data for each biosorbent were well described by pseudo-second order kinetic model. Overall, Pseudomonas sp. I3 seemed to be an effective biosorbent for cleansing Pb 2+ from contaminated wastewater at low temperature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Kinetic, Equilibrium and thermodynamic studies on the biosorption ...

    African Journals Online (AJOL)

    Michael Horsfall

    the biosorption process of the metal ion followed the pseudo-second-order and intraparticle diffusion models ... is feasible, spontaneous, endothermic and highly disordered in nature under the experimental conditions. ... method of heavy metal recovery (Sari et al., 2008; .... favourably bound to the negatively charged active.

  6. Biosorption of uranium from wastewater by ZVI-SRB immobilized in calcium alginate

    International Nuclear Information System (INIS)

    Wang Aihe; Zhang Wei; Hu Kaiguang

    2009-01-01

    A ZVI-SRB was immobilized in calcium alginate gel beads,and the immobilized ZVI-SRB was used for removing uranium from wasterwater. The kinetics of uranium biosorption by the immobilized ZVI-SRB and the immobilized SRB was investigated. The results show that the immobilized ZVI-SRB and SRB were effective in removing uranium from wasterwater, and their maximal absorption capacities were up to 312.50 and 256.41 mg/g respectively. The kinetics of uranium biosorption onto the immobilized ZVI-SRB and SRB followed pseudo-second order model. (authors)

  7. Separation of uranium by biosorption

    International Nuclear Information System (INIS)

    Volesky, B.; Tsezos, M.

    1983-01-01

    This invention relates to metal ion separation processes and more particularly to processes of extraction of specific ions of or containing heavy metals from waste liquids by means of biosorption. The invention is based upon the discovery that the biomass produced as the result of the growth of a certain carefully selected microbial genus, namely species of the genus Rhizopus, such as Rhizopus arihizus, has an outstanding ability for selective adsorption of uranium and thorium ions from aqueous solution or suspension

  8. Biosorption optimization of lead(II), cadmium(II) and copper(II) using response surface methodology and applicability in isotherms and thermodynamics modeling

    International Nuclear Information System (INIS)

    Singh, Rajesh; Chadetrik, Rout; Kumar, Rajender; Bishnoi, Kiran; Bhatia, Divya; Kumar, Anil; Bishnoi, Narsi R.; Singh, Namita

    2010-01-01

    The present study was carried out to optimize the various environmental conditions for biosorption of Pb(II), Cd(II) and Cu(II) by investigating as a function of the initial metal ion concentration, temperature, biosorbent loading and pH using Trichoderma viride as adsorbent. Biosorption of ions from aqueous solution was optimized in a batch system using response surface methodology. The values of R 2 0.9716, 0.9699 and 0.9982 for Pb(II), Cd(II) and Cu(II) ions, respectively, indicated the validity of the model. The thermodynamic properties ΔG o , ΔH o , ΔE o and ΔS o by the metal ions for biosorption were analyzed using the equilibrium constant value obtained from experimental data at different temperatures. The results showed that biosorption of Pb(II) ions by T. viride adsorbent is more endothermic and spontaneous. The study was attempted to offer a better understating of representative biosorption isotherms and thermodynamics with special focuses on binding mechanism for biosorption using the FTIR spectroscopy.

  9. Biosorption optimization of lead(II), cadmium(II) and copper(II) using response surface methodology and applicability in isotherms and thermodynamics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Rajesh; Chadetrik, Rout; Kumar, Rajender; Bishnoi, Kiran; Bhatia, Divya; Kumar, Anil [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana (India); Bishnoi, Narsi R., E-mail: nrbishnoi@gmail.com [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana (India); Singh, Namita [Department of Bio and Nanotechnology, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana (India)

    2010-02-15

    The present study was carried out to optimize the various environmental conditions for biosorption of Pb(II), Cd(II) and Cu(II) by investigating as a function of the initial metal ion concentration, temperature, biosorbent loading and pH using Trichoderma viride as adsorbent. Biosorption of ions from aqueous solution was optimized in a batch system using response surface methodology. The values of R{sup 2} 0.9716, 0.9699 and 0.9982 for Pb(II), Cd(II) and Cu(II) ions, respectively, indicated the validity of the model. The thermodynamic properties {Delta}G{sup o}, {Delta}H{sup o}, {Delta}E{sup o} and {Delta}S{sup o} by the metal ions for biosorption were analyzed using the equilibrium constant value obtained from experimental data at different temperatures. The results showed that biosorption of Pb(II) ions by T. viride adsorbent is more endothermic and spontaneous. The study was attempted to offer a better understating of representative biosorption isotherms and thermodynamics with special focuses on binding mechanism for biosorption using the FTIR spectroscopy.

  10. Biotechnological potential of Azolla filiculoides for biosorption of Cs and Sr: Application of micro-PIXE for measurement of biosorption.

    Science.gov (United States)

    Ghorbanzadeh Mashkani, Saeid; Tajer Mohammad Ghazvini, Parisa

    2009-03-01

    The presence of Cs and Sr in culture medium of Azolla filiculoides caused about 27.4% and 46.3% inhibition of biomass growth, respectively, in comparison to A. filiculoides control weight which had not metals. Biosorption batch experiments were conducted to determine the Cs and Sr binding ability of native biomass and chemically modified biosorbents derived from Azolla namely ferrocyanide Azolla sorbents type 1 and type 2 (FAS1 and FAS2) and hydrogen peroxide Azolla sorbent (HAS). The best Cs and Sr removal results were obtained when A. filiculoides was treated by 2M MgCl(2) and 30ml H(2)O(2) 8mM at pH 7 for 12h and it was then washed by NaOH solution at pH 10.5 for 6h. Pretreatment of Azolla have been suggested to modify the surface characteristics which could improve biosorption process. The binding of Cs and Sr on the cell wall of Azolla was studied with micro-PIXE and FT-IR.

  11. Biosorption kinetics of Cd (II, Cr (III and Pb (II in aqueous solutions by olive stone

    Directory of Open Access Journals (Sweden)

    M. Calero

    2009-06-01

    Full Text Available A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II, Cr (III and Pb (II from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is the one that best describes the biosorption of the three metal ions for all the range of experimental conditions investigated. For the three metal ions, the maximum biosoption capacity and the initial biosorption rate increase when the initial metal concentration rises. However, the kinetic constant decreases when the initial metal concentration increases. The temperature effect on biosorption capacity for Cd (II and Cr (III is less significant; however, for Pb (II the effect of temperature is more important, especially when temperature rises from 25 to 40ºC. The biosorption capacity at mmol/g of olive stone changes in the following order: Cr>Cd>Pb. Thus, for an initial concentration of 220 mg/ℓ, a maximum sorption capacity of 0.079 mmol/g for Cr (III, 0.065 mmol/g for Cd (II and 0.028 mmol/g for Pb (II has been obtained.

  12. Biosorption of Cu(II) from aqueous solutions by mimosa tannin gel

    Energy Technology Data Exchange (ETDEWEB)

    Sengil, I. Ayhan [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54100 Sakarya (Turkey)], E-mail: asengil@sakarya.edu.tr; Ozacar, Mahmut [Department of Chemistry, Science and Arts Faculty, Sakarya University, 54100 Sakarya (Turkey)

    2008-09-15

    The biosorption of Cu(II) from aqueous solutions by mimosa tannin resin (MTR) was investigated as a function of particle size, initial pH, contact time and initial metal ion concentration. The aim of this study was to understand the mechanisms that govern copper removal and find a suitable equilibrium isotherm and kinetic model for the copper removal in a batch reactor. The experimental isotherm data were analysed using the Langmuir, Freundlich and Temkin equations. The equilibrium data fit well in the Langmiur isotherm. The experimental data were analysed using four sorption kinetic models - the pseudo-first- and second-order equations, and the Elovich and the intraparticle diffusion equation - to determine the best fit equation for the biosorption of copper ions onto mimosa tannin resin. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process, whereas the Elovich equation also fits the experimental data well. Thermodynamic parameters such as the entropy change, enthalpy change and Gibb's free energy change were found out to be 153.0 J mol{sup -1} K{sup -1}, 42.09 kJ mol{sup -1} and -2.47 kJ mol{sup -1}, respectively.

  13. Biosorption of copper by marine algae Gelidium and algal composite material in a packed bed column.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Loureiro, José M; Boaventura, Rui A R

    2008-09-01

    Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption-desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l(-1) of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of approximately 13 and 3 mg g(-1), respectively, for algae Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1M HNO(3) solution was 100% effective. After two consecutive sorption-desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.

  14. Biosorption and bioaccumulation of thallium by thallium-tolerant fungal isolates.

    Science.gov (United States)

    Sun, Jialong; Zou, Xiao; Xiao, Tangfu; Jia, Yanlong; Ning, Zengping; Sun, Min; Liu, Yizhang; Jiang, Tao

    2015-11-01

    Little is known about the biosorption and bioaccumulation capacity of thallium (Tl) by microorganisms that occur in Tl-polluted soil. The present study focused on characterizing the biosorption and bioaccumulation of Tl by Tl-tolerant fungi isolated from Tl-polluted soils. Preliminary data showed a positive correlation between the biomass and the biosorbed Tl content. The Tl-tolerant strains were capable of bioaccumulating Tl, up to 7189 mg kg(-1) dry weight. The subcellular distribution of Tl showed obvious compartmentalization: cytoplasm ≫ cell wall > organelle. The majority of Tl (up to 79%) was found in the cytoplasm, suggesting that intracellular compartmentalization appeared to be responsible for detoxification. These findings further suggest the applicability of the fungal isolates for cleanup of Tl in Tl-polluted water and soil.

  15. Biosorption of uranium by cross-linked and alginate immobilized residual biomass from distillery spent wash

    International Nuclear Information System (INIS)

    Bustard, M.; McHale, A.P.

    1997-01-01

    Residual biomass from a whiskey distillery was examined for its ability to function as a biosorbent for uranium. Biomass recovered and lyophilised exhibited a maximum biosorption capacity of 165-170 mg uranium/g dry weight biomass at 15 C. With a view towards the development of continuous or semi-continuous flow biosorption processes it was decided to immobilize the material by (1) cross-linking with formaldehyde and (2) introducing that material into alginate matrices. Cross-linking the recovered biomass resulted in the formation of a biosorbent preparation with a maximum biosorption capacity of 185-190 mg/g dry weight biomass at 15 C. Following immobilization of biomass in alginate matrices it was found that the total amount of uranium bound to the matrix did not change with increasing amounts of biomass immobilized. It was found however, that the proportion of uranium bound to the biomass within the alginate-biomass matrix increased with increasing biomass concentration. Further analysis of these preparations demonstrated that the alginate-biomass matrix had a maximum biosorption capacity of 220 mg uranium/g dry weight of the matrix, even at low concentrations of biomass. (orig.). With 3 figs., 1 tab

  16. Optimization of Chromium Biosorption by Fungal Adsorbent, Trichoderma sp. BSCR02 and its Desorption Studies

    Directory of Open Access Journals (Sweden)

    John Rose Mercy Benila Smily

    2017-04-01

    Full Text Available Heavy metal pollution in water because of the discharge of industrial effluent imposes serious environmental concern. Chromium is one of such pollutants which is considered as toxic, non-biodegradable and persistent in nature. In the present study, the fungal strains isolated from the water samples of Manjakkudi lake were screened for their resistance towards the heavy metal, chromium. The Trichoderma sp. BSCR02 showing resistance towards increased chromium concentration (4 mg/mL was selected for the biosorption studies. The chromium biosorption ability of the untreated and alkali-treated mycelium of Trichoderma sp. BSCR02 was compared and found the alkali treatment as better biosorbent. The process parameters governing chromium biosorption by the dead biomass of Trichoderma sp. were optimized and maximum chromium removal was observed at pH 5 with 200 mg/L initial metal concentration at 35°C when supplemented 1.6 mg/mL of biosorbent for the contact time of 120 min. The biosorbent was found to be active for five cycles of biosorption. The results revealed the applicability of the Trichoderma sp. BSCR2 for the effective removal of chromium from the contaminated water bodies.

  17. Biosorption of uranium by cross-linked and alginate immobilized residual biomass from distillery spent wash

    Energy Technology Data Exchange (ETDEWEB)

    Bustard, M. [Biotechnology Research Group, School of Applied Biological and Chemical Sciences, University of Ulster, Coleraine (United Kingdom); McHale, A.P. [Biotechnology Research Group, School of Applied Biological and Chemical Sciences, University of Ulster, Coleraine (United Kingdom)

    1997-08-01

    Residual biomass from a whiskey distillery was examined for its ability to function as a biosorbent for uranium. Biomass recovered and lyophilised exhibited a maximum biosorption capacity of 165-170 mg uranium/g dry weight biomass at 15 C. With a view towards the development of continuous or semi-continuous flow biosorption processes it was decided to immobilize the material by (1) cross-linking with formaldehyde and (2) introducing that material into alginate matrices. Cross-linking the recovered biomass resulted in the formation of a biosorbent preparation with a maximum biosorption capacity of 185-190 mg/g dry weight biomass at 15 C. Following immobilization of biomass in alginate matrices it was found that the total amount of uranium bound to the matrix did not change with increasing amounts of biomass immobilized. It was found however, that the proportion of uranium bound to the biomass within the alginate-biomass matrix increased with increasing biomass concentration. Further analysis of these preparations demonstrated that the alginate-biomass matrix had a maximum biosorption capacity of 220 mg uranium/g dry weight of the matrix, even at low concentrations of biomass. (orig.). With 3 figs., 1 tab.

  18. Heavy metal biosorption sites in Penicillium cyclopium | Tsekova ...

    African Journals Online (AJOL)

    The biomass of Penicillium cyclopium was subjected to chemical treatment to study the role of the functional groups in the biosorption of heavy metal ions. The modifications of the functional groups were examined with infrared spectroscopy. Hydroxyl groups were identified as providing the major sites of heavy metal ...

  19. Kinetic, Equilibrium and thermodynamic studies on the biosorption ...

    African Journals Online (AJOL)

    The kinetics, equilibrium and thermodynamics of the biosorption of Cd (II) from aqueous solution by the leaf biomass of Calotropis procera popularly known in western Nigeria as 'bom bom'and genrally known as Sodom apple were investigated at different experimental conditions. Optimum conditions of pH, contact time, ...

  20. Biosorption characteristics of Aspergillus fumigatus in removal of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... in growth medium, thus about 20% of the isolates can grow up to 50 mg Cd/100 ml medium and only ... have the highest Cd biosorption, compared to yeast malt extract (YM) and sabourad (Sb) media. ... chemical parameters of the solution, say, temperature, ...... inactivated Phanerochaete chrysosporium.

  1. Biosorption characteristic of Alcaligenes sp. BAPb.1 for removal of lead(II) from aqueous solution.

    Science.gov (United States)

    Jin, Yu; Yu, Sumei; Teng, Chunying; Song, Tao; Dong, Liying; Liang, Jinsong; Bai, Xin; Xu, Xiuhong; Qu, Juanjuan

    2017-06-01

    In this study, strain BAPb.1 was isolated from lead mining area and used as an adsorbent to remove lead(II) ions from aqueous solution. The physicochemical characteristics, heavy metal resistance and antibiotic sensitivity of strain BAPb.1 were investigated. Biosorption capacity was evaluated by batch biosorption experiments, and isothermal characteristics were discussed. Atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectrometry (FTIR) were conducted to explore the mechanism for lead(II) adsorption. Based on morphological and physiological characteristics as well as the phylogenetic analysis of 16S rDNA sequences, strain BAPb.1 was identified as a member of the genus Alcaligenes. It exhibited high resistances to multiple heavy metals such as lead(II), copper(II), zinc(II), nickel(II) and chromium(VI), and to antibiotics such as kanamycin, ampicillin, streptomycin, chloramphenicol, and tetracycline. The optimum conditions for maximum biosorption rate of 85.2% and maximum capacity of 56.8 mg g -1 were found at pH of 5, adsorbent dosage of 1.5 g L -1 (dry weight), initial lead(II) concentration of 100 mg L -1 , and contact time of 30 min at 30 °C. Biosorption isotherms were well fitted with Langmuir isotherm model. Mechanism analysis reveals that the lead(II) ions may exchange with sodium and potassium ions, and the hydroxyl, carbonyl and phosphate groups on the cell surface can chelate the lead(II) ions, therefore, surface adsorption play significant role in the biosorption process.

  2. Biosorption of mercury from aqueous solutions using highly characterised peats

    Directory of Open Access Journals (Sweden)

    A.M. Rizzuti

    2015-02-01

    Full Text Available This research investigated the biosorption of mercury from aqueous solutions by six highly characterised peats. Samples of the peats were tested both in unaltered condition and after being treated with hydrochloric acid (HCl to free up any occupied exchange sites. Other variables tested were sample dose, contact time, mixing temperature, and the concentration and pH of the mercury solution. Desorption studies were also performed, and tests were done to determine whether the peats could be re-used for mercury biosorption. The results indicate that all six peat types biosorb mercury from aqueous solutions extremely well (92−100 % removal and that their mercury removal capacities are not significantly affected by manipulation of the various factors tested. The factor that had the greatest impact on the mercury removal capacities of the peats was the pH of the mercury solution. The optimal mercury solution pH for mercury removal was in the range 5−7 for four of the peats and in the range 2−3 for the other two. The desorption results indicate that it may be possible to recover up to 41 % of the removed mercury. All of the peat types tested can be repeatedly re-used for additional mercury biosorption cycles. Hence, their disposal should not become a hazardous waste problem.

  3. Removal of thorium(IV) from aqueous solution by biosorption onto modified powdered waste sludge. Experimental design approach

    International Nuclear Information System (INIS)

    Yunus Pamukoglu, M.; Mustafa Senyurt; Bulent Kirkan

    2017-01-01

    The biosorption of radioactive Th(IV) ions in the aqueous solutions onto the modified powdered waste sludge (MPWS) has been examined. In this context, the parameters affecting biosorption of Th(IV) from aqueous solutions has been examined by using MPWS biosorbent in Box Behnken statistical experimental design. The structure of MPWS biosorbent was characterized by using SEM and BET techniques. According to the experimental design results, MPWS and Th(IV) concentrations should be kept high to achieve the maximum efficiency in Th(IV) biosorption. On the other hand, MPWS, which is also used as a biosorbent, is an economical, effective and natural biosorbent. (author)

  4. Biosorption of Cr(VI) in Aqueous Solution using Microorganisms: Comparison of the Use of Rhizopus oryzae, Bacillus firmus, and Trichoderma viride

    Science.gov (United States)

    Safitri, Anna; Mahardini, Putri; Prasetyawan, Sasangka; Roosdiana, Anna

    2018-01-01

    In this work, the study of biosorption of Cr(VI) from aqueous solution was conducted using Rhizopus oryzae, Bacillus firmus, and Trichoderma viride as microorganisms that can absorb Cr(VI). The research is focused on determination of optimum conditions including pH, the number of R. oryzae, B. firmus, and T. viride (inoculums), and initial concentrations of Cr(VI) used. Optimum pH was obtained at pH 5, 4.5 and 6, for biosorption of Cr(VI) with R. oryzae, B. firmus, and T. viride, respectively, in the capacity of 45.3%, 24.5%, and 90.3%. The highest amount of Cr(VI) adsorbed for biosorption with R. oryzae, B. firmus, and T. viride, were 55.4%, 18.5%, and 74.5%, respectively, using 6-mL inoculums. The equilibrium concentrations achieved for R. oryzae, B. firmus, and T. viride were 60 mg/mL, 40 mg/mL, and 40 mg/mL, with the amount of Cr(VI) adsorbed were 32.4%, 28.2%, and 89.3%, respectively. The adsorption capacity for R. oryzae, B. firmus, and T. viride were 45.3 mg/1×106 colonies, 36.2 mg/1×106 cells, and 77.8 mg/1×106 colonies, respectively. Overall, the biosorbents effectivity order in the biosorption process of Cr(VI) are T. viride > R. oryzae > B. firmus.

  5. Biosorption and toxicity responses to arsenite (As[III]) in Scenedesmus quadricauda.

    Science.gov (United States)

    Zhang, Jianying; Ding, Tengda; Zhang, Chunlong

    2013-08-01

    Toxicity and biosorption responses to arsenite (As[III]) were examined in a 96-h exposure study using Scenedesmus quadricauda, one of the most popular green algae distributed in freshwaters in China. Results indicated that the pH-dependent distribution of two arsenite species (H2AsO3(-) and H3AsO3) played an important role in biosorption and toxicity. The undissociated H3AsO3 was more toxic than its monoanionic H2AsO3(-) through comparison of algal cell numbers, chlorophyll-a contents, and algal ultrastructural changes observed with transmission electron microscopy. An effective biosorption of 89.0mgg(-1) at 100mgL(-1) As[III] was found in the treatments with an initial pH of 9.3 and 25.2μgg(-1) at 0.03mgL(-1) As[III] at an initial pH of 8.2 as a result of the predominant species of H2AsO3(-) under the ambient pH and Eh conditions. Our results imply that S. quadricauda may provide a new means for the removal of toxic arsenite species present in contaminated surface water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Biosorption of chromium from electroplating and galvanizing industrial effluents under extreme conditions using Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    G. Sibi

    2016-07-01

    Full Text Available Hexavalent chromium [Cr(VI] is a toxic oxidized form and an important metal pollutant in the water bodies. Biosorption of chromium(VI offers a potential alternative to conventional metal removal methods. Dried biomass of Chlorella vulgaris was used as biosorbent for the removal of Cr(VI from electroplating and galvanizing industry effluents as a function of biosorbent dosage, contact time, pH, salinity and initial metal ion concentration. Batch experiments were conducted for biosorption and the optimum conditions were 1 g/L biomass, 4 h contact time, pH 2 and 2.893 mS/cm of electrical conductivity. The chromium biosorption was strictly pH dependent with a maximum Cr removal of 63.2 mg/L at pH 2. Highest Cr removal at a concentration of 81.3 mg/L was observed at Electrical conductivity (EC value of 2.893 mS/cm. A comparison of Langmuir and Freundlich isotherm models revealed that Freundlich isotherm model fitted the experimental data based on R2, qmax and standard error values. The results suggest that C. vulgaris biomass could be considered a promising low-cost biosorbent for the removal of Cr(VI from electroplating and galvanizing industry effluents. Keywords: Biosorption, Chlorella vulgaris, Microalgae, Hexavalent chromium

  7. Screening of various types of lignin products for biosorption of heavy metals (Cu, Ni, Zn)

    Energy Technology Data Exchange (ETDEWEB)

    Gouda, H [Nile Research Inst., National Water Research Center, El Qanater (Egypt)

    2000-07-01

    This paper discussed the need to develop new technologies and approaches to meet strict environmental legislation and standards regarding the discharge of heavy metals to the environment by industry. A study was conducted to determine the feasibility of using different lignin materials for heavy metal removal using the BioElecDetox process. This process uses an unique combination of existing water and wastewater equipment and technology. The heavy metal removal efficiencies of grape stalks, pine bark, larch bark, pine sawdust, broccoli stems, and paper pulp were tested for their biosorption capacity, sedimentation, desorption and recycling for single solutions of copper, nickel and zinc (Cu, Ni and Zn respectively). Results showed that the grape stalk was the best biosorbent among the biomasses examined for Cu, Ni and Zn ions from single solution. The biomass biosorption capacity was determined using the Langmuir equation. Pine bark also gave good results and was considered to be the second best biosorbent. The biosorption for single metal solution was high for all metals. Biomass recycling had no impact on the efficiency of biosorption. It was recommended that future experiments should be conducted for industrial effluent using different biomasses at laboratory scale for the BioElecDetox process. 5 refs., 1 tab., 2 figs.

  8. Chromium (VI) biosorption properties of multiple resistant bacteria isolated from industrial sewerage.

    Science.gov (United States)

    Oyetibo, Ganiyu Oladunjoye; Ilori, Matthew Olusoji; Obayori, Oluwafemi Sunday; Amund, Olukayode Oladipo

    2013-08-01

    Chromium (VI) [Cr (VI)] biosorption by four resistant autochthonous bacterial strains was investigated to determine their potential for use in sustainable marine water-pollution control. Maximum exchange between Cr (VI) ions and protons on the cells surfaces were at 30-35 °C, pH 2.0 and 350-450 mg/L. The bacterial strains effectively removed 79.0-90.5 % Cr (VI) ions from solution. Furthermore, 85.3-93.0 % of Cr (VI) ions were regenerated from the biomasses, and 83.4-91.7 % of the metal was adsorbed when the biomasses was reused. Langmuir isotherm performed better than Freundlich isotherm, depicting that Cr (VI) affinity was in the sequence Rhodococcus sp. AL03Ni > Burkholderia cepacia AL96Co > Corynebacterium kutscheri FL108Hg > Pseudomonas aeruginosa CA207Ni. Biosorption isotherms confirmed that Rhodococcus sp. AL03Ni was a better biosorbent with a maximum uptake of 107.46 mg of Cr (VI) per g (dry weight) of biomass. The results highlight the high potential of the organisms for bacteria-based detoxification of Cr (VI) via biosorption.

  9. Biosorption of cationic basic dye and cadmium by the novel biosorbent Bacillus catenulatus JB-022 strain.

    Science.gov (United States)

    Kim, Su Young; Jin, Mi Ra; Chung, Chang Ho; Yun, Yeoung-Sang; Jahng, Kwang Yeop; Yu, Kang-Yeol

    2015-04-01

    Biosorption of heavy metals and dyes is a promising technology that involves the removal of toxic metals from industrial wastes. The present study aims to screen the bacterial strains isolated from soils and polluted pond for their potential biosorption of both cationic dye and cadmium. Bacillus catenulatus JB-022 strain removed 58% and 66% of cationic basic blue 3 (BB3) and cadmium (Cd(II)) at the respective concentrations of 2000 mg/L and 150 mg/L. The biosorption equilibrium data were well fitted by the Langmuir adsorption isotherm, and the kinetic studies indicated that the biosorption followed the pseudo-second-order model. The biosorption kinetics showed that the equilibrium was reached within 10 min and 5 min for BB3 and Cd(II), respectively. According to the Langmuir model, the maximum uptakes of BB3 and Cd(II) by the JB-022 biomass were estimated to be 139.74 and 64.28 mg/g, respectively. To confirm the surface morphology and functional groups, field emission scanning electron microscope, energy-dispersive X-ray spectrometer, X-ray diffraction, and Fourier transform infrared spectroscopy analyses were carried out, and the results revealed that the biomass of JB-022 has carboxyl and phosphonate groups as potential surface functional groups capable of binding to cationic pollutants. In conclusion, B. catenulatus JB-022 is proposed as an excellent biosorbent with potentially important applications in removal of cationic pollutants from wastewaters. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. REMOVAL OF CRYSTAL VIOLET BY BIOSORPTION ONTO DATE STONES

    Directory of Open Access Journals (Sweden)

    NOUREDDINE EL MESSAOUDI

    2016-07-01

    Full Text Available The biosorption has the advantage that it can be applied to effluent disposal and thus brings various responses to the regulatory requirements for environmental protection. This study presents the results obtained from the use of date stones (DS for the elimination of crystal violet (CV from aqueous medium. Several analysis techniques were used to determine the different characteristics of biosorbent studied (FTIR, TGA-DTA, SEM and pHzpc.The physico-chemical parameters influence of the biosorption such as biosorbent dosage, contact time, temperature, biosorbent particles size and initial dye pH were investigated under static conditions in order to evaluate the process system. The test results show that a gram of date stones may set a maximum amount adsorbed 90.89 mg·g-1 of CV at 50 °C according to the Langmuir isotherm with pseudo-second-order kinetic. Thermodynamic calculations performed shows also that sorption is spontaneous, endothermic and increased randomness in the solid / solution interface.

  11. Biosorption of Cd(II) and Pb(II) ions by aqueous solutions of novel alkalophillic Streptomyces VITSVK5 spp. biomass

    Science.gov (United States)

    Saurav, Kumar; Kannabiran, Krishnan

    2011-03-01

    Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Biosorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal of these pollutants from aqueous solution. The search of marine actinobacteria with potential heavy metal biosorption ability resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species. The biosorption property of Streptomyces VITSVK5 spp. was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb). Physiochemical characteristics and trace metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L-1, cadmium 3.1±0.3μg L-1, zinc 8.4±2.6μg L-1 and copper 0.3±0.1μg L-1, whereas mercury was well below the detection limit. The effect of pH and biomass dosage on removal efficiency of heavy metal ions was also investigated. The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84% biosorption respectively. The biosorbent dosage was optimized as 3 g L-1 for both the trace metals. Fourier transform infrared absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (-COOH), hydroxyl (-CHOH) and amine (-NH2) groups of biomass with the metal ions. This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp. The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments.

  12. Artificial intelligence modeling of cadmium(II) biosorption using rice straw

    Science.gov (United States)

    Nasr, Mahmoud; Mahmoud, Alaa El Din; Fawzy, Manal; Radwan, Ahmed

    2017-05-01

    The biosorption efficiency of Cd2+ using rice straw was investigated at room temperature (25 ± 4 °C), contact time (2 h) and agitation rate (5 Hz). Experiments studied the effect of three factors, biosorbent dose BD (0.1 and 0.5 g/L), pH (2 and 7) and initial Cd2+ concentration X (10 and 100 mg/L) at two levels "low" and "high". Results showed that, a variation in X from high to low revealed 31 % increase in the Cd2+ biosorption. However, a discrepancy in pH and BD from low to high achieved 28.60 and 23.61 % increase in the removal of Cd2+, respectively. From 23 factorial design, the effects of BD, pH and X achieved p value equals to 0.2248, 0.1881 and 0.1742, respectively, indicating that the influences are in the order X > pH > BD. Similarly, an adaptive neuro-fuzzy inference system indicated that X is the most influential with training and checking errors of 10.87 and 17.94, respectively. This trend was followed by "pH" with training error (15.80) and checking error (17.39), after that BD with training error (16.09) and checking error (16.29). A feed-forward back-propagation neural network with a configuration 3-6-1 achieved correlation ( R) of 0.99 (training), 0.82 (validation) and 0.97 (testing). Thus, the proposed network is capable of predicting Cd2+ biosorption with high accuracy, while the most significant variable was X.

  13. Optimization of chromium biosorption in aqueous solution by marine ...

    African Journals Online (AJOL)

    Optimization of a chromium biosorption process was performed by varying three independent variables pH (0.5 to 3.5), initial chromium ion concentration (10 to 30 mg/L), and Yarrowia lipolytica dosage (2 to 4 g/L) using a Doehlert experimental design (DD) involving response surface methodology (RSM). For the maximum ...

  14. Biosorptive removal of Hg(II) ions by Rhizopus oligosporus ...

    African Journals Online (AJOL)

    In this study, corn processing wastewater was used as a new low-cost substrate to produce Rhizopus oligosporus. Dried biomass of R. oligosporus was evaluated as a biosorbent for treatment of synthetically contaminated waters with Hg(II) ions. The biosorption process was carried out in a batch process and the effects of ...

  15. Biosorption of americium-241 by immobilized Rhizopus arrihizus

    International Nuclear Information System (INIS)

    Liao Jiali; Yang Yuanyou; Luo Shunzhong; Liu Ning; Jin Jiannan; Zhang Taiming; Zhao Pengji

    2004-01-01

    Rhizopus arrihizus (R. arrihizus), a fungus, which in previous experiments had shown encouraging ability to remove 241 Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting 241 Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb 241 Am as efficiently as free R. arrihizus, but that also can be used repeatedly or continuously. The biosorption equilibrium was achieved within 2 h, and more than 94% of 241 Am was removed from 241 Am solutions of 1.08 MBq/l by immobilized R. arrihizu in the pH range 1-7. Temperature did not affect the adsorption on immobilized R. arrihizus in the range 15-45 deg. C. After repeated adsorption for 8 times, the immobilized R. arrihizus still adsorbed more than 97% of 241 Am. At this time, the total adsorption of 241 Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed 241 Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO 3

  16. Biosorption of heavy metals under anaerobic conditions. Final report; Biosorption von Schwermetallen unter anaeroben Bedingungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kreikenbohm, R.

    1996-12-31

    The precipitation of heavy metals as hydroxides is the standard technique for the decontamination of waste water streams polluted by these elements. On the other side, progress in research has been made concerning the biosorption onto dead biomass and bioprecipitation supported by physiologically active bacteria. As the aim of this study, a flexible strategy has been envisaged cleaning a waste water with definite heavy metal load underlying the process mentioned above. Suitable bacteria were enriched and the process was tested in a technical plant. As result, a very high efficiency of heavy metal elimination has been found. The field of application covered by the acquired process is identical with the whole range of the waste water streams polluted by heavy metals. In addition, a second stage may be necessary if there are any further contaminants to be removed. (orig.) [Deutsch] Bei der Reinigung von schwermetallhaltigen Abwaessern ist der derzeitige Stand der Technik gegeben durch die Neutralisationsfaellung als Hydroxide, waehrend in der Forschung damit begonnen wurde, Biosorption an devitaler Biomasse oder Biopraezipitation durch physiologisch aktive Bakterien zu untersuchen. Ziel des Vorhabens war die Ermittlung einer flexiblen Strategie fuer die Prozessfuehrung zur Abwasserreinigung bei vorgegebener Schadstoffbelastung auf der Basis des zuletzt genannten Prozesses. Dazu wurden geeignete Bakterien angereichert und das Verfahren in einer Technikumsanlage erprobt. Als Ergebnis wurde bei Zufuhr verschiedener Industrieabwaesser eine sehr hohe Effizienz in der Schwermetallelimination gefunden. Das Anwendungsgebiet des erarbeiteten Verfahrens erstreckt sich auf eine Vielzahl schwermetallbelasteter Abwaesser, wobei - je nach Art der weiteren Inhaltsstoffe - eine zusaetzliche Reinigungsstufe vor- oder nachgeschaltet werden muss. (orig.)

  17. On the biosorption, by brown seaweed, Lobophora variegata, of Ni(II) from aqueous solutions: equilibrium and thermodynamic studies.

    Science.gov (United States)

    Basha, Shaik; Jaiswar, Santlal; Jha, Bhavanath

    2010-09-01

    The biosorption equilibrium isotherms of Ni(II) onto marine brown algae Lobophora variegata, which was chemically-modified by CaCl(2) were studied and modeled. To predict the biosorption isotherms and to determine the characteristic parameters for process design, twenty-three one-, two-, three-, four- and five-parameter isotherm models were applied to experimental data. The interaction among biosorbed molecules is attractive and biosorption is carried out on energetically different sites and is an endothermic process. The five-parameter Fritz-Schluender model gives the most accurate fit with high regression coefficient, R (2) (0.9911-0.9975) and F-ratio (118.03-179.96), and low standard error, SE (0.0902-0.0.1556) and the residual or sum of square error, SSE (0.0012-0.1789) values to all experimental data in comparison to other models. The biosorption isotherm models fitted the experimental data in the order: Fritz-Schluender (five-parameter) > Freundlich (two-parameter) > Langmuir (two-parameter) > Khan (three-parameter) > Fritz-Schluender (four-parameter). The thermodynamic parameters such as DeltaG (0), DeltaH (0) and DeltaS (0) have been determined, which indicates the sorption of Ni(II) onto L. variegata was spontaneous and endothermic in nature.

  18. Biosorption of heavy metals using a dead macro fungus schizophyllum commune fries: evaluation of equilibrium and kinetic models

    International Nuclear Information System (INIS)

    Javid, A.; Bajwa, R.; Javid, A.

    2010-01-01

    Biomass of a wood rotting fungus viz., Schizophyllum commune Fries was utilized for the treatment of electroplating wastewater that contained Cu(II), Ni(II), Zn(II) and Cr(VI) ions. Preliminary batch assays were conducted with synthetic pure metal-bearing solutions. Results obtained showed that among various parameters studied, solution pH between a range of 2.0-6.0 induced negligible uptake at pH < 3.5 and exhibited maximum at around 4.5-5.5 for Ni(II), Cu(II) and Zn(II) ions, while for Cr(VI) ion the highest was evidenced at pH 2.0-2.5. The kinetics of all metal ions was fast and biosorption equilibrium was established in 1 hour with appropriateness of pseudo-second-order. A temperature change in the range of 15 - 45 deg. C did not affect the biosorption capacity of the candidate fungus. The biosorption of metal ion increased on elevating initial metal ions concentrations (20-100 mg L/sup -1/) in the medium. The maximum biosorption capacity of fungus biomass was 9.0, 21.27, 4.83, 18.54 mg g/sup -1/ for Ni(II), Cu(II) and Zn(II) and Cr(VI), respectively. The experimental data was best adjusted by Langmuir, Freundlich and modified Langmuir models. Biosorption assays conducted with actual electroplating effluents under pre-optimized conditions revealed efficiency of 72.01, 53.16, 7.08 and 19.87% for Cu(II), Ni(II), Zn(II) and Cr(VI) ions, respectively by candidate biomass. (author)

  19. A Novel Pb-Resistant Bacillus subtilis Bacterium Isolate for Co-Biosorption of Hazardous Sb(III and Pb(II: Thermodynamics and Application Strategy

    Directory of Open Access Journals (Sweden)

    Yue Cai

    2018-04-01

    Full Text Available The present work is the first to study co-biosorption of Pb(II and Sb(III by a novel bacterium and its application strategy. The biosorption characteristics of Pb(II and Sb(III ions from aqueous solution using B. subtilis were investigated. Optimum pH, biomass dosage, contact time and temperature were determined to be 5.00, 6.00 mg/L, 45 min and 35 °C, respectively. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R models were applied to describe the biosorption isotherm of the metal ions by B. subtilis. Results showed that Langmuir model fitted the equilibrium data of Pb(II better than others, while biosorption of Sb(III obeyed the Freundlich model well. The biosorption capacity of B. subtilis biomass for Pb(II and Sb(III ions was found to be 17.34 ± 0.14 and 2.32 ± 0.30 mg/g, respectively. Kinetic data showed the biosorption process of Pb(II and Sb(III ions both followed the pseudo-second-order kinetic model, with R2 ranging from 0.974 to 0.999 for Pb(II and from 0.967 to 0.979 for Sb(III. The calculated thermodynamic parameters, negative ∆G and positive ∆H and ∆S values, indicated the biosorption of Pb(II and Sb(III ions onto B. subtilis biomass in water was feasible, endothermic, and spontaneous. Bacterial bioleaching experiment revealed B. subtilis can increase the mobility of Pb(II and Sb(III in polluted soil when pH was close to 6 at low temperature. Consequently, B. subtilis, as a cheap and original bacterial material, could be a promising biomass to remove Pb or isolate Sb from industrial wastewater and to assist phytoremediation of Pb and Sb from weak acid or near neutral pH polluted soils at low temperature.

  20. Programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae and ashing analysis: A decrement solution for nuclide and heavy metal disposal

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Mingxue [Life Science and Engineering College, Southwest University of Science and Technology, Mianyang, 621010 (China); Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Dong, Faqin, E-mail: fqdong@swust.edu.cn [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Zhang, Wei [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Nie, Xiaoqin [Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory, Mianyang, 621010 (China); Sun, Shiyong [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Wei, Hongfu; Luo, Lang; Xiang, Sha; Zhang, Gege [Life Science and Engineering College, Southwest University of Science and Technology, Mianyang, 621010 (China)

    2016-08-15

    Highlights: • A programmed gradient descent biosorption process was designed. • The adsorption and bioaccumulation quantity of strontium ions by yeast cell were measured. • The decrement of biosorbents after biosorption by ashing was analyzed. • A technological flow process of decrement solution for waste disposal was proposed. - Abstract: One of the waste disposal principles is decrement. The programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae regarding bioremoval and ashing process for decrement were studied in present research. The results indicated that S. cerevisiae cells showed valid biosorption for strontium ions with greater than 90% bioremoval efficiency for high concentration strontium ions under batch culture conditions. The S. cerevisiae cells bioaccumulated approximately 10% of strontium ions in the cytoplasm besides adsorbing 90% strontium ions on cell wall. The programmed gradient descent biosorption presented good performance with a nearly 100% bioremoval ratio for low concentration strontium ions after 3 cycles. The ashing process resulted in a huge volume and weight reduction ratio as well as enrichment for strontium in the ash. XRD results showed that SrSO{sub 4} existed in ash. Simulated experiments proved that sulfate could adjust the precipitation of strontium ions. Finally, we proposed a technological flow process that combined the programmed gradient descent biosorption and ashing, which could yield great decrement and allow the supernatant to meet discharge standard. This technological flow process may be beneficial for nuclides and heavy metal disposal treatment in many fields.

  1. Biosorption of heavy metals by a marine bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Anita [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India); Mody, Kalpana [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)]. E-mail: khmody@csmcri.org; Jha, Bhavanath [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)

    2005-03-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here.

  2. Biosorption of heavy metals by a marine bacterium

    International Nuclear Information System (INIS)

    Iyer, Anita; Mody, Kalpana; Jha, Bhavanath

    2005-01-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here

  3. Heavy metals in handloom-dyeing effluents and their biosorption by agricultural byproducts.

    Science.gov (United States)

    Nahar, Kamrun; Chowdhury, Md Abul Khair; Chowdhury, Md Akhter Hossain; Rahman, Afzal; Mohiuddin, K M

    2018-03-01

    The Madhabdi municipality in the Narsingdi district of Bangladesh is a well-known area for textile, handloom weaving, and dyeing industries. These textile industries produce a considerable amount of effluents, sewage sludge, and solid waste materials every day that they directly discharge into surrounding water bodies and agricultural fields. This disposal poses a serious threat to the overall epidemic and socio-economic pattern of the locality. This research entailed the collection of 34 handloom-dyeing effluent samples from different handloom-dyeing industries of Madhabdi, which were then analyzed to determine the contents of the heavy metals iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mn), lead (Pb), and cadmium (Cd). Average concentrations of Fe, Cr, Cu, Pb, Mn, and Zn were 3.81, 1.35, 1.70, 0.17, 0.75, and 0.73 mg L -1 , respectively, whereas Cd content was below the detectable limit of the atomic adsorption spectrophotometer. The concentrations of Fe, Cr, Cu, Pb, and Mn exceed the industrial effluent discharge standards (IEDS) for inland surface water and irrigation water guideline values. A biosorption experiment of the heavy metals (Fe, Cr, Cu, Mn, and Zn) was conducted without controlling for any experimental parameters (e.g., pH, temperature, or other compounds present in the effluent samples) by using four agricultural wastes or byproducts, namely rice husk, sawdust, lemon peel, and eggshell. Twenty grams of each biosorbent was added to 1 L of effluent samples and stored for 7 days. The biosorption capacity of each biosorbent is ranked as follows: eggshell, sawdust, rice husk, and lemon peel. Furthermore, the biosorption affinity of each metal ion was found in the following order: Cu and Cr (both had similar biosorption affinity), Zn, Fe, Mn. The effluents should not be discharged before treatment, and efficient treatment of effluents is possible with eggshell powder or sawdust at a rate of 20 g of biosorbent per liter of effluents.

  4. Biosorption of Foron turquoise SBLN using mixed biomass of white ...

    African Journals Online (AJOL)

    In the present study, biosorption of Foron turquoise SBLN using mixed biomass of white rot fungi was investigated in batch mode. The effect of process parameters such as pH of solution, medium temperature, biosorbent concentration, dye initial concentration, contact time etc. was investigated for enhanced removal of the ...

  5. Mechanism of thorium biosorption by the cells of the soil fungal isolate Geotrichum sp. dwc-1

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Congcong; Feng, Su [Sichuan Univ., Chengdu (China). Key Laboratory of Biological Resource and Ecological Environment; Li, Xiaolong [Sichuan Univ., Chengdu (China). Key Laboratory of Radiation Physics and Technology; and others

    2014-04-01

    In order to understand the impact of microorganisms on the fate of thorium in soils, we investigated the thorium biosorption behavior and the corresponding mechanisms by the cells of Geotrichum sp. dwc-1, one of the dominant species of fungal group isolated from 3.5 m depth soil layer in Southwest China. It was observed that fast thorium adsorption onto cells of G. sp. dwc-1 could take place, with a high distribution coefficient K{sub d} (0.93 mL/mg) obtained, when Geotrichum sp. dwc-1and thorium concentrations were 5 g/L and 10 mg/L, respectively. The thorium biosorption behavior was dependent on the pH value, and the lower pH could disrupt cell membrane of G. sp. dwc-1. At pH 1, thorium was accumulated in the cytoplasmic region of the cells. When pH was higher than 1, thorium was adsorbed on the cell surface of G. sp. dwc-1, like in periplasmic region or in the outer membrane. FTIR study combined with biosorption experiments further indicated that the thorium distribution and binding behavior on cell surface were associated with amino, hydroxyl groups and phosphate or sulphur functional groups, and might also be governed by electrostatic interaction. Moreover, PIXE and EPBS showed that ion-exchange mechanism contributed to the thorium biosorption process, in which the tetravalent thorium ions replaced smaller counter-ions (K{sup +}, Ca{sup 2+} and Fe{sup 3+}) occuring on the cell surface. (orig.)

  6. BIOSORPTION OF Cr(VI FROM SYNTHETIC WASTEWATER USING THE FRUIT SHELL OF GULMOHAR (Delonix regia: APPLICATION TO ELECTROPLATING WASTEWATER

    Directory of Open Access Journals (Sweden)

    Attimodde Girirajanna Devi Prasad

    2010-05-01

    Full Text Available The biosorption of Cr(VI from synthetic solutions and electroplating wastewater using the fruit shell of gulmohar has been investigated in a batch system. The effects of various parameters such as pH, contact time, adsorbent dosage, and initial concentration of Cr(VI on the biosorption process were studied. The complete removal of Cr(VI was observed at pH < 3.0. Studies indicated that both biosorption and bioreduction were involved in the removal of Cr(VI. The sorption equilibrium exhibited a better fit to the Langmuir isotherm than the Freundlich isotherm. The maximum biosorption capacity of fruit shell of gulmohar to remove Cr(VI was 12.28 mg/g. A kinetic model of pseudo-second order provided a good description of the experimental data as compared to a pseudo-first order kinetic model. The sorption rate was found to be dependent on the initial concentration of Cr(VI and biomaterials dosage. The study showed that the abundant and inexpensive fruit shell of gulmohar biosorbent has a potential application in the removal of Cr(VI from electroplating wastewater and its conversion into less or non-toxic Cr (III.

  7. Biosorption of Acid Blue 290 (AB 290) and Acid Blue 324 (AB 324) dyes on Spirogyra rhizopus

    International Nuclear Information System (INIS)

    Ozer, Ayla; Akkaya, Goenuel; Turabik, Meral

    2006-01-01

    In this study, the biosorption of Acid Blue 290 and Acid Blue 324 on Spirogyra rhizopus, a green algae growing on fresh water, was studied with respect to initial pH, temperature, initial dye concentration and biosorbent concentration. The optimum initial pH and temperature values for AB 290 and AB 324 biosorption were found to be 2.0, 30 deg. C and 3.0, 25 deg. C, respectively. It was observed that the adsorbed AB 290 and AB 324 amounts increased with increasing the initial dye concentration up to 1500 and 750 mg/L, respectively. The Langmuir, Freundlich, Redlich-Peterson and Koble-Corrigan isotherm models were applied to the experimental equilibrium data and the isotherm constants were determined by using Polymath 4.1 software. The monolayer coverage capacities of S. rhizopus for AB 290 and AB 324 dyes were found as 1356.6 mg/g and 367.0 mg/g, respectively. The intraparticle diffusion model and the pseudo-second order kinetic model were applied to the experimental data in order to describe the removal mechanism of these acidic dyes by S. rhizopus. The pseudo-second order kinetic model described very well the biosorption kinetics of AB 290 and AB 324 dyes. Thermodynamic studies showed that the biosorption of AB 290 and AB 324 on S. rhizopus was exothermic in nature

  8. The use of instrumental neutron activation analysis method in bio-sorption determination

    International Nuclear Information System (INIS)

    Khamidova, Kh.M.; Mutavalieva, Z.S.; Muchamedshina, N.M.; Mirzagatova, A.A.

    2005-01-01

    Full text: Recently, much attention is paid to the research and development of effective metal remediation methods. In industry, for the removal of metals from the industrial solutions and wastes, the expensive ion-exchange resin method of metal sorption is used today. The microbiological methods are much less expensive, are available and provide its application in natural conditions. The search for molybdenum bio sorbent was performed amongst Actinomyces strains. The 18 of Streptomyces strains were used. The data showed that all investigated strains uptake the molybdenum from the solution in various degrees. The molybdenum determination was performed using neutron activation analysis technique. In a nuclear reactor, the samples were treated with a steady flow of neutrons (5.1·10 13 ) n·cm -2 sec -1 in 20 hours. The samples were stored for 6-7 days before analysis. The Actinomyces biomass uptake capacity was up to 94.5 %. The 8 cultures have the most high uptake capacity that varied from 87.4 to 94.5 %. Streptomyces sp. 39 and Streptomyces sp.32 have the lowest bio-sorption capacity amongst studied strains, which was 46.6% and 40 % respectively, whereas the bio sorption capacity of other cultures varied from 55.8 to 64.1%. The influence of some physical and chemical parameters (culture age, pH, temperature) on molybdenum bio-sorption was studied. Data showed that the change in pH, temperature and cultivation period lead to the increase of bio-sorption capacity

  9. Biosorption of chromium (VI) from aqueous solutions and ANN modelling.

    Science.gov (United States)

    Nag, Soma; Mondal, Abhijit; Bar, Nirjhar; Das, Sudip Kumar

    2017-08-01

    The use of sustainable, green and biodegradable natural wastes for Cr(VI) detoxification from the contaminated wastewater is considered as a challenging issue. The present research is aimed to assess the effectiveness of seven different natural biomaterials, such as jackfruit leaf, mango leaf, onion peel, garlic peel, bamboo leaf, acid treated rubber leaf and coconut shell powder, for Cr(VI) eradication from aqueous solution by biosorption process. Characterizations were conducted using SEM, BET and FTIR spectroscopy. The effects of operating parameters, viz., pH, initial Cr(VI) ion concentration, adsorbent dosages, contact time and temperature on metal removal efficiency, were studied. The biosorption mechanism was described by the pseudo-second-order model and Langmuir isotherm model. The biosorption process was exothermic, spontaneous and chemical (except garlic peel) in nature. The sequence of adsorption capacity was mango leaf > jackfruit leaf > acid treated rubber leaf > onion peel > bamboo leaf > garlic peel > coconut shell with maximum Langmuir adsorption capacity of 35.7 mg g -1 for mango leaf. The treated effluent can be reused. Desorption study suggested effective reuse of the adsorbents up to three cycles, and safe disposal method of the used adsorbents suggested biodegradability and sustainability of the process by reapplication of the spent adsorbent and ultimately leading towards zero wastages. The performances of the adsorbents were verified with wastewater from electroplating industry. The scale-up study reported for industrial applications. ANN modelling using multilayer perception with gradient descent (GD) and Levenberg-Marquart (LM) algorithm had been successfully used for prediction of Cr(VI) removal efficiency. The study explores the undiscovered potential of the natural waste materials for sustainable existence of small and medium sector industries, especially in the third world countries by protecting the environment by eco-innovation.

  10. Kinetics of biosorption of hazardous metals by green soil supplement

    Science.gov (United States)

    Bagla, Hemlata; Khilnani, Roshan

    2016-04-01

    The process of metal retention by soil may include ion exchange, adsorption and precipitation. These reaction mechanisms have been defined through fitting the data into different equilibrium and kinetic models. The natural organic matter in soil consists of various fractions like macro-organic material, plant residues, soil biomass and stable humus. Most of the organic matter is dominated with large amount of humic substances. Humic fractions in soil are known to have indirect and direct effects on plant growth and crop production. Humic substances increase the cation exchange capacity, providing a strong buffer capacity to resist sudden drastic chemical changes in soil which enhance soil fertility and environmental quality. The cation-humic interactions exert control on the reactivity of the cation, influencing its bioavailability in the soil system. The investigation of metal concentrations adsorbed with time can be useful to estimate the metal bioavailability in soil. Understanding how metals interact and compete for adsorption sites is of great interest to those involved in environmental remediation. Cow Dung is bio-organic, complex, polymorphic fecal matter of the bovine species, enriched with 'Humic acid' (HA), 'Fulvic Acid', etc. The HA in Cow Dung has been successfully extracted using neutralization reaction and its presence was confirmed by comparison with FTIR spectra of standard HA (IHSS). Since, dry Cow dung powder (DCP) is being added as a soil supplement to enhance the quality of soil, it is important to understand the kinetics associated with it. This work reports kinetic studies of various toxic and hazardous elements such as Cr(III), Cr(VI), Sr(II), Cd(II), Hg(II) and Co(II) adsorption by dry Cow dung powder. Kinetic experiments demonstrated rapid metal uptake. The Kinetic biosorption data were obtained by Batch experiments to explore the rate of biosorption by DCP at optimum parameters and varying the time of reaction from 1-30 min. The dynamics

  11. Uranium biosorption by Trichoderma harzianum entrapped in polyester foam beads

    International Nuclear Information System (INIS)

    Khalid, A.M.; Shemsi, A.M.; Akhtar, K.; Anwar, M.A.

    1993-01-01

    Mechanism of uranium biosorption by resting cells of Trichoderma harzianum was studied at pH 4.5. Time-dependent uptake of uranium by Trichoderma harzianum was also determined. Various cations (Na, K, Ca and Fe, etc.) were found to affect the adsorption capability of these cells. Different theoretical thermodynamic models governing the adsorption behavior of uranium were also tested and it was found to follow the Langmuir and Freundlich adsorption isotherms. The constants of Freundlich adsorption isotherm A and 1/n were found to be 1.5 x 10 -6 mole/g and 0.31 respectively. Dubinin Radushkevich equation was tested and the maximum adsorption capacity (X m ) of Trichoderma harzianum and sorption energy (E s ) for the ion exchange process computed. Data of uranium sorption were also examined using Weber Morris's equation. The upscaling of uranium biosorption by Trichoderma harzianum entrapped in commercial foam (polyesters) was carried out in glass columns. It was found to recover more than 85% of the total uranium present in bacterial leachate

  12. Fixed-bed biosorption of cadmium using immobilized Scenedesmus obliquus CNW-N cells on loofa (Luffa cylindrica) sponge.

    Science.gov (United States)

    Chen, Bor-Yann; Chen, Chun-Yen; Guo, Wan-Qian; Chang, Hao-Wei; Chen, Wen-Ming; Lee, Duu-Jong; Huang, Chieh-Chen; Ren, Nan-Qi; Chang, Jo-Shu

    2014-05-01

    A continuous fixed-bed biosorption process was established for cadmium (Cd) removal by Scenedesmus obliquus CNW-N (isolated from southern Taiwan) cells immobilized onto loofa sponge. This immobilized-cell biosorption process allows better recovery and reusability of the microalgal biomass. The growth of microalgae on the matrix support with appropriate nutrient supplementation could enhance the overall metal removal activity. Major operating parameters (e.g., feeding flow rate, cycle number of medium replacement, and particle diameter of the sponge) were studied for treatability evaluation. The most promising cell growth on the sponge support was obtained at a flow rate of 0.284 bed volume (BV)/min, sponge particle diameter of 1 cm, and with one cycle of medium replacement. The performance of fixed-bed biosorption (adsorption capacity of 38.4 mg, breakthrough time at 15.5 h) was achieved at a flow rate of 5 ml/min with an influent concentration of 7.5 mg Cd/l. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. The process of biosorption of heavy metals in bioreactors loaded with sanitary sewage sludge

    Directory of Open Access Journals (Sweden)

    A. J. Morais Barros

    2006-06-01

    Full Text Available This work on the process of biosorption of nickel and chromium in an ascendant continuous-flow, fixed packed-bed bioreactor of sanitary sewage sludge was conducted in a search for solutions to the environmental problem caused by heavy metals. Analysis of the results demonstrated that the absorbent had an extraordinary capacity for biosorption of the heavy metals studied at about 9.0 pH of the effluent, with a removal percentage of over 90.0% for the two metals. Chemometric study results demonstrated that 20 days of the experimental system function were sufficient for achieving the maximum efficiency of sorption of the heavy metals studied by the sanitary sewage sludge employed.

  14. Biosorption of Cu (II onto chemically modified waste mycelium of Aspergillus awamori: Equilibrium, kinetics and modeling studies

    Directory of Open Access Journals (Sweden)

    ZDRAVKA VELKOVA

    2012-01-01

    Full Text Available The biosorption potential of chemically modified waste mycelium of industrial xylanase-producing strain Aspergillus awamori for Cu (II removal from aqueous solutions was evaluated. The influence of pH, contact time and initial Cu (II concentration on the removal efficiency was evaluated. Maximum biosorption capacity was reached by sodium hydroxide treated waste fungal mycelium at pH 5.0. The Langmuir adsorption equation matched very well the adsorption equilibrium data in the studied conditions. The process kinetic followed the pseudo-firs order model.

  15. Biosorption of Strontium from Simulated Nuclear Wastewater by Scenedesmus spinosus under Culture Conditions: Adsorption and Bioaccumulation Processes and Models

    Science.gov (United States)

    Liu, Mingxue; Dong, Faqin; Kang, Wu; Sun, Shiyong; Wei, Hongfu; Zhang, Wei; Nie, Xiaoqin; Guo, Yuting; Huang, Ting; Liu, Yuanyuan

    2014-01-01

    Algae biosorption is an ideal wastewater treatment method when coupled with algae growth and biosorption. The adsorption and bioaccumulation of strontium from simulated nuclear wastewater by Scenedesmus spinosus were investigated in this research. One hundred mL of cultured S. spinosus cells with a dry weight of 1.0 mg in simulated nuclear wastewater were used to analyze the effects on S. spinosus cell growth as well as the adsorption and bioaccumulation characters under conditions of 25 ± 1 °C with approximately 3,000 lux illumination. The results showed that S. spinosus had a highly selective biosorption capacity for strontium, with a maximum bioremoval ratio of 76%. The adsorbed strontium ion on cell walls was approximately 90% of the total adsorbed amount; the bioaccumulation in the cytoplasm varied by approximately10%. The adsorption quantity could be described with an equilibrium isotherm. The pseudo-second-order kinetic model suggested that adsorption was the rate-limiting step of the biosorption process. A new bioaccumulation model with three parameters was proposed and could give a good fit with the experiment data. The results suggested that S. spinosus may be a potential biosorbent for the treatment of nuclear wastewater in culture conditions. PMID:24919131

  16. Biosorption of Strontium from Simulated Nuclear Wastewater by Scenedesmus spinosus under Culture Conditions: Adsorption and Bioaccumulation Processes and Models

    Directory of Open Access Journals (Sweden)

    Mingxue Liu

    2014-06-01

    Full Text Available Algae biosorption is an ideal wastewater treatment method when coupled with algae growth and biosorption. The adsorption and bioaccumulation of strontium from simulated nuclear wastewater by Scenedesmus spinosus were investigated in this research. One hundred mL of cultured S. spinosus cells with a dry weight of 1.0 mg in simulated nuclear wastewater were used to analyze the effects on S. spinosus cell growth as well as the adsorption and bioaccumulation characters under conditions of 25 ± 1 °C with approximately 3,000 lux illumination. The results showed that S. spinosus had a highly selective biosorption capacity for strontium, with a maximum bioremoval ratio of 76%. The adsorbed strontium ion on cell walls was approximately 90% of the total adsorbed amount; the bioaccumulation in the cytoplasm varied by approximately10%. The adsorption quantity could be described with an equilibrium isotherm. The pseudo-second-order kinetic model suggested that adsorption was the rate-limiting step of the biosorption process. A new bioaccumulation model with three parameters was proposed and could give a good fit with the experiment data. The results suggested that S. spinosus may be a potential biosorbent for the treatment of nuclear wastewater in culture conditions.

  17. Evaluation of hybrid neutralization/biosorption process for zinc ions removal from automotive battery effluent by dolomite and fish scales.

    Science.gov (United States)

    Ribeiro, C; Scheufele, F B; Alves, H J; Kroumov, A D; Espinoza-Quiñones, F R; Módenes, A N; Borba, C E

    2018-02-26

    This work focused in the evaluation of Oreochromis niloticus fish scales (FS) as biosorbent material in the removal of Zn from a synthetic effluent based on automotive battery industry effluent and, further, a hybrid neutralization/biosorption process, aiming at a high-quality treated effluent, by a cooperative use of dolomite and FS. For this, a physicochemical and morphological characterization (i.e. SEM-EDX, FTIR, XRD, and TXRF) was performed, which helped to clarify a great heterogeneity of active sites (phosphate, carbonate, amide, and hydroxyl) on the biosorbent; also the inorganic constituents (apatites) leaching from the FS was identified. Biosorption results pointed out to a pH-dependent process due to changes in the functional group's anionic character (i.e. electrostatic interactions), where an initial pH = 3 favored the Zn uptake. Kinetic and equilibrium studies confirmed the heterogeneous surface and cooperative sorption, wherein experimental data were described by Generalized Elovich kinetic model and the favorable isotherm profile by Langmuir-Freundlich isotherm ([Formula: see text] = 15.38 mg g -1 and [Formula: see text]). Speciation diagram of Zn species along with the leached species demonstrated that, for the studied pH range, the biosorption was the most likely phenomena rather than precipitation. Finally, the hybrid neutralization/biosorption process showed great potential since both the Zn concentration levels and the pH reached the legislation standards (C Zn  = 4 mg L -1 ; pH = 5). Hence, based on the characterization and biosorption results, a comprehensive evaluation of the involved mechanisms in such complex system helped to verify the prospective of FS biosorbent for the Zn treatment from solution, in both individual and hybrid processes.

  18. Biosorption of eriochrome black t and astrazon fggl blue using almond and cotton seed oil cake biomass in a batch mode

    International Nuclear Information System (INIS)

    Safa, Y.

    2014-01-01

    In the present research study, the biosorption of Eriochrome Black T (EBT) and Astrazon FGGL blue (A-FGGL) onto novel biomasses Almond (Prunus dulcis) oil cake and Cotton seed oil cake respectively was investigated in the batch mode using different process parameters like pH, particle size, biosorbent dose, initial dye concentration, contact time and temperature. Maximum biosorption capacity was observed at pH 3 for EBT onto almond oil cake and pH2 for Astrazon FGGL blue onto cotton seed oil cake.The biosorption capacity was efficient at the smallest particle size of biosorbent. The amount of dye sorbed (mg/g) decreased with the decrease in biosorbent dose and increased with increase in initial dye concentration and temperature. Optimum contact time for equilibrium to achieve was found to be 120 and 180 minutes for EBT and A-FGGL blue, respectively. The Langmuir isotherm model was best fitted to experimental data. The biosorption followed the pseudo-second order kinetic model suggesting a chemisorption mechanism. The positive value of deltaH showed the endothermic nature of the process. In this research, the influence of electrolytes, heavy metals and surfactants on the removal of dyes was also examined. (author)

  19. Biosorption of Fe (II) and Cd (II) ions from aqueous solution using a ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Biosorption of Fe (II) and Cd (II) ions from aqueous solution using a low cost ... human activities in the environment poses a lot of risk ... ion exchange or reverse osmosis, electrochemical treatment ..... is the adsorption coefficient, n indicates the.

  20. Biosorption of cadmium (II) and lead (II) from aqueous solutions using mushrooms: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Vimala, R., E-mail: vimararagu@yahoo.co.in [School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore 632014, Tamil Nadu (India); Das, Nilanjana [School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore 632014, Tamil Nadu (India)

    2009-08-30

    Sorption capacity of oyster mushroom (Pleurotus platypus), button mushroom (Agaricus bisporus) and milky mushroom (Calocybe indica) were evaluated on biosorption of heavy metals, viz. cadmium (II) and lead (II) from aqueous solutions. The optimum sorption conditions were studied for each metal separately. The desired pH of the aqueous solution was found to be 6.0 for the removal of cadmium (II) and 5.0 for removal of lead (II) for all the mushrooms. The percent removal of both the metals was found to increase with the increase in biosorbent dosage and contact time. The fitness of the biosorption data for Langmuir and Freundlich adsorption models was investigated. It was found that biosorption of cadmium (II) and lead (II) ions onto the biomass of the three mushrooms were better suitable to Langmuir than Freundlich adsorption model. P. platypus showed the highest metal uptake potential for cadmium (q{sub max} 34.96 mg/g) whereas A. bisporus exhibited maximum potential for lead (q{sub max} 33.78 mg/g). Milky mushroom showed the lowest metal uptake capacity for both the metals. The present data confirms that mushrooms may be used as efficient biosorbent for the removal of cadmium (II) and lead (II) ions from aqueous solution.

  1. Biosorptive removal of Pb2+, Cd2+ and Zn2+ ions from water by ...

    African Journals Online (AJOL)

    2010-09-20

    Sep 20, 2010 ... such as seaweeds (Williams and Edyvean, 1997), sugarcane bagasse ... due to their structural composition (they mainly contain cel- lulose ...... study of chromium biosorption by red, green and brown seaweed biomass.

  2. Removal of oxytetracycline and determining its biosorption properties on aerobic granular sludge.

    Science.gov (United States)

    Mihciokur, Hamdi; Oguz, Merve

    2016-09-01

    This study investigates biosorption of Oxytetracycline, a broad-spectrum antibiotic, using aerobic granular sludge as an adsorbent in aqueous solutions. A sequencing batch reactor fed by a synthetic wastewater was operated to create aerobic granular sludge. Primarily, the pore structure and surface area of granular sludge, the chemical structure and the molecular sizes of the pharmaceutical, operating conditions, such as pH, stirring rate, initial concentration of Oxytetracycline, during adsorption process was verified. Subsequently, thermodynamic and kinetic aspects of the adsorption were examined and adsorption isotherm studies were carried out. It was shown that the aerobic granular sludge was a good alternative for biosorption of this pharmaceutical. The pharmaceutical was adsorbed better at pH values of 6-8. The adsorption efficiency increased with rising ionic strength. Also, it was seen that the adsorption process was an exothermic process in terms of thermodynamics. The adsorption can be well explained by Langmuir isotherm model. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Enhancement of uranium(VI) biosorption by chemically modified marine-derived mangrove endophytic fungus Fusarium sp. ZZF51

    International Nuclear Information System (INIS)

    Chen, F.; Tan, N.; Long, W.; Yang, S.K.; She, Z.G.; Lin, Y.C.

    2014-01-01

    Fusarium sp. ZZF51, mangrove endophytic fungus originated from South China Sea coast, was chemically modified by formaldehyde, methanol and acetic acid to enhance its affinity of uranium(VI) from waste water. The influencing factors about uranium(VI) adsorption such as contact time, solution pH, the ratio of solid/liquid (S/L) and initial uranium(VI) concentration were investigated, and the suitable adsorption isotherm and kinetic models were determined. In addition, the biosorption mechanism was also discussed by FTIR analysis. Experimental results show that the maximum biosorption capacity of formaldehyde-treated biomass for uranium(VI) at the optimized condition of pH 6.0, S/L 0.6 and equilibrium time 90 min is 318.04 mg g -1 , and those of methanol-treated and HAc-treated biomass are 311.95 and 351.67 mg g -1 at the same pH and S/L values but different equilibrium time of 60 and 90 min, respectively. Thus the maximum biosorption capacity of the three kind of modified biomass have greatly surpassed that of the raw biomass (21.42 mg g -1 ). The study of kinetic exhibits a high level of compliance with the Lagergren's pseudo-second-order kinetic models. Langumir and Freundlich models have proved to be well able to explain the sorption equilibrium with the satisfactory correlation coefficients higher than 0.96. FTIR analysis reveals that the carboxyl, amino and hydroxyl groups on the cell wall of Fusarium sp. ZZF51 play an important role in uranium(VI) biosorption process. (author)

  4. Study on the primary mechanism of uranium biosorption by rhodotorula glutinis

    International Nuclear Information System (INIS)

    Bai Jing; Zhang Li'na; Fan Fangli; Lin Maosheng; Ding Huajie; Qin Zhi

    2008-01-01

    In this paper, the primary mechanism of uranium biosorption by Rhodotorula glutinis was studied using SEM and FTIR. Obvious changes were observed in the biomass SEM picture before and after uranium adsorption, and the peak of UO 2 at wave number of 904 cm -1 was detected by FTIR, indicated that uranium was really absorbed to Rhodotorula glutinis. (authors)

  5. REMOVAL OF CRYSTAL VIOLET BY BIOSORPTION ONTO DATE STONES

    OpenAIRE

    NOUREDDINE EL MESSAOUDI; MOHAMMED EL KHOMRI; SAFAE BENTAHAR; ABDELLAH DBIK; ABDELLAH LACHERAI

    2016-01-01

    The biosorption has the advantage that it can be applied to effluent disposal and thus brings various responses to the regulatory requirements for environmental protection. This study presents the results obtained from the use of date stones (DS) for the elimination of crystal violet (CV) from aqueous medium. Several analysis techniques were used to determine the different characteristics of biosorbent studied (FTIR, TGA-DTA, SEM and pHzpc).The physico-chemical parameters influence of the bio...

  6. Assessment of the biosorption characteristics of a macro-fungus for the decolorization of Acid Red 44 (AR44) dye

    International Nuclear Information System (INIS)

    Akar, Tamer; Tosun, Ilknur; Kaynak, Zerrin; Kavas, Emine; Incirkus, Gonul; Akar, Sibel Tunali

    2009-01-01

    This study focuses on the possible use of macro-fungus Agaricus bisporus to remove Acid Red 44 dye from aqueous solutions. Batch equilibrium studies were carried out as a function of pH, biomass amount, contact time and temperature to determine the decolorization efficiency of biosorbent. The highest dye removal yield was achieved at pH 2.0. Equilibrium occurred within about 30 min. Biosorption data were successfully described by Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum monolayer biosorption capacity of biosorbent material was found as 1.19 x 10 -4 mol g -1 . Thermodynamic parameters indicated that the biosorption of Acid Red 44 onto fungal biomass was spontaneous and endothermic in nature. Fourier transform infrared spectroscopy and scanning electron microscopy were used for the characterization of possible dye-biosorbent interaction and surface structure of biosorbent, respectively. Finally the proposed biosorbent was successfully used for the decolorization of Acid Red 44 in synthetic wastewater conditions.

  7. Application of experimental design and derivative spectrophotometry methods in optimization and analysis of biosorption of binary mixtures of basic dyes from aqueous solutions.

    Science.gov (United States)

    Asfaram, Arash; Ghaedi, Mehrorang; Ghezelbash, Gholam Reza; Pepe, Francesco

    2017-05-01

    Simultaneous biosorption of malachite green (MG) and crystal violet (CV) on biosorbent Yarrowia lipolytica ISF7 was studied. An appropriate derivative spectrophotometry technique was used to evaluate the concentration of each dye in binary solutions, despite significant interferences in visible light absorbances. The effects of pH, temperature, growth time, initial MG and CV concentration in batch experiments were assessed using Design of Experiment (DOE) according to central composite second order response surface methodology (RSM). The analysis showed that the greatest biosorption efficiency (>99% for both dyes) can be obtained at pH 7.0, T=28°C, 24h mixing and 20mgL -1 initial concentrations for both MG and CV dyes. The quadratic constructed equation ability for fitting experimental data is judged based on criterions like R 2 values, significant p and lack-of-fit value strongly confirm its high adequacy and applicability for prediction of revel behavior of the system under study. The proposed model showed very high correlation coefficients (R 2 =0.9997 for CV and R 2 =0.9989 for MG), while supported by closeness of predicted and experimental value. A kinetic analysis was carried out, showing that for both dyes a pseudo-second order kinetic model adequately describes the available data. The Langmuir isotherm model in single and binary components has better performance for description of dyes biosorption with maximum monolayer biosorption capacity of 59.4 and 62.7mgg -1 in single component and 46.4 and 50.0mgg -1 for CV and MB in binary components, respectively. The surface structure of biosorbents and the possible biosorbents-dyes interactions between were also evaluated by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The values of thermodynamic parameters including ΔG° and ΔH° strongly confirm which method is spontaneous and endothermic. Copyright © 2017. Published by Elsevier Inc.

  8. The effect of silica concentration on the biosorption of Cu 2+ and Co ...

    African Journals Online (AJOL)

    cations were studied to ascertain the optimal conditions for biosorption to take place. Test solutions contained 0.002 M, 0.07 M and 0.2 M of either copper or cobalt ions. The Bacillus strains removed the copper and cobalt more efficiently from ...

  9. Equilibrium and kinetic studies of copper biosorption by dead Ceriporia lacerata biomass isolated from the litter of an invasive plant in China.

    Science.gov (United States)

    Li, Xiaona; Li, Airong; Long, Mingzhong; Tian, Xingjun

    2015-01-01

    Ceriporia lacerata, a strain of white-rot fungus isolated from the litter of an invasive plant (Solidago canadensis) in China, was little known about its properties and utilization. In this work, the copper(II) biosorption characteristics of formaldehyde inactivated C. lacerata biomass were examined as a function of initial pH, initial copper(II) concentration and contact time, and the adsorptive equilibrium and kinetics were simulated, too. The optimum pH was found to be 6.0 at experimental conditions of initial copper(II) concentration 100 mg/L, biomass dose 2 g/L, contact time 12 h, shaking rate 150 r/min and temperature 25°C. Biosorption equilibrium cost about 1 hour at experimental conditions of pH 6.0, initial copper(II) concentration 100 mg/L, C. lacerata dose 2 g/L, shaking rate 150 r/min and temperature 25°C. At optimum pH 6.0, highest copper(II) biosorption amounts were 6.79 and 7.76 mg/g for initial copper(II) concentration of 100 and 200 mg/L, respectively (with other experimental parameters of C. lacerata dose 2 g/L, shaking rate 150 r/min and temperature 25°C). The pseudo second-order adsorptive model gave the best adjustment for copper(II) biosorption kinetics. The equilibrium data fitted very well to both Langmuir and Freundlich adsorptive isotherm models. Without further acid or alkali treatment for improving adsorption properties, formaldehyde inactivated C. lacerata biomass possesses good biosorption characteristics on copper(II) removal from aqueous solutions.

  10. Biosorption of uranium, radium, and cesium

    International Nuclear Information System (INIS)

    Strandberg, G.W.

    1982-01-01

    Some fundamental aspects of the biosorption of metals by microbial cells were investigated. These studies were carried out in conjunction with efforts to develop a process to utilize microbial cells as biosorbents for the removal of radionuclides from waste streams generated by the nuclear fuel cycle. It was felt that an understanding of the mechanism(s) of metal uptake would potentially enable the enhancement of the metal uptake phenomenon through environmental or genetic manipulation of the microorganisms. Also presented are the results of a preliminary investigation of the applicability of microorganisms for the removal of 137 cesium and 226 radium from existing waste solutions. The studies were directed primarily at a characterization of uranium uptake by the yeast, Saccharomyces cerevisiae, and the bacterium, Pseudomonas aeruginosa

  11. Biosorption potential of synthetic dyes by heat-inactivated and live Lentinus edodes CCB-42 immobilized in loofa sponges.

    Science.gov (United States)

    Gimenez, Gabriela Gregolin; Ruiz, Suelen Pereira; Caetano, Wilker; Peralta, Rosane Marina; Matioli, Graciette

    2014-12-01

    Lentinus edodes CCB-42 was immobilized in loofa sponges and applied to the biosorption of the synthetic dyes congo red, bordeaux red and methyl violet. Live immobilized microorganisms achieved average decolorations of congo red, bordeaux red and methyl violet of 97.8, 99.7 and 90.6 %, respectively. The loofa sponge was the support and the coadjuvant promoting dye adsorption. The biosorption conditions were optimized for each dye, yielding 30 °C, pH 5.0 and a 12 h reaction time for congo red; 25 °C, pH 3.0 and 36 h for bordeaux red; and 25 °C, pH 8.0 and 24 h for methyl violet. Operational stability was evaluated over five consecutive cycles, with both bordeaux red and congo red exhibiting decolorations above 90 %, while the decoloration of methyl violet decreased after the third cycle. In the sixth month of storage, congo red, bordeaux red and methyl violet had decolorations of 93.1, 79.4 and 73.8 %, respectively. Biosorption process best fit the pseudo-second-order kinetic and Freundlich isotherm models. Maximum biosorption capacity of heat-treated L. edodes immobilized in loofa sponge was determined as 143.678, 500.00 and 381.679 mg/g for congo red, bordeaux red and methyl violet, respectively. Treatment with immobilized L. edodes reduced the phytotoxicity of the medium containing dyes. FT-Raman experiments suggested the occurrence of interactions between loofa sponge fibers, L. edodes and dye. L. edodes CCB-42 immobilized in loofa sponges represents a promising new mode of treatment of industrial effluents.

  12. Microbial remediation of soil pollution from ore mining. Part 3: Cyanide removal and biosorption of heavy metals in mining and processing water; Untersuchungen zur mikrobiellen Sicherung von Erzbergbaualtlasten. Teilvorhaben 3: Cyanidabbau und Biosorption von Schwermetallen in Abwaessern aus Erzbergbau- und Aufbereitungsbetrieben. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Blumenroth, P.; Bosecker, K.

    1999-12-01

    1. Cyanide degradation: Of the cyanide- and thiocyanate-degrading bacteria, Burkholderia cepacia and Pseudomonas spec. were the most effective. 2. Biosorption: Of the isolates suited for biosorption of heavy metals, 597-A (non-identifiable) and 597-A2 (Aspergillus fumigatis) had the biggest potential. The sorption capacity of the fungi for metals varied with the C source used for their growth: apple juice > molasses > glucose. The fungi are not cyanide-sensitive and can even degrade cyanide. Living biomass had better metal sorption efficiencies than dead mycelium. The biosorption rates in waste water were usually higher than in broth. Depending on the metal composition and concentrations and on the exposure time and volume of the mycelia, up to 85 % of the initial concentration was removed from the liquid phase. The capacity of different biomasses for the sorption of metal mixtures was between 65 and 80 mg/g of dry matter depending on the experimental conditions, with peak rates up to 100 mg/g. [German] 1. Cyanidabbau: Von den zum Abbau von Cyaniden und Thiocyanat befaehigten Bakterien erwiesen sich Burkholderia cepacia und Pseudomonas spec. als am besten geeignet. 2. Biosorption: Von den zur Biosorption von Schwermetallen befaehigten Isolaten wiesen 597-A1 (nicht identifizierbar) und 597-A2 (Aspergillus fumigatus) das groesste Potential auf. Die Sorptionsleistung der Pilze fuer Metalle war abhaengig von der C-Quelle, die zur Anzucht verwendet wurde: Apfelsaft>Melasse>Glucose. Die Pilze sind unempfindlich gegenueber Cyanid und sogar zu dessen Abbau in der Lage. Lebende Biomasse sorbierte mehr Metalle als abgetoetetes Pilzmyzel. Die in Abwaessern ermittelten Biosorptionsraten waren meist hoeher als die in Medium erzielten Raten. Je nach Zusammensetzung und Konzentration der Metalle sowie Einwirkdauer und Menge des eingesetzten Pilzmyzels wurden bis zu 85% des Ausgangsgehaltes aus der Fluessigphase entfernt. Die Kapazitaet verschiedener Biomassen fuer die Sorption

  13. Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

    2016-11-01

    The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The effect of surfactant on pollutant biosorption of Trametes versicolor

    Science.gov (United States)

    Gül, Ülküye Dudu; Silah, Hülya; Akbaş, Halide; Has, Merve

    2016-04-01

    The major problem concerning industrial wastewater is treatment of dye and heavy metal containing effluents. Industrial effluents are also contained surfactants that are used as levelling, dispersing and wetting agents. The purpose of this study was to investigate the effect of surfactant on textile dye biosorption properties of a white rot fungus named Trametes versicolor. Reactive dyes are commonly used in textile industry because of their advantages such as brightness and excellent color fastness. A recative textile dye, called Everzol Black, was used in this study. The low-cost mollasses medium is used for fungal growth. The usage of mollases, the sugar refinery effluent as a source of energy and nutrients, gained importance because of reducing the cost and also reusing another waste. In biosorption process the effect of surfactant on dye removal properties of T. versicolor was examined as a function of pH, dye consentration and surfactant concentration. The results of this study showed that the surfactant enhanced the dye removal capacity of Trametes versicolor. The dye and surfactant molecules were interacted electrostatically and these electrostatic interactions improved dye removal properties of filamentous fungus T. versicolor. The results of this study recommended the use of surfactants as an inducer in textile wastewater treatment technologies.

  15. Biosorption of thorium(IV) from aqueous solution by living biomass of marine-derived fungus Fusarium sp. ZZF51

    International Nuclear Information System (INIS)

    Yang, S.K.; Tan, N.; Wu, W.L.; Hou, X.J.; Xiang, K.X.; Lin, Y.C.

    2015-01-01

    The biosportion of Th(IV) by the marine-derived Fungus Fusarium sp. ZZF51 was study. The Biosorption was found to be at a maximum (79.24 %), in a solution containing 50 mg Th/L, at pH 5.0, with 0.28 g dry biomass. The Temkin isotherm model and pseudo-second-order kinetic model was found to fit the data very well over the entire range of concentrations. The FTIR analysis reveals that the carboxyl, amino and hydroxyl groups on the cell wall of Fusarium sp. ZZF51 play an important role in Th(IV) biosorption process. (author)

  16. Uranium uptake by the filamentous fungal biomass, Aspergillus fumigatus and mechanism of biosorption

    International Nuclear Information System (INIS)

    Bhainsa, Kuber C.; D'Souza, S.F.

    2010-01-01

    Uptake of uranium by Aspergillus fumigatus was investigated in a batch study. Previously, we had reported good uranium uptake capacity, i.e., 423 mg U/g by this fungal biomass. The objective of the present study was to investigate the uranium uptake and mechanism of biosorption by Aspergillus fumigatus. The metal uptake was rapid and 80% of metal ion could be removed within 4 minutes of contact time. Kinetic modeling indicated that the uptake of uranium followed Lagergren's pseudo-second order reaction indicating the process to be mediated through chemisorption mechanism. Further studies on isotherm modeling were carried out using D-R isotherm to confirm the same. The energy of biosorption obtained from D-R isotherm was found to be 14.4 kJ/mol. This energy corresponds to the energy of chemisorption (ion-exchange) which varies between 8-16 kJ/mol. All these results suggest that uranium uptake by Aspergillus fumigatus is mediated through chemisorptions mechanism. (author)

  17. Biosorption of hexavalent chromium in a tannery industry wastewater using fungi species

    International Nuclear Information System (INIS)

    Sivakumar, D.

    2016-01-01

    The isolated fungi species of different kinds from chromium contaminated soil sites located in Nagalkeni, Chennai were used for reducing chromium(VI) in a tannery industry wastewater of Nagalkeni, Chennai. The experiments were conducted to know biosorption potential of isolated fungi species for removing chromium(VI) in a tannery industry wastewater against the different p H, fungi biomass and chromium(VI) concentration (dilution ratio). The results of this study indicated that the order of maximum removal of chromium(VI) by an isolated fungi species at an optimum pH of 3, fungi biomass of 4g and an initial chromium(VI) concentration of 18.125 mg/L (dilution ratio 4) is A. niger > A. flavus > A. fumigatus > A. nidulans > A. heteromorphus > A. foetidus > A. viridinutans. This study found that the maximum removal of chromium(VI) was achieved by Aspergillus niger (96.3 %) than other fungi species at chromium(VI) concentration of 18.125 mg/L in a tannery industry wastewater. The chromium removal from tannery industry wastewater was validated by checking chromium removal in an aqueous solution and by checking the removal efficiency of other parameters in a tannery industry wastewater using same isolated A. niger. Biosorption model was proposed to simulate the experimental condition for removing chromium(VI) in a tannery industry wastewater by all isolated fungi species. The R2 and x2 values of the proposed model predicted that the proposed biosorption model is very much useful for predicting the trend of reduction potential of chromium(VI) in a tannery industry wastewater by all isolated fungi species. This study suggested that one could select the type of fungi species, ion concentration level, selection of treatment period, quantity of biomass to be used, and p H level of the medium, to achieve the highest reduction of any toxic metals from any contaminated water, wastewater and soil environment.

  18. Biosorption of Cr (VI) ions from electroplating industrial effluent using immobilized Aspergillus niger biomass.

    Science.gov (United States)

    Chhikara, S; Dhankhar, R

    2008-09-01

    A fungus, Aspergillus niger was chemically treated with 0.1 M H2SO4 and 0.1 N NaOH to form biosorbent and it was immobilized in calcium alginate beads. The biosorption capacity of immobilized biosorbents for Cr (VI) was found to depend on pH, contact time, biosorbent dose and initial concentration of Cr (VI). The maximum uptake of Cr (VI) was 92.5, 95.9 and 98.4 mg respectively at a pH of 1.5 and with an increase in pH up to 10.5 the metal uptake decreased gradually up to 38.75, 50.19 and 65.28 mg respectively for acid treated, untreated and base treated fungal biosorbents. Increase in biosorbent dose up to 1 g of biomass and contact time up to 60 min resulted in an increase in biosorption from 19.6, 15.6 and 26.1 mg at a biosorbent dose of 0.1 g 100 ml(-1) to 92.45, 95.7 and 98.52 mg at a biosorbent dose of 1.0 g 100 ml(-1) and then further increase in adsorbent dose and contact time did not resulted in more Cr (VI) adsorption by per unit weight of biosorbent. The value of Kad (adsorption rate constant) revealed the pseudo-first order nature of biosorption. The percentage metal uptake by the biosorbent was found to decrease upto 62.33, 52.67 and 83.5 percent respectively for acid treated, untreated and base treated fungal biosorbents at the 300 mgl(-1) Cr (VI) ion concentration. The resulted data was found to fit well in Langmuir model of adsorption isotherm with a high value of correlation coefficient. The value of Qmax, b (Langmuir constants), R(L) (separation factor) and delta G (Gibb's free energy) revealed the favourable nature of adsorption. The biosorbed metal was eluted from the biosorbent by using 0.1 M H2SO4 as elutant. Immobilized biosorbent can be reused for five consecutive biosorption/desorption cycles without apparent loss of efficiency after its reconditioning. The biosorbent was found to perform well in the electroplating industrial effluent.

  19. The role of pH in heavy metal detoxification by biosorption from ...

    African Journals Online (AJOL)

    The high level of toxic metal pollution in the environment is a result of increased human activities. The hydrogen ion concentration of solutions has been known to affect reactions in solutions. The role of pH in As(V), Pb(II) and Hg(II) ions detoxification by bio-sorption from aqueous solutions using coconut fiber and sawdust ...

  20. Lanthanide and actinide ion phytoextraction: investigations of biosorption chemistry

    International Nuclear Information System (INIS)

    Rayson, Gary D.; Serna, Debbie D.; Moore, Jessica L.

    2009-01-01

    Investigations of the chemical interactions responsible for passive biosorption of a lanthanide (Eu (III)) and an actinide (U (VI)) metal ion is described. Spectroscopic methods for the elucidation of chemical functionalities on cultured anther cell walls from the plant Datura innoxia include metal ion luminescence measurements. These have revealed the presence of distinctly different binding environments involving one, two, and three carboxylate moieties for Eu (III) and UO 2 2+ binding and sulfonates (or sulfates) and phosphates for sequestration of Eu (III) on the uranyl ion, respectively. Additional investigations of the apparent affinities of these metals to this material have revealed the presence of both low and high affinity sites for the binding of Eu (III) with weak electrostatic attractions proposed for binding at high metal concentrations (i.e., low affinities) and surface coordination interactions responsible for higher affinities. Conversely, total uranyl ion binding revealed only a single distribution of interactions based on apparent affinities. (author)

  1. Biosorption of Fe, Al and Mn of acid drainage from coal mine using brown seaweed sargassum sp. in continuous process

    International Nuclear Information System (INIS)

    Diaz, Andrea; Arias, John; Gelves, Genaro; Maldonado, Alfonso; Laverde, Dionisio; Pedraza, Julio; Escalante, Humberto

    2003-01-01

    The acid mine drainage (AMD) are leaches as result of a coal mining running, it have low ph and high concentrations of heavy metals that convert them in strong polluter; with the purpose of reduce its concentration, a continuous biosorption system was designed by removing heavy metals from drainages using a cheap biosorbent material. The brown seaweed was pre-treatment with solutions 0,1 N of NaOH, Ca(OH) 2 NaCl, CaCl 2 , NaSO 4 y H 2 SO 4 for to study the effect on biosorption process; the removal percentage were determined, which are better than 80% with the exception of pre-treatment with H 2 SO 4 who cancel the algae sorption capacity. The seaweed was packed in plastic mesh and polyester tulle in the shape of a rectangular prism; there isn't effect on the biosorption process by using this packet. The continuous biosorption process was studied in two units of operation: a packed-bed flow-through sorption column and an horizontal vessel like a canal with baffles, which treated adequately 3,5 and 4,71 of AMD respectively, using in each one of them 100 g of algae. The burning of algae was studied like an alternative for the problem of handling of residual algae. The ashes kept the metals removed from AMD, furthermore keep stable too by the attack of solutions of different pH

  2. Studies on biosorption of Cr(VI) on a green resin: dry cow dung powder and tracer technique

    International Nuclear Information System (INIS)

    Barot, N.S.; Bagla, H.K.

    2012-01-01

    The present investigation entails the application of dry cow dung powder (DCP) as an indigenous, inexpensive and eco-friendly material for the removal of Cr(VI) from aqueous medium. Batch biosorption experiments were conducted employing 51 Cr(VI) as a tracer and the effect of various process parameters such as optimum pH, temperature, amount of resin, time of equilibration, agitation speed, concentration of metal ions and interfering effect of different salts etc. were studied. The kinetic studies were carried out employing various models but the best fitting was given by Lagergren Pseudo-second order model with high correlation coefficient R 2 value of 0.997 and adsorption capacity of 10.20 mg/g. The thermodynamic parameters for biosorption were evaluated as ΔG = -2.837 kJ/mol, ΔH = -4.757 kJ/mol and ΔS = 16.64 J/mol K, which indicated spontaneous and exothermic process with high affinity of DCP for Cr(VI). Many naturally available materials are used for the biosorption of heavy metal pollutants, where most of them are physically or chemically modified. In this research work, DCP has been utilized without any pre or post chemical treatment. Thus it manifests the principle of green chemistry and proves to be an eco-friendly resin. (orig.)

  3. Studies on biosorption of Cr(VI) on a green resin: dry cow dung powder and tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Barot, N.S.; Bagla, H.K. [Kishinchand Chellaram College, Mumbai (India). Nuclear and Radiochemistry Dept.

    2012-07-01

    The present investigation entails the application of dry cow dung powder (DCP) as an indigenous, inexpensive and eco-friendly material for the removal of Cr(VI) from aqueous medium. Batch biosorption experiments were conducted employing {sup 51}Cr(VI) as a tracer and the effect of various process parameters such as optimum pH, temperature, amount of resin, time of equilibration, agitation speed, concentration of metal ions and interfering effect of different salts etc. were studied. The kinetic studies were carried out employing various models but the best fitting was given by Lagergren Pseudo-second order model with high correlation coefficient R{sup 2} value of 0.997 and adsorption capacity of 10.20 mg/g. The thermodynamic parameters for biosorption were evaluated as {Delta}G = -2.837 kJ/mol, {Delta}H = -4.757 kJ/mol and {Delta}S = 16.64 J/mol K, which indicated spontaneous and exothermic process with high affinity of DCP for Cr(VI). Many naturally available materials are used for the biosorption of heavy metal pollutants, where most of them are physically or chemically modified. In this research work, DCP has been utilized without any pre or post chemical treatment. Thus it manifests the principle of green chemistry and proves to be an eco-friendly resin. (orig.)

  4. Engineering bacterial biopolymers for the biosorption of heavy metals; new products and novel formulations

    International Nuclear Information System (INIS)

    Gutnick, D.L.; Bach, H.

    2000-01-01

    Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology. One of the approaches considered for application involves biosorption either to biomass or to isolated biopolymers. Many bacterial polysaccharides have been shown to bind heavy metals with varying degrees of specificity and affinity. While various approaches have been adopted to generate polysaccharide variants altered in both structure and activity, metal biosorption has not been examined. Polymer engineering has included structural modification through the introduction of heterologous genes of the biosynthetic pathway into specific mutants, leading either to alterations in polysaccharide backbone or side chains, or to sugar modification. In addition, novel formulations can be designed which enlarge the family of available bacterial biopolymers for metal-binding and subsequent recovery. An example discussed here is the use of amphipathic bioemulsifiers such as emulsan, produced by the oil-degrading Acinetobacter lwoffii RAG-1, that forms stable, concentrated (70%), oil-in-water emulsions (emulsanosols). In this system metal ions bind primarily at the oil/water interface, enabling their recovery and concentration from relatively dilute solutions. In addition to the genetic modifications described above, a new approach to the generation of amphipathic bioemulsifying formulations is based on the interaction of native or recombinant esterase and its derivatives with emulsan and other water-soluble biopolymers. Cation-binding emulsions are generated from a variety of hydrophobic substrates. The features of these and other systems will be discussed, together with a brief consideratiton of possible applications. (orig.)

  5. Biomass of Spirulina maxima enriched by biosorption process as a new feed supplement for swine.

    Science.gov (United States)

    Saeid, A; Chojnacka, K; Korczyński, M; Korniewicz, D; Dobrzański, Z

    2013-04-01

    This paper deals with the new mineral feed additives with Cu produced in a biosorption process from a semi-technical scale. The natural biomass of edible microalga Spirulina sp. was enriched with Cu(II) and then used as a mineral supplement in feeding experiments on swine to assess its nutrition properties. A total of 24 piglets divided into two groups (control and experimental) were used to determine the bioavailability of a new generation of mineral feed additives based on Spirulina maxima . The control group was feed using traditional inorganic supplements of microelements, while the experimental group was fed with the feed containing the biomass of S. maxima enriched with Cu by biosorption. The apparent absorption was 30 % ( P  maxima -is a promising alternative to currently used inorganic salts as the source of nutritionally important microelements.

  6. Biosorption of Methylene Blue by De-Oiled Algal Biomass: Equilibrium, Kinetics and Artificial Neural Network Modelling

    Science.gov (United States)

    Maurya, Rahulkumar; Ghosh, Tonmoy; Paliwal, Chetan; Shrivastav, Anupama; Chokshi, Kaumeel; Pancha, Imran; Ghosh, Arup; Mishra, Sandhya

    2014-01-01

    The main objective of the present study is to effectively utilize the de-oiled algal biomass (DAB) to minimize the waste streams from algal biofuel by using it as an adsorbent. Methylene blue (MB) was used as a sorbate for evaluating the potential of DAB as a biosorbent. The DAB was characterized by SEM, FTIR, pHPZC, particle size, pore volume and pore diameter to understand the biosorption mechanism. The equilibrium studies were carried out by variation in different parameters, i.e., pH (2–9), temperature (293.16–323.16 K), biosorbent dosage (1–10 g L−1), contact time (0–1,440 min), agitation speed (0–150 rpm) and dye concentration (25–2,500 mg L−1). MB removal was greater than 90% in both acidic and basic pH. The optimum result of MB removal was found at 5–7 g L−1 DAB concentration. DAB removes 86% dye in 5 minutes under static conditions and nearly 100% in 24 hours when agitated at 150 rpm. The highest adsorption capacity was found 139.11 mg g−1 at 2,000 mg L−1 initial MB concentration. The process attained equilibrium in 24 hours. It is an endothermic process whose spontaneity increases with temperature. MB biosorption by DAB follows pseudo-second order kinetics. Artificial neural network (ANN) model also validates the experimental dye removal efficiency (R2 = 0.97) corresponding with theoretically predicted values. Sensitivity analysis suggests that temperature and agitation speed affect the process most with 23.62% and 21.08% influence on MB biosorption, respectively. Dye adsorption capacity of DAB in fixed bed column was 107.57 mg g−1 in preliminary study while it went up to 139.11 mg g−1 in batch studies. The probable mechanism for biosorption in this study is chemisorptions via surface active charges in the initial phase followed by physical sorption by occupying pores of DAB. PMID:25310576

  7. Biosorption of aqueous lead (II) on rice straws (oryza sativa) by flash column process

    International Nuclear Information System (INIS)

    Khalid, H.N.; Hassan, M.U.; Jamil, N.; Ahmad, D.; Bushra, H.; Khatoon, S.

    2010-01-01

    Biosorption of Pb (II) on rice straws has been studied with the variation in the parameters and on modified rice straws by flash column process. Different parameters like particle size of adsorbent, initial concentration of metal ions, length and width of columns were studied. A comparative study of modification of adsorbent was also done for which rice straws were modified with EDTA, acids, bases, and volatile organic solvents. Base modified adsorbents have shown an increase in adsorption capacity while acid modified adsorbents proved to be the poor adsorbents for metal ions similarly ash of rice straws used as adsorbent given higher adsorption and EDTA modified adsorbents have shown least adsorption of metal ions. Polar volatile organic solvents modified adsorbent gave less adsorption efficiency and non polar adsorbent shown no influence on Pb (II) uptake capacity of rice straws. Rice straws proved to be the best biosorbent for Pb(II) in aqueous solution. The biosorption characteristics fit well with Langmuir and Freundlich isotherm. (author)

  8. Neural fuzzy modelization of copper removal from water by biosorption in fixed-bed columns using olive stone and pinion shell.

    Science.gov (United States)

    Calero, M; Iáñez-Rodríguez, I; Pérez, A; Martín-Lara, M A; Blázquez, G

    2018-03-01

    Continuous copper biosorption in fixed-bed column by olive stone and pinion shell was studied. The effect of three operational parameters was analyzed: feed flow rate (2-6 ml/min), inlet copper concentration (40-100 mg/L) and bed-height (4.4-13.4 cm). Artificial Neural-Fuzzy Inference System (ANFIS) was used in order to optimize the percentage of copper removal and the retention capacity in the column. The highest percentage of copper retained was achieved at 2 ml/min, 40 mg/L and 4.4 cm. However, the optimum biosorption capacity was obtained at 6 ml/min, 100 mg/L and 13.4 cm. Finally, breakthrough curves were simulated with mathematical traditional models and ANFIS model. The calculated results obtained with each model were compared with experimental data. The best results were given by ANFIS modelling that predicted copper biosorption with high accuracy. Breakthrough curves surfaces, which enable the visualization of the behavior of the system in different process conditions, were represented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Biosorption of Cd(II) and Cs(I) from aqueous solution by live and dead cells of Saccharomyces carlsbergensis PTCC 5051.

    Science.gov (United States)

    Sayyadi, Shayan; Ahmady-Asbchin, Salman; Kamali, Kasra

    2018-02-01

    The biosorption characteristics of Cd(II) and Cs(I) using live and dead cells of Saccharomyces carlsbergensis PTCC 5051 as biosorbents have been investigated in the present research. The influence of different experimental parameters such as initial pH (pHi), shaking rate, sorption time and initial metal concentration was evaluated. The optimum pH was obtained as 4 for Cd(II) and 7 for Cs(I). The experimental adsorption data were fitted to the Langmuir linear equation adsorption model. The highest metal uptake values of 0.593 and 0.473 mmol g -1 were calculated for Cd(II) and Cs(I), respectively. The results of Fourier transform infrared analysis suggested the involvement of amine, carboxyl and hydroxyl groups during the biosorption process and also indicated that more functional groups were involved in the biosorption process of live adsorbents, compared with those linked to dead biomass. The results showed that the biomass of S. carlsbergensis PTCC 5051 is a suitable biosorbent for the removal of Cd(II) and Cs(I) from the aqueous solutions.

  10. Uranium and neodymium biosorption using novel chelating polysaccharide.

    Science.gov (United States)

    Elsalamouny, Ahmed R; Desouky, Osman A; Mohamed, Saad A; Galhoum, Ahmed A; Guibal, Eric

    2017-11-01

    A direct reaction is described to prepare hydrophobic α-aminomethylphosphonic acid as a novel chitosan-based material. It exhibits chelating properties for polyvalent metal ions such as U(VI) and Nd(III) ions. The new sorbent was fully characterized using Elemental analysis, scanning electron microscope (SEM) and FTIR spectra. Different parameters were examined in order to evaluate the optimum conditions for U(VI) and Nd(III) ions biosorption. Sorption mechanisms of metal ions were investigated using kinetic and isotherm models. In addition, the sorbent selectivity was tested for both metal ions together in a binary solution. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The biosorption of Cd2+ ions by wood pulp of Pinus negra Arnold

    International Nuclear Information System (INIS)

    Loucka, T.; Janos, P.

    2001-01-01

    Biosorption is one of those processes that use biomass (mostly inanimate) for elimination of various chemical substances (e.g. heavy metals) from environment. Until now algae have been studied as bio-sorbents in most cases, but we can also take advantage of wood pulp (or sawdust) that is normal waste material resulting in large amounts from various productions. Considering the fact that bio-sorbent can be taken as natural ion exchanger containing slightly acidic or basic functional groups (2,3,4), it is necessary to suppose that part of functional groups is filled by various metals before starting the measurements. Substituting these bound metallic cations by protonization we can gain biomass in given condition and some important information about the content of cations bound to bio-sorbent through ion exchange. The material used for biosorption observation was sawdust of Pinus negra Arnold. For measurements we used the part which passed through the 0.6 mm sieve. By dehydrating at the 1200 C for the time of 24 hours we gained the water part that was 5.44% of original weight

  12. Immobilization of aluminum by biomass of microscopic fungi - an introduction to the study of processes of biosorption and bioaccumulation in the environment

    International Nuclear Information System (INIS)

    Simkova, L.; Urik, M.; Matus, P.; Cernansky, S.; Simonovicova, A.

    2010-01-01

    The aim of this work was to study Al immobilization from aqueous solutions using biomass of microscopic fungi (Aspergillus niger, Aspergillus clavatus, Neosartorya fischeri) in vitro. For this purpose, have been studied the processes of its biosorption and bioaccumulation by compact form and pelletising of biomass with respect to the further optimization of experimental conditions for the streamlining of the procedures. Effect of both processes was observed, the course of pH and impact of potential metabolism of biomass on biosorption of aluminium.

  13. Lead Biosorption by Self-Immobilized Rhizopus nigricans Pellets in a Laboratory Scale Packed Bed Column: Mathematical Model and Experiment

    Directory of Open Access Journals (Sweden)

    Adela Kogej

    2010-01-01

    Full Text Available The biosorption of lead ions from aqueous solution on a self-immobilized Rhizopus nigricans biomass has been studied. Experiments were performed in a laboratory scale packed bed column at different liquid flow rates and biosorbent bed heights. Recorded experimental breakthrough curves were compared to those predicted by a mathematical model, which was developed to simulate a packed bed biosorption process by a soft, self-immobilized fungal biosorbent. In the range of examined experimental conditions, the biomass characteristics such as pellet porosity and biosorption capacity substantially affected the predicted response curve. General correlations for the estimation of the intra-pellet effective diffusivity, the external mass transfer coefficient, as well as axial dispersion were successfully applied in this biological system with specific mechanical properties. Under the experimental conditions, mass transfer is controlled by the external film resistance, while the intra-pellet mass transfer resistance, as well as the effect of axial dispersion, can be neglected. A new parameter α, the fraction of active biomass, with an average value of α=0.7, was introduced to take into account the specific biomass characteristics, and consequently the observed non-ideal liquid flow through the bed of fungal pellets.

  14. Characterization of the biosorption of cadmium, lead and copper with the brown alga Fucus vesiculosus

    International Nuclear Information System (INIS)

    Mata, Y.N.; Blazquez, M.L.; Ballester, A.; Gonzalez, F.; Munoz, J.A.

    2008-01-01

    The recovery of cadmium, lead and copper with the brown alga Fucus vesiculosus was characterized and quantified. The biosorption data fitted the pseudo-second order and Langmuir isotherm models, but did not adjust to the intraparticle diffusion model. The metal uptakes deduced from the pseudo-second order kinetic model and the Langmuir isotherm model followed a similar sequence: Cu > Cd ∼ Pb. The Langmuir maximum metal uptakes were: 0.9626 mmol/g, Pb 1.02 mmol/g, and Cu 1.66 mmol/g. According to the equilibrium constants of this isotherm model, the affinity of metals for the biomass followed this order: Pb > Cu > Cd. Biosorption was accomplished by ion exchange between metals in solution and algal protons, calcium and other light metals, and by complexation of the adsorbed metals with algal carboxyl groups. FTIR spectra showed a shift in the bands of carboxyl, hydroxyl and sulfonate groups

  15. Biosorption of the metal-complex dye Acid Black 172 by live and heat-treated biomass of Pseudomonas sp. strain DY1: Kinetics and sorption mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Du, Lin-Na; Wang, Bing [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China); Li, Gang [Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, 325006 Wenzhou, Zhejiang Province (China); Wang, Sheng [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China); Crowley, David E., E-mail: crowley@ucr.edu [Department of Environmental Science, University of California, Riverside, CA 92521 (United States); Zhao, Yu-Hua, E-mail: yhzhao225@zju.edu.cn [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer The maximum amount of Acid Black 172 sorption was about 2.98 mmol/g biomass. Black-Right-Pointing-Pointer Amine groups played a major role in the biosorption of Acid Black 172. Black-Right-Pointing-Pointer The reasons of increased dye sorption by heat-treated biomass were proposed. - Abstract: The ability of Pseudomonas sp. strain DY1 to adsorb Acid Black 172 was studied to determine the kinetics and mechanisms involved in biosorption of the dye. Kinetic data for adsorption fit a pseudo-second-order model. Increased initial dye concentration could significantly enhance the amount of dye adsorbed by heat-treated biomass in which the maximum amount of dye adsorbed was as high as 2.98 mmol/g biomass, whereas it had no significant influence on dye sorption by live biomass. As treated temperature increased, the biomass showed gradual increase of dye sorption ability. Experiments using potentiometric titration and Fourier transform infrared spectroscopy (FTIR) indicated that amine groups (NH{sub 2}) played a prominent role in biosorption of Acid Black 172. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM) analysis indicated that heat treatment of the biomass increased the permeability of the cell walls and denatured the intracellular proteins. The results of biosorption experiments by different cell components confirmed that intracellular proteins contributed to the increased biosorption of Acid Black 172 by heat-treated biomass. The data suggest that biomass produced by this strain may have application for removal of metal-complex dyes from wastewater streams generated from the dye products industry.

  16. Biosorption of lead ions on biosorbent prepared from plumb shells (spondias mombin): kinetics and equilibrium studies

    International Nuclear Information System (INIS)

    Adeogen, A.I.; Bello, O.S.; Adeboye, M.D.

    2010-01-01

    Plumb shell was used to prepare an adsorbent for biosorption of lead ions in aqueous solution at 25 degree C. The adsorption capacity of the adsorbent at equilibrium was found to increase from 2.8 to 49.0 mg/g with an increase in the initial lead ion concentration from 50 to 200 mg/L. Using the equilibrium and kinetics studies, isotherm of the lead ions on the biosorbent was determined and correlated with common isotherm equations. The equilibrium data for lead ion adsorption fitted well into the Freundlich equation, with a value of 0.76 (R2 = 0.9), with distribution coefficient of 4.90. The biosorption of lead ions on the adsorbent from plumb shells could best be described by the pseudo-second-order equation. The kinetic parameters of this best-fit model were calculated and discussed. (author)

  17. Biosorption of uranium by immobilized cells of Rhodotorula glutinis

    International Nuclear Information System (INIS)

    Jing Bai; Zhan Li; Fangli Fan; Xiaolei Wu; Xiaojie Yin; Longlong Tian; Zhi Qin; Junsheng Guo

    2014-01-01

    Biosorption of uranium ions from diluted solution (≤40 mg L -1 ) onto immobilized cells of Rhodotorula glutinis was investigated in a batch system. Equilibrium, kinetic and thermodynamic studies were conducted by considering the effect of initial uranium concentration, contact time and temperature. Non-linear forms of Langmuir, Freundlich and Sips isotherm models were used to fit the equilibrium data, Sips model was designated as the best one. Kinetic data were simulated by non-linear pseudo-first-order, pseudo-second-order and intra-particle diffusion equations. Pseudo-first-order kinetic equation described the experimental data better than pseudo-second-order equation and intra-particle diffusion equation can fit the kinetic data with two independent curves. Thermodynamic parameters, including ∆H 0, ∆G 0 and ∆S 0, were evaluated, the sorption process was determined to be spontaneous and endothermic. Uranium sorption from pure uranium solutions and uranium pit wastewater by immobilized biomass and blank beads, as well as the regeneration results indicated that immobilized R. glutinis can be use to recovery uranium from uranium pit wastewater. (author)

  18. BIOSORPTION AND RECOVERY OF HEAVY METALS FROM AQUEOUS SOLUTIONS BY EICHHORNIA CRASSIPES (WATER HYACINTH ASH

    Directory of Open Access Journals (Sweden)

    Tariq Mahmood

    2010-04-01

    Full Text Available Heavy metal’s release without treatment poses a significant threat to the environment. Heavy metals are non-biodegradable and persistent. In the present study the ash of water hyacinth (Eichhornia crassipes, was used to remove six metals from aqueous solutions through biosorption. Results of batch and column experiments showed excellent adsorption capacity. Removal of lead, chromium, zinc, cadmium, copper, and nickel was 29.83, 1.263, 1.575, 3.323, 2.984 and 1.978 µgg-1, respectively. The biosorptive capacity was maximum with pH >8.00. Desorption in µgg-1 of ash for lead, chromium, zinc, cadmium, copper, and nickel was 18.10, 9.99, 11.99, 27.54, 21.09, and 3.71 respectively. Adsorption/desorption of these metals from ash showed the potential of this technology for recovery of metals for further usages. Hydrogen adsorption was also studied with a Sievert-type apparatus. Hydrogen adsorption experiments showed significant storage capacity of water hyacinth ash.

  19. Removal of Cr(VI) and Ni(II) from aqueous solution by fused yeast: Study of cations release and biosorption mechanism

    International Nuclear Information System (INIS)

    Yin Hua; He Baoyan; Peng Hui; Ye Jinshao; Yang Feng; Zhang Na

    2008-01-01

    Biosorption of Cr(VI) and Ni(II) by a fused yeast from Candida tropicalis and Candida lipolytica under varying range of pH, initial metal concentration and reaction time was investigated. Net cation release and Cr removal reached 2.000 mmol/l and 81.37% when treating 20 mg/l Cr(VI) at pH 2 with 25 mg/l biomass for 30 min, while for Ni were 0.351 mmol/l and 64.60%, respectively. Trace metal elements such as Co, Cu, Mn, Mo, Se and Zn played active role in biosorption as important ingredients of functional enzymes. Cr(VI) was reduced to less toxic Cr(III) and chelated with extracellular secretions, and further accumulated inside the cells. For Ni biosorption, however, largely a passive uptake process influenced by ion gradient led to lower adsorption capacity and cations release. Fourier transform infrared (FTIR) spectrum analysis indicated that amide and pyridine on cells were involved in binding with Cr, but for Ni, bound-OH and nitro-compounds were the main related functional groups. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis confirmed that considerable amounts of metals precipitated on cell surface when dealing with high concentration metals

  20. Potential Malaysia agricultural waste materials for the biosorption of cadmium(II) from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Foo, L.P.Y.; Tee, C.Z.; Raimy, N.R.; Hassell, D.G.; Lee, L.Y. [University of Nottingham Malaysia Campus, Semenyih, Selangor (Malaysia)

    2012-04-15

    Biosorption of cadmium(II) ions (Cd{sup 2+}) onto Ananas comosus (AC) peel, Parkia speciosa (PS) pods and Psidium guajava (PG) peel were investigated in this study. Batch sorption experiments were performed by investigating the effect of initial pH. It was found that Cd{sup 2+} uptake was highly dependent on the initial pH and Cd{sup 2+} removal efficiency was highest for PG peel, followed by AC peel and PS pods. Biosorption experiments were carried out using different initial Cd{sup 2+} concentration and the experimental data obtained was fitted to both Langmuir and Freundlich isotherms. The experimental data was found to best fit the Langmuir isotherm, and adsorption capacities of 18.21 mg/g (AC peel), 25.64 mg/g (PS pods) and 39.68 mg/g (PG peel) were obtained. Comparison with published adsorption capacities for other low-cost biosorbents indicates that PS pods and PG peel have potential as low-cost biosorbent materials for the removal of Cd{sup 2+} from aqueous solution. (orig.)

  1. Biosorption study of radiotoxic nuclide and toxic heavy metals using green adsorbent

    International Nuclear Information System (INIS)

    Bagla, Hemlata K.

    2014-01-01

    Our research scientifically illuminates the pioneering and successful application of the ancient Indian epitome of energy, Dry Cow Dung Powder, DCP, a combo humiresin, in its naive 'as it is form' for the bioremediation of toxic pollutants. The potential of DCP to sequester toxic heavy metal ions such as Cr(III), Cr(VI). Cd(II), Hg(II) and radionuclide 90 Sr(II) has been successfully demonstrated, employing tracer technique. The Batch equilibration method and all the important parameters such as pH, dose of sorbent, metal ion concentration, contact time, agitation speed, temperature and interference of different salts have been studied and optimized. The study on thermodynamic, kinetic and isotherm modeling of biosorption indicates that it is feasible, eco-friendly and efficient process to employ DCP for the removal of metal ions from aqueous medium. Spectroscopic analysis by FTIR and EDAX effectively explain the mechanism involved in the biosorption by DCP. The adsorption capacity and the pseudo-second order rate constant were also obtained by regression analysis. Thus DCP proves to be Eco-friendly resin for the removal of these toxic pollutants such as Cr(III), Cr(VI), Cd(II), Hg(II) and 90 Sr(II) from aqueous medium. (author)

  2. Biosorption and biotransformation of chromium by Serratia sp. isolated from tannery effluent.

    Science.gov (United States)

    Srivastava, Shaili; Thakur, Indu Shekhar

    2012-01-01

    A bacterium isolated from soil and sediment ofa leather tanning mill's effluent was identified as Serratia sp. by the analysis of 16S rDNA. Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and transmission electron microscopy (TEM) were used to assess morphological changes and confirm chromium biosorption in Serratia sp. both in a shake-flask culture containing chromium and in a tannery wastewater. The SEMEDX and the elemental analysis of the chromate-containing samples confirmed the binding of chromium with the bacterial biomass. The TEM exhibited chromium accumulation throughout the bacterial cell, with some granular deposits in the cell periphery and in the cytoplasm. X-ray diffraction analysis (XRD) was used to quantify the chromium and to determine the chemical nature of the metal-microbe interaction. The XRD data showed the crystalline character of the precipitates, which consisted of mainly calcium chromium oxide, chromium fluoride phosphate and related organo-Cr(III) complex crystals. The XRD data also revealed a strong involvement of cellular carboxyl and phosphate groups in chromium binding by the bacterial biomass. The results of the study indicated that a combined mechanism of ion-exchange, complexation, croprecipitation and immobilization was involved in the biosorption of chromium by bacterial cells in contaminated environments.

  3. Cadmium biosorption properties of the metal-resistant ochrobactrum cytisi Azn6.2

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Llorente, Ignacio D.; Gamane, Djamila; Lafuente, Alejandro; Dary, Mohammed; El Hamdaoui, Abdelaziz; Delgadillo, Julian; Doukkali, Bouchra; Caviedes, Miguel A.; Pajuelo, Eloisa [Departamento de Microbiologia, Facultad de Farmacia, Universidad de Sevilla, Sevilla (Spain)

    2010-02-15

    The aim of this work was to establish the conditions for using Ochrobactrum cytisi Azn6.2 as a metal biosorbent. Azn6.2 is a novel strain from the legume symbiont O. cytisi that has been isolated from nodules of Medicago polymorpha plants grown on heavy metal-polluted soils. Compared with the strain ESC1, Azn6.2 showed some biochemical differences, as well as antibiotic susceptibility, Azn6.2 was multi-resistant to heavy metals, such as Cu, Cd and Zn, and bacterial pellets were able to biosorb high amounts of Cd and Zn. As shown by scanning electron microscopy coupled to energy dispersive X-ray, most of Cd was attached to the cell surface. Optimal conditions for Cd biosorption were established, being 1 mM Cd ions in solution and 2 h of contact with the biosorbent at room temperature. At these conditions, maximal Cd loading capacity reached 32-34 mg/g. Cd desorption from bacterial pellets was achieved after washing with EDTA or, at higher efficiency, at pH 1.0. These results indicated that biosorption/desorption on O. cytisi Azn6.2 biomass should be a cost-effective method for Cd recovery from contaminated solutions. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Heavy metal recovery from contaminated biomass ashes by chemical leaching, bioleaching and biosorption

    International Nuclear Information System (INIS)

    Pirker, K.

    2000-01-01

    Ashes from biomass combustion plants contain plant nutrients which makes their application as fertilizers economically interesting. The possibility of recycling the ash can be looked upon as a contribution to obtain a sustainable energy utilization from biomass. The ash contains heavy metals which have to be removed. The possibility of decontaminating the ash by chemical and biological leaching was investigated. The leaching capacity of commercially available organic and inorganic acids and of citric acid produced by the fungus Penicillium simplicissimus were determined. A process for heavy metal recovery from biomass ashes consisting of four steps was designed. All environmentally relevant heavy metals (except lead) were removed from contaminated biomass ashes by chemical leaching. The heavy metals were recovered and enriched by precipitation and subsequent biosorption. Inactivated bacteria and fungi were used as biosorbents. The overall costs and the washing-out of plant nutrients from the ashes by chemical leaching were drawbacks of the metal recovering process. Biosorption in combination with existing processes of waste water treatment would offer another promising possibility for achieving the low Austrian limiting values for heavy metals in waste water. (author)

  5. Effect of Cu(II), Cd(II) and Zn(II) on Pb(II) biosorption by algae Gelidium-derived materials.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2008-06-15

    Biosorption of Pb(II), Cu(II), Cd(II) and Zn(II) from binary metal solutions onto the algae Gelidium sesquipedale, an algal industrial waste and a waste-based composite material was investigated at pH 5.3, in a batch system. Binary Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II) solutions have been tested. For the same equilibrium concentrations of both metal ions (1 mmol l(-1)), approximately 66, 85 and 86% of the total uptake capacity of the biosorbents is taken by lead ions in the systems Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II), respectively. Two-metal results were fitted to a discrete and a continuous model, showing the inhibition of the primary metal biosorption by the co-cation. The model parameters suggest that Cd(II) and Zn(II) have the same decreasing effect on the Pb(II) uptake capacity. The uptake of Pb(II) was highly sensitive to the presence of Cu(II). From the discrete model it was possible to obtain the Langmuir affinity constant for Pb(II) biosorption. The presence of the co-cations decreases the apparent affinity of Pb(II). The experimental results were successfully fitted by the continuous model, at different pH values, for each biosorbent. The following sequence for the equilibrium affinity constants was found: Pb>Cu>Cd approximately Zn.

  6. Short and long term biosorption of silica-coated iron oxide nanoparticles in heterotrophic biofilms

    International Nuclear Information System (INIS)

    Herrling, Maria P.; Lackner, Susanne; Tatti, Oleg; Guthausen, Gisela; Delay, Markus; Franzreb, Matthias; Horn, Harald

    2016-01-01

    The increased application of engineered nanoparticles (ENP) in industrial processes and consumer products has raised concerns about their impact on health and environmental safety. When ENP enter the global water cycle by e.g. wastewater streams, wastewater treatment plants (WWTP) represent potential sinks for ENP. During biological WWT, the attachment of ENP to biofilms is responsible for the desired removal of ENP from the water phase avoiding their release into the aquatic environment. However, the fundamental mechanisms guiding the interactions between ENP and biofilms are not yet fully understood. Therefore, this study investigates the behavior and biosorption of inorganic ENP, here magnetic iron oxide nanoparticles coated with silica (scFe_3O_4-NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe_3O_4-NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe_3O_4-NP at short contact times (5 min) in flow cells and complementary, scFe_3O_4-NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe_3O_4-NP sorbed to the biofilm within a few minutes, but that the total biosorption was rather low (3.2 μg Fe/mg TSS). scFe_3O_4-NP mainly sorbed to the biofilm surface inducing the detachment of outer biofilm parts starting after an exposure time of 3 h in the MBBR. The biosorption depended on the exposure concentration of scFe_3O_4-NP, but less on the contact time. Most scFe_3O_4-NP exited the flow cell (up to 65%) and the MBBR (57%) via the effluent. This effect was favored by the stabilization of scFe_3O_4-NP in the bulk liquid by organic matter leading to a low retention capacity of the MBBR system. The results contribute to improve our understanding about the fate of ENP in environmental and in technical biofilm systems and give indications for future investigations needed

  7. Biosorption characteristics of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions by Chara sp. and Cladophora sp.

    Science.gov (United States)

    Elmaci, Ayşe; Yonar, Taner; Ozengin, Nihan

    2007-09-01

    The aim of this research was to expose individual removals of copper, chromium, nickel, and lead from aqueous solutions via biosorption using nonliving algae species, Chara sp. and Cladophora sp. Optimum pH values for biosorption of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions were determined to be 6, 7, 7, and 3 for Cladophora sp. and 5, 3, 5, and 4 for Chara sp. respectively. Maximum adsorption capacities of Chara sp. [10.54 for chromium (III) and 61.72 for lead (II)] and Cladophora sp. [6.59 for chromium (III) and 16.75 and 23.25 for lead (II)] for chromium (III) and lead (II) are similar. On the other hand, copper (II) and nickel (II) biosorption capacity of Cladophora sp. [14.28 for copper (II) and 16.75 for nickel (II)] is greater than Chara sp. [6.506 for copper (II) and 11.76 for nickel (II)]. Significantly high correlation coefficients indicated for the Langmuir adsorption isotherm models can be used to describe the equilibrium behavior of copper, chromium, nickel, and lead adsorption onto Cladophora sp. and Chara sp.

  8. Bioaccumulation and biosorption of bismuth Bi (III) by filamentous fungus Aspergillus clavatus; Bioakumulacia a biosorpcia bizmutu Bi(III) mikroskopickou vlaknitou hubou Aspergillus clavatus

    Energy Technology Data Exchange (ETDEWEB)

    Boriova, K.; Matus, P. [Univerzita Komenskeho, Prirodovedecka fakulta, Ustav laboratorneho vyskumu geomaterialov, 84215 Bratislava (Slovakia); Cernansky, S.; Bujdos, M. [Univerzita Komenskeho, Prirodovedecka fakulta, Katedra Katedra environmentalnej ekologie, 84215 Bratislava (Slovakia)

    2013-04-16

    In this work we focused on bismuth (III) biosorption and bioaccumulation. Prior the bioaccumulation experiments the 7-day-old conidia were collected from mycelia surface of filamentous fungus Aspergillus clavatus and used as inocula for 50 ml of nutrient media with different bismuth (III) concentrations. After 15-day cultivation under laboratory conditions (dark, 25 grad C) the bismuth concentration in grown fungal biomass was measured using ICP OES. Maximum achieved accumulation capacity of dry biomass was 112 {mu}mol.g{sup -1}. Batch biosorption experiments were performed in Erlenmeyer flasks with pelletized wet fungal biomass/solution ratio 1.8% and with various bismuth (III) concentrations. The equilibrium time was studied within the time interval of 0-240 min. The reaction kinetics were well described by both pseudo-first and pseudo-second order rate models, and equilibrium was reached after 50 min. Langmuir and Freundlich isotherm models were used to represent equilibrium data, and the calculated maximum biosorption capacity of fungal biomass for bismuth(III) was 0.40 mmol.g{sup -1}. (authors)

  9. Biosorption of Microelements by Spirulina: Towards Technology of Mineral Feed Supplements

    Science.gov (United States)

    Chojnacka, Katarzyna

    2014-01-01

    Surface characterization and metal ion adsorption properties of Spirulina sp. and Spirulina maxima were verified by various instrumental techniques. FTIR spectroscopy and potentiometric titration were used for qualitative and quantitative determination of metal ion-binding groups. Comparative FTIR spectra of natural and Cu(II)-treated biomass proved involvement of both phosphoryl and sulfone groups in metal ions sorption. The potentiometric titration data analysis provided the best fit with the model assuming the presence of three types of surface functional groups and the carboxyl group as the major binding site. The mechanism of metal ions biosorption was investigated by comparing the results from multielemental analyses by ICP-OES and SEM-EDX. Biosorption of Cu(II), Mn(II), Zn(II), and Co(II) ions by lyophilized Spirulina sp. was performed to determine the metal affinity relationships for single- and multicomponent systems. Obtained results showed the replacement of naturally bound ions: Na(I), K(I), or Ca(II) with sorbed metal ions in a descending order of Mn(II) > Cu(II) > Zn(II) > Co(II) for single- and Cu(II) > Mn(II) > Co(II) > Zn(II) for multicomponent systems, respectively. Surface elemental composition of natural and metal-loaded material was determined both by ICP-OES and SEM-EDX analysis, showing relatively high value of correlation coefficient between the concentration of Na(I) ions in algal biomass. PMID:25386594

  10. Comparative study on metal biosorption by two macroalgae in saline waters: single and ternary systems.

    Science.gov (United States)

    Figueira, Paula; Henriques, Bruno; Teixeira, Ana; Lopes, Cláudia B; Reis, Ana T; Monteiro, Rui J R; Duarte, A C; Pardal, M A; Pereira, E

    2016-06-01

    The biosorption capability of two marine macroalgae (green Ulva lactuca and brown Fucus vesiculosus) was evaluated in the removal of toxic metals (Hg, Cd and Pb) from saline waters, under realistic conditions. Results showed that, independently of the contamination scenario tested, both macroalgae have a remarkable capacity to biosorb Hg and Pb. In single-contaminant systems, by using only c.a. 500 mg of non-pre-treated algae biomass (size macroalgae exhibited a similar selectivity toward the target metals: Hg > Pb> > Cd, although Pb removal by U. lactuca was more inhibited than that achieved by F. vesiculosus. Under the experimental conditions used, none of the macroalgae was effective to remove Cd (maximum removal of 20 %). In all cases, the kinetics of biosorption was mathematically described with success. Globally, it became clear that the studied macroalgae may be part of simple, efficient, and cost-effective water treatment technologies. Nevertheless, Fucus vesiculosus has greater potential, since it always presented higher initial sorption rates and higher removal efficiencies.

  11. Study of Mo (VI Removal from Aqueous Solution: Application of Different Mathematical Models to Continuous Biosorption Data

    Directory of Open Access Journals (Sweden)

    Fatemeh Kafshgari

    2013-01-01

    Full Text Available Molybdenum (VI biosorption process was investigated by marine algae Cystoseria indica pretreated with 0.1 M CaCl2 solution in a packed bed column. The biosorbent was characterized by FTIR, BET and SEM analyses. The results showed that Mo (VI ions should be chelated with the hydroxyl, carboxyl and amine groups of the biomass. The effects of inlet metal concentration and flow rate on biosorption process were investigated and the experimental breakthrough curves were obtained. Results showed that the maximum biosorption capacity of Ca-pretreated C. indica for Mo (VI was found to be 18.32 mg/g at optimum flow rate of (1.4 mL/min. The controlled-rate step shifted from external to internal mass transfer limitations, as the flow rate increased. Also, it was observed that the breakthrough and exhaustion time decreased from 17.14 hr to 9.05 hr and from 0.006 h to 0.002 hr respectively, with the increase of flow rate from 0.7 to 2.1 ML/min. The increase in the initial concentration of Mo (VI solution from 30 to 95 ml min-1 increases the adsorption capacity from 18.32 to 30.19 mg/g and decreases the percentage of Mo (VI removal from 61 to 38%. Also, the treated volume was the greatest (1.42 L at the lowest inlet concentration. Column data obtained under different conditions were described using the Thomas, Yoon and Nelson, Yan and Belter models. The breakthrough curve predictions by Belter model were found to be very satisfactory.

  12. Biosorptive removal of inorganic arsenic species and fluoride from aqueous medium by the stem of Tecomella undulate.

    Science.gov (United States)

    Brahman, Kapil Dev; Kazi, Tasneem Gul; Baig, Jameel Ahmed; Afridi, Hassan Imran; Arain, Sadaf Sadia; Saraj, Saima; Arain, Muhammad B; Arain, Salma Aslam

    2016-05-01

    Simultaneous removal of fluoride (F(-)), inorganic arsenic species, As(III) and As(V), from aqueous samples has been performed using an economic indigenous biosorbent (Stem of Tecomella undulata). The inorganic As species in water samples before and after biosorption were determined by cloud point and solid phase extraction methods, while F(-) was determined by ion chromatography. Batch experiments were carried out to evaluate the equilibrium adsorption isotherm studies for As(III), As(V) and F(-) in aqueous solutions. Several parameters of biosorption were optimized such as pH, biomass dosage, analytes concentration, time and temperature. The surface of biosorbent was characterized by SEM and FTIR. The FTIR study indicated the presence of carbonyl and amine functional groups which may have important role in the sorption/removal of these ions. Thermodynamic and kinetic study indicated that the biosorption of As(III), As(V) and F(-) were spontaneous, exothermic and followed by pseudo-second-order. Meanwhile, the interference study revealed that there was no significant effect of co-existing ions for the removal of inorganic As species and F(-) from aqueous samples (p > 0.05). It was observed that the indigenous biosorbent material simultaneously adsorbed As(III) (108 μg g(-1)), As(V) (159 μg g(-1)) and F(-) (6.16 mg g(-1)) from water at optimized conditions. The proposed biosorbent was effectively regenerated and efficiently used for several experiments, to remove the As(III), As(V) and F(-) from real water sample collected from endemic area of Pakistan. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The use of Neem biomass for the biosorption of zinc from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Arshad, Mamoona [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Bioprocess Technology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O. Box 577, Faisalabad (Pakistan); Zafar, Muhammad Nadeem [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Department of Analytical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden)], E-mail: MNadeem.Zafar@analykem.lu.se; Younis, Sadaf; Nadeem, Raziya [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan)

    2008-09-15

    An adsorbent was developed from mature leaves and stem bark of the Neem (Azadirachta indica) tree for removing zinc from water. Adsorption was carried out in a batch process with several different concentrations of zinc by varying pH. The uptake of metal was very fast initially, but gradually slowed down indicating penetration into the interior of the adsorbent particles. The data showed that optimum pH for efficient biosorption of zinc by Neem leaves and stem bark was 4 and 5, respectively. The maximum adsorption capacity showed that the Neem biomass had a mass capacity for zinc (147.08 mg Zn/g for Neem leaves and 137.67 mg Zn/g Neem bark). The experimental results were analyzed in terms of Langmuir and Freundlich isotherms. The adsorption followed pseudo-second-order kinetic model. The thermodynamic assessment of the metal ion-Neem tree biomass system indicated the feasibility and spontaneous nature of the process and {delta}G{sup o} values were evaluated as ranging from -26.84 to -32.75 (Neem leaves) kJ/mol and -26.04 to -29.50 (Neem bark) kJ/mol for zinc biosorption. Due to its outstanding zinc uptake capacity, the Neem tree was proved to be an excellent biomaterial for accumulating zinc from aqueous solutions.

  14. Short and long term biosorption of silica-coated iron oxide nanoparticles in heterotrophic biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Herrling, Maria P. [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Lackner, Susanne [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Urban Bioengineering for Resource Recovery, Bauhaus-Institute for Infrastructure Solutions, Bauhaus-Universität Weimar, Coudraystraße 7, 99423 Weimar (Germany); Tatti, Oleg [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Guthausen, Gisela [Pro" 2NMR, Institute for Biological Interfaces 4 and Institute for Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, Adenauerring 20b, 76131 Karlsruhe (Germany); Delay, Markus [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Franzreb, Matthias [Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Horn, Harald, E-mail: harald.horn@kit.edu [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); DVGW Research Laboratories for Water Chemistry and Water Technology, Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany)

    2016-02-15

    The increased application of engineered nanoparticles (ENP) in industrial processes and consumer products has raised concerns about their impact on health and environmental safety. When ENP enter the global water cycle by e.g. wastewater streams, wastewater treatment plants (WWTP) represent potential sinks for ENP. During biological WWT, the attachment of ENP to biofilms is responsible for the desired removal of ENP from the water phase avoiding their release into the aquatic environment. However, the fundamental mechanisms guiding the interactions between ENP and biofilms are not yet fully understood. Therefore, this study investigates the behavior and biosorption of inorganic ENP, here magnetic iron oxide nanoparticles coated with silica (scFe{sub 3}O{sub 4}-NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe{sub 3}O{sub 4}-NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe{sub 3}O{sub 4}-NP at short contact times (5 min) in flow cells and complementary, scFe{sub 3}O{sub 4}-NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe{sub 3}O{sub 4}-NP sorbed to the biofilm within a few minutes, but that the total biosorption was rather low (3.2 μg Fe/mg TSS). scFe{sub 3}O{sub 4}-NP mainly sorbed to the biofilm surface inducing the detachment of outer biofilm parts starting after an exposure time of 3 h in the MBBR. The biosorption depended on the exposure concentration of scFe{sub 3}O{sub 4}-NP, but less on the contact time. Most scFe{sub 3}O{sub 4}-NP exited the flow cell (up to 65%) and the MBBR (57%) via the effluent. This effect was favored by the stabilization of scFe{sub 3}O{sub 4}-NP in the bulk liquid by organic matter leading to a low retention capacity of the MBBR system. The results contribute to improve our understanding about the fate of ENP in environmental and in

  15. Biosorption of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 possessing high heavy-metal resistance

    International Nuclear Information System (INIS)

    Lu, W.-B.; Shi, J.-J.; Wang, C.-H.; Chang, J.-S.

    2006-01-01

    This study was undertaken to investigate biosorption kinetics and equilibria of lead (Pb), copper (Cu) and cadmium (Cd) ions using the biomass of Enterobacter sp. J1 isolated from a local industry wastewater treatment plant. Efficiency of metal ion recovery from metal-loaded biomass to regenerate the biosorbent was also determined. The results show that Enterobacter sp. J1 was able to uptake over 50 mg of Pb per gram of dry cell, while having equilibrium adsorption capacities of 32.5 and 46.2 mg/g dry cell for Cu and Cd, respectively. In general, Langmuir and Freundlich models were able to describe biosorption isotherm fairly well, except that prediction of Pb adsorption was relatively poor with Langmuir model, suggesting a different mechanism for Pb biosorption. Adjusting the pH value to 3.0 led to nearly complete desorption of Cd from metal-loaded biomass, while over 90% recovery of Pb and Cu ions was obtained at pH ≤ 2. After four repeated adsorption/desorption cycles, biomass of Enterobacter sp. J1 retained 75, 79 and 90% of original capacity for adsorption of Pb, Cu and Cd, respectively, suggesting good reusability of the biosorbent. A combinative model was proposed to describe the kinetics of heavy-metal adsorption by Enterobacter sp. J1 and the model appeared to have an excellent prediction of the experimental data. The model simulation results also seemed to suggest that intracellular accumulation may occur during the uptake of Pb

  16. Biosorption of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 possessing high heavy-metal resistance

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W.-B. [Department of Cosmetic Science, Chung Hwa College of Medical Technology, Tainan, Taiwan (China); Shi, J.-J. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Wang, C.-H. [Department of Biological Engineering, Yung Ta Institute of Technology and Commerce, Pingtung, Taiwan (China); Chang, J.-S. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China)]. E-mail: changjs@mail.ncku.edu.tw

    2006-06-30

    This study was undertaken to investigate biosorption kinetics and equilibria of lead (Pb), copper (Cu) and cadmium (Cd) ions using the biomass of Enterobacter sp. J1 isolated from a local industry wastewater treatment plant. Efficiency of metal ion recovery from metal-loaded biomass to regenerate the biosorbent was also determined. The results show that Enterobacter sp. J1 was able to uptake over 50 mg of Pb per gram of dry cell, while having equilibrium adsorption capacities of 32.5 and 46.2 mg/g dry cell for Cu and Cd, respectively. In general, Langmuir and Freundlich models were able to describe biosorption isotherm fairly well, except that prediction of Pb adsorption was relatively poor with Langmuir model, suggesting a different mechanism for Pb biosorption. Adjusting the pH value to 3.0 led to nearly complete desorption of Cd from metal-loaded biomass, while over 90% recovery of Pb and Cu ions was obtained at pH {<=} 2. After four repeated adsorption/desorption cycles, biomass of Enterobacter sp. J1 retained 75, 79 and 90% of original capacity for adsorption of Pb, Cu and Cd, respectively, suggesting good reusability of the biosorbent. A combinative model was proposed to describe the kinetics of heavy-metal adsorption by Enterobacter sp. J1 and the model appeared to have an excellent prediction of the experimental data. The model simulation results also seemed to suggest that intracellular accumulation may occur during the uptake of Pb.

  17. Biosorption of malachite green onto Haematococcus pluvialis observed through synchrotron-FTIR microspectroscopy.

    Science.gov (United States)

    Liu, J H; Zhang, L; Zha, D C; Chen, L Q; Chen, X X; Qi, Z M

    2018-06-28

    Microalgae have emerged as promising biosorbents for the treatment of malachite green in wastewater. However, the underlying mechanism for the biosorption of malachite green onto microalgae is still unclear and needs further intensive study. In this work, synchrotron Fourier-transform infrared (synchrotron-FTIR) microspectroscoy in combination with biochemical assay is employed to evaluate malachite green removal efficiency (95.2%, 75.6% and 66.5%) by three stages of Haematococcus pluvialis. Meanwhile, the various vital changes of algal cells including lipids, proteins, polysaccharides and carotenoids, is distinguished and quantified in situ. This study illustrates that synchrotron-FTIR microspectroscopy is an effective and powerful tool to scrutinize the mechanism for the interactions between the malachite green dye and microalgal cells and it even provides an effective and none-invasive new approach to screen potentially proper biosorbents for the removal of dyes from wastewater. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Metallic Biosorption Using Yeasts in Continuous Systems

    Directory of Open Access Journals (Sweden)

    Karla Miriam Hernández Mata

    2013-01-01

    Full Text Available Mining effluents were found to be the main source of pollution by heavy metals of the surface water in the San Pedro River in Sonora, Mexico. The overall objective of this study was to determine the biosorption of Zn, Cu, Mn, and Fe with yeasts isolated from San Pedro River in a continuous system. The tests conducted in two reactors packed with zeolite connected in series. The first reactor was inoculated mixing two yeasts species, and the effluent of the first reactor was fed to second reactor. Subsequently, the first reactor was fed with contaminated water of San Pedro River and effluent from this was the second reactor influent. After 40 days of the experiment a reduction of 81.5% zinc, 76.5% copper, manganese 95.5%, and 99.8% of iron was obtained. These results show that the selected yeasts are capable of biosorbing zinc, copper, manganese, and iron under these conditions.

  19. An Evaluation of Kinetic Parameters of Cadmium and Copper Biosorption by Immobilized Cells

    Directory of Open Access Journals (Sweden)

    Nelly Georgieva

    2007-10-01

    Full Text Available Bioremediation is the use of living organisms to reduce or eliminate environmental hazards resulting from the accumulation of toxic chemicals and other hazardous wastes. This technology is based on the utilization of microorganisms to transform organic and inorganic compounds. The filamentous yeast Trichosporon cutaneum strain R57, immobilized and free cells was cultivated as batch culture on a liquid medium in the presence of various concentrations of cadmium and copper ions. The simultaneous uptake and accumulation of Cd2+ and Cu2+ ions by Tr. cutaneum cells depending on the initial concentration of Cd2+ and Cu2+ in the medium were studied. The potential use of the free and immobilized cells of Trichosporon cutaneum to remove cadmium and copper ions, from aqueous solutions was evaluated. Two important physicochemical aspects for the evaluation of the sorption process as a unit operation are the equilibrium of sorption and the kinetics. The Cd2+ and Cu2+ ions biosorption capacities of all tested adsorbent were presented as a function of the initial concentration of metal ions within the aqueous biosorption medium. The individual, as well as bicomponent sorption kinetics of copper and cadmium ions by immobilised cells of Trichosporon cutaneum R57 is presented. A second order kinetic model obtains kinetic parameters for the copper and cadmium ions.

  20. Biosorption of Zn(II) from industrial effluents using sugar beet pulp and F. vesiculosus: From laboratory tests to a pilot approach.

    Science.gov (United States)

    Castro, Laura; Blázquez, M Luisa; González, Felisa; Muñoz, Jesús A; Ballester, Antonio

    2017-11-15

    The aim of this work was to demonstrate the feasibility of the application of biosorption in the treatment of metal polluted wastewaters through the development of several pilot plants to be implemented by the industry. The use as biosorbents of both the brown seaweed Fucus vesiculosus and a sugar beet pulp was investigated to remove heavy metal ions from a wastewater generated in an electroplating industry: Industrial Goñabe (Valladolid, Spain). Batch experiments were performed to study the effects of pH, contact time and initial metal concentration on metal biosorption. It was observed that the adsorption capacity of the biosorbents strongly depended on the pH, increasing as the pH rises from 2 to 5. The adsorption kinetic was studied using three models: pseudo first order, pseudo second order and Elovich models. The experimental data were fitted to Langmuir and Freundlich isotherm models and the brown alga F. vesiculosus showed higher metal uptake than the sugar beet pulp. The biomasses were also used for zinc removal in fixed-bed columns. The performance of the system was evaluated in different experimental conditions. The mixture of the two biomasses, the use of serial columns and the inverse flow can be interesting attempts to improve the biosorption process for large-scale applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Bio-sorption of uranium and plutonium with Eichhornia crassipes (Water Hyacinth)

    International Nuclear Information System (INIS)

    Pulhani, Vandana; Dafauti, Sunita; Hegde, A.G.

    2010-01-01

    The continuous expansion in nuclear energy program and an aim of zero discharge makes waste management a challenging task. Waste effluents containing long-lived radionuclides such as 137 Cs, 90 Sr, 238+239+240 Pu and uranium along with other toxic elements have to he suitably treated to bring down the radioactivity levels before it is discharged in to the environment. Biological materials have emerged as an economic and eco-friendly option for removal of toxic heavy metals to an environmentally safe level. Bio-sorption is a phenomenon of rapid passive metal uptake, an ideal alternative for decontamination of metal containing effluents. Bio-sorption of uranium and plutonium from aqueous solutions by dried biomass of Eichhornia crassipes or water hyacinth, a hyper-accumulator, which can tolerate highly toxic condition, was studied. The adsorption of Pu by roots biomass was seen to be more in the pH range from 3-8 and a similar trend was shown by leaves. The adsorption of U by both roots and leaves was more in the pH range of 4-8. Distribution coefficient for Pu in roots and leaf was an average of 1349 ml/g and 3152 ml/g for uranium studied using a wide activity range from 10 Bq to 200 Bq. The presence of anions inhibited the uptake and showed the trend sulphate> nitrate> chloride>> carbonates. The effect of other cations on the absorption capacity was also checked. Effluent solutions from an effluent treatment plant were also subjected to remediation with this biomass. Biomass related metal removal processes may not necessarily replace existing treatment processes but may complement them. (author)

  2. Biosorption of heavy metals and uranium by starfish and Pseudomonas putida.

    Science.gov (United States)

    Choi, Jaeyoung; Lee, Ju Young; Yang, Jung-Seok

    2009-01-15

    Biosorption of heavy metals and uranium from contaminated wastewaters may represent an innovative purification process. This study investigates the removal ability of unit mass of Pseudomonas putida and starfish for lead, cadmium, and uranium by quantifying the adsorption capacity. The adsorption of heavy metals and uranium by the samples was influenced by pH, and increased with increasing Pb, Cd, and U concentrations. Dead cells adsorbed the largest quantity of all heavy metals than live cells and starfish. The adsorption capacity followed the order: U(VI)>Pb>Cd. The results also suggest that bacterial membrane cells can be used successfully in the treatment of high strength metal-contaminated wastewaters.

  3. Biosorption of heavy metals and uranium by starfish and Pseudomonas putida

    International Nuclear Information System (INIS)

    Choi, Jaeyoung; Lee, Ju Young; Yang, Jung-Seok

    2009-01-01

    Biosorption of heavy metals and uranium from contaminated wastewaters may represent an innovative purification process. This study investigates the removal ability of unit mass of Pseudomonas putida and starfish for lead, cadmium, and uranium by quantifying the adsorption capacity. The adsorption of heavy metals and uranium by the samples was influenced by pH, and increased with increasing Pb, Cd, and U concentrations. Dead cells adsorbed the largest quantity of all heavy metals than live cells and starfish. The adsorption capacity followed the order: U(VI) > Pb > Cd. The results also suggest that bacterial membrane cells can be used successfully in the treatment of high strength metal-contaminated wastewaters

  4. Elements to diminish radioactive accidents

    International Nuclear Information System (INIS)

    Cortes I, M.E.; Ramirez G, F.P.

    1998-01-01

    In this work it is presented an application of the cause-effect diagram method or Ichikawa method identifying the elements that allow to diminish accidents when the radioactive materials are transported. It is considered the transport of hazardous materials which include radioactive materials in the period: December 1996 until March 1997. Among the identified elements by this method it is possible to mention: the road type, the radioactive source protection, the grade driver responsibility and the preparation that the OEP has in the radioactive material management. It is showed the differences found between the country inner roads and the Mexico City area. (Author)

  5. Comparison Of Cd2+ Biosorption And Bioaccumulation By Bacteria – A Radiometric Study

    Directory of Open Access Journals (Sweden)

    Machalová Linda

    2015-12-01

    Full Text Available In this work, bioaccumulation and biosorption characteristics of Cd2+ ions by both dead and living non-growing biomass of gram-positive bacteria Kocuria palustris and Micrococcus luteus isolated from spent nuclear fuel pools were compared. The radioindicator method with radionuclide 109Cd was used to obtain precise and reliable data characterizing Cd compartmentalization in bacterial cells. The following cellular distribution of Cd in living non-growing biomass after 4 h incubation in solutions containing different concentration of Cd2+ ions (100, 250, 500, 750 and 1000 µmol/L spiked with 109CdCl2 under aeration at 30 °C were obtained: in M. luteus almost 85 % of Cd was localized on the cell surface and 15 % in cytoplasm. Similarly, in K. palustris 83 % of Cd was localized on the cell surface and 17 % in cytoplasm. The data were obtained by gamma spectrometry of extracts and solids after sequential extraction of biomass with 5 mM Ca(NO32 and 20 mM EDTA. Biosorption of Cd by non-living bacterial biomass is a rapid process strongly affected by solution pH and as was confirmed by FTIR analysis beside carboxylate ions also other functional groups such as amino and phosphate contribute to Cd binding by bacterial cell surfaces. Maximum sorption capacities Qmax (μmol/g calculated from the Langmuir isotherm were 444 ± 15 μmol/g for M. luteus and 381 ± 1 μmol/g for K. palustris.

  6. Performance of dead Azolla filiculoides biomass in Biosorption of Au from wastewater.

    Science.gov (United States)

    Umali, L J; Duncan, J R; Burgess, J E

    2006-01-01

    Dried milled biomass of Azolla filiculoides removed up to 98.2% of gold from wastewater from a gold plating factory containing 5 mg gold/l in solution in batch biosorption. The gold uptake capacity of the biomass was 98 mg/g. Whole dried biomass used in a continuous flow column removed up to 100% of gold from diluted wastewater. A similar column was linked to a sulphide precipitation process to provide a two-step system which was able to remove 98% of gold from undiluted wastewater containing 41 mg Au/l. The lifetime of the column was five days.

  7. Spectrophotometric study of bio-sorption of uranium on glass grade spodumene shell powder

    International Nuclear Information System (INIS)

    Parakudyil, A.S.; Pillai, A.K.; Reddy, A.V.R.; Singal, R.K.; Sharma, P.K.; Michael, K.M.

    2012-01-01

    Separation of uranium found in iron ore leachates was done by extraction chromatography using glass grade spodumene shellpowder (GSS) in nitric acid medium and analyzed spectrophotometrically. The influences of metal ion concentration, pH and adsorption capacity of biomass were investigated. Biosorption is a potential method of separation of heavy and trace metals from waste water and effluents from various sources. The adsorption capacities of biomass were investigated by batch experiments and column experiments. In the present study, glass grade spodumene shell powder (GSS) in acidic medium is being used as a biosorbent

  8. Biosorption of uranium and lead by Streptomyces longwoodensis

    International Nuclear Information System (INIS)

    Friis, N.; Myers-Keith, P.

    1986-01-01

    Biosorption of uranium and lead by lyophilized cells of Streptomyces longwoodensis was examined as a function of metal concentration, pH, cell concentration, and culture age. Cells harvested from the stationary growth phase exhibited an exceptionally high capacity for uranium (0.44 g U/g dry weight) at pH 5. Calculated values of the distribution coefficient and separation factor indicated a strong preference of the cell mass for uranyl ions over lead ions. The specific uranium uptake was similar for the cell wall and the cytoplasmic fraction. Uranium uptake was associated with an increase in hydrogen ion concentration, and phosphorus analysis of whole cells indicated a simple stoichiometric ratio between uranium uptake and phosphorus content. It is proposed that metal ions are bound to phosphodiester residues present both in the cell wall and cytoplasmic fractions. Based on this model, it was shown that uranium accumulation exhibits a maximum at pH 4.6 that is supported by experimental data from previous investigations

  9. Biosorption of Cd(II), Ni(II) and Pb(II) from aqueous solution by dried biomass of aspergillus niger: application of response surface methodology to the optimization of process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Amini, Malihe; Younesi, Habibollah [Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor (Iran)

    2009-10-15

    In this study, the biosorption of Cd(II), Ni(II) and Pb(II) on Aspergillus niger in a batch system was investigated, and optimal condition determined by means of central composite design (CCD) under response surface methodology (RSM). Biomass inactivated by heat and pretreated by alkali solution was used in the determination of optimal conditions. The effect of initial solution pH, biomass dose and initial ion concentration on the removal efficiency of metal ions by A. niger was optimized using a design of experiment (DOE) method. Experimental results indicated that the optimal conditions for biosorption were 5.22 g/L, 89.93 mg/L and 6.01 for biomass dose, initial ion concentration and solution pH, respectively. Enhancement of metal biosorption capacity of the dried biomass by pretreatment with sodium hydroxide was observed. Maximal removal efficiencies for Cd(II), Ni(III) and Pb(II) ions of 98, 80 and 99% were achieved, respectively. The biosorption capacity of A. niger biomass obtained for Cd(II), Ni(II) and Pb(II) ions was 2.2, 1.6 and 4.7 mg/g, respectively. According to these observations the fungal biomass of A. niger is a suitable biosorbent for the removal of heavy metals from aqueous solutions. Multiple response optimization was applied to the experimental data to discover the optimal conditions for a set of responses, simultaneously, by using a desirability function. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  10. Genetic characterization, nickel tolerance, biosorption, kinetics, and uptake mechanism of a bacterium isolated from electroplating industrial effluent.

    Science.gov (United States)

    Nagarajan, N; Gunasekaran, P; Rajendran, P

    2015-04-01

    Electroplating industries in Madurai city produce approximately 49,000 L of wastewater and 1200 L of sludge every day revealing 687-5569 ppm of nickel (Ni) with other contaminants. Seventeen Ni-tolerant bacterial strains were isolated from nutrient-enriched effluents. Among them one hyper Ni accumulating strain was scored and identified as Bacillus cereus VP17 on the basis of morphology, biochemical tests, 16S rDNA gene sequencing, and phylogenetic analysis. Equilibrium data of Ni(II) ions using the bacterium as sorbent at isothermal conditions (37 °C) and pH 6 were best adjusted by Langmuir (R(2) = 0.6268) and Freundlich models (R(2) = 0.9505). Experimental validation reveals Ni sorption takes place on a heterogeneous surface of the biosorbent, and predicted metal sorption capacity is 434 ppm. The pseudo-second-order kinetic model fitted the biosorption kinetic data better than the pseudo-first-order kinetic model (R(2) = 0.9963 and 0.3625). Scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy studies of the bacterial strain with and without Ni(II) ion reveals the biosorption mechanism. The results conclude possibilities of using B. cereus VP17 for Ni bioremediation.

  11. Preparation of nano-biomaterials with Leptolyngbia foveolarum and heavy metal biosorption by free and immobilized algal cells

    International Nuclear Information System (INIS)

    Toncheva-Panova, T.; Pouneva, I.; Sholeva, M.; Chernev, G.

    2010-01-01

    Using the sol-gel procedure nano-biomaterials with incorporation of Leptolyngbia foveolarum in the silica matrix were manufactured. The immobilization of algal cells was confirmed with Scanning Electron Microscopy (SEM) investigations and photos. Observation of nano-biomaterials with Atomic Force Microscopy (AFM) shows nanostructure with well-defined nanounits and their aggregates. The potential of the Antarctic isolate L. foveolarum for sorption of Cu 2+ and Cd 2+ was studied by incubation of free algal cells and those immobilized in nano-biomaterials in the salts solutions of the two heavy metals. The rest of the heavy metal was determined with inductively coupled plasma atomic emission spectrometer (ICP-AES). It was established that the heavy metal biosorption capacity demonstrated by the free Leptolyngbia cells was retained after their incorporation in the nano-matrices. Free cells as well as embedded in silica nano-matrix sequestered the two heavy metals with greater affinity for copper. The highest binding capacity, 76% of the initial Cu 2+ concentration possessed nano-biomaterials with incorporated vegetative L. foveolarum cells, compared to 68% of free cells. For cadmium the degree of biosorption was lower - 35% by free cells and 30.2% by those incorporated in the biocer. (authors)

  12. Chemical treatment of olive pomace: effect on acid-basic properties and metal biosorption capacity.

    Science.gov (United States)

    Martín-Lara, M A; Pagnanelli, F; Mainelli, S; Calero, M; Toro, L

    2008-08-15

    In this study, olive pomace, an agricultural waste that is very abundant in Mediterranean area, was modified by two chemical treatments in order to improve its biosorption capacity. Potentiometric titrations and IR analyses were used to characterise untreated olive pomace (OP), olive pomace treated by phosphoric acid (PAOP) and treated by hydrogen peroxide (HPOP). Acid-base properties of all investigated biosorbents were characterised by two main kinds of active sites, whose nature and concentration were determined by a mechanistic model assuming continuous distribution for the proton affinity constants. Titration modelling denoted that all investigated biosorbents (OP, PAOP and HPOP) were characterised by the same kinds of active sites (carboxylic and phenolic), but with different total concentrations with PAOP richer than OP and HPOP. Single metal equilibrium studies in batch reactors were carried out to determine the capacity of these sorbents for copper and cadmium ions at constant pH. Experimental data were analysed and compared using the Langmuir isotherm. The order of maximum uptake capacity of copper and cadmium ions on different biosorbents was PAOP>HPOP>OP. The maximum adsorption capacity of copper and cadmium, was obtained as 0.48 and 0.10 mmol/g, respectively, for PAOP. Metal biosorption tests in presence of Na(+) in solution were also carried out in order to evaluate the effect of chemical treatment on biomass selectivity. These data showed that PAOP is more selective for cadmium than the other sorbents, while similar selectivity was observed for copper.

  13. Chemical treatment of olive pomace: Effect on acid-basic properties and metal biosorption capacity

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Lara, M.A. [Departamento de Ingenieria Quimica, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain)], E-mail: marianml@ugr.es; Pagnanelli, F. [Dipartimento di Chimica, Facolta di S.M.F.N., Universita degli Studi ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy)], E-mail: francesca.pagnanelli@uniroma1.it; Mainelli, S. [Dipartimento di Chimica, Facolta di S.M.F.N., Universita degli Studi ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy); Calero, M. [Departamento de Ingenieria Quimica, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain); Toro, L. [Dipartimento di Chimica, Facolta di S.M.F.N., Universita degli Studi ' La Sapienza' , P.le A. Moro, 5, 00185 Roma (Italy)

    2008-08-15

    In this study, olive pomace, an agricultural waste that is very abundant in Mediterranean area, was modified by two chemical treatments in order to improve its biosorption capacity. Potentiometric titrations and IR analyses were used to characterise untreated olive pomace (OP), olive pomace treated by phosphoric acid (PAOP) and treated by hydrogen peroxide (HPOP). Acid-base properties of all investigated biosorbents were characterised by two main kinds of active sites, whose nature and concentration were determined by a mechanistic model assuming continuous distribution for the proton affinity constants. Titration modelling denoted that all investigated biosorbents (OP, PAOP and HPOP) were characterised by the same kinds of active sites (carboxylic and phenolic), but with different total concentrations with PAOP richer than OP and HPOP. Single metal equilibrium studies in batch reactors were carried out to determine the capacity of these sorbents for copper and cadmium ions at constant pH. Experimental data were analysed and compared using the Langmuir isotherm. The order of maximum uptake capacity of copper and cadmium ions on different biosorbents was PAOP > HPOP > OP. The maximum adsorption capacity of copper and cadmium, was obtained as 0.48 and 0.10 mmol/g, respectively, for PAOP. Metal biosorption tests in presence of Na{sup +} in solution were also carried out in order to evaluate the effect of chemical treatment on biomass selectivity. These data showed that PAOP is more selective for cadmium than the other sorbents, while similar selectivity was observed for copper.

  14. Fungal Biosorption, An Innovative Treatment for the Decolourisation and Detoxification of Textile Effluents

    Directory of Open Access Journals (Sweden)

    Antonella Pannocchia

    2010-08-01

    Full Text Available Textile effluents are among the most difficult-to-treat wastewaters, due to their considerable amount of recalcitrant and toxic substances. Fungal biosorption is viewed as a valuable additional treatment for removing pollutants from textile wastewaters. In this study the efficiency of Cunninghamella elegans biomass in terms of contaminants, COD and toxicity reduction was tested against textile effluents sampled in different points of wastewater treatment plants. The results showed that C. elegans is a promising candidate for the decolourisation and detoxification of textile wastewaters and its versatility makes it very competitive compared with conventional sorbents adopted in industrial processes.

  15. Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications

    International Nuclear Information System (INIS)

    Jalali-Rad, R.; Ghafourian, H.; Asef, Y.; Dalir, S.T.; Sahafipour, M.H.; Gharanjik, B.M.

    2004-01-01

    Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (q max values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in <2 min and equilibrium reached within the first 30 min of contact. Biosorption of cesium by FASs1 derived from P. australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1 mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles

  16. Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications

    Energy Technology Data Exchange (ETDEWEB)

    Jalali-Rad, R. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of)]. E-mail: rjalali@aeoi.org.ir; Ghafourian, H. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Asef, Y. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Dalir, S.T. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Sahafipour, M.H. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Gharanjik, B.M. [Offshore Fisheries Research Center, Chabahar (Iran, Islamic Republic of)

    2004-12-10

    Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (q{sub max} values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in <2 min and equilibrium reached within the first 30 min of contact. Biosorption of cesium by FASs1 derived from P. australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1 mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles.

  17. Electrospun alginate nanofibres as potential bio-sorption agent of heavy metals in water treatment

    CSIR Research Space (South Africa)

    Mokhena, Teboho C

    2017-03-01

    Full Text Available nanofibres as potential bio-sorption agent of heavy metals in water treatment T.C. Mokhena1,2, N.V Jacobs1,3, A.S. Luyt4* 1 CSIR Materials Science and Manufacturing, Polymers and Composites, Port Elizabeth, South Africa 2 Department of Chemistry...-303 (2011). http://dx.doi.org/10.1016/j.jare.2011.01.008 [2] Taha A.A., Wu Y.-N., Wang H., Li F.: Preparation and application of functionalized cellulose acetate/silica composite nanofibrous membrane via electrospinning for Cr (VI) ion removal from...

  18. Biosorption removal of benzene and toluene by three dried macroalgae at different ionic strength and temperatures: Algae biochemical composition and kinetics.

    Science.gov (United States)

    Flores-Chaparro, Carlos E; Chazaro Ruiz, Luis Felipe; Alfaro de la Torre, Ma Catalina; Huerta-Diaz, Miguel Angel; Rangel-Mendez, Jose Rene

    2017-05-15

    Release of low-molecular aromatic hydrocarbons (HC) into natural waters brings severe consequences to our environment. Unfortunately very limited information is available regarding the treatment of these pollutants. This work evaluated the use of brown, green and red macroalgae biomass as biosorbents of benzene and toluene, two of the most soluble HC. Raw seaweed biomasses were completely characterized, then evaluated under different temperatures and ionic strengths to assess their potential as biosorbents and to elucidate the biosorption mechanisms involved. Brown macroalgae registered the highest removal capacities for benzene and toluene (112 and 28 mg·g -1 , respectively), and these were not affected at ionic strength < 0.6 M. Langmuir and Sips isotherm equations well described biosorption data, and the pseudo-second order model provided the best fit to the kinetics rate. Hydrocarbons are adsorbed onto the diverse chemical components of the cell wall by London forces and hydrophobic interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Biosorption of lead(II) and cadmium(II) by protonated Sargassum glaucescens biomass in a continuous packed bed column

    International Nuclear Information System (INIS)

    Naddafi, Kazem; Nabizadeh, Ramin; Saeedi, Reza; Mahvi, Amir Hossein; Vaezi, Forough; Yaghmaeian, Kamyar; Ghasri, Azar; Nazmara, Shahrokh

    2007-01-01

    Biosorption of lead(II) and cadmium(II) from aqueous solutions by protonated Sargassum glaucescens biomass was studied in a continuous packed bed column. The selective uptake of Pb 2+ and Cd 2+ was investigated in a binary system with initial concentration of 1 mM for each metal ion. The selective uptake capacities of Pb 2+ and Cd 2+ at complete exhaustion point were obtained 1.18 and 0.22 mmol/g, respectively; therefore, the biosorbent showed much higher relative affinity for Pb 2+ than for Cd 2+ . The optimum range of empty bed contact time (EBCT) was identified as 5-10 min in the packed bed column. The efficiency of biosorbent regeneration by 0.1 M HCl was achieved about 60%, so that the maximum uptake capacity of Pb 2+ by the regenerated biomass was determined to be 0.75 mmol/g while the same value for the original biomass was 1.24 mmol/g. The Thomas model was found in a suitable fitness with the experimental data (R 2 > 0.90 and ε% + with the uptake of heavy metals; hence, ion exchange was confirmed to be one of the main biosorption mechanisms

  20. Evaluation of the biosorption capacity of lead by filamentous fungi native to the Ticapampa mining tailings (Recuay, Ancash)

    International Nuclear Information System (INIS)

    Perez, Mirella; Rosas, Paola; Villena, Gretty; Leon, Kety; Espinoza, Marco

    2015-01-01

    Lead biosorption was determined in five fungal biomasses isolated from the mining waste from the town of Ticapampa (Recuay province, Ancash Region) of which the strains with the highest percentage of lead sorption were studied. The process of biosorption was evaluated using a system of polyethylene tubes each containing 40 ml of solution contaminated with 200 ppm lead incubated at 30 °C under constant agitation at 150 rpm using 1 g/L of inactive fungal biomass. Removal of lead was measured by atomic absorption using the technique of flame, finding that the biomass of the species Talaromyces muroii, Talaromyces flavus and Penicillium velutinun (identified by DNA sequencing) are the most efficient to decrease the concentration of lead in aqueous solution thus achieving a maximum of its capacity of sorption of 189.7 mg/L, 82.7 mg/L and 33.8 mg/L, pH 6.0 respectively in approximately 48 hours of incubation. The results indicate that the native fungi isolated from environmental mining liabilities could be a cost effective biosorbent and easily cultivable for the removing of metal ions such as lead as in the case of environmental contamination by heavy metals. (author)

  1. Biosorption of platinum and palladium for their separation/preconcentration prior to graphite furnace atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Godlewska-Zylkiewicz, Beata E-mail: bgodlew@uwb.edu.pl

    2003-08-15

    Inexpensive baker's yeast Saccharomyces cerevisiae and green algae Chlorella vulgaris, either free or immobilized on silica gel have been shown to selectively accumulate platinum and palladium from water samples in acidic medium (pH 1.6-1.8). Optimization of conditions of metals biosorption (sample pH, algae and yeast masses, adsorption time, temperature) was performed in batch mode. The procedure of matrix separation based on biosorption of platinum and palladium on algae C. vulgaris covalently immobilized on silica gel in flow mode was developed. The use of algae in flow procedure offers several advantages compared with its use in the batch mode. The procedure shows better reproducibility (<2%), improved efficiency of platinum retention on the column (93.3{+-}1.6%), is less laborious and less time consuming. The best recovery of biosorbed metals from column (87.7{+-}3.3% for platinum and 96.8{+-}1.1 for palladium) was obtained with solution of 0.3 mol l{sup -1} thiourea in 1 mol l{sup -1} hydrochloric acid. The influence of thiourea on analytical signals of examined metals during GFAAS determination is discussed. The procedure has been applied for separation of noble metals from tap and waste water samples spiked with platinum and palladium.

  2. Optimization of copper, lead and cadmium biosorption onto newly isolated bacterium using a Box-Behnken design.

    Science.gov (United States)

    Choińska-Pulit, Anna; Sobolczyk-Bednarek, Justyna; Łaba, Wojciech

    2018-03-01

    Due to the progressive development of industrial and technological activities, heavy metal contamination is increasing each year and it poses a serious health and environmental risk. Microorganisms are capable of removing heavy metals from a contaminated environment. In this work, 51 microbial strains were isolated from heavy metal contaminated water and soil. The JAW1 strain, identified as Pseudomonas azotoformans, was selected and applied in bioremediation of the specific mixture of metals (Cd, Cu, and Pb) in an aqueous medium. The Box-Behnken design was used to optimize the biosorption process, with three factors: pH, initial metal concentration, concentration of the biosorbent. For the strain P. azotoformans JAW1, the optimal conditions were pH = 6.0, 25mg/L of each metal and 2g/L, following removal levels were achieved: Cd 44,67%; Cu 63,32%; Pb 78,23%. The possible interactions of cell-metal ions were evaluated using FT-IR analysis. The study indicated the presence of groups, which may be responsible for bonding of metal ions. The studies conducted on bioremediation mechanisms indicated that metal accumulation could occur on the cell surface (biosorption) where the amount of adsorbed metals reached: Cd 98,57%, Cu 69,76%, Pb 88,58%. P. azotoformans JAW1 exhibited a potential for application in the bioremediation of mining wastewater with complex metal contaminations. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Biosorption kinetics of Cd (II), Cr (III) and Pb (II) in aqueous solutions by olive stone

    OpenAIRE

    M. Calero; F. Hernáinz; G. Blázquez; M. A. Martín-Lara; G. Tenorio

    2009-01-01

    A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II), Cr (III) and Pb (II) from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is th...

  4. Kinetic modelling for zinc (II) ions biosorption onto Luffa cylindrica

    International Nuclear Information System (INIS)

    Oboh, I.; Aluyor, E.; Audu, T.

    2015-01-01

    The biosorption of Zinc (II) ions onto a biomaterial - Luffa cylindrica has been studied. This biomaterial was characterized by elemental analysis, surface area, pore size distribution, scanning electron microscopy, and the biomaterial before and after sorption, was characterized by Fourier Transform Infra Red (FTIR) spectrometer. The kinetic nonlinear models fitted were Pseudo-first order, Pseudo-second order and Intra-particle diffusion. A comparison of non-linear regression method in selecting the kinetic model was made. Four error functions, namely coefficient of determination (R 2 ), hybrid fractional error function (HYBRID), average relative error (ARE), and sum of the errors squared (ERRSQ), were used to predict the parameters of the kinetic models. The strength of this study is that a biomaterial with wide distribution particularly in the tropical world and which occurs as waste material could be put into effective utilization as a biosorbent to address a crucial environmental problem

  5. Kinetics, equilibrium and thermodynamic studies on biosorption of Ag(I) from aqueous solution by macrofungus Pleurotus platypus.

    Science.gov (United States)

    Das, Devlina; Das, Nilanjana; Mathew, Lazar

    2010-12-15

    Reports are available on silver binding capacity of some microorganisms. However, reports on the equilibrium studies on biosorption of silver by macrofungi are seldom known. The present study was carried out in a batch system using dead biomass of macrofungus Pleurotus platypus for the sorption of Ag(I). P. platypus exhibited the highest silver uptake of 46.7 mg g(-1) of biomass at pH 6.0 in the presence of 200 mg L(-1) Ag(I) at 20°C. Kinetic studies based on fractional power, zero order, first order, pseudo-first order, Elovich, second order and pseudo-second order rate expressions have been carried out. The results showed a very good compliance with the pseudo-first order model. The experimental data were analyzed using two parameter isotherms (Langmuir, Freundlich, Dubinin-Radushkevich, Temkin and Halsey), three parameter isotherms (Redlich-Peterson, Sips, Khan, Koble-Corrigan, Hill, Toth, Radke-Prausmitz, Jossens, Langmuir-Freundlich), four parameter isotherms (Weber-van Vliet, Fritz-Schlunder, Baudu) and five parameter isotherm (Fritz-Schlunder). Thermodynamic parameters of the biosorption (ΔG, ΔH and ΔS) were also determined. The present study confirmed that macrofungus P. platypus may be used as a cost effective efficient biosorbent for the removal of Ag(I) ions from aqueous solution. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Biosorption of Cadmium by Non-Toxic Extracellular Polymeric Substances (EPS Synthesized by Bacteria from Marine Intertidal Biofilms

    Directory of Open Access Journals (Sweden)

    Juan Carlos Camacho-Chab

    2018-02-01

    Full Text Available Cadmium is a major heavy metal found in polluted aquatic environments, mainly derived from industrial production processes. We evaluated the biosorption of solubilized Cd2+ using the extracellular polymeric substances (EPS produced by Bacillus sp. MC3B-22 and Microbacterium sp. MC3B-10 (Microbactan; these bacteria were originally isolated from intertidal biofilms off the coast of Campeche, Mexico. EPS were incubated with different concentrations of cadmium in ultrapure water. Residual Cd2+ concentrations were determined by Inductive Coupled Plasma-Optic Emission Spectrometry and the maximum sorption capacity (Qmax was calculated according to the Langmuir model. EPS were characterized by X-ray photoelectron spectroscopy (XPS before and after sorption. The Qmax of Cd2+ was 97 mg g−1 for Microbactan and 141 mg g−1 for MC3B-22 EPS, these adsorption levels being significantly higher than previously reported for other microbial EPS. In addition, XPS analysis revealed changes in structure of EPS after biosorption and showed that amino functional groups contributed to the binding of Cd2+, unlike other studies that show the carbohydrate fraction is responsible for this activity. This work expands the current view of bacterial species capable of synthesizing EPS with biosorbent potential for cadmium and provides evidence that different chemical moieties, other than carbohydrates, participate in this process.

  7. Batch and column studies on biosorption of acid dyes on fresh water macro alga Azolla filiculoides.

    Science.gov (United States)

    Padmesh, T V N; Vijayaraghavan, K; Sekaran, G; Velan, M

    2005-10-17

    The biosorption of Acid red 88 (AR88), Acid green 3 (AG3) and Acid orange 7 (AO7) by deactivated fresh water macro alga Azolla filiculoides was investigated in batch mode. Langmuir and Freundlich adsorption models were used for the mathematical description of the batch biosorption equilibrium data and model constants were evaluated. The adsorption capacity was pH dependent with a maximum value of 109.0 mg/g at pH 7 for AR88, 133.5 mg/g at pH 3 for AG3 and 109.6 mg/g at pH 3 for AO7, respectively, was obtained. The pseudo first and second order kinetic models were also applied to the experimental kinetic data and high correlation coefficients favor pseudo second order model for the present systems. The ability of A. filiculoides to biosorb AG3 in packed column was also investigated. The column experiments were conducted to study the effect of important design parameters such as initial dye concentration (50-100 mg/L), bed height (15-25 cm) and flow rate (5-15 mL/min) to the well-adsorbed dye. At optimum bed height (25 cm), flow rate (5 mL/min) and initial dye concentration (100 mg/L), A. filiculoides exhibited 28.1mg/g for AG3. The Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated.

  8. Are there Diminishing Returns to R&D?

    DEFF Research Database (Denmark)

    Madsen, Jakob B.

    Semi-endogenous models and, to some extent, also Schumpeterian models are based on the assumption of diminishing returns to R&D. This paper shows that the null hypothesis of constant returns to R&D cannot be rejected for the OECD countries......Semi-endogenous models and, to some extent, also Schumpeterian models are based on the assumption of diminishing returns to R&D. This paper shows that the null hypothesis of constant returns to R&D cannot be rejected for the OECD countries...

  9. The radiation resistance and cobalt biosorption activity of yeast strains isolated from the Lanyu low-level radioactive waste repository in Taiwan.

    Science.gov (United States)

    Li, Chia-Chin; Chung, Hsiao-Ping; Wen, Hsiao-Wei; Chang, Ching-Tu; Wang, Ya-Ting; Chou, Fong-In

    2015-08-01

    The ubiquitous nature of microbes has made them the pioneers in radionuclides adsorption and transport. In this study, the radiation resistance and nuclide biosorption capacity of microbes isolated from the Lanyu low-level radioactive waste (LLRW) repository in Taiwan was assessed, the evaluation of the possibility of using the isolated strain as biosorbents for (60)Co and Co (II) from contaminated aqueous solution and the potential impact on radionuclides release. The microbial content of solidified waste and broken fragments of containers at the Lanyu LLRW repository reached 10(5) CFU/g. Two yeast strains, Candida guilliermondii (CT1) and Rhodotorula calyptogenae (RT1) were isolated. The radiation dose necessary to reduce the microbial count by one log cycle of CT1 and RT1 was 2.1 and 0.8 kGy, respectively. Both CT1 and RT1 can grow under a radiation field with dose rate of 6.8 Gy/h, about 100 times higher than that on the surface of the LLRW container in Lanyu repository. CT1 and RT1 had the maximum (60)Co biosorption efficiency of 99.7 ± 0.1% and 98.3 ± 0.2%, respectively in (60)Co aqueous solution (700 Bq/mL), and the (60)Co could stably retained for more than 30 days in CT 1. Nearly all of the Co was absorbed and reached equilibrium within 1 h by CT1 and RT1 in the 10 μg/g Co (II) aqueous solution. Biosorption efficiency test showed almost all of the Co (II) was adsorbed by CT1 in 20 μg/g Co (II) aqueous solution, the efficiency of biosorption by RT1 in 10 μg/g of Co (II) was lower. The maximum Co (II) sorption capacity of CT1 and RT1 was 5324.0 ± 349.0 μg/g (dry wt) and 3737.6 ± 86.5 μg/g (dry wt), respectively, in the 20 μg/g Co (II) aqueous solution. Experimental results show that microbial activity was high in the Lanyu LLRW repository in Taiwan. Two isolated yeast strains, CT1 and RT1 have high potential for use as biosorbents for (60)Co and Co (II) from contaminated aqueous solution, on the other hand, but may have the

  10. Biomass selection for biosorption study of 226 Ra and 137 Cd radionuclides

    International Nuclear Information System (INIS)

    Costa, Wilson Cervi da

    2003-01-01

    The main goal of this work was to verify the potentialities to apply the biosorption technique to synthetic and real solution containing 226 Ra and 137 Cs, utilizing the seaweed Sargassum sp. and the microorganisms Penicillium sp., Saccharomyces cerevisiae and Monoraphidium sp. Indeed, the screening of the most effective biomass to remove the radionuclides was also a central objective. 226 Ra was selected due to its high radiotoxicity and the fact that it can be assimilated and incorporated by living organism through substitution og Mg 2+ and Ca 2+ , two essential nutrients. On the other hand, the selection of 137 Cs, a radionuclide of medium toxicity, was due to its mobility in the environment, which increases the possibility to be assimilated by the organisms as the essential nutrients Na + and K + . (author)

  11. Agroindustrial Waste for Lead and Chromium Biosorption

    Directory of Open Access Journals (Sweden)

    Susana P. Boeykens

    2018-06-01

    Full Text Available There is a need to re-evaluate the residues generated in industrial processes for the production of new raw material, reducing the volume of waste. In this regard, the biosorption is a low-cost alternative method for treating effluents compared to conventional methods. The main objectives of this research were: the evaluation of the biosorbent capacity of six waste materials for the extraction of chromium(VI and lead(II ions from aqueous solutions and, the determination of the adsorption and kinetic parameters for the more efficient system. The materials evaluated were: peanut shell (Arachis hypagaea, sugarcane bagasse (Saccharum officinarum, avocado peel (Persea americana, pecan nutshell (Carya illinoinensis, wheat bran (Triticum aestivum and banana peel (Mussa paradisiaca. The highest percentage of lead removal was obtained with wheat bran (89%. For chromium, the percentage was generally much lower compared with lead for all tested biosorbents, the banana peel being the most efficient with a 10% removal. The models that better describe the adsorption processes were: Langmuir and Freundlich. The pseudo-second order kinetic model allowed obtaining the parameters for both systems. The equilibrium time, in both systems, was reached after 60 minutes. The study of Fourier Transformed Infrared spectra and the results of desorption experiments allowed to hypothesize on the mechanisms involved in the adsorption of these metals.

  12. The association of neurocognitive impairment with diminished expression and apathy in schizophrenia.

    Science.gov (United States)

    Hartmann-Riemer, Matthias N; Hager, Oliver M; Kirschner, Matthias; Bischof, Martin; Kluge, Agne; Seifritz, Erich; Kaiser, Stefan

    2015-12-01

    Negative symptoms can be grouped into the two dimensions of diminished expression and apathy, which have been shown to be dissociable regarding external validators, such as functional outcome. Here, we investigated whether these two dimensions differentially relate to neurocognitive impairment in schizophrenia. 47 patients with schizophrenia or schizoaffective disorder and 33 healthy control participants were subjected to a neurocognitive test battery assessing multiple cognitive domains (processing speed, working memory, verbal fluency, verbal learning and memory, mental planning), which are integrated into a composite cognition score. Negative symptoms in patients were assessed using the Brief Negative Symptom Scale. We found that diminished expression significantly related to neurocognitive impairment, while severity of apathy symptoms was not directly associated with neurocognition. Other assessed clinical variables include chlorpromazine equivalents, positive symptoms, and depressive symptoms and did not influence the results. Our results are in line with a cognitive resource limitation model of diminished expression in schizophrenia and indicate that cognitive remediation therapy might be helpful to ameliorate expressive deficits. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Biosorption of the Copper and Cadmium Ions - a Study through Adsorption Isotherms Analysis

    Directory of Open Access Journals (Sweden)

    Marcia T. Veit

    2007-10-01

    Full Text Available In this work, the biosorption process of copper-cadmium ions binary mixture by using marine algae Sargassum filipendula was investigated. A set of experiments was performed to obtain equilibrium data for the given batch operational conditions - T=30°C, pH=5. The interpretation of equilibrium data was based on the binary adsorption isotherms models in the Langmuir and Freundlich forms. To evaluate the models parameters, nonlinear identification procedure was used based on the Least Square statistical method and SIMPLEX local optimizer. An analysis of the obtained results showed that the marine algae biomass has higher affinity to copper ions than to cadmium ones. The biomass maximum adsorption capacity for the binary system was about 1.16 meq/g.

  14. Radionuclide and heavy metal biosorption by Pseudomonas biomass

    International Nuclear Information System (INIS)

    Sar, Pinaki; D'Souza, S.F.; Kazy, Sufia K.; Singh, S.P.

    2001-01-01

    Biosorptive metal (nickel and copper) and radionuclide (uranium) uptake capacity of two Pseudomonas strains was investigated in order to develop biotechnological strategies for toxic metals remediation. Lyophilized Pseudomonas biomass showed a very high uranium loading of 541 mg g -1 dry wt. Compared to this, the other bacterial strain of Pseudomonas aeruginosa used for nickel and copper removal yielded a maximum value of 265 mg g -1 and 137 mg g -1 respectively. Cation binding by both the biomass was fast saturating, pH -dependent process with optimum pH for U, Cu and Ni was pH 5.0, 7.0 and 8.0, respectively. In bimetallic combination, U sorption was inhibited only by Fe 3+ , Al 3+ and Cu 2+ suggesting a selective cation binding by the Pseudomonas biomass. In case of Ni and Cu, presence of Na, K or Ca increased the metal binding while Cd and Pb was antagonistic. Mineral acids could recover more than 75% (on average) of sorbed Ni or Cu. Noticeably, uranium and copper desorption was specifically high (88-90%) with sodium carbonate while calcium carbonate showed a good result for nickel. The overall data are in favour of deployment of the test biomass as efficient metal/radionuclide removal/recovery system. (author)

  15. Socioeconomic Status and Self-Rated Oral Health; Diminished Return among Hispanic Whites.

    Science.gov (United States)

    Assari, Shervin

    2018-04-24

    Background. An extensive body of knowledge has documented weaker health effects of socio-economic status (SES) for Blacks compared to Whites, a phenomenon also known as Blacks’ diminished return. It is, however, unknown whether the same diminished return also holds for other ethnic minorities such as Hispanics or not. Aim. Using a nationally representative sample, the current study aimed to compare Non-Hispanic and Hispanic Whites for the effects of SES on self-rated oral health. Methods. For the current cross-sectional study, we used data from the Collaborative Psychiatric Epidemiology Surveys (CPES), 2001⁻2003. With a nationally representative sampling, CPES included 11,207 adults who were either non-Hispanic Whites ( n = 7587) or Hispanic Whites ( n = 3620. The dependent variable was self-rated oral health, treated as dichotomous measure. Independent variables were education, income, employment, and marital status. Ethnicity was the focal moderator. Age and gender were covariates. Logistic regressions were used for data analysis. Results. Education, income, employment, and marital status were associated with oral health in the pooled sample. Although education, income, employment, and marital status were associated with oral health in non-Hispanic Whites, none of these associations were found for Hispanic Whites. Conclusion. In a similar pattern to Blacks’ diminished return, differential gain of SES indicators exists between Hispanic and non-Hispanic Whites, with a disadvantage for Hispanic Whites. Diminished return of SES should be regarded as a systemically neglected contributing mechanism behind ethnic oral health disparities in the United States. Replication of Blacks’ diminished return for Hispanics suggests that these processes are not specific to ethnic minority groups, and non-White groups gain less because they are not enjoying the privilege and advantage of Whites.

  16. A sigmoidal model for biosorption of heavy metal cations from aqueous media.

    Science.gov (United States)

    Özen, Rümeysa; Sayar, Nihat Alpagu; Durmaz-Sam, Selcen; Sayar, Ahmet Alp

    2015-07-01

    A novel multi-input single output (MISO) black-box sigmoid model is developed to simulate the biosorption of heavy metal cations by the fission yeast from aqueous medium. Validation and verification of the model is done through statistical chi-squared hypothesis tests and the model is evaluated by uncertainty and sensitivity analyses. The simulated results are in agreement with the data of the studied system in which Schizosaccharomyces pombe biosorbs Ni(II) cations at various process conditions. Experimental data is obtained originally for this work using dead cells of an adapted variant of S. Pombe and represented by Freundlich isotherms. A process optimization scheme is proposed using the present model to build a novel application of a cost-merit objective function which would be useful to predict optimal operation conditions. Copyright © 2015. Published by Elsevier Inc.

  17. A further insight into the biosorption mechanism of Pt(IV by infrared spectrometry

    Directory of Open Access Journals (Sweden)

    Xu Zhenling

    2009-07-01

    Full Text Available Abstract Background Platinum nanomaterial is one of the significant noble metal catalysts, and the interaction of platinum with microbe is one of the key factors in influencing the size and the distribution of the platinum nanoparticles on the microbial biomass. Some properties of Pt(IV adsorption and reduction by resting cells of Bacillus megatherium D01 biomass have once been investigated, still the mechanism active in the platinum biosorption remains to be seen and requires further elucidating. Result A further insight into the biosorption mechanism of Pt(IV onto resting cells of Bacillus megatherium D02 biomass on a molecular level has been obtained. The image of scanning electron microscopy (SEM of the D02 biomass challenged with Pt(IV displayed a clear distribution of bioreduced platinum particles with sizes of nanometer scale on the biomass. The state of Pt(IV bioreduced to elemental Pt(0 examined via X-ray photoelectron spectroscopy (XPS suggested that the biomass reduces the Pt(IV to Pt(II followed by a slower reduction to Pt(0. The analysis of glucose content in the hydrolysates of D02 biomass for different time intervals using ultraviolet-visible (UV-vis spectrophotometry indicated that certain reducing sugars occur in the hydrolyzed biomass and that the hydrolysis of polysaccharides of the biomass is a rapid process. The infrared (IR spectrometry on D02 biomass and that challenged with Pt(IV, and on glucose and that reacted with Pt(IV demonstrated that the interaction of the biomass with Pt(IV seems to be through oxygenous or nitrogenous chemical functional groups on the cell wall biopolymers; that the potential binding sites for Pt species include hydroxyl of saccharides, carboxylate anion and carboxyl of amino acid residues, peptide bond, etc.; and that the free monosaccharic group bearing hemiacetalic hydroxyl from the hydrolyzed biomass behaving as an electron donor, in situ reduces the Pt(IV to Pt(0. And moreover, the binding of

  18. Biosorption of methylene blue from aqueous solution by fallen phoenix tree's leaves

    International Nuclear Information System (INIS)

    Han Runping; Zou Weihua; Yu Weihong; Cheng Shujian; Wang Yuanfeng; Shi Jie

    2007-01-01

    A new adsorbent, the fallen phoenix tree's leaf, has been investigated in order to remove methylene blue (MB) from aqueous solutions. Variables of the system, including contact time, leaf dose, solution pH, salt concentration and initial MB concentration, were adopted to study their effects on MB biosorption. The results showed that as the dose of leaf increased, the percentage of MB sorption increased accordingly. There was no significant difference about the quantity of MB adsorbed onto leaf as the pH was within the range 4.5-10.0. The salt concentration has negative effect on MB removal. The equilibrium data were analyzed using the Langmuir and the Freundlich isotherms. The results of non-linear regressive analysis are that the Langmuir isotherm is better fit than the Freundlich isotherm at different temperature according to the values of determined coefficients (R 2 ) and χ 2 -statistic (SS). The Langmuir monolayer saturation capacities of MB adsorbed onto leaf are 80.9, 83.8, 89.7 mg g -1 at 295, 309 and 323 K, respectively. Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters, such as ΔG o , ΔH o and ΔS o , have been calculated. The thermodynamics parameters of MB/leaf system indicate spontaneous and endothermic process. It was concluded that an increase in temperature be advantage to adsorb MB onto leaf

  19. Description of two-metal biosorption equilibria by Langmuir-type models.

    Science.gov (United States)

    Chong, K H; Volesky, B

    1995-08-20

    A biosorbent prepared from Ascophyllum nodosum seaweed biomass, FCAN2, was examined for its sorption capacity. Equilibrium batch sorption studies were performed using two-matal systems containing either (Cu + Zn), (Cu + Cd), or (Zn + Cd). In the evaluation of the two-metal sorption system performance, simple isotherm curves had to be replaced by three-dimensional sorption isotherm surfaces. In order to describe the isotherm surfaces mathematically, three Langmuir-type models were evaluated. The apparent one-parameter Langmuir constant (b) was used to quantify FCAN2 "affinity" for one metal in the presence of another one. The uptake of Zn decreased drastically when Cu or Cd were present. The uptake of Cd wasmuch more sensitive to the presence of Cu than to that of Zn. The presence of Cd and Zn alter the "affinity" of FCAN2 for Cu the least at high Cu equilibrium concentrations. The mathematical model of the two-metal sorption system enabled quantitative estimation of one-metal (bio)sorption inhibition due to the influence of a second metal. (c) 1995 John Wiley & Sons Inc.

  20. Interaction of polybrominated diphenyl ethers and aerobic granular sludge: biosorption and microbial degradation.

    Science.gov (United States)

    Ni, Shou-Qing; Cui, Qingjie; Zheng, Zhen

    2014-01-01

    As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209). Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contact time, and sludge dosage increased or solution pH dropped. Ionic strength had a negative influence on BDE-209 adsorption. The modified pseudo first-order kinetic model was appropriate to describe the adsorption kinetics. Microbial debromination of BDE-209 did not occur during the first 30 days of operation. Further study found that aerobic microbial degradation of 4,4(')-dibromodiphenyl ether happened with the production of lower BDE congeners.

  1. Interaction of Polybrominated Diphenyl Ethers and Aerobic Granular Sludge: Biosorption and Microbial Degradation

    Directory of Open Access Journals (Sweden)

    Shou-Qing Ni

    2014-01-01

    Full Text Available As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209. Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contact time, and sludge dosage increased or solution pH dropped. Ionic strength had a negative influence on BDE-209 adsorption. The modified pseudo first-order kinetic model was appropriate to describe the adsorption kinetics. Microbial debromination of BDE-209 did not occur during the first 30 days of operation. Further study found that aerobic microbial degradation of 4,4′-dibromodiphenyl ether happened with the production of lower BDE congeners.

  2. Biosorption of aluminum on Pseudomonas aeruginosa loaded on Chromosorb 106 prior to its graphite furnace atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Soylak, Mustafa

    2008-01-01

    A biosorption procedure for separation-enrichment of aluminum in environmental samples has been presented in this work. Pseudomonas aeruginosa loaded on Chromosorb 106 has been used as biosorbent for that purpose. P. aeruginosa is a gram-negative, aerobic rod. The influences of pH of the aqueous solution, eluent type, eluent volume, sample volume, etc. were examined on the quantitative recovery of aluminum in P. aeruginosa loaded on Chromosorb 106. The effects of concomitant ions on the recoveries of aluminum were also investigated. The detection limit based on 3 sigma for aluminum is 30 ng L -1 . Three certified reference materials (LGC 6010 Hard Drinking Water, NIST-SRM 1568a Rice Flour and NRCC-DORM-2 Dogfish Muscle) were analyzed for the validation of the presented procedure. The proposed procedure was applied to the determination of aluminum in environmental samples including natural water and food samples. The concentration of aluminum in real samples was found at ppb level

  3. The radiation resistance and cobalt biosorption activity of yeast strains isolated from the Lanyu low-level radioactive waste repository in Taiwan

    International Nuclear Information System (INIS)

    Li, Chia-Chin; Chung, Hsiao-Ping; Wen, Hsiao-Wei; Chang, Ching-Tu; Wang, Ya-Ting; Chou, Fong-In

    2015-01-01

    The ubiquitous nature of microbes has made them the pioneers in radionuclides adsorption and transport. In this study, the radiation resistance and nuclide biosorption capacity of microbes isolated from the Lanyu low-level radioactive waste (LLRW) repository in Taiwan was assessed, the evaluation of the possibility of using the isolated strain as biosorbents for 60 Co and Co (II) from contaminated aqueous solution and the potential impact on radionuclides release. The microbial content of solidified waste and broken fragments of containers at the Lanyu LLRW repository reached 10 5  CFU/g. Two yeast strains, Candida guilliermondii (CT1) and Rhodotorula calyptogenae (RT1) were isolated. The radiation dose necessary to reduce the microbial count by one log cycle of CT1 and RT1 was 2.1 and 0.8 kGy, respectively. Both CT1 and RT1 can grow under a radiation field with dose rate of 6.8 Gy/h, about 100 times higher than that on the surface of the LLRW container in Lanyu repository. CT1 and RT1 had the maximum 60 Co biosorption efficiency of 99.7 ± 0.1% and 98.3 ± 0.2%, respectively in 60 Co aqueous solution (700 Bq/mL), and the 60 Co could stably retained for more than 30 days in CT 1. Nearly all of the Co was absorbed and reached equilibrium within 1 h by CT1 and RT1 in the 10 μg/g Co (II) aqueous solution. Biosorption efficiency test showed almost all of the Co (II) was adsorbed by CT1 in 20 μg/g Co (II) aqueous solution, the efficiency of biosorption by RT1 in 10 μg/g of Co (II) was lower. The maximum Co (II) sorption capacity of CT1 and RT1 was 5324.0 ± 349.0 μg/g (dry wt) and 3737.6 ± 86.5 μg/g (dry wt), respectively, in the 20 μg/g Co (II) aqueous solution. Experimental results show that microbial activity was high in the Lanyu LLRW repository in Taiwan. Two isolated yeast strains, CT1 and RT1 have high potential for use as biosorbents for 60 Co and Co (II) from contaminated aqueous solution, on the other hand, but may have the impact on

  4. Cell-phone use diminishes self-awareness of impaired driving.

    Science.gov (United States)

    Sanbonmatsu, David M; Strayer, David L; Biondi, Francesco; Behrends, Arwen A; Moore, Shannon M

    2016-04-01

    Multitasking diminishes the self-awareness of performance that is often essential for self-regulation and self-knowledge. Participants drove in a simulator while either talking or not talking on a hands-free cell phone. Following previous research, participants who talked on a cell phone made more serious driving errors than control participants who did not use a phone while driving. Control participants' assessments of the safeness of their driving and general ability to drive safely while distracted were negatively correlated with the actual number of errors made when they were driving. By contrast, cell-phone participants' assessments of the safeness of their driving and confidence in their driving abilities were uncorrelated with their actual errors. Thus, talking on a cell phone not only diminished the safeness of participants' driving, it diminished their awareness of the safeness of their driving.

  5. Toxic metals biosorption by Jatropha curcas deoiled cake: equilibrium and kinetic studies.

    Science.gov (United States)

    Rawat, Anand P; Rawat, Monica; Rai, J P N

    2013-08-01

    The equilibrium sorption of Cr(VI) and Cu(II) from aqueous solution using Jatropha curcas deoiled cake, has been studied with respect to adsorbent dosage, contact time, pH, and initial metal concentration in batch mode experiments. Removal of Cu(II) by deoiled cake was greater than that of Cr(VI). The adsorbent chemical characteristics, studied by Fourier transform-infrared analysis, suggested that the presence of Cr(VI) and Cu(II) in the biomass influenced the bands corresponding to hydroxyl and carboxyl groups. Desorption studies revealed that maximum metals recovery was achieved by HNO3 followed by CH3COOH and HCl. The Freundlich isotherm model showed good fit to the equilibrium adsorption data. The adsorption kinetics followed the pseudo-second-order model, which provided the best correlation for the biosorption process, and suggested that J. curcas deoiled cake can be used as an efficient biosorbent over other commonly used sorbents for decontamination of Cr(VI)- and Cu(II)-containing wastewater.

  6. Optimal decision making and matching are tied through diminishing returns.

    Science.gov (United States)

    Kubanek, Jan

    2017-08-08

    How individuals make decisions has been a matter of long-standing debate among economists and researchers in the life sciences. In economics, subjects are viewed as optimal decision makers who maximize their overall reward income. This framework has been widely influential, but requires a complete knowledge of the reward contingencies associated with a given choice situation. Psychologists and ecologists have observed that individuals tend to use a simpler "matching" strategy, distributing their behavior in proportion to relative rewards associated with their options. This article demonstrates that the two dominant frameworks of choice behavior are linked through the law of diminishing returns. The relatively simple matching can in fact provide maximal reward when the rewards associated with decision makers' options saturate with the invested effort. Such saturating relationships between reward and effort are hallmarks of the law of diminishing returns. Given the prevalence of diminishing returns in nature and social settings, this finding can explain why humans and animals so commonly behave according to the matching law. The article underscores the importance of the law of diminishing returns in choice behavior.

  7. On convexity and Schoenberg's variation diminishing splines

    International Nuclear Information System (INIS)

    Feng, Yuyu; Kozak, J.

    1992-11-01

    In the paper we characterize a convex function by the monotonicity of a particular variation diminishing spline sequence. The result extends the property known for the Bernstein polynomial sequence. (author). 4 refs

  8. Equilibrium, thermodynamic and kinetic studies on biosorption of Mn(II) from aqueous solution by Pseudomonas sp., Staphylococcus xylosus and Blakeslea trispora cells

    International Nuclear Information System (INIS)

    Gialamouidis, D.; Mitrakas, M.; Liakopoulou-Kyriakides, M.

    2010-01-01

    Biosorption of Mn(II) from aqueous solutions using Pseudomonas sp., Staphylococcus xylosus and Blakeslea trispora cells was investigated under various experimental conditions of pH, biomass concentration, contact time and temperature. The optimum pH value was determined to 6.0 and the optimum biomass concentration to 1.0 g L -1 for all types of cells. Mn(II) biosorption was found to fit better to the Langmuir model for Pseudomonas sp. and B. trispora and to Freundlich model for S. xylosus. Langmuir model gave maximum Mn(II) uptake capacity 109 mg g -1 for Pseudomonas sp. and much lower, 59 mg g -1 and 40 mg g -1 for S. xylosus and B. trispora, respectively. Pseudo-second-order kinetic model was also found to be in good agreement with the experimental results. Thermodynamic parameters of the adsorption confirmed the endothermic nature of sorption process with positive heat of enthalpy, accompanied by a positive value of entropy change. Interestingly, desorption experiments by treating biomass with 0.1 M HNO 3 solution resulted to more than 88% recovery of the adsorbed Mn(II) from Pseudomonas sp. and almost 95% and 99% from S. xylosus and B. trispora cells respectively, thus indicating that Mn(II) can be easily and quantitatively recovered from biomass.

  9. Batch removal and optimization of Cu(II) ions from aqueous solution by biosorption on to native and pretreated mangifera indica seeds

    International Nuclear Information System (INIS)

    Noreen, A.; Ali, G.; Jabeen, M.

    2011-01-01

    Biosorption is a process that utilizes biomass to sequester toxic heavy metals and is particularly useful for the removal of contaminants from industrial effluents. Present study involved batch experiments for the sorption of Cu(II) onto Mangifera indica seeds kernel particles in order to optimize the biosorbent dose, agitation rate, pH, contact time and initial metal ion concentration. The effect of citric acid pretreatment was also studied. Maximum uptake was observed at pH 5, biosorbent dose 0.5 g and agitation rate 150 rpm. A direct correlation was found to exist between adsorbed Cu(II) ion concentration and initial metal concentration upto a certain level then it reached a saturation value at about 250 mg/L. Biosorption equilibrium was established by 60 min. The maximum metal uptake capacity was 13.2 mg/g at optimized conditions. The uptake capacity of the biomass was increased by chemical pretreatment with citric acid (15.2 mg/g) when compared with the raw biomass (13.2 mg/g). Equilibrium data was fitted to Freundlich and Langmuir isotherm equations and the data was found to well represented by Langmuir isotherm equation with r/sup 2/ = 0.9981 and q/sub max/ = 17.939 mg/g for raw biomass and with r/sup 2/ = 0.9984 and qmax 18.57 mg/g for modified biomass. (author)

  10. Determination of Optimal Temperature for Biosorption of Heavy Metal Mixture from Aqueous Solution by Pretreated Biomass of Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Javad Yousefi

    2012-01-01

    Full Text Available Biosorption is a novel technology that uses dead and inactive biomass for removal of heavy metals from aqueous solution. Some parameters such as temperature, contact time, solution pH, initial metal concentration, biosorbent dose and also agitating speed of solution and biosorbent mixing can affect the amount of metal sorption by biosorbent. The aim of this study was to investigate the effects of different treatments of temperatures (25, 35, 45 and 55oC on biosorption of metals mixture in order to determine optimal temperature for more metals removal from aqueous solution. This study uses dead and pretreated biomass of Aspergillus niger with 0.5N NaOH for removal of Zn(II, Co(II and Cd(II. In all temperature treatments and in the case of all of heavy metals, maximum amount of metal sorption and concentration decrease was occurred in first 5 minutes and achieved to equilibrium after 20 minute. The percent of metals sorption show growth trend with temperature increase. Between 4 experimental treatments, 55oC treatment was shown maximum sorption and 25oC was shown minimum sorption amount. The percent of Cr(II sorption was increase from 28.5% in 25oC to 44.7% in 55oC. Also, this increase was from 40% to 58% for Cd(II and from 37.7% to 65.6% for Zn(II. About 60% of increase in sorption by A. niger was due to increase in temperature. Therefore the amount of metals sorption can be increase, only with temperature increase and without any biomass addition.

  11. Artificial intelligence and regression analysis for Cd(II) ion biosorption from aqueous solution by Gossypium barbadense waste.

    Science.gov (United States)

    Fawzy, Manal; Nasr, Mahmoud; Nagy, Heba; Helmi, Shacker

    2018-02-01

    In this study, batch biosorption experiments were conducted to determine the removal efficiency of Cd(II) ion from aqueous solutions by Gossypium barbadense waste. The biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) connected with energy dispersive X-ray (EDX). The sorption mechanism was described by complexation/chelation of Cd 2+ with the functional groups of O-H, C=O, -COO-, and C-O, as well as, cation-exchange with Mg 2+ and K + . At initial Cd(II) ion concentration (C o ), 50 mg/L, the adsorption equilibrium of 89.2% was achieved after 15 min under the optimum experimental factors of pH 6.0, biosorbent dosage 10 g/L, and particle diameter 0.125-0.25 mm. Both Langmuir and Freundlich models fitted well to the sorption data, suggesting the co-existence of monolayer coverage along with heterogenous surface biosorption. Artificial neural network (ANN) with a structure of 5-10-1 was performed to predict the Cd(II) ion removal efficiency. The ANN model provided high fit (R 2 0.923) to the experimental data and indicated that C o was the most influential input. A pure-quadratic model was developed to determine the effects of experimental factors on Cd(II) ion removal efficiency, which indicated the limiting nature of pH and biosorbent dosage on Cd(II) adsorption. Based on the regression model (R 2 0.873), the optimum experimental factors were pH 7.61, biosorbent dosage 24.74 g/L, particle size 0.125-0.25 mm, and adsorption time 109.77 min, achieving Cd 2+ removal of almost 100% at C o 50 mg/L.

  12. Lhe law of diminishing elasticity of demand in Harrod’s trade cycle

    OpenAIRE

    Michaël Assous; Olivier Bruno; Muriel Dal-Pont

    2014-01-01

    In The Trade Cycle, Roy Harrod [1936a] propounded the Law of Diminishing Elasticity of Demand. The present paper tries to clarify the precise role Harrod assigned to this law in his The Trade Cycle Theory. We discuss the micro and macro foundations of the Law of Diminishing Elasticity of Demand and argue that it explains one of the main mechanisms that stabilize the economy during the trade cycle. In addition, we highlight how the Law of Diminishing Elasticity of Demand allowed Harrod to micr...

  13. Uptake of Cationic Dyes from Aqueous Solution by Biosorption Using Granulized Annona squmosa Seed

    Directory of Open Access Journals (Sweden)

    T. Santhi

    2009-01-01

    Full Text Available A new, low cost, locally available biomaterial was tested for its ability to remove cationic dyes from aqueous solution. A sample of granulized Annona squmosa seeds had been utilized as a sorbent for uptake of three cationic dyes, methylene blue (MB, methylene red (MR and malachite green (MG. The effects of various experimental parameters (e.g., contact time, dye concentration, adsorbent dose and pH were investigated and optimal experimental conditions were ascertained. Above the value of initial pH 5, three dyes studied could be removed effectively. The isothermal data fitted the Langmuir model in the case of MB sorption and the Freundlich model for all three dyes sorption. The biosorption processes followed the pseudo first order rate kinetics. The results in this study indicated that granulized Annona squmosa seed was an attractive candidate for removing cationic dyes from the dye wastewater.

  14. Elements to diminish radioactive accidents; Elementos para disminuir accidentes radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Cortes I, M.E.; Ramirez G, F.P. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, C.P. 07730 Mexico D.F. (Mexico)

    1998-12-31

    In this work it is presented an application of the cause-effect diagram method or Ichikawa method identifying the elements that allow to diminish accidents when the radioactive materials are transported. It is considered the transport of hazardous materials which include radioactive materials in the period: December 1996 until March 1997. Among the identified elements by this method it is possible to mention: the road type, the radioactive source protection, the grade driver responsibility and the preparation that the OEP has in the radioactive material management. It is showed the differences found between the country inner roads and the Mexico City area. (Author)

  15. The Law of Diminishing Elasticity of Demand in Harrod’s Trade Cycle (1936)

    OpenAIRE

    Michaël Assous; Olivier Bruno; Muriel Dal-Pont Legrand

    2015-01-01

    In The Trade Cycle, Roy Harrod [1936a] propounded the Law of Diminishing Elasticity of Demand. The present paper tries to clarify the precise role Harrod assigned to this law in order to understand his trade cycle theory. We discuss the micro and macro foundations of the Law of Diminishing Elasticity of Demand and how, according to Harrod, it explains one of the main mechanisms that stabilize the economy during the trade cycle. In addition, we show how the Law of Diminishing Elasticity of Dem...

  16. The biosorption of heavy metals from aqueous solution by Spirogyra and Cladophora filamentous macroalgae.

    Science.gov (United States)

    Lee, Yi-Chao; Chang, Shui-Ping

    2011-05-01

    The aim of this research was to develop a low cost adsorbent for wastewater treatment. The prime objective of this study was to search for suitable freshwater filamentous algae that have a high heavy metal ion removal capability. This study evaluated the biosorption capacity from aqueous solutions of the green algae species, Spirogyra and Cladophora, for lead (Pb(II)) and copper (Cu(II)). In comparing the analysis of the Langmuir and Freundlich isotherm models, the adsorption of Pb(II) and Cu(II) by these two types of biosorbents showed a better fit with the Langmuir isotherm model. In the adsorption of heavy metal ions by these two types of biosorbents, chemical and physical adsorption of particle surfaces was perhaps more significant than diffusion and adsorption between particles. Continuous adsorption-desorption experiments discovered that both types of biomass were excellent biosorbents with potential for further development. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Biosorption of Pb(II) ions by modified quebracho tannin resin

    Energy Technology Data Exchange (ETDEWEB)

    Yurtsever, Meral [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54187 Sakarya (Turkey)], E-mail: mevci@sakarya.edu.tr; Sengil, I. Ayhan [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54187 Sakarya (Turkey)

    2009-04-15

    In this study, the effect of temperature, pH and initial metal concentration on Pb(II) biosorption on modified quebracho tannin resin (QTR) was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to investigate QTR structure and morphology. Besides, the specific BET surface area and zeta-potential of the QTR were analysed. Thermodynamic functions, the change of free energy ({delta}G{sup o}), enthalpy ({delta}H{sup o}) and entropy ({delta}S{sup o}) of Pb adsorption on modified tannin resin were calculated as -5.43 kJ mol{sup -1} (at 296 {+-} 2 K), 31.84 kJ mol{sup -1} and 0.127 J mmol{sup -1} K{sup -1}, respectively, indicating the spontaneous, endothermic and the increased randomness nature of Pb{sup 2+} adsorption. The kinetic data was tested using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion model. The results suggested that the pseudo-second-order model (R{sup 2} > 0.999) was the best choice among all the kinetic models to describe the adsorption behavior of Pb(II) onto QTR. Langmuir, Freundlich and Tempkin adsorption models were used to represent the equilibrium data. The best interpretation for the experimental data was given by the Langmuir isotherm and the maximum adsorption capacity (86.207 mg g{sup -1}) of Pb(II) was obtained at pH 5 and 296 K.

  18. Ultrastructural localization of uranium biosorption in Penicillium digitatum by stem x-ray microanalysis

    International Nuclear Information System (INIS)

    Galun, M.; Galun, E.

    1987-01-01

    When Penicillium digitatum Saccardo cultures are exposed to aqueous solutions containing soluble uranium salts, considerable amounts of this element are accumulated in the fungal mycelium. The accumulated uranium is retained after thorough rinsing with distilled water but is removed by alkali carbonate solutions. Analysis of thick sections (0.5 μm) of the fungal hyphae with TEM, after incubation in UO 2 Cl 2 solutions of varying concentrations under both light and dark conditions, revealed conspicuous crystal-like deposits in UO 2 Cl 2 -exposed hyphae, but none in the control hyphae. Thick sections were necessary for crystal visualization. Using energy-dispersive X-ray analysis, uranium was detected as the only heavy element in these crystals. Uranium crystal biosorption was localized on the outside surface of the hyphal cell wall (following short exposures to relatively low uranium concentrations) or inside the cell wall (following long exposure to relatively high uranium concentrations). In some cases, crystal-like deposits of uranium salts were located on the outside surface as well as inside the cell. (author)

  19. Cadmium biosorption by Streptomyces sp. F4 isolated from former uranium mine.

    Science.gov (United States)

    Siñeriz, Manuel Louis; Kothe, Erika; Abate, Carlos Mauricio

    2009-09-01

    46 actinomycetes were isolated from two polluted sites and one unpolluted site. One strain, F4, was selected through primary qualitative screening assays because of its cadmium resistance, and physiologically and taxonomically characterized. F4 was able to grow at 7.5% NaCl and 100 microg/ml lysozyme and at a pH between 6 and 10. 16S rDNA sequence analysis showed that F4 was closely related to Streptomyces tendae. Growth of Streptomyces sp. F4 on culture medium with 8 mg/l Cd(2+) for 8 days showed 80% inhibition. Maximum specific biosorption was 41.7 mg Cd(2+)/g dry weight after 7 days of growth and highest Cd(2+ )concentration was found in the cell wall (41.2%). The exopolysaccharide layer only contained 7.4%, whereas 39.4% of Cd(2+) was found in the cytosolic fraction. Twelve % was found in the ribosomes and membrane fraction. This was verified with TEM, showing Streptomyces sp. F4 cytoplasm with dark granulate appearance. This study could present the potential capacity of Streptomyces sp. F4 for Cd(2+) bioremediation. Copyright 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Spectroscopic characterization of Au 3+ biosorption by waste biomass of Saccharomyces cerevisiae

    Science.gov (United States)

    Lin, Zhongyu; Wu, Jianming; Xue, Ru; Yang, Yong

    2005-02-01

    Some spectroscopic characteristics of Au 3+ biosorption by waste biomass of Saccharomyces cerevisiae have been reported in this paper. The effect of temperature on the correlation parameters of chemical kinetics and thermodynamics of the binding reaction was investigated by using AAS. XRD diffraction pattern of gold-loaded biomass revealed that the Au 3+ bound on the cell wall of the biomass had been reduced into gold particle. FTIR spectrophotometry on blank and gold-loaded biomass demonstrated that active groups such as the hydroxyl group of saccharides, and the carboxylate anion of amino-acid residues, from the peptidoglycan layer on the cell wall seem to be the sites for the Au 3+ binding, and the free aldehyde group of the hemiacetalic hydroxyl group from reducing sugars, i.e. the hydrolysates of the polysaccharides on the peptidoglycan layer, serving as the electron donor, in situ reduced the Au 3+ to Au 0. XPS and IR characterizations of the interaction between glucose and Au 3+ further supported that the reduction of Au 3+ to Au 0 can directly occur at the aldehyde group of the reducing sugars.

  1. Biosorption of diethyl phthalate ester by living and nonliving Burkholderia cepacia and the role of its cell surface components.

    Science.gov (United States)

    Luo, Si; Li, Langlang; Chen, Anwei; Zeng, Qingru; Xia, Hao; Gu, Ji-Dong

    2017-07-01

    In this study, the dibutyl phthalate (DBP) binding properties of a DBP-tolerant bacterium (B. cepacia) were characterized in terms of adsorption kinetics and isotherm. Living and nonliving cells both exhibited rapid removal of DBP, achieving more than 80% of maximum sorption within 30 min of contact and reached the equilibrium after 3 h. The adsorption isotherms were well fitted with the Sips model and the nonliving cells have greater biosorption capacity and affinity for DBP than the living cells. Furthermore, the absence of an active mechanism dependent on metabolism implied that the DBP bioaccumulation by living cells was mainly attribute to passive surface binding. The optimum pH for DBP adsorption by living and nonliving cells were both observed to be 6.0. The biosorptive mechanism of DBP binding by B. cepacia was further confirmed by FTIR analysis and various chemical treatments. FTIR results indicated that the phosphate and CH 2 groups on B. cepacia were the main bounding sites for DBP. Furthermore, 2.28, 2.15, 1.93 and 0.87 g of pretreated cells were obtained from 2.40 g of native cells via extracellular polymeric substances (EPS), superficial layer-capsule, lipids components and cell membrane removal treatments, respectively. Total binding amount of DBP on the native cells, EPS-removed cells, capsule-removed cells, lipids-extracted cells and membrane-removed cells were 26.69, 24.84, 24.93, 16.11 and 10.80 mg, respectively, suggesting that the cell wall lipids, proteins or peptidoglycan might play important roles in the sorption of DBP by B. cepacia. The information could be applied in understanding on the mobility, transport and ultimate fate of PAEs in soil and related environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Soybean meal enriched with microelements by biosorption--a new biological feed supplement for laying hens. Part I. Performance and egg traits.

    Science.gov (United States)

    Witkowska, Z; Chojnacka, K; Korczyński, M; Świniarska, M; Saeid, A; Opaliński, S; Dobrzański, Z

    2014-05-15

    The aim of the study was to evaluate the effect of soybean meal enriched with Cu(II), Zn(II), Fe(II) and Cr(III) by biosorption on egg traits (egg weight, eggshell strength, eggshell thickness, yolk colour, albumen height) and performance of laying hens. Also, the effect of increased microelement doses in biological form on egg quality parameters and hens performance was investigated. A consumer questionnaire was undertaken to evaluate the organoleptic parameters of the eggs. Generally, our study showed that in the groups fed with the new biological supplement, egg quality parameters improved, including eggshell strength, eggshell thickness, albumen height and yolk colour. The biological form of microelements also improved the feed conversion rate, especially in the group fed with a biological form of Cr(III). Moreover, the new supplement improved organoleptic parameters of the eggs, in comparison to the inorganic form of microelements as well as to chelate. Enriched soybean meal could constitute an alternative for currently used feed additives with microelements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Co-biosorption of copper and glyphosate by Ulva lactuca.

    Science.gov (United States)

    Trinelli, María Alcira; Areco, María Mar; Afonso, María dos Santos

    2013-05-01

    This study investigated the adsorption of glyphosate (PMG) onto the green algae Ulva lactuca. PMG was not adsorbed by U. lactuca but PMG was adsorbed when the process was mediated by Cu(II) with molar ratios Cu(II):PMG≥1.5:1. U. lactuca was characterized by water adsorption surface area, FTIR, SEM and EDS. The Langmuir and Freundlich models were applied. Results showed that the biosorption processes for copper and PMG in the presence of copper were described described by the Langmuir model (qmax=0.85±0.09 mmol g(-1), KL=0.55±0.14 l mmol(-1) and qmax=3.65±0.46 mmol g(-1), KL=0.103±0.03 l mmol(-1), respectively). Copper adsorption was greater in the presence of PMG than in the absence of the pesticide and the adsorption can only be represented by the Freundlich model (KF=0.08±0.01, 1/n=1.86±0.07). In all cases studied, the maximum metal uptake (qmax) increased with increasing pH. Surface complexes with a stoichiometry ranging from ≡Cu-PMG-Cu to ≡Cu-PMG-Cu3 are suggested as reaction products of the process. Due to the increasing amounts of PMG applied in Argentina, natural reservoirs present considerable amounts of this herbicide. The value of this work resides in using U. lactuca, a marine seaweed commonly found along coastlines all over the world, as a biosorbent for PMG. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. MINDFULNESS – MAY DIMINISH STRESS AND INCREASE ENERGY

    Directory of Open Access Journals (Sweden)

    Andronicus TORP

    2015-06-01

    Full Text Available Mindfulness is increasingly being applied in companies as a means to increase, among others, employee wellbeing and energy, and in the same time to diminish stress. This paper argues that there seems to be scientific evidence showing that certain mindfulness techniques may diminish stress and increase energy, yet it seems that there is a period in the beginning of the mindfulness practice where the techniques have the opposite effects. These findings seem to be contradictory to past findings, which indicated that only two thirds of people practicing mindfulness techniques have positive effects from that practice. It may be that everybody can have positive effects from the practice of the mentioned techniques, just that some need to practice for a longer period before obtaining these positive effects. Further scientific studies seem to be needed in order to clarify the full spectrum of effects and consequences of practicing different mindfulness techniques, and just as important, if these effects are valid for everybody.

  5. Biosorption of arsenic from groundwater using Vallisneria gigantea plants. Kinetics, equilibrium and photophysical considerations.

    Science.gov (United States)

    Iriel, Analia; Lagorio, M Gabriela; Fernández Cirelli, Alicia

    2015-11-01

    Arsenic (V) uptake from groundwater by using Vallisneria gigantea plants was studied using batch experiments. Reflectance and fluorescence of intact plants were investigated and changes in photophysical properties following arsenic absorption were reported. Good correlations have been found between arsenic concentration in groundwater and parameters derived from reflectance and fluorescence measurements. This system reached its equilibrium after seven days when the removal quantities were strongly dependent on the initial arsenic concentration. Interestingly, Vallisneria plants were able to accumulate from 100 to 600 mg As kg(-1) in roots and fronds although the translocation factors were low (0.6-1.6). Kinetic data for biosorption process followed a first-order law. At low arsenic concentrations the uptake in plants was governed by diffusion aspects. Langmuir, Freundlich and Dubinin-Radushkevich models were applied and results demonstrated that arsenic uptake was better described by the Langmuir model. As a final remark we concluded that a plant of this species should be able to remove 1mg As per week. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A plausible mechanism of biosorption in dual symbioses by vesicular-arbuscular mycorrhizal in plants.

    Science.gov (United States)

    Azmat, Rafia; Hamid, Neelofer

    2015-03-01

    Dual symbioses of vesicular-arbuscular mycorrhizal (VAM) fungi with growth of Momordica charantia were elucidated in terms of plausible mechanism of biosorption in this article. The experiment was conducted in green house and mixed inoculum of the VAM fungi was used in the three replicates. Results demonstrated that the starch contents were the main source of C for the VAM to builds their hyphae. The increased plant height and leaves surface area were explained in relation with an increase in the photosynthetic rates to produce rapid sugar contents for the survival of plants. A decreased in protein, and amino acid contents and increased proline and protease activity in VAM plants suggested that these contents were the main bio-indicators of the plants under biotic stress. The decline in protein may be due to the degradation of these contents, which later on converted into dextrose where it can easily be absorbed by for the period of symbioses. A mechanism of C chemisorption in relation with physiology and morphology of plant was discussed.

  7. Incidental finding of hypertension and diminished femoral pulses ...

    African Journals Online (AJOL)

    2012-06-08

    Jun 8, 2012 ... Case Study: Incidental finding of hypertension and diminished femoral pulses. 168. Vol 55 No 2. S Afr Fam Pract 2013. Introduction. Coarctation of the aorta is ... Surgery of the aorta and its branches. Philadelphia: WB Saunders Company, 2000; p. 3-10. 2. Rao PS. Coarctation of the aorta. Curr Cardiol Rep.

  8. Multi-layered see-through movie in diminished reality

    Science.gov (United States)

    Uematsu, Yuko; Hashimoto, Takanori; Inoue, Takuya; Shimizu, Naoki; Saito, Hideo

    2012-03-01

    This paper presents generating a multi-layered see-through movie for an auto-stereoscopic display. This work is based on Diminished Reality (DR), which is one of the research fields of Augmented Reality (AR). In the usual AR, some virtual objects are added on the real world. On the other hand, DR removes some real objects from the real world. Therefore, the background is visualized instead of the real objects (obstacles) to be removed. We use multiple color cameras and one TOF depth camera. The areas of obstacles are defined by using the depth camera based on the distance of obstacles. The background behind the obstacles is recovered by planarprojection of multiple cameras. Then, the recovered background is overlaid onto the removed obstacles. For visualizing it through the auto-stereoscopic display, the scene is divided into multiple layers such as obstacles and background. The pixels corresponding to the obstacles are not visualized or visualized semi-transparently at the center viewpoints. Therefore, we can see that the obstacles are diminished according to the viewpoints.

  9. Outcomes of first IVF/ICSI in young women with diminished ovarian reserve.

    Science.gov (United States)

    Cohen, Jonathan; Mounsambote, Leonisse; Prier, Perrine; Mathieu d'ARGENT, Emmanuelle; Selleret, Lise; Chabbert-Buffet, Nathalie; Delarouziere, Vanina; Levy, Rachel; Darai, Emile; Antoine, Jean-Marie

    2017-08-01

    There is no consensual definition of diminished ovarian reserve and the best therapeutic strategy has not yet been demonstrated. We performed a retrospective study to evaluate outcomes following a first in-vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) cycle in young women with diminished ovarian reserve. Women with tubal factor, endometriosis or previous stimulation cycle were excluded. We defined diminished ovarian reserve as women ≤38 years with an AMH ≤1.1 ng/mL or antral follicular count ≤7. Among 59 IVF/ICSI cycles (40% IVF/60% ICSI), the pregnancy rate was 17% (10/59) and live birth rate 8.5% (5/59). Miscarriage rate was 50%. Baseline characteristics and IVF outcomes of the pregnant and not pregnant women were compared. No differences in age, antral follicular count, AMH, protocol used or number of harvested oocytes were found between the groups. A higher gonadotropin starting dose in the pregnancy group (397.5±87 IU vs. 314.8±103 IU; P=0.02) and a trend to a higher total dose received (4720±1349 IU vs. 3871±1367 IU; P=0.07) were noted. The present study confirms that women with diminished ovarian reserve have low live birth rates after a first IVF-ICSI cycle and that a higher gonadotropin starting dose might be associated with better outcomes.

  10. Biosorption of cadmium by Brevundimonas sp. ZF12 strain, a novel biosorbent isolated from hot-spring waters in high background radiation areas

    International Nuclear Information System (INIS)

    Masoudzadeh, Nasrin; Zakeri, Fardideh; Lotfabad, Tayebe bagheri; Sharafi, Hakimeh; Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza; Noghabi, Kambiz Akbari

    2011-01-01

    Highlights: ► Isolation and characterization of a novel cadmium-biosorbent (Brevundimonas sp. ZF12) from high background radiation areas. ► Brevundimonas sp. ZF12 caused 50% removal of cadmium at the concentration level of 250 ppm. ► Solution pH values used for the reusability study have powerful desorptive features to recover Cd ions sorbed onto the biomass. ► This is the first study carried out so far for the cadmium removal from aqueous solutions by a novel biosorbent Brevundimonas sp. ZF12. ► In our opinion, the isolate can be an attractive alternative to remove the cadmium-containing wastewaters. - Abstract: The aim of this study is to screen cadmium biosorbing bacterial strains isolated from soils and hot-springs containing high concentrations of radium ( 226 Ra) in Ramsar using a batch system. Brevundimonas sp. ZF12 strain isolated from the water with high 226 Ra content caused 50% removal of cadmium at a concentration level of 250 ppm. The biosorption equilibrium data are fitted well by the Langmuir adsorption isotherm and kinetic studies indicated that the biosorption follows pseudo second-order model. The effect of different physico-chemical parameters like biomass concentration, pH, cadmium concentration, temperature and contact time on cadmium sorption was also investigated using FTIR, SEM and XRD analytical techniques. A high desorption efficiency (above 90%) was obtained using a pH range of 2.0–4.0. Reusability of the biomass was examined under consecutive biosorption–desorption cycles repeated thrice. In conclusion, Brevundimonas sp. ZF12 is proposed as an excellent cadmium biosorbent that may have important applications in Cd removal from wastewaters.

  11. Repeated exposure to media violence is associated with diminished response in an inhibitory frontolimbic network.

    Directory of Open Access Journals (Sweden)

    Christopher R Kelly

    Full Text Available BACKGROUND: Media depictions of violence, although often claimed to induce viewer aggression, have not been shown to affect the cortical networks that regulate behavior. METHODOLOGY/PRINCIPAL FINDINGS: Using functional magnetic resonance imaging (fMRI, we found that repeated exposure to violent media, but not to other equally arousing media, led to both diminished response in right lateral orbitofrontal cortex (right ltOFC and a decrease in right ltOFC-amygdala interaction. Reduced function in this network has been previously associated with decreased control over a variety of behaviors, including reactive aggression. Indeed, we found reduced right ltOFC responses to be characteristic of those subjects that reported greater tendencies toward reactive aggression. Furthermore, the violence-induced reduction in right ltOFC response coincided with increased throughput to behavior planning regions. CONCLUSIONS: These novel findings establish that even short-term exposure to violent media can result in diminished responsiveness of a network associated with behaviors such as reactive aggression.

  12. Biosorptive behavior of some dead biomasses in the removal of Sr(85+89) from aqueous solutions

    International Nuclear Information System (INIS)

    Mishra, S.P.; Tiwari, D.

    2002-01-01

    Biosorptive behavior of some dead biomasses (viz., bark of Azadirachta indica and Mangifera indica and rice hulls) was assessed for the removal of an important fission fragment, Sr(II) ions from aqueous solutions using radiotracer technique. Single batch experiments revealed that the increase in sorptive concentration (1.0 x 10 -8 to 1.0 x 10 -2 mol x dm -3 ), temperature (298 to 328 K) and solution pH (3.0 to 10.5) greatly enhanced the removal of Sr(II) ions and the 'ion-exchange' along with surface complexation type uptake of Sr(II) followed the Freundlich adsorption isotherm for the entire concentration range (1.0 x 10 -2 to 1.0 x 10 -8 mol x dm -3 ). Desorption experiments suggest that the uptake is irreversible and the irradiation of these materials enhanced their applicability as showed greater stability towards ionizing radiations from a 300 mCi (Ra-Be) neutron source. (author)

  13. Biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Usta, Canan; Soylak, Mustafa

    2007-01-01

    The biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin for preconcentration-separation of them have been investigated. The sorbed analytes on biosorbent were eluted by using 1 mol L -1 HCl and analytes were determined by flame atomic absorption spectrometry. The influences of analytical parameters including amounts of pH, B. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. The effects of alkaline, earth alkaline ions and some metal ions on the retentions of the analytes on the biosorbent were also examined. Separation and preconcentration of Cu, Pb, Fe and Co ions from real samples was achieved quantitatively. The detection limits by 3 sigma for analyte ions were in the range of 0.20-0.75 μg L -1 for aqueous samples and in the range of 2.5-9.4 ng g -1 for solid samples. The validation of the procedure was performed by the analysis of the certified standard reference materials (NRCC-SLRS 4 Riverine Water, SRM 2711 Montana soil and GBW 07605 Tea). The presented method was applied to the determination of analyte ions in green tea, black tea, cultivated mushroom, boiled wheat, rice and soil samples with successfully results

  14. Biosorption of Lead by Pseudomonas sp Isolated from Oil-Contaminated Wastewaters in Khuzestan

    Directory of Open Access Journals (Sweden)

    Seyed Mansour Meybodi

    2015-05-01

    Full Text Available Biosorption is a most effective technology for the removal of such toxic substances as heavy metals. The objective of this study was four-fold: 1 to isolate lead resistant Pseudomonas strains, 2 to determine the optimal conditions of their growth, 3 to obtain the minimum inhibitory concentration of lead, and 4 to evaluate the bioremoval of lead from culture solutions. For the purposes of this study, oil-contaminated wastewater samples were collected from Khuzestan region and transferred to laboratory where they were homogenized and serially diluted up to 10-10 with sterile saline before they were cultured in Luria Bertani agar medium containing 5ppm of lead nitrate. Resistant strains were then isolated at 37°C for 24h. The samples were subsequently cultured in Macconkey agar for isolation of appropriate gram negative strains. Biochemical tests were used to identify the bacteria, 10 strains of which were screened as lead resistant ones from all the 24 isolates. The bacterial colonies were selected and tested with different concentrations (100- 2100 ppm of lead for their resistance. The plates were then incubated at 37ºC for 24h and Mso1 was chosen from among the lead resistant colonies for further experiments. This strain showed resistance to chloramphenicol (30µg and erythromycin (15µg when subjected to the antimicrobial susceptibility test. Optimal growth conditions included a temperature of 40°C at 100 rpm and a pH level of 6 in the presence of lead by spectrophotometry at 600nm. Absorption tests showed that the Mso1 strain had a metal removal efficiency of 38.45% from an aqueous solution containing 100 ppm of lead over 24h. The results confirmed the capability of Pseudomonassp in the bioremediation of Pb-contaminated wastewaters.

  15. Diminished ovarian reserve in patients with psoriasis

    Directory of Open Access Journals (Sweden)

    Burcu Tuğrul Ayanoğlu

    2018-04-01

    Full Text Available Objective: Psoriasis is a multi-systemic chronic inflammatory skin disease. Previous data suggests that women with some chronic inflammatory diseases have diminished ovarian reserve. This study explores ovarian reserve in patients with psoriasis. Materials and methods: We prospectively analyzed 14 female patients with psoriasis and 35 healthy age and body mass index matched controls. An interview explored demographic characteristics, obstetrical history and menstrual characteristics. Psoriatic area severity index (PASI in patients was assessed. Estrogen, follicle-stimulating hormone (FSH, luteinizing hormone (LH, thyroid stimulating hormone and with gynecologic ultrasonography, ovarian volume and antral follicular count (AFC were measured in both study and control groups. These values were analyzed with changes of the PASI in the patient group. Results: Patients with psoriasis had significantly higher levels of FSH and FSH/LH ratio than healthy controls (p = 0.039, p = 0.005 respectively. AFC of psoriasis patients were significantly lower than healthy controls (p = 0.002.There were no significant difference among other hormone levels and ovarian volumes (p > 0.05. The hormone levels, ovarian volume and AFC were not correlated with PASI of the patients. Conclusion: The results of the study suggest that patients with psoriasis may have diminished ovarian reserve. Keywords: Psoriasis, Ovarian reserve, Psoriatic area severity index, Antral follicular count, Follicle-stimulating hormone

  16. Mechanism of Biosorption of Nickel Ions from Polluted Effluent by Bacillus sp. Strain MGL-75

    Directory of Open Access Journals (Sweden)

    Salman Ahmadi Asbchin

    2013-08-01

    Full Text Available The aim of this work was to investigate Bacillus sp. strain MGL-75 as biosorbent, for the fixation of Ni ion in batch reactor. Pollution of the environment by toxic metals is a major environmental concern. In a first step, biosorption kinetics and isotherms have been performed at pH 7. The equilibrium time was about 5 min and the adsorption equilibrium data were well described by the Langmuir`s equation. The point of zero net proton charge (PZNPC was found close to pH 5.7. Using the single extrapolation method, three kinds of acidic functional groups with three intrinsic pka were determined at 4.4, 6.9 and 11.2. The maximum capacity has been extrapolated to 0/52 mmol/g. Finally the effect of autoclave, 2, 4 Dinitrophenol (DNF and Na-Azid (NaN3, and the effect of pH values, were studied. These results indicated that the Bacillus sp. strain MGL-75 is an excellent candidate for use in reactor to remove Nickel ions from polluted aqueous effluents.

  17. Recovery of gold as a type of porous fiber by using biosorption followed by incineration.

    Science.gov (United States)

    Park, Seong-In; Kwak, In Seob; Bae, Min A; Mao, Juan; Won, Sung Wook; Han, Do Hyeong; Chung, Yong Sik; Yun, Yeoung-Sang

    2012-01-01

    This study introduces a new process for the recovery of gold in porous fiber form by the incineration of Au-loaded biosorbent fiber from gold-cyanide solutions. For the recovery of gold from such aqueous solutions, polyethylenimine (PEI)-modified bacterial biosorbent fiber (PBBF) and PEI-modified chitosan fiber (PCSF) were developed and used. The maximum uptakes of Au(I) ions were estimated as 421.1 and 251.7 mg/g at pH 5.5 for PBBF and PCSF, respectively. Au-loaded biosorbents were freeze-dried and then incinerated to oxidize their organic constituents while simultaneously obtaining reduced gold. As a result, porous metallic gold fibers were obtained with 60 μm of diameter. Scanning electron microscopic (SEM) analysis and mercury porosimetry revealed the fibers to have 60 μm of diameter and to be highly porous and hollow. The proposed process therefore offers the potential for the efficient recovery of metallic porous gold fibers using combined biosorption and incineration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Kinetic modeling of the biosorption of Cd2+ ions from aqueous solutions onto Eichhornia crassipes roots using potentiometry: low-cost alternative to conventional methods

    Directory of Open Access Journals (Sweden)

    Carolina Martínez-Sánchez

    2013-01-01

    Full Text Available This work presents the use of potentiometric measurements for kinetic studies of biosorption of Cd2+ ions from aqueous solutions on Eichhornia crassipes roots. The open circuit potential of the Cd/Cd2+ electrode of the first kind was measured during the bioadsorption process. The amount of Cd2+ ions accumulated was determined in real time. The data were fit to different models, with the pseudo-second-order model proving to be the best in describing the data. The advantages and limitations of the methodology proposed relative to the traditional method are discussed.

  19. Diminished Dynamic Physical Performance Is Associated With Orthostatic Hypotension in Geriatric Outpatients.

    Science.gov (United States)

    de Bruïne, Eline S; Reijnierse, Esmee M; Trappenburg, Marijke C; Pasma, Jantsje H; de Vries, Oscar J; Meskers, Carel G M; Maier, Andrea B

    2018-03-23

    Orthostatic hypotension (OH), a blood pressure drop after postural change, is a highly prevalent and disabling syndrome in older adults. Yet, the association between physical performance and OH is not clearly established. The aim of this study was to determine whether different types of physical performance are associated with OH in a clinically relevant population of geriatric outpatients. This cross-sectional study included 280 geriatric outpatients (mean age: 82.2 years, standard deviation: 7.1). Orthostatic hypotension was determined using intermittently measured blood pressure and continuously measured blood pressure in a random subgroup of 58 patients. Physical performance was classified into a dynamic type (4-m Walk Test, Chair Stand Test, and Timed Up and Go test) and a static type (standing balance tests, handgrip strength). Associations were analyzed using logistic regression models with adjustments for age, sex, weight, and height. Diminished physical performance on the Chair Stand Test was associated with OH measured intermittently. Diminished physical performance on all dynamic physical domains (4-m Walk Test, Chair Stand Test, and Timed Up and Go test) was associated with OH measured continuously. Static physical performance was not significantly associated with OH. Dynamic physical performance tests with a substantial postural change and center of mass displacement were significantly associated with OH. The influence of physical performance on OH in daily routine activities should be further explored to establish counteracting interventions.

  20. Biosorption of uranium by Pseudomonas aeruginosa strain CSU: Characterization and comparison studies

    International Nuclear Information System (INIS)

    Hu, M.Z.C.; Norman, J.M.; Faison, B.D.; Reeves, M.E.

    1996-01-01

    Pseudomonas aeruginosa strain CSU, a nongenetically engineered bacterial strain known to bind dissolved hexavalent uranium (as UO 2 2+ and/or its cationic hydroxo complexes) was characterized with respect to its sorptive activity. The uranium biosorption equilibrium could be described by the Langmuir isotherm. The rate of uranium adsorption increased following permeabilization of the outer and/or cytoplasmic membrane by organic solvents such as acetone. P. aeruginosa CSU biomass was significantly more sorptive toward uranium than certain novel, patented biosorbents derived from algal or fungal biomass sources. P. aeruginosa CSU biomass was also competitive with commercial cation-exchange resins, particularly in the presence of dissolved transition metals. Uranium binding by P. aeruginosa CSU was clearly pH dependent. Uranium loading capacity increased with increasing pH under acidic conditions, presumably as a function of uranium speciation and due to the H + competition at some binding sites. Nevertheless, preliminary evidence suggests that this microorganism is also capable of binding anionic hexavalent uranium complexes. Ferric iron was a strong inhibitor of uranium binding to P. aeruginosa CSU biomass, and the presence of uranium also decreased the Fe 3+ loading when the biomass was not saturated with Fe 3+ . Thus, a two-state process in which iron and uranium are removed in consecutive steps was proposed for efficient use of the biomass as a biosorbent in uranium removal from mine wastewater, especially acidic leachates

  1. Diminishing-cues retrieval practice: A memory-enhancing technique that works when regular testing doesn't.

    Science.gov (United States)

    Fiechter, Joshua L; Benjamin, Aaron S

    2017-08-28

    Retrieval practice has been shown to be a highly effective tool for enhancing memory, a fact that has led to major changes to educational practice and technology. However, when initial learning is poor, initial retrieval practice is unlikely to be successful and long-term benefits of retrieval practice are compromised or nonexistent. Here, we investigate the benefit of a scaffolded retrieval technique called diminishing-cues retrieval practice (Finley, Benjamin, Hays, Bjork, & Kornell, Journal of Memory and Language, 64, 289-298, 2011). Under learning conditions that favored a strong testing effect, diminishing cues and standard retrieval practice both enhanced memory performance relative to restudy. Critically, under learning conditions where standard retrieval practice was not helpful, diminishing cues enhanced memory performance substantially. These experiments demonstrate that diminishing-cues retrieval practice can widen the range of conditions under which testing can benefit memory, and so can serve as a model for the broader application of testing-based techniques for enhancing learning.

  2. Chromium (VI) biosorption and removal of chemical oxygen demand by Spirulina platensis from wastewater-supplemented culture medium.

    Science.gov (United States)

    Magro, Clinei D; Deon, Maitê C; De Rossi, Andreia; Reinehr, Christian O; Hemkemeier, Marcelo; Colla, Luciane M

    2012-01-01

    The inappropriate discharge of wastewater containing high concentrations of toxic metals is a serious threat to the environment. Given that the microalga Spirulina platensis has demonstrated a capacity for chromium VI (Cr (VI) biosorption, we assessed the ideal concentration of chromium-containing wastewater required for maximum removal of Cr (VI) and chemical oxygen demand (COD) from the environment by using this microalga. The Paracas and Leb-52 strains of S. platensis, with initial wastewater concentrations of 0%, 12.5%, 25%, and 50%, were cultured in Zarrouk medium diluted to 50% under controlled air, temperature, and lighting conditions. The cultures were maintained for 28 days, and pH, biomass growth, COD, and Cr (VI) were assessed. The wastewater concentration influenced microalgal growth, especially at high concentrations. Removal of 82.19% COD and 60.92% Cr (VI) was obtained, but the COD removal was greater than the Cr (VI) removal in both strains of S. platensis.

  3. Effect of Yushen zhuyun decoction on rats with diminished ovarian ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of Yushen zhuyun decoction (YSZYF) on rats with diminished ovarian reserve (DOR). Methods: High-performance liquid chromatography (HPLC) was used to determine the major phytochemical constituents of YSZYF. Rats with DOR (DOR rats) were prepared by administration of ...

  4. Studies on Biosorption of Methylene Blue from Aqueous Solutions by Powdered Palm Tree Flower (Borassus flabellifer

    Directory of Open Access Journals (Sweden)

    M. Srinivas Kini

    2014-01-01

    Full Text Available Biosorption experiments were carried out for the removal of methylene blue (MB using palm tree male flower (PTMF as the biosorbent at various pH, temperature, biosorbent, and adsorbate concentration. The optimum pH was found to be 6.0. The kinetic data were fitted in pseudofirst-order and second-order models. The equilibrium data were well-fitted in Langmuir isotherm and the maximum equilibrium capacities of the biosorbent were found to be 143.6, 153,9, 157.3 mg/g at 303, 313, and 323 K, respectively. Thermodynamic data for the adsorption system indicated spontaneous and endothermic process. The enthalpy and entropy values for adsorption were obtained as 15.06 KJ/mol and 0.129 KJ/mol K, respectively, in the temperature range of 303–323 K. A mathematical model for MB transported by molecular diffusion from the bulk of the solution to the surface of PTMF was derived and the values of liquid phase diffusivity and external mass transfer coefficient were estimated.

  5. Biossorção de níquel e cromo de um efluente de galvanoplastia utilizando alga marinha pré-tratada em coluna = Biosorption of nickel and chromium from a galvanization effluent using seaweed pre-treated on a fixed-bed column

    Directory of Open Access Journals (Sweden)

    Márcia Teresinha Veit

    2009-04-01

    Full Text Available Este trabalho teve por objetivo o estudo da biossorção dos íons cromo e níquel presentes no efluente do processo de uma indústria de galvanoplastia, utilizando como biossorvente a biomassa de alga marinha pré-tratada Sargassum filipendula. As condições deoperação da coluna foram: massa de biossorvente de 8 g, pH do efluente de alimentação 3,85, temperatura de 30ºC, vazão de 6 mL min.-1 e concentrações iniciais de alimentação (cromo+níquel de 7,12 e 3,66 meq L-1. Foi empregado um modelo matemático para representar a dinâmica da biossorção em coluna de leito fixo. O modelo da isotermamulticomponente de Langmuir (qm= 2,78 meq g-1, bCr = 0,85 L meq-1, bNi = 0,08 L meq-1 foi utilizado para representar os dados de equilíbrio da coluna e para simular a dinâmica de biossorção dos íons. Os resultados da simulação demonstraram que o modelo matemáticoempregado foi capaz de descrever satisfatoriamente a complexa dinâmica de biossorção dos íons presentes no efluente.This work investigated the biosorption of chromium (III and nickel (II present in the effluent of a galvanoplasty plant using the pre-treated biomass of Sargassum filipendula seaweed. The column operation conditions were 8 g of biosorbent mass, 3.85 pH for the feed effluent, 30ºC temperature, 6 mL min.-1 flow rate, 7.12 meq L-1 initial chromium concentration and 3.66 meq L-1 initialnickel concentration. A mathematical model was used to represent the dynamics of biosorption of the metals in a fixed-bed column. The Langmuir multicomponent isotherm model (qm = 2.78 meq g-1, bCr = 0.85 L meq-1, bNi = 0.08 L meq-1 was used to represent the equilibrium data of the column and to simulate the biosorption dynamics of the ions. The simulation results showed that the mathematical model described satisfactory the complex binary biosorption of chromium and nickel in the effluent.

  6. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation

    Science.gov (United States)

    Liu, Ling-ling; Jia, Bo; Zhao, Fang; Huang, Wei-dong; Zhan, Ji-cheng

    2015-01-01

    At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China’s stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress. PMID:26030864

  7. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

    Directory of Open Access Journals (Sweden)

    Xiang-Yu Sun

    Full Text Available At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.

  8. Pregnancy causes diminished myogenic tone and outward hypotrophic remodeling of the cerebral vein of Galen.

    Science.gov (United States)

    van der Wijk, Anne-Eva; Schreurs, Malou P H; Cipolla, Marilyn J

    2013-04-01

    Pregnancy increases the risk of several complications associated with the cerebral veins, including thrombosis and hemorrhage. In contrast to the cerebral arteries and arterioles, few studies have focused on the effect of pregnancy on the cerebral venous side. Here, we investigated for the first time the effect of pregnancy on the function and structure of the cerebral vein of Galen in rats. Our major finding was that cerebral veins from late-pregnant (LP, n=11) rats had larger lumen diameters and thinner walls than veins from nonpregnant (NP, n=13) rats, indicating that pregnancy caused outward hypotrophic remodeling of the vein of Galen. Moreover, veins from NP animals had a small amount of myogenic tone at 10 mm Hg (3.9±1.0%) that was diminished in veins during pregnancy (0.8±0.3%; Ppregnancy. Using immunohistochemistry, we show that the vein of Galen receives perivascular innervation, and that serotonergic innervation of cerebral veins is significantly higher in veins from LP animals. Outward hypotrophic remodeling and diminished tone of cerebral veins during pregnancy may contribute to the development of venous pathology through elevated wall tension and wall stress, and possibly by promoting venous blood stasis.

  9. Nutrient removal using biosorption activated media: Preliminary biogeochemical assessment of an innovative stormwater infiltration basin

    International Nuclear Information System (INIS)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Xuan, Zhemin; Harris, Willie G.

    2012-01-01

    Soil beneath a stormwater infiltration basin receiving runoff from a 23 ha predominantly residential watershed in north-central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop an innovative stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO 3 − /Cl − ) ratios for the shallow groundwater indicates that prior to using BAM, NO 3 − concentrations were substantially influenced by nitrification or variations in NO 3 − input. In contrast, for the new basin utilizing BAM, NO 3 − /Cl − ratios indicate minor nitrification and NO 3 − losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest that NO 3 − losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by the increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO 4 3− ) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO 4 3− /Cl − ratios for shallow

  10. Income and Self-Rated Mental Health: Diminished Returns for High Income Black Americans

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2018-05-01

    Full Text Available Background: The minorities’ diminished return theory suggests that socioeconomic position (SEP generates smaller health gains for racial/ethnic minorities compared to Whites. The current study was a Black–White comparison of the association between household income and self-rated mental health (SRMH. Methods: This cross-sectional study used data from the 2017 State of the State Survey (SOSS. With representative sampling, the SOSS generates results that are generalizable to the state of Michigan. This study included 881 adults, (n = 92 Black and (n = 782 White. The independent variable was household income. The dependent variable was SRMH, measured using a single item. Age, gender, and participation in the labor force were covariates. Race/ethnicity was the focal moderator. Logistic regression models were used for data analysis. Results: Overall, higher household income was associated with better SRMH, net of covariates. An interaction was found between race/ethnicity and household income on SRMH, suggesting a smaller, or nonexistent, protective effect for Blacks compared to Whites. In race/ethnicity-stratified models, higher household income was associated with better SRMH for Whites but not Blacks. Conclusion: Supporting the minorities’ diminished return theory, our study documents differential effects for income on SRHM for Blacks and Whites, where Whites but not Blacks appear to benefit from their income. Given this, researchers and policy makers are cautioned against making assumptions that racial groups benefit equally from similar economic resources.

  11. Lead biosorption of probiotic bacteria: effects of the intestinal content from laying hens.

    Science.gov (United States)

    Xing, Sicheng; Wang, Jie; Liang, Juan Boo; Jahromi, Mohammad Faseleh; Zhu, Cui; Shokryazdan, Parisa; Laudadio, Vito; Tufarelli, Vincenzo; Liao, Xindi

    2017-05-01

    This study investigated the effects and the possible mechanisms of intestinal content (IC) from laying hens on in vitro lead (Pb 2+ ) biosorption of four probiotic bacterial strains (Bifidobacterium longum BB79, Lactobacillus paracasei Kgl6, Lactobacillus pentosus ITA23, and Lactobacillus acidipiscis ITA44). The total Pb 2+ removal capacity of the four probiotic strains, with and without capsule polysaccharides (CPSs), increased in the presence of IC compared to the control (without IC). SEM imaging revealed certain unidentified particles from the IC adhered on the surface of bacterial cells sorted out using flow cytometry. Follow-up experiment showed an overall trend of increase in the Pb 2+ removal capacity of the sorted bacteria, but statistically significant for L. pentosus ITA23 and B. longum BB79 after incubation with IC, particularly with the suspended solid portion of the IC. In addition, the Fourier transform infrared spectrophotometer data showed that functional groups such as C-H, O-H, C=O, and C-O-C which possibly associated with Pb 2+ binding were mainly presented in the suspended solid portion of IC. Putting the above together, we postulated that the enhanced Pb 2+ binding capacity the probiotic bacteria incubated in IC is due to the adherence of the yet to be identified particles which could much exist in suspended solid portion of IC containing negatively charged functional groups which bind with the positive Pb 2+ ions.

  12. Biosorption of lead phosphates by lead-tolerant bacteria as a mechanism for lead immobilization.

    Science.gov (United States)

    Rodríguez-Sánchez, Viridiana; Guzmán-Moreno, Jesús; Rodríguez-González, Vicente; Flores-de la Torre, Juan Armando; Ramírez-Santoyo, Rosa María; Vidales-Rodríguez, Luz Elena

    2017-08-01

    The study of metal-tolerant bacteria is important for bioremediation of contaminated environments and development of green technologies for material synthesis due to their potential to transform toxic metal ions into less toxic compounds by mechanisms such as reduction, oxidation and/or sequestration. In this study, we report the isolation of seven lead-tolerant bacteria from a metal-contaminated site at Zacatecas, México. The bacteria were identified as members of the Staphylococcus and Bacillus genera by microscopic, biochemical and 16S rDNA analyses. Minimal inhibitory concentration of these isolates was established between 4.5 and 7.0 mM of Pb(NO 3 ) 2 in solid and 1.0-4.0 mM of Pb(NO 3 ) 2 in liquid media. A quantitative analysis of the lead associated to bacterial biomass in growing cultures, revealed that the percentage of lead associated to biomass was between 1 and 37% in the PbT isolates. A mechanism of complexation/biosorption of lead ions as inorganic phosphates (lead hydroxyapatite and pyromorphite) in bacterial biomass, was determined by Fourier transform infrared spectroscopy and X-ray diffraction analyses. Thus, the ability of the lead-tolerant isolates to transform lead ions into stable and highly insoluble lead minerals make them potentially useful for immobilization of lead in mining waste.

  13. Biosorption of metal and salt tolerant microbial isolates from a former uranium mining area. Their impact on changes in rare earth element patterns in acid mine drainage.

    Science.gov (United States)

    Haferburg, Götz; Merten, Dirk; Büchel, Georg; Kothe, Erika

    2007-12-01

    The concentration of metals in microbial habitats influenced by mining operations can reach enormous values. Worldwide, much emphasis is placed on the research of resistance and biosorptive capacities of microorganisms suitable for bioremediation purposes. Using a collection of isolates from a former uranium mining area in Eastern Thuringia, Germany, this study presents three Gram-positive bacterial strains with distinct metal tolerances. These strains were identified as members of the genera Bacillus, Micrococcus and Streptomyces. Acid mine drainage (AMD) originating from the same mining area is characterized by high metal concentrations of a broad range of elements and a very low pH. AMD was analyzed and used as incubation solution. The sorption of rare earth elements (REE), aluminum, cobalt, copper, manganese, nickel, strontium, and uranium through selected strains was studied during a time course of four weeks. Biosorption was investigated after one hour, one week and four weeks by analyzing the concentrations of metals in supernatant and biomass. Additionally, dead biomass was investigated after four weeks of incubation. The maximum of metal removal was reached after one week. Up to 80% of both Al and Cu, and more than 60% of U was shown to be removed from the solution. High concentrations of metals could be bound to the biomass, as for example 2.2 mg/g U. The strains could survive four weeks of incubation. Distinct and different patterns of rare earth elements of the inoculated and non-inoculated AMD water were observed. Changes in REE patterns hint at different binding types of heavy metals regarding incubation time and metabolic activity of the cells. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Application of numerical method in calculating the internal rate of return of joint venture investment using diminishing musyarakah model

    Science.gov (United States)

    Ruslan, Siti Zaharah Mohd; Jaffar, Maheran Mohd

    2017-05-01

    Islamic banking in Malaysia offers variety of products based on Islamic principles. One of the concepts is a diminishing musyarakah. The concept of diminishing musyarakah helps Muslims to avoid transaction which are based on riba. The diminishing musyarakah can be defined as an agreement between capital provider and entrepreneurs that enable entrepreneurs to buy equity in instalments where profits and losses are shared based on agreed ratio. The objective of this paper is to determine the internal rate of return (IRR) for a diminishing musyarakah model by applying a numerical method. There are several numerical methods in calculating the IRR such as by using an interpolation method and a trial and error method by using Microsoft Office Excel. In this paper we use a bisection method and secant method as an alternative way in calculating the IRR. It was found that the diminishing musyarakah model can be adapted in managing the performance of joint venture investments. Therefore, this paper will encourage more companies to use the concept of joint venture in managing their investments performance.

  15. Diminished creatinine clearance in anorexia nervosa: reversal with weight gain.

    OpenAIRE

    Boag, F; Weerakoon, J; Ginsburg, J; Havard, C W; Dandona, P

    1985-01-01

    To assess whether patients with anorexia nervosa have abnormalities in creatinine clearance, we measured plasma creatinine concentration, urinary creatinine excretion, and creatinine clearance in 10 patients with anorexia nervosa before and during treatment. Urinary creatinine excretion and creatinine clearance were diminished in all patients. Nine patients had significant decreases in their plasma creatinine and creatinine clearance was increased even when corrected for body weight and body ...

  16. Biosorption phenomena of chromium, copper, iron and zink by dispersed bacterial extracellular polymeric substance

    International Nuclear Information System (INIS)

    Zainus Salimin; Endang Nuraeni; Mirawaty

    2015-01-01

    Heavy metals removing is generally performed using chemical coagulant that generates the chemical pollutant, so it is necessary to replace it by another alternative material as the Extracellular Polymeric Substance (EPS) resulting from the extraction of bacteria. The EPS contains the negatively functional groups (RCOOH, ROPO 3 H, ROPO 3 Na, ROSO 3 H, ROSO 3 Na, etc) as the cation sorbent and the positively functional groups (ROH, RC(NH 2 )HCOOH, etc) as the anion sorbent. The EPS absorbs the ion pollutants, then EPS containing the loaded metals be settled by gravitation. The utilization of EPS for removing of chromium, copper, iron, and zink was performed for biosorption phenomena study. Two hundred mg of EPS is mixed with 300 ml of the liquid waste having the pH of 2,4 containing 3,06 ppm of chromium; 4,83 ppm of copper; 1,6 ppm of iron and 15,07 ppm of zink. The solution is then agitated on 150 rpm and the pH of 7. The separated water supernatant is then sampled every 2 hours for its analysis of metals content. The experiment is repeated again for the solution pH of 4 and 8. The results of experiment indicates that the EPS composition are 11% of polysaccharides, 77% of protein, and 11% of fat ,and EPS contains the chemical bounding of C-H, OH, NH, and C=O. Indicating that EPS contains RCOOH, ROH and (RC(NH 2 )HCOOH. The best condition for metals biosorption is pH 8, and on the 6 hours of process time, the metal concentration on the water supernatant for chromium, copper, iron and zinc are 0,99 ppm; 0,51 ppm; 0,17 ppm; and 4,61 ppm respectively. Its selectivities are Fe 3+ > Cr 3+ >Cu 2+ >Fe 2+ >Zn 2+ , on the 6 hours of process time the location of cations functional groups was filled by the cations of Cr 3+ ,Cu 2+ , dan Fe 2+ . The cation of Zn 2+ enters to that location on the end of period so on the 6 hours of process time its concentration of 4,61 ppm not conforms to its concentration of regulation value of 2 ppm. On the process time of 6 hours the removing

  17. Direct Instruction and Music Literacy: One Approach to Augmenting the Diminishing?

    Science.gov (United States)

    Lowe, Geoffrey; Belcher, Steven

    2012-01-01

    One of the many challenges facing music educators is diminishing class time in lower secondary school in the face of the increasingly crowded curriculum and the advent of arts "taster" courses. However, music educators are still expected to be able to produce musically literate students capable of completing high level music courses in…

  18. Equilibrium, thermodynamic and kinetic studies for the biosorption of aqueous lead(II), cadmium(II) and nickel(II) ions on Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Seker, Ayseguel [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: aysegulseker@iyte.edu.tr; Shahwan, Talal [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: talalshahwan@iyte.edu.tr; Eroglu, Ahmet E. [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: ahmeteroglu@iyte.edu.tr; Yilmaz, Sinan [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: sinanyilmaz@iyte.edu.tr; Demirel, Zeliha [Department of Biology, Ege University, Bornova 35100, Izmir (Turkey)], E-mail: zelihademirel@gmail.com; Dalay, Meltem Conk [Department of Bioengineering, Ege University, Bornova 35100, Izmir (Turkey)], E-mail: meltemconkdalay@gmail.com

    2008-06-15

    The biosorption of lead(II), cadmium(II) and nickel(II) ions from aqueous solution by Spirulina platensis was studied as a function of time, concentration, temperature, repetitive reactivity, and ionic competition. The kinetic results obeyed well the pseudo second-order model. Freundlich, Dubinin Radushkevich and Temkin isotherm models were applied in describing the equilibrium partition of the ions. Freundlich isotherm was applied to describe the design of a single-stage batch sorption system. According to the thermodynamic parameters such as {delta}G{sup o}, {delta}H{sup o}and {delta}S{sup o} calculated, the sorption process was endothermic and largely driven towards the products. Sorption activities in a three metal ion system were studied which indicated that there is a relative selectivity of the biosorbent towards Pb{sup 2+} ions. The measurements of the repetitive reusability of S. platensis indicated a large capacity towards the three metal ions.

  19. Punishment diminishes the benefits of network reciprocity in social dilemma experiments.

    Science.gov (United States)

    Li, Xuelong; Jusup, Marko; Wang, Zhen; Li, Huijia; Shi, Lei; Podobnik, Boris; Stanley, H Eugene; Havlin, Shlomo; Boccaletti, Stefano

    2018-01-02

    Network reciprocity has been widely advertised in theoretical studies as one of the basic cooperation-promoting mechanisms, but experimental evidence favoring this type of reciprocity was published only recently. When organized in an unchanging network of social contacts, human subjects cooperate provided the following strict condition is satisfied: The benefit of cooperation must outweigh the total cost of cooperating with all neighbors. In an attempt to relax this condition, we perform social dilemma experiments wherein network reciprocity is aided with another theoretically hypothesized cooperation-promoting mechanism-costly punishment. The results reveal how networks promote and stabilize cooperation. This stabilizing effect is stronger in a smaller-size neighborhood, as expected from theory and experiments. Contrary to expectations, punishment diminishes the benefits of network reciprocity by lowering assortment, payoff per round, and award for cooperative behavior. This diminishing effect is stronger in a larger-size neighborhood. An immediate implication is that the psychological effects of enduring punishment override the rational response anticipated in quantitative models of cooperation in networks. Copyright © 2017 the Author(s). Published by PNAS.

  20. Diminished mental- and physical function and lack of social support are associated with shorter survival in community dwelling older persons of Botswana

    Directory of Open Access Journals (Sweden)

    Molebatsi Robert M

    2007-07-01

    Full Text Available Abstract Background Mortality rates for older persons in Botswana have been unavailable and little is known of predictors of mortality in old age. This study may serve as a precursor for more detailed assessments. The objective was to assess diminished function and lack of social support as indicators of short term risk of death. Methods A national population based prospective survey was undertaken in Botswana; twelve rural areas and three urban centers were included. 372 community-dwelling persons aged sixty years and over, were included; 265 were followed-up. Sixteen subjects were deceased at follow-up. Subjects were interviewed and clinically assessed at home. Measures of cognitive function, depression and physical function and sociodemographic information were collected. Subjects were followed-up at average 6.8 months after baseline. Results Overall mortality rate was 10.9 per 100 person years. Age-adjusted odds ratios (OR for death during follow-up were; 4.2 (CI 1.4–12.5 and 3.6 (CI 1.0–12.7 for those with diminished physical- and cognitive function, respectively. Indicators of limited social support; household with only 1 or 2 persons and eating alone, yielded age adjusted ORs of 4.3 (CI 1.5–12.5 and 6.7 (CI 2.2–20, respectively, for death during follow-up. Conclusion Older community dwelling persons with diminished cognitive- or physical function, solitary daily meals and living in a small household have a significantly increased risk of rapid deterioration and death. Health policy should include measures to strengthen informal support and expand formal service provisions to older persons with poor function and limited social networks in order to prevent premature deaths.

  1. Biosorption of Congo Red from aqueous solution onto burned root of Eichhornia crassipes biomass

    Science.gov (United States)

    Roy, Tapas Kumar; Mondal, Naba Kumar

    2017-07-01

    Biosorption is becoming a promising alternative to replace or supplement the present dye removal processes from dye containing waste water. In this work, adsorption of Congo Red (CR) from aqueous solution on burned root of Eichhornia crassipes ( BREC) biomass was investigated. A series of batch experiments were performed utilizing BREC biomass to remove CR dye from aqueous systems. Under optimized batch conditions, the BREC could remove up to 94.35 % of CR from waste water. The effects of operating parameters such as initial concentration, pH, adsorbent dose and contact time on the adsorption of CR were analyzed using response surface methodology. The proposed quadratic model for central composite design fitted very well to the experimental data. Response surface plots were used to determine the interaction effects of main factors and optimum conditions of the process. The optimum adsorption conditions were found to be initial CR concentration = 5 mg/L-1, pH = 7, adsorbent dose = 0.125 g and contact time = 45 min. The experimental isotherms data were analyzed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherm equations and the results indicated that the Freundlich isotherm showed a better fit for CR adsorption. Thermodynamic parameters were calculated from Van't Hoff plot, confirming that the adsorption process was spontaneous and exothermic. The high CR adsorptive removal ability and regeneration efficiency of this adsorbent suggest its applicability in industrial/household systems and data generated would help in further upscaling of the adsorption process.

  2. Modeling the effect of pH on biosorption of heavy metals by citrus peels

    International Nuclear Information System (INIS)

    Schiewer, Silke; Patil, Santosh B.

    2008-01-01

    Biosorption by materials such as citrus peels could be a cost effective technique for removing toxic heavy metals from wastewater. Orange peels, lemon peels and lemon-based protonated pectin peels (PPP) had Langmuir sorption capacities of 0.7-1.2 mequiv./g (39-67 mg/g) of Cd per biosorbent dry weight. A potentiometric titration was interpreted using a continuous pK a spectrum approach. It revealed four acidic sites with pK a values of 3.8, 6.4, 8.4 and 10.7, and a total site quantity of 1.14 mequiv./g. Sorption isotherms of untreated citrus peels showed an unusual shape with two plateau values. Protonated pectin peels on the other hand showed a typical Langmuir behavior with a higher sorption capacity than untreated peels. At lower pH, metal binding was reduced due to increased competition by protons. This was modeled using pH-sensitive isotherm equations. It was not necessary to assume four binding sites; using one site with pK a 3.8 and a quantity of 1.14 mequiv./g was sufficient. It was possible to accurately predict metal uptake at one pH using the metal binding constant determined at a different pH. A 1:1 stoichiometry model fit the sorption isotherms shape better than a 1:2 stoichiometry. For constant pH, the 1:1 stoichiometry reduces to the Langmuir model

  3. Response surface approach for the biosorption of Cr{sup 6+} ions by mucor racemosus

    Energy Technology Data Exchange (ETDEWEB)

    Jabasingh, Sekarathil A. [Department of Chemical Engineering, Sathyabama University, Jeppiaar Nagar, Chennai, Tamil Nadu (India); Pavithra, Garre [Department of Biotechnology, Sathyabama University, Jeppiaar Nagar, Chennai, Tamil Nadu (India)

    2010-06-15

    Response surface methodology (RSM) employing the Box-Behnken design was used to optimize the biosorption of chromium (Cr{sup 6+}) by Mucor racemosus in submerged culture. The initial Cr{sup 6+} concentration (20-100 mg/L), pH (3.0-7.0), biomass dosage (5.0-9.0 mg), and time of sorption (2.0-6.0 h) were chosen as the process variables for the optimization. Two response values were chosen, i.e., sorption capacity (mg/g) and sorption percentage are optimized. A four-factor-three-level Box-Behnken design was used to evaluate the effects of these parameters on the sorption percentage. A second-order quadratic model suggested the optimum conditions (initial Cr{sup 6+} concentration 100 mg/L, pH of 5.0, biomass dosage of 5.0 mg, and time of sorption 4 h) resulted in the improvement of sorption of Cr{sup 6+} from 12.47 to 49.98% as well as the improvement of the sorption capacity from 0.1036 to 0.5 mg/g. Analysis of variance (ANOVA) for the above-mentioned response variables yielded a high coefficient of determination (R{sup 2}) value of 0.9985 and 0.9025 for the sorption capacity and sorption percentage, respectively. The desirability plot and overlay plot suggested the significance of the designed model. This is the first report on Cr{sup 6+} sorption by M. racemosus using statistical experimental design employing RSM. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Modeling the effect of pH on biosorption of heavy metals by citrus peels

    Energy Technology Data Exchange (ETDEWEB)

    Schiewer, Silke [Department of Civil and Environmental Engineering, University of Alaska Fairbanks, PO Box 755900, Fairbanks, AK 99775 (United States)], E-mail: ffsos@uaf.edu; Patil, Santosh B. [Department of Civil and Environmental Engineering, University of Alaska Fairbanks, PO Box 755900, Fairbanks, AK 99775 (United States)

    2008-08-30

    Biosorption by materials such as citrus peels could be a cost effective technique for removing toxic heavy metals from wastewater. Orange peels, lemon peels and lemon-based protonated pectin peels (PPP) had Langmuir sorption capacities of 0.7-1.2 mequiv./g (39-67 mg/g) of Cd per biosorbent dry weight. A potentiometric titration was interpreted using a continuous pK{sub a} spectrum approach. It revealed four acidic sites with pK{sub a} values of 3.8, 6.4, 8.4 and 10.7, and a total site quantity of 1.14 mequiv./g. Sorption isotherms of untreated citrus peels showed an unusual shape with two plateau values. Protonated pectin peels on the other hand showed a typical Langmuir behavior with a higher sorption capacity than untreated peels. At lower pH, metal binding was reduced due to increased competition by protons. This was modeled using pH-sensitive isotherm equations. It was not necessary to assume four binding sites; using one site with pK{sub a} 3.8 and a quantity of 1.14 mequiv./g was sufficient. It was possible to accurately predict metal uptake at one pH using the metal binding constant determined at a different pH. A 1:1 stoichiometry model fit the sorption isotherms shape better than a 1:2 stoichiometry. For constant pH, the 1:1 stoichiometry reduces to the Langmuir model.

  5. [Physical activity diminishes aging-related decline of physical and cognitive performance].

    Science.gov (United States)

    Apor, Péter; Babai, László

    2014-05-25

    Aging-related decline of muscle force, walking speed, locomotor coordination, aerobic capacity and endurance exert prognostic impact on life expectancy. Proper use of training may diminish the aging process and it may improve the quality of life of elderly persons. This paper provides a brief summary on the impact of training on aging-related decline of physical and cognitive functions.

  6. Nonsuicidal self-injury and diminished pain perception: the role of emotion dysregulation

    NARCIS (Netherlands)

    Franklin, J.C.; Aaron, R.V.; Arthur, M.S.; Shorkey, S.P.; Prinstein, M.J.

    2012-01-01

    Nonsuicidal self-injury (NSSI) is the deliberate destruction of one's own body tissue in the absence of suicidal intent (e.g., cutting or burning the skin). Previous studies have found that people with a history of NSSI display diminished pain perception. However, it remains unclear why this effect

  7. Simultaneous biosorption of selenium, arsenic and molybdenum with modified algal-based biochars.

    Science.gov (United States)

    Johansson, Charlotte L; Paul, Nicholas A; de Nys, Rocky; Roberts, David A

    2016-01-01

    Ash disposal waters from coal-fired power stations present a challenging water treatment scenario as they contain high concentrations of the oxyanions Se, As and Mo which are difficult to remove through conventional techniques. In an innovative process, macroalgae can be treated with Fe and processed through slow pyrolysis into Fe-biochar which has a high affinity for oxyanions. However, the effect of production conditions on the efficacy of Fe-biochar is poorly understood. We produced Fe-biochar from two algal sources; "Gracilaria waste" (organic remnants after agar is extracted from cultivated Gracilaria) and the freshwater macroalgae Oedogonium. Pyrolysis experiments tested the effects of the concentration of Fe(3+) in pre-treatment, and pyrolysis temperatures, on the efficacy of the Fe-biochar. The efficacy of Fe-biochar increased with increasing concentrations of Fe(3+) in the pre-treatment solutions, and decreased with increasing pyrolysis temperatures. The optimized Fe-biochar for each biomass was produced by treatment with a 12.5% w/v Fe(3+) solution, followed by slow pyrolysis at 300 °C. The Fe-biochar produced in this way had higher a biosorption capacity for As and Mo (62.5-80.7 and 67.4-78.5 mg g(-1) respectively) than Se (14.9-38.8 mg g(-1)) in single-element mock effluents, and the Fe-biochar produced from Oedogonium had a higher capacity for all elements than the Fe-biochar produced from Gracilaria waste. Regardless, the optimal Fe-biochars from both biomass sources were able to effectively treat Se, As and Mo simultaneously in an ash disposal effluent from a power station. The production of Fe-biochar from macroalgae is a promising technique for treatment of complex effluents containing oxyanions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. A further insight into the mechanism of Ag + biosorption by Lactobacillus sp. strain A09

    Science.gov (United States)

    Lin, Zhongyu; Zhou, Chaohui; Wu, Jianming; Zhou, Jianzhang; Wang, Lin

    2005-04-01

    The mechanism of Ag + biosorption by resting cell of Lactobacillus sp. strain A09 has been further investigated at the molecular level using spectroscopic techniques. The values of estimated equilibrium constants, rate constants, half-life periods and apparent enthalpies of the binding reaction were calculated via the determination of Ag + adsorbed by the biomass using atomic absorption spectrophotometry (AAS). The reductive ratio of the Ag + to Ag 0 by the A09 biomass was examined by X-ray photoelectron spectroscopy (XPS). Analysis for sulfur and nitrogen atomic contents in dry powder of the biomass with EA-1110 elemental analysis (EA) showed that amino acid residues retaining the reductive property of Ag + to Ag 0 are very small quantity, whereas glucose content in the hydrolysates of the biomass analyzed by ultraviolet-visible spectrophotometry (UV-vis) indicated that the amount of reducing sugars in the biomass is much larger than 2.71%. The fourier transform infrared (FTIR) spectrophotometry on blank and silver-loaded biomass demonstrated that the chemical functional group such as the free aldehyde group of the hemiacetalic hydroxyl group from reducing sugars, i.e. the hydrolysates of the polysaccharides from the cell wall plays a leading role in serving as the electron donor for reducing the Ag + to Ag 0. This result was further supported by characterizations on the interaction of the Ag + with glucose using X-ray powder diffractometry (XRD) and FTIR spectroscopy.

  9. A case of diminished pericardial effusion after treatment of a giant hepatic cyst.

    Science.gov (United States)

    Okano, Hiroshi; Tochio, Tomomasa; Kumazawa, Hiroaki; Isono, Yoshiaki; Tanaka, Hiroki; Matsusaki, Shimpei; Sase, Tomohiro; Saito, Tomonori; Mukai, Katsumi; Nishimura, Akira; Kitamura, Tetsuya; Mori, Takuya

    2017-08-01

    A 75-year-old woman was discovered to have a pericardial effusion when she was admitted to our hospital because of a giant hepatic cyst. We could not detect the cause of the effusion and diagnosed idiopathic pericardial effusion. The patient underwent transcutaneous drainage of the hepatic cyst and an injection of antibiotics. There was no communication between the pericardial effusion and the hepatic cyst. Although the hepatic cyst was reduced in size, the pericardial effusion showed no remarkable change immediately after treatment; however, 5 months later, the pericardial effusion was found to be diminished. The pericardial effusion might have been caused by the physical pressure of the giant hepatic cyst and disturbance in the balance between the production and reabsorption of the pericardial fluid. When we experience a huge hepatic cyst, we should take into account its influence against the surrounding organs, including the intrapleural space.

  10. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Directory of Open Access Journals (Sweden)

    Chunxiang Yao

    Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  11. Biosorption of lead (II and copper (II by biomass of some marine algae

    Directory of Open Access Journals (Sweden)

    Chaisuksant, Y.

    2004-09-01

    Full Text Available Biosorption of heavy metal ions by algae is a potential technology for treating wastewater contaminated with heavy metals. Adsorption of lead (II and copper (II in aqueous solutions by some marine algae available in large quantities in Pattani Bay including Gracilaria fisheri, Ulva reticulata and Chaetomorpha sp. were investigated. The effect of pH on metal sorption of the algal biomass and the metal uptake capacity of the algal biomass comparing to that of synthetic adsorbents including activated carbon and siliga gel were studied by using batch equilibrium experiments. Each dried adsorbent was stirred in metal ions solutions with different pH or different concentration at room temperature for 24 hours and the residual metal ions were analysed using atomic absorption spectrophotometer. The initial concentrations of lead and copper ionswere 70 µg/l and 20 mg/l, respectively. It was found that the effect of pH on metal sorption was similar in each algal biomass. The metal uptake capacity increased as pH of the solution increased from 2.0 to 4.0 and reached a plateau at pH 5.0-7.0. The metal uptake capacities of each algal biomass were similar. At low concentrations of metal ions, the metal adsorption occurred rapidly while at higher metal concentration less metal adsorption by each algal biomass was observed. The metal adsorption of activated carbon and silica gel occurred gradually and was less than those of algal biomass. The equilibrium data of copper and lead ions fitted well to the Langmuir and Freundlich isotherm models. The maximum sorption capacity (Qm values (mean±SD of Chaetomorpha sp., U. reticulata, G. fisheri, activated carbon and silica gel for lead ions were 1.26±0.14, 1.19±0.14, 1.18±0.15, 1.14±0.11 and 1.15±0.12 mg/g, respectively. For copper adsorption, the Qm values for G. fisheri, U. reticulata and Chaetomorpha biomass were 15.87±1.03, 14.71±1.02 and 12.35± 1.03 mg/g, respectively. While those of activated carbon and

  12. Pollutant tracking for 3 Western North Atlantic sea grasses by remote sensing: Preliminary diminishing white light responses of Thalassia testudinum, Halodule wrightii, and Zostera marina

    International Nuclear Information System (INIS)

    Thorhaug, Anitra; Berlyn, Graeme P.; Poulos, Helen M.; Goodale, Uromi M.

    2015-01-01

    Highlights: • Sea grass accessory pigments are more important than Chl at medium to low light intensity. • Partial absorption changes in Thalassia and also in Halodule at low intensity visible light ranges. • NDVI and chlNDI do not detect these changes or low light responses of sea grasses. • Intertidal sea grasses are less stressed than the subtidal species at low and high light. • Chl b is an important photosynthetic pigment in tropical/subtropical species. - Abstract: Sea grasses are foundation species for estuarine ecosystems. The available light for sea grasses diminishes rapidly during pollutant spills, effluent releases, disturbances such as intense riverine input, and tidal changes. We studied how sea grasses’ remote-sensing signatures and light-capturing ability respond to short term light alterations. In vivo responses were measured over the entire visible-light spectra to diminishing white-light on whole-living-plants’ spectral reflectance, including 6 h of full oceanic-light fluences from 10% to 100%. We analyzed differences by various reflectance indices. We compared the sea grasses species responses of tropical vs. temperate and intertidals (Halodule wrightii, and Zostera marina) vs. subtidal (Thalassia testudinum). Reflectance diminished with decreasing light intensity that coincided with greater accessory pigment stimulation (anthocyanin, carotenoids, xanthins). Chlorophyll a and Chlorophyll b differed significantly among species (Thalassia vs. Halodule). Photosynthetic efficiency diminished at high light intensities. The NDVI index was inadequate to perceive these differences. Our results demonstrate the leaf-level utility of data to remote sensing for mapping sea grass and sea grass stress

  13. Influence of operating conditions on the removal of brilliant vital red dye from aqueous media by bio-sorption using rice husk

    International Nuclear Information System (INIS)

    Rehman, R.; Anwar, J.; Mahmud, T.; Salman, M.; Shafique, U.

    2011-01-01

    Bio-sorption is emerging as an economical and eco friendly methodology for the removal of hazardous and toxic chemicals from waste water. The operating conditions have a great influence on the efficiency of this process. Conventional and indigenous bio sorbents like bagasse, wheat husk and rice husk have been evaluated for their removing efficiency of Brilliant Vital Red dye from water. Rice husk is proved better among them. The effect of important operating conditions for the removal of the dye using rice husk were studied. The observed optimum values for various factors are; 0.2 g of bio sorbent, 25 ppm initial dye concentration, 30 deg. C temperature, 15 minutes contact time, 300 rpm stirring speed and 2.0 ph. Langmuir adsorption isotherm model was also applied to evaluate maximum adsorption capacity of rice husk for Brilliant Vital Red dye. Q/sub max/ value was 15.06 which indicated that rice husk can effectively be used for the removal of Brilliant Vital Red dye from wastewater using the optimized operational conditions. This study would be accommodative with regard to practical wastewater treatment. (author)

  14. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste.

    Science.gov (United States)

    Vilar, Vítor J P; Loureiro, José M; Botelho, Cidália M S; Boaventura, Rui A R

    2008-06-15

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO3 as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions.

  15. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: vilar@fe.up.pt; Loureiro, Jose M. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: loureiro@fe.up.pt; Botelho, Cidalia M.S. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: cbotelho@fe.up.pt; Boaventura, Rui A.R. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: bventura@fe.up.pt

    2008-06-15

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO{sub 3} as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions.

  16. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste

    International Nuclear Information System (INIS)

    Vilar, Vitor J.P.; Loureiro, Jose M.; Botelho, Cidalia M.S.; Boaventura, Rui A.R.

    2008-01-01

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO 3 as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions

  17. Metabolic Evidence of Diminished Lipid Oxidation in Women With Polycystic Ovary Syndrome

    OpenAIRE

    Whigham, Leah D.; Butz, Daniel E.; Dashti, Hesam; Tonelli, Marco; Johnson, LuAnn K.; Cook, Mark E.; Porter, Warren P.; Eghbalnia, Hamid R.; Markley, John L.; Lindheim, Steven R.; Schoeller, Dale A.; Abbott, David H.; Assadi-Porter, Fariba M.

    2014-01-01

    Polycystic ovary syndrome (PCOS), a common female endocrinopathy, is a complex metabolic syndrome of enhanced weight gain. The goal of this pilot study was to evaluate metabolic differences between normal (n=10) and PCOS (n=10) women via breath carbon isotope ratio, urinary nitrogen and nuclear magnetic resonance (NMR)-determined serum metabolites. Breath carbon stable isotopes measured by cavity ring down spectroscopy (CRDS) indicated diminished (p

  18. Image-Based Models for Specularity Propagation in Diminished Reality.

    Science.gov (United States)

    Said, Souheil Hadj; Tamaazousti, Mohamed; Bartoli, Adrien

    2018-07-01

    The aim of Diminished Reality (DR) is to remove a target object in a live video stream seamlessly. In our approach, the area of the target object is replaced with new texture that blends with the rest of the image. The result is then propagated to the next frames of the video. One of the important stages of this technique is to update the target region with respect to the illumination change. This is a complex and recurrent problem when the viewpoint changes. We show that the state-of-the-art in DR fails in solving this problem, even under simple scenarios. We then use local illumination models to address this problem. According to these models, the variation in illumination only affects the specular component of the image. In the context of DR, the problem is therefore solved by propagating the specularities in the target area. We list a set of structural properties of specularities which we incorporate in two new models for specularity propagation. Our first model includes the same property as the previous approaches, which is the smoothness of illumination variation, but has a different estimation method based on the Thin-Plate Spline. Our second model incorporates more properties of the specularity's shape on planar surfaces. Experimental results on synthetic and real data show that our strategy substantially improves the rendering quality compared to the state-of-the-art in DR.

  19. RECOMMENDATION OF FERTILIZERS BASED ON THE LAW OF DIMINISHING RETURN

    Directory of Open Access Journals (Sweden)

    Geicimara Guimarães

    2011-07-01

    Full Text Available The objective of this work was to demonstrate the viability of making recommendation of fertilizers for corn and bean cultures based on models of saturation kinetics, following the Law of diminishing return, aiming to improve the efficiency of nutrient use, reducing the costs of production and avoiding the excessive use of non renewable natural resources. In the corn culture (grain hybrid they were utilized levels of 0.0, 0.25, 0.5, 1, 2, 4, 8, 16 and 32 g/hole of fertilizer NPK 4-14-8 in seeding and same amounts of ammonium sulfate 34 days later. The space between plants was of 20 x 70 cm (71.429 plants/hectare, with eight replicates per each level, totalizing 72 plants in the experimental area. In bean culture (red variety they were utilized levels of 0.0, 0.25, 0.50, 1, 2, 4, 8, 16 and 32 g/hole of NPK 4-14-8 in planting. The space between plants was of 20 x 50 cm, with two grains per hole (71.429 plants/hectare, with eight holes per each level, totalizing 144 plants in the experimental area. The models of saturation kinetics of Lineweaver-Burk presented good adjustments for responses of corn and beans to fertilization, following the Law of diminishing return, in which 4 to 8 g of fertilizer per hole caused good part of the productive response for corn and 2 grams for bean. The employee of moderate level of fertilization leads to a more sustainable and economically viable agriculture to the household producer.

  20. Selection of Parasites with Diminished Drug Sensitivity by Amodiaquine-Containing Antimalarial Regimens in Uganda

    Science.gov (United States)

    Nawaz, Fatima; Nsobya, Samuel L.; Kiggundu, Moses; Joloba, Moses; Rosenthal, Philip J.

    2009-01-01

    Background Amodiaquine (AQ) is paired with artesunate (AS) or sulfadoxine-pyrimethamine (SP) in recommended antimalarial regimens. It is unclear how readily AQ resistance will be selected with combination chemotherapy. Methods We collected 61 Plasmodium falciparum samples from a cohort of Ugandan children randomized to treatment with AQ/SP, AS/AQ, or artemether-lumefantrine (AL) for uncomplicated malaria. In vitro sensitivity to monodesethylamodiaquine (MDAQ) was measured with a histidine rich protein-2-based ELISA, and potential resistance-mediating polymorphisms pfmdr-1were evaluated. Results Parasites from subjects previously treated with AQ/SP or AS/AQ within 12 weeks were less sensitive to MDAQ (n=18; mean IC50 62.9 nM; range 12.7–158.3 nM) than parasites from those not treated within 12 weeks (n=43; mean IC50 37.5 nM; range 6.3–184.7 nM; p=0.0085) or only those in the treatment arm that did not contain AQ (n=20; mean IC50 28.8 nM; range 6.3–121.8 nM; p=0.0042). The proportion of strains with polymorphisms expected to mediate diminished response to AQ (pfmdr-1 86Y and 1246Y) increased after prior AQ therapy, although differences were not significant. Conclusions Prior therapy selected for diminished response to MDAQ, suggesting that AQ-containing regimens may rapidly lose efficacy in Africa. The mechanism of diminished MDAQ response is not fully explained by known mutations in pfmdr-1. PMID:19905933

  1. Diminishing Footprints: Exploring the Local and Global Challenges to Place-Based Environmental Education

    Science.gov (United States)

    Chang, David

    2017-01-01

    An efficacious response to the ecological crisis requires a thorough examination of our material entitlements and a willingness to reduce our ecological impact by diminishing current levels of consumption. Drawing on the example of air pollution in China, I present a case for the reduction of consumption and impact as a worthy outcome of…

  2. Epstein-Barr virus reactivation associated with diminished cell-mediated immunity in antarctic expeditioners

    Science.gov (United States)

    Mehta, S. K.; Pierson, D. L.; Cooley, H.; Dubow, R.; Lugg, D.

    2000-01-01

    Epstein-Barr virus (EBV) reactivation and cell-mediated immune (CMI) responses were followed in 16 Antarctic expeditioners during winter-over isolation at 2 Australian National Antarctic Research Expedition stations. Delayed-type hypersensitivity (DTH) skin testing was used as an indicator of the CMI response, that was evaluated 2 times before winter isolation and 3 times during isolation. At all 5 evaluation times, 8 or more of the 16 subjects had a diminished CMI response. Diminished DTH was observed on every test occasion in 4/16 subjects; only 2/16 subjects exhibited normal DTH responses for all 5 tests. A polymerase chain reaction (PCR) assay was used to detect EBV DNA in saliva specimens collected before, during, and after the winter isolation. EBV DNA was present in 17% (111/642) of the saliva specimens; all 16 subjects shed EBV in their saliva on at least 1 occasion. The probability of EBV shedding increased (P = 0.013) from 6% before or after winter isolation to 13% during the winter period. EBV appeared in saliva during the winter isolation more frequently (P viruses.

  3. Diminished Antimicrobial Peptide and Antifungal Antibiotic Activities against Candida albicans in Denture Adhesive

    Directory of Open Access Journals (Sweden)

    Amber M. Bates

    2017-02-01

    Full Text Available The underlying causes of denture stomatitis may be related to the long-term use of adhesives, which may predispose individuals to oral candidiasis. In this study, we hypothesize that antimicrobial peptides and antifungal antibiotics have diminished anti-Candida activities in denture adhesive. To show this, nine antimicrobial peptides and five antifungal antibiotics with and without 1.0% denture adhesive were incubated with Candida albicans strains ATCC 64124 and HMV4C in radial diffusion assays. In gels with 1.0% adhesive, HNP-1, HBD2, HBD3, IP-10, LL37 (only one strain, histatin 5 (only one strain, lactoferricin B, and SMAP28 showed diminished activity against C. albicans. In gels with 1.0% adhesive, amphotericin B and chlorhexidine dihydrochloride were active against both strains of C. albicans. These results suggest that denture adhesive may inactivate innate immune mediators in the oral cavity increasing the risk of C. albicans infections, but inclusion of antifungal antibiotics to denture adhesive may aid in prevention or treatment of Candida infections and denture stomatitis.

  4. Biosorption of heavy metals and radionuclide from aqueous solutions by pre-treated arca shell biomass

    International Nuclear Information System (INIS)

    Dahiya, Sudhir; Tripathi, R.M.; Hegde, A.G.

    2008-01-01

    In this study biosorption potential of pre-treated arca shell biomass for lead, copper, nickel, cobalt and cesium was explored from the artificially prepared solution containing known amount of metals. The effects of pH, initial concentration, biosorbent dosage and contact time were studied in batch experiments. Effects of common ions like sodium, potassium, calcium and magnesium on the sorption capacity of pre-treated arca biomasses were also studied. To analyse the homogeneity of the biomaterial, experiments were performed for eight lots arca shell biomass for all the studies elements and it was observed that relative standard deviation in uptake capacity was within 10% for all elements. At equilibrium, the maximum total uptake by shell biomaterial was 18.33 ± 0.44, 17.64 ± 0.31, 9.86 ± 0.17, 3.93 ± 0.11 and 7.82 ± 0.36 mg/g for lead, copper, nickel, cesium and cobalt, respectively, under the optimised condition of pH, initial concentration, biosorbent dose and contact time. Effect of all the common ions jointly up to concentration of 50 ppm was negligible for all the elements but at higher levels the cations affects the uptake capacity. Sorption isotherms were studied to explain the removal mechanism of both elements by fitting isotherms data into Lagergren, Freundlich and Langmuir equations. Halls separation factor estimated under optimised condition also favours the sorption potential of these elements using arca shell biomass. Arca shell biomass can be effectively and efficiently employed for removal of studied elements after optimisation of parameters

  5. Impact of a program to diminish gender insensitivity and sexual harassment at a medical school.

    Science.gov (United States)

    Jacobs, C D; Bergen, M R; Korn, D

    2000-05-01

    To measure the effect of an intervention to reduce gender insensitivity and sexual harassment at one medical school. Stanford University School of Medicine undertook a multifaceted program to educate faculty and students regarding gender issues and to diminish sexual harassment. The authors developed a survey instrument to assess the faculty's perceptions regarding environment (five scales) and incidences of sexual harassment. Faculty were surveyed twice during the interventions (1994 and 1995). Between the two years, the authors measured significant improvements in mean ratings for positive climate (p = .004) and cohesion (p = .006) and decreases in the faculty's perceptions of sexual harassment (p = 0006), gender insensitivity (p = .001), and gender discrimination (p = .004). The faculty also reported fewer observations of harassing behavior during the study period. An intervention program to diminish gender insensitivity and sexual harassment can measurably improve a medical school's environment.

  6. Family Structure and Subsequent Anxiety Symptoms; Minorities’ Diminished Return

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2018-05-01

    Full Text Available Background: Minorities’ Diminished Return (MDR theory suggests that socioeconomic position (SEP may have a smaller effect on health and well-being of members of the minority than the majority groups. Aim: Built on the MDR theory, this study compared Whites and African Americans for the effects of three family SEP indicators (family type, parental education, and parental employment during adolescence on subsequent symptoms of anxiety 18 years later during young adulthood. Methods: Flint Adolescents Study (FAS, 1994–2012, followed 359 youth (ages 13 to 17, 295 African American and 64 Whites for 18 years. The independent variables were family type, parental education, and parental employment during adolescence. The dependent variable was subsequent symptoms of anxiety, measured using the Brief Symptom Inventory (BSI, 18 years later. Age and gender were the covariates and race/ethnicity was the focal effect modifier (moderator. Four linear regression models were estimated to investigate the effects of the three family SEP indicators at age 15 on subsequent symptoms of anxiety at age 33 in the pooled sample and also by race/ethnicity. Results: In the pooled sample, having married parents at age 15 was inversely associated with symptoms of anxiety at age 33. We found an interaction between race/ethnicity and family type, indicating a smaller protective effect of having married parents against symptoms of anxiety for African American compared to White participants. The other two SEP indicators did not show any effect and did not interact with race/ethnicity on the outcome. Conclusion: In support of the MDR theory, marital status of parents during adolescence protects White but not African American young adults against anxiety symptoms. Diminished return of SEP is one of many underlying mechanisms involved in shaping racial and ethnic disparities in anxiety, however, that is often overlooked. Future research that examines economic and social

  7. Adaptive training diminishes distractibility in aging across species.

    Science.gov (United States)

    Mishra, Jyoti; de Villers-Sidani, Etienne; Merzenich, Michael; Gazzaley, Adam

    2014-12-03

    Aging is associated with deficits in the ability to ignore distractions, which has not yet been remediated by any neurotherapeutic approach. Here, in parallel auditory experiments with older rats and humans, we evaluated a targeted cognitive training approach that adaptively manipulated distractor challenge. Training resulted in enhanced discrimination abilities in the setting of irrelevant information in both species that was driven by selectively diminished distraction-related errors. Neural responses to distractors in auditory cortex were selectively reduced in both species, mimicking the behavioral effects. Sensory receptive fields in trained rats exhibited improved spectral and spatial selectivity. Frontal theta measures of top-down engagement with distractors were selectively restrained in trained humans. Finally, training gains generalized to group and individual level benefits in aspects of working memory and sustained attention. Thus, we demonstrate converging cross-species evidence for training-induced selective plasticity of distractor processing at multiple neural scales, benefitting distractor suppression and cognitive control. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Diminished alternative reinforcement as a mechanism linking conduct problems and substance use in adolescence: a longitudinal examination.

    Science.gov (United States)

    Khoddam, Rubin; Cho, Junhan; Jackson, Nicholas J; Leventhal, Adam M

    2018-06-01

    To determine whether diminished alternative reinforcement (i.e. engagement and enjoyment from substance-free activities) mediated the longitudinal association of conduct problems with substance use in early-mid-adolescence. Structural equation modeling tested whether the association between wave 1 (baseline) conduct problems and wave 3 (24-month follow-up) substance use outcomes was mediated by diminished alternative reinforcement at wave 2 (12-month follow-up). Additional analyses tested whether sex and socio-economic status moderated this association. Ten high schools in Los Angeles, CA, USA, 2013-15. Students (n = 3396, 53.5% female, mean [standard deviation (SD)] age at wave 1 baseline = 14.1 (0.42) years). Self-reported conduct problems (11-item questionnaire), alternative reinforcement (44-item questionnaire) and use of alcohol, marijuana and combustible cigarettes during the past 6 months (yes/no) and the past 30 days (nine-level ordinal response based on days used in past 30 days). Significant associations of wave 1 conduct problems with wave 3 marijuana use during the past 6 months (β = 0.25) and past 30 days (β = 0.26) were mediated by wave 2 diminished alternative reinforcement (β indirect effect : 6 months = 0.013, 30 days = 0.017, Ps alternative reinforcement. All associations did not differ by sex and socio-economic status. Diminished alternative reinforcement may be a modifiable mechanism linking early adolescent conduct problems and subsequent marijuana use that could be targeted in prevention programs to offset the adverse health and social sequelae associated with comorbid conduct problems and marijuana use in early-mid adolescence. © 2018 Society for the Study of Addiction.

  9. Diminishing musyarakah investment model based on equity

    Science.gov (United States)

    Jaffar, Maheran Mohd; Zain, Shaharir Mohamad; Jemain, Abdul Aziz

    2017-11-01

    Most of the mudharabah and musyarakah contract funds are involved in debt financing. This does not support the theory that profit sharing contract is better than that of debt financing due to the sharing of risks and ownership of equity. Indeed, it is believed that Islamic banking is a financial model based on equity or musyarakah which emphasis on the sharing of risks, profit and loss in the investment between the investor and entrepreneur. The focus of this paper is to introduce the mathematical model that internalizes diminishing musyarakah, the sharing of profit and equity between entrepreneur and investor. The entrepreneur pays monthly-differed payment to buy out the equity that belongs to the investor (bank) where at the end of the specified period, the entrepreneur owns the business and the investor (bank) exits the joint venture. The model is able to calculate the amount of equity at any time for both parties and hence would be a guide in helping to estimate the value of investment should the entrepreneur or investor exit before the end of the specified period. The model is closer to the Islamic principles for justice and fairness.

  10. Diminished insulin-mediated forearm blood flow and muscle glucose uptake in young men with low birth weight

    DEFF Research Database (Denmark)

    Sonne, M P; Højbjerre, L; Alibegovic, A C

    2009-01-01

    BACKGROUND: Low birth weight (LBW) is associated with increased risk of type 2 diabetes and cardiovascular disease. We studied endothelial function and insulin sensitivity in young men with LBW (n = 22) and controls (n = 22). METHODS: Insulin sensitivity and endothelial function was studied...... with venous occlusion plethysmography and intra-arterial infusions of adenosine and acetylcholine, before and during a hyperinsulinemic isoglycemic clamp. RESULTS: Forearm blood flow response to systemic hyperinsulinemia was diminished in LBW compared to controls (p ... extraction was similar, and consequently insulin-stimulated forearm glucose clearance was diminished in LBW compared with controls (0.8 +/- 0.09 vs. 1.4 +/- 0.36 ml x 100 ml(-1) x min(-1), respectively, p

  11. Breadnut peel as a highly effective low-cost biosorbent for methylene blue: Equilibrium, thermodynamic and kinetic studies

    Directory of Open Access Journals (Sweden)

    Linda B.L. Lim

    2017-05-01

    Full Text Available This work reports the potential use of peel of breadnut, Artocarpus camansi, as an effective low-cost biosorbent for the removal of methylene blue (MB. Oven dried A. camansi peel (ACP, which had a point of zero charge at pH = 4.8, showed maximum biosorption capacity which was far superior to most literature reported fruit biomasses, including samples that have been activated. Isotherm studies on biosorption of MB onto ACP gave a maximum biosorption capacity of 409 mg g−1. The Langmuir model was found to give the best fit among various isotherm models investigated and error analyses performed. Kinetics studies were fast with 50% dye being removed in less than 8 min from a 50 mg L−1 dye solution and further, kinetics followed the pseudo second order. Thermodynamic studies indicated that the biosorption process was both spontaneous and exothermic. Fourier transform infrared (FT-IR of ACP before and after MB adsorption was investigated. It can be concluded that oven dried breadnut peel is a highly promising low-cost biosorbent with great potential for the removal of MB.

  12. The immune receptor Trem1 cooperates with diminished DNA damage response to induce preleukemic stem cell expansion.

    Science.gov (United States)

    Du, W; Amarachintha, S; Wilson, A; Pang, Q

    2017-02-01

    Fanconi anemia (FA) is an inherited bone marrow failure syndrome with extremely high risk of leukemic transformation. Here we investigate the relationship between DNA damage response (DDR) and leukemogenesis using the Fanca knockout mouse model. We found that chronic exposure of the Fanca -/- hematopoietic stem cells to DNA crosslinking agent mitomycin C in vivo leads to diminished DDR, and the emergence/expansion of pre-leukemia stem cells (pre-LSCs). Surprisingly, although genetic correction of Fanca deficiency in the pre-LSCs restores DDR and reduces genomic instability, but fails to prevent pre-LSC expansion or delay leukemia development in irradiated recipients. Furthermore, we identified transcription program underlying dysregulated DDR and cell migration, myeloid proliferation, and immune response in the Fanca -/- pre-LSCs. Forced expression of the downregulated DNA repair genes, Rad51c or Trp53i13, in the Fanca -/- pre-LSCs partially rescues DDR but has no effect on leukemia, whereas shRNA knockdown of the upregulated immune receptor genes Trem1 or Pilrb improves leukemia-related survival, but not DDR or genomic instability. Furthermore, Trem1 cooperates with diminished DDR in vivo to promote Fanca -/- pre-LSC expansion and leukemia development. Our study implicates diminishing DDR as a root cause of FA leukemogenesis, which subsequently collaborates with other signaling pathways for leukemogenic transformation.

  13. Biosorption of multi-heavy metals by coral associated phosphate solubilising bacteria Cronobacter muytjensii KSCAS2.

    Science.gov (United States)

    Saranya, Kailasam; Sundaramanickam, Arumugam; Shekhar, Sudhanshu; Meena, Moorthy; Sathishkumar, Rengasamy Subramaniyan; Balasubramanian, Thangavel

    2018-06-02

    This paper examines the potential detoxification efficiency of heavy metals by phosphate solubilising bacteria (PSB) that were isolated from coral, sea grass and mangrove environment. Initially, four potential bacterial isolates were selected based on their phosphate solubilisation index from 42 strains and were used for the metal tolerance test. Among the four isolates, KSCAS2 exhibited maximum tolerance to heavy metals and the phenotype indicated the production of extra polymeric substances. In a multi-heavy metal experimental setup at two concentrations (100 and 200 mg L -l ), it has been demonstrated that the bacteria have extracellularly sequestered metal ions in amorphous deposits and this has been confirmed by scanning electron microscopy. In experiments with a 100 mg L -1 initial metal concentration, the percentages of metal removal by bacteria were 55.23% of Cd, 72.45% of Cr, 76.51% of Cu and 61.51% of Zn, respectively. In subsequent experiments, when the metal concentration was increased up to 200 mg L -l , the metal removal capacity decreased as follows: 44.62%, 63.1%, 67% and 52.80% for Cd, Cr, Cu and Zn, respectively. In addition, the biosorption of heavy metals was confirmed by the Fourier transform infrared Spectroscopy (FT-IR) and scanning electron microscopy (SEM) analysis. The heavy metal concentrations in a broth culture were analysed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The study suggests that PSB Cronobacter muytjensii KSCAS2 can efficiently remove the heavy metals and these bacteria could be used for the metal removal from the agricultural soils. Copyright © 2018. Published by Elsevier Ltd.

  14. Removal of heavy metals from waste water of tanning leather ...

    African Journals Online (AJOL)

    The most dominant A. candidus on the isolation plates exhibited the highest activity for biosorption of heavy metals. The results indicate that fungi of contaminated soils have high level of metal biosorption capacities. Keywords: Fungi, industrial wastewater, biosorption, heavy metals. African Journal of Biotechnology Vol.

  15. When is diminishment a form of enhancement? Rethinking the enhancement debate in biomedical ethics

    Directory of Open Access Journals (Sweden)

    Brian D. Earp

    2014-02-01

    Full Text Available The enhancement debate in neuroscience and biomedical ethics tends to focus on the augmentation of certain capacities or functions: memory, learning, attention, and the like. Typically, the point of contention is whether these augmentative enhancements are permissible for individuals with no particular ‘medical’ disadvantage along any of the dimensions of interest. Less frequently addressed in the literature, however, is the fact that sometimes the diminishment of a capacity or function, under the right set of circumstances, could plausibly contribute to an individual’s overall well-being: more is not always better, and sometimes less is more. Such cases may be especially likely, we suggest, when trade-offs in our modern environment have shifted since the environment of evolutionary adaptation. In this article, we introduce the notion of diminishment as enhancement and go on to defend a welfarist conception of enhancement. We show how this conception resolves a number of definitional ambiguities in the enhancement literature, and we suggest that it can provide a useful framework for thinking about the use of emerging neurotechnologies to promote human flourishing.

  16. The problem of social exclusion diminishing in the context of European parliament recommendations

    Directory of Open Access Journals (Sweden)

    Arvydas

    2015-12-01

    Full Text Available European Parliament is one of the most significant EU institutions which are responsible for the tasks of social dimension‘s aims declaration and implementation. One of the most actual tasks, solved by European Parliament, is social security measures fitness to real minimal subsistence level and social inequality and exclusion diminishing in the member states. Strengthening of social dimension and lessening of social exclusion can also suffer from economic difficulties, which appeared in the member states after 2008–2009 economic crisis – when there is still no breaking with the crisis past and the new downfall is still possible. In the article the impact of crisis for social exclusion diminishing is analyzed in the context of European Parliament recommendations. Social security measures had only limited impact for stabilization in the member states, however, the author argues and the European Parliament documents prove, that social security measures are not the burden, but the reserve for development in the member states. In this case, European Parliament together with International Labour Organization, according the author, are the most socially exposed organizations in the world. In the end of the article there is suggested the significant social reintegration indicator for the measurement of social security‘s efficiency and effectiveness.

  17. Cell phone use diminishes self-awareness of the adverse effects of cell phone use on driving.

    Science.gov (United States)

    2017-03-01

    Multitasking may diminish the self-awareness of performance that is often essential for self-regulation : and self-knowledge. Participants in an experiment drove on a simulator while talking or not talking on a : cell phone. The errors they made whil...

  18. Less Guilty by Reason of Adolescence: Developmental Immaturity, Diminished Responsibility, and the Juvenile Death Penalty

    Science.gov (United States)

    Steinberg, Laurence; Scott, Elizabeth S.

    2003-01-01

    The authors use a developmental perspective to examine questions about the criminal culpability of juveniles and the juvenile death penalty. Under principles of criminal law, culpability is mitigated when the actor's decision-making capacity is diminished, when the criminal act was coerced, or when the act was out of character. The authors argue…

  19. Bio-Remediation of Acid Mine Drainage in the Sarcheshmeh Porphyry Copper Mine by Fungi: Batch and Fixed Bed Process

    Directory of Open Access Journals (Sweden)

    Hanieh Soleimanifar

    2012-12-01

    Full Text Available Acid mine drainage (AMD containing high concentrations of iron and sulphate, low pH and variableconcentrations of heavy metals leads to many environmental problems. The concentrations of Cu and Mnare high in the AMD of the Sarcheshmeh porphyry copper mine, Kerman province, south of Iran. In thisstudy, the bio-remediation of Cu and Mn ions from acid mine drainage was investigated using two nativefungi called Aspergillus niger and Phanerochaete chrysosporium which were extracted from the soil andsediment samples of the Shour River at the Sarcheshmeh mine. The live fungi was first harvested andthen killed by boiling in 0.5 N NaOH solution. The biomass was finally dried at 60 C for 24 h andpowdered. The optimum biosorption parameters including pH, temperature, the amount of biosorbent andcontact time were determined in a batch system. The optimum pH varied between 5 and 6. It was foundthat the biosorption process increased with an increase in temperature and the amount of biosorbent.Biosorption data were attempted by Langmuir and Freundlich isotherm models and showed a good match.Kinetic studies were also carried out in the present study. The results show that the second-order kineticsmodel fits well the experimental data. The biosorption experiments were further investigated with acontinuous system to compare the biosorption capacities of two systems. The results show thatbiosorption process using a continuous system increases efficiency up to 99%. A desorption process waseventually performed in order to recover Copper and Manganese ions. This process was successful andfungi could be used again.

  20. Study of the interaction mechanism in the biosorption of copper(II) ions onto posidonia oceanica and peat

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Marta; Marzal, Paula; Gabaldon, Carmen [Departamento de Ingenieria Quimica, Escuela Tecnica Superior de Ingenieria, Universitat de Valencia, Valencia (Spain); Silvetti, Margherita; Castaldi, Paola [Dipartimento di Scienze Ambientali e Agrarie e Biotecnologie Agro-Alimentari, Sez. Chimica Agraria ed Ambientale, University of Sassari, Sassari (Italy)

    2012-04-15

    A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption-desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4-6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q{sub max}) at pH 6 of 85.78 and 49.69 mg g{sup -1}, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO{sub 3}){sub 2}, and EDTA was applied to copper-saturated biosorbents. Around 65-70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH{sub 2}, and CH{sub 3} in aliphatic structures, COO{sup -} and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to Si-O groups on the surface of peat. The results of SEM-EDX and FTIR analysis of copper-saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption-desorption processes affected the thermal stability of the biosorbents. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Awe, the diminished self, and collective engagement: Universals and cultural variations in the small self.

    Science.gov (United States)

    Bai, Yang; Maruskin, Laura A; Chen, Serena; Gordon, Amie M; Stellar, Jennifer E; McNeil, Galen D; Peng, Kaiping; Keltner, Dacher

    2017-08-01

    Awe has been theorized as a collective emotion, one that enables individuals to integrate into social collectives. In keeping with this theorizing, we propose that awe diminishes the sense of self and shifts attention away from individual interests and concerns. In testing this hypothesis across 6 studies (N = 2137), we first validate pictorial and verbal measures of the small self; we then document that daily, in vivo, and lab experiences of awe, but not other positive emotions, diminish the sense of the self. These findings were observed across collectivist and individualistic cultures, but also varied across cultures in magnitude and content. Evidence from the last 2 studies showed that the influence of awe upon the small self accounted for increases in collective engagement, fitting with claims that awe promotes integration into social groups. Discussion focused on how the small self might mediate the effects of awe on collective cognition and behavior, the need to study more negatively valenced varieties of awe, and other potential cultural variations of the small self. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Removal of Cu(II) from aqueous solution by agricultural by-product: Peanut hull

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Chunshui, E-mail: silk588@126.com [School of Environment Science and Spatial Informatics, China university of Mining and technology, Xuzhou, Jiangsu 221008 (China) and School of Chemical Engineering, Huai-hai institute of Technology, Lian Yungang, Jiangsu 222005 (China); Wang Liping [School of Environment Science and Spatial Informatics, China university of Mining and technology, Xuzhou, Jiangsu 221008 (China); Chen Wenbin [School of Environment Science and Spatial Informatics, China university of Mining and technology, Xuzhou, Jiangsu 221008 (China); School of Chemical Engineering, Huai-hai institute of Technology, Lian Yungang, Jiangsu 222005 (China)

    2009-09-15

    Peanut hull, an agricultural by-product abundant in China, was used as adsorbent for the removal of Cu(II) from aqueous solutions. The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration and reaction temperature. The Cu(II) removal was pH-dependent, reaching a maximum at pH 5.5. The biosorption process followed pseudo-second-order kinetics and equilibrium was attained at 2 h. The rate constant increased with the increase of temperature indicates endothermic nature of biosorption. The activation energy (E{sub a}) of Cu(II) biosorption was determined at 17.02 kJ/mol according to Arrhenius equation which shows that biosorption may be an activated chemical biosorption. Other activation parameters such as {Delta}H{sup numbersign}, {Delta}S{sup numbersign}, and {Delta}G{sup numbersign} were also determined from Eyring equation. The equilibrium data were analyzed using the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models depending on temperature. The equilibrium biosorption capacity of Cu(II) determined from the Langmuir equation was 21.25 mg/g at 30 deg. C. The mean free energy E (kJ/mol) got from the D-R isotherm also indicated a chemical ion-exchange mechanism. The thermodynamic parameters such as changes in Gibbs free energy ({Delta}G{sup 0}), enthalpy ({Delta}H{sup 0}) and entropy ({Delta}S{sup 0}) were used to predict the nature of biosorption process. The negative {Delta}G{sup 0} values at various temperatures confirm the biosorption processes are spontaneous.

  3. Discovery and Computational Rationalization of Diminishing Alternation in [n]Dendralenes.

    Science.gov (United States)

    Saglam, Mehmet F; Fallon, Thomas; Paddon-Row, Michael N; Sherburn, Michael S

    2016-01-27

    The [n]dendralenes are a family of acyclic hydrocarbons which, by virtue of their ability to rapidly generate structural complexity, have attracted significant recent synthetic attention. [3]Dendralene through [8]dendralene have been previously prepared but no higher member of the family has been reported to date. Here, we describe the first chemical syntheses of the "higher" dendralenes, [9]dendralene through [12]dendralene. We also report a detailed investigation into the spectroscopic properties and chemical reactivity of the complete family of fundamental hydrocarbons, [3]dendralene to [12]dendralene. These studies reveal the first case of diminishing alternation in behavior in a series of related structures. We also report a comprehensive series of computational studies, which trace this dampening oscillatory effect in both spectroscopic measurements and chemical reactivity to conformational preferences.

  4. Gesturing more diminishes recall of abstract words when gesture is allowed and concrete words when it is taboo.

    Science.gov (United States)

    Matthews-Saugstad, Krista M; Raymakers, Erik P; Kelty-Stephen, Damian G

    2017-07-01

    Gesture during speech can promote or diminish recall for conversation content. We explored effects of cognitive load on this relationship, manipulating it at two scales: individual-word abstractness and social constraints to prohibit gestures. Prohibited gestures can diminish recall but more so for abstract-word recall. Insofar as movement planning adds to cognitive load, movement amplitude may moderate gesture effects on memory, with greater permitted- and prohibited-gesture movements reducing abstract-word recall and concrete-word recall, respectively. We tested these effects in a dyadic game in which 39 adult participants described words to confederates without naming the word or five related words. Results supported our expectations and indicated that memory effects of gesturing depend on social, cognitive, and motoric aspects of discourse.

  5. Extreme cognitions are associated with diminished ability to use disconfirming evidence.

    Science.gov (United States)

    Haigh, Matthew; Dodd, Alyson L

    2017-03-01

    An Integrative Cognitive Model of mood swings and bipolar disorder proposes that cognitive styles characterized by extreme self-referent appraisals of internal states (e.g., 'If I have a bad night's sleep it means that I am about to have a breakdown') interfere with mood regulation. The aim of this study is to determine whether strong endorsement of such appraisals is predicted by a diminished ability to access disconfirming counterexamples. We examined whether the ability to access two different categories of counterexample (known as Disabling Conditions and Alternative Causes) would predict endorsement of extreme appraisals (measured by the Hypomanic Attitudes and Positive Predictions Inventory; HAPPI) and mania risk (measured by the Hypomanic Personality Scale; HPS). A non-clinical sample of 150 students completed the HAPPI, the HPS and a conditional reasoning task that indexed the ability to access Disabling Conditions and Alternative Causes. Current mood was controlled for using the Internal States Scale. The ability to make use of disabling counterexamples during the reasoning task was inversely related with scores on the HAPPI (r = -.19, p referent appraisals to a greater extent. There was no association between the use of alternative cause counterexamples and the HAPPI, and no association between either measure of counterexample generation and the HPS. A diminished ability to use disconfirming evidence when reasoning about the world may reinforce problematic cognitive styles such as extreme, personalized appraisals of experience, which can interfere with mood regulation. Problematic cognitive styles such as extreme, personalized appraisals of experience may be reinforced by the inability to produce or access evidence that disconfirms these maladaptive beliefs. This reasoning bias may be associated with cognitive styles underlying psychopathology. There may be clinical utility in exploring the use of disabler generation in psychological interventions, to

  6. Rehearsal Strategies Can Enlarge or Diminish the Spacing Effect: Pure versus Mixed Lists and Encoding Strategy

    Science.gov (United States)

    Delaney, Peter F.; Verkoeijen, Peter P. J. L.

    2009-01-01

    Using 5 experiments, the authors explored the dependency of spacing effects on rehearsal patterns. Encouraging rehearsal borrowing produced opposing effects on mixed lists (containing both spaced and massed repetitions) and pure lists (containing only one or the other), magnifying spacing effects on mixed lists but diminishing spacing effects on…

  7. Sorption of 241Am by Aspergillus niger spore and hyphae

    International Nuclear Information System (INIS)

    Yuanyou Yang; Ning Liu; Jiali Liao; Jiannan Jin; Shunzhong Luo; Taiming Zhang; Pengji Zhao

    2004-01-01

    Biosorption of 241 Am by a fungus A. niger, including the spore and hyphae, was investigated. The preliminary results showed that the adsorption of 241 Am by the microorganism was efficient. More than 96% of the total 241 Am could be removed from 241 Am solutions of 5.6-111 MBq/l (C 0 ) by spore and hyphae of A. niger, with adsorbed 241 Am metal (Q) of 7.2-142.4 MBq/g biomass, and 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 hour and the optimum pH range was pH 1-3. No obvious effects on 241 Am adsorption by the fungus were observed at 10-45 deg C, or in solutions containing Au 3+ or Ag + , even 2000 times above the 241 Am concentration. The 241 Am biosorption by the fungus obeys the Freundlich adsorption equation. There was no significant difference between the adsorption behavior of A. niger spore and hyphae. (author)

  8. Does too much work hamper innovation? Evidence for diminishing returns of work hours for patent grants

    NARCIS (Netherlands)

    Celbis, M.G.; Turkeli, S.

    2014-01-01

    This study suggests that individual time is an important factor that needs to be considered in innovation research. We define two types of time: work time and free time. We find that work time has a positive but diminishing effect on innovative output such that after a certain point the

  9. Isolation and identification of Trichoderma harzianum from groundwater: An effective biosorbent for defluoridation of groundwater.

    Science.gov (United States)

    Koshle, Shalini; Mahesh, S; Swamy, S Nanjunda

    2016-01-01

    The ability of non-viable form of Trichoderma harzianum, isolated from fluoride rich groundwater, was investigated as biosorbent for defluoridation of groundwater. Biosorption experiments were carried out at laboratory scale for removal of fluoride from groundwater. Significant effect of operational parameters on fluoride biosorption using Trichoderma harzianum as biosorbent was evaluated by varying operational parameters such as: initial fluoride concentration (2-8 mgl(-1)), biosorbent dose (0.4-1.6g/100ml), groundwater pH (6-10), temperature (30-50 degrees C) and biosorption time (30-120 min). The fluoride adsorption isotherms were modeled by Langmuir and Freundlich isotherms. Our result showed that fluoride biosorption, significantly increased with increase in groundwater pH, biosorbent dose, temperature and biosorption time, whereas increase in initial fluoride concentration reduced fluoride removal. The fluoride biosorption was rapid and maximum fluoride uptake was attained with 1.6g 100ml(-1) biosorbent within 60 min. Optimal pH 10 and temperature 50 degrees C gave maximum defluoridation efficiency. Freundlich isotherm fits well for defluoridation of groundwater using Trichoderma harzianum as biosorbent which indicated that biosorbent surface sites were heterogeneous in nature and fitted into heterogeneous site binding model.

  10. Biomass selection for biosorption study of {sup 226} Ra and {sup 137} Cd radionuclides; Selecao de biomassas para o estudo da biossorcao dos radionuclideos {sup 226} Ra e {sup 137} Cs

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Wilson Cervi da

    2003-07-01

    The main goal of this work was to verify the potentialities to apply the biosorption technique to synthetic and real solution containing {sup 226} Ra and {sup 137} Cs, utilizing the seaweed Sargassum sp. and the microorganisms Penicillium sp., Saccharomyces cerevisiae and Monoraphidium sp. Indeed, the screening of the most effective biomass to remove the radionuclides was also a central objective. {sup 226} Ra was selected due to its high radiotoxicity and the fact that it can be assimilated and incorporated by living organism through substitution og Mg{sup 2+} and Ca{sup 2+}, two essential nutrients. On the other hand, the selection of {sup 137} Cs, a radionuclide of medium toxicity, was due to its mobility in the environment, which increases the possibility to be assimilated by the organisms as the essential nutrients Na{sup +} and K{sup +}. (author)

  11. Diminished Auditory Responses during NREM Sleep Correlate with the Hierarchy of Language Processing.

    Directory of Open Access Journals (Sweden)

    Meytal Wilf

    Full Text Available Natural sleep provides a powerful model system for studying the neuronal correlates of awareness and state changes in the human brain. To quantitatively map the nature of sleep-induced modulations in sensory responses we presented participants with auditory stimuli possessing different levels of linguistic complexity. Ten participants were scanned using functional magnetic resonance imaging (fMRI during the waking state and after falling asleep. Sleep staging was based on heart rate measures validated independently on 20 participants using concurrent EEG and heart rate measurements and the results were confirmed using permutation analysis. Participants were exposed to three types of auditory stimuli: scrambled sounds, meaningless word sentences and comprehensible sentences. During non-rapid eye movement (NREM sleep, we found diminishing brain activation along the hierarchy of language processing, more pronounced in higher processing regions. Specifically, the auditory thalamus showed similar activation levels during sleep and waking states, primary auditory cortex remained activated but showed a significant reduction in auditory responses during sleep, and the high order language-related representation in inferior frontal gyrus (IFG cortex showed a complete abolishment of responses during NREM sleep. In addition to an overall activation decrease in language processing regions in superior temporal gyrus and IFG, those areas manifested a loss of semantic selectivity during NREM sleep. Our results suggest that the decreased awareness to linguistic auditory stimuli during NREM sleep is linked to diminished activity in high order processing stations.

  12. Diminished Auditory Responses during NREM Sleep Correlate with the Hierarchy of Language Processing.

    Science.gov (United States)

    Wilf, Meytal; Ramot, Michal; Furman-Haran, Edna; Arzi, Anat; Levkovitz, Yechiel; Malach, Rafael

    2016-01-01

    Natural sleep provides a powerful model system for studying the neuronal correlates of awareness and state changes in the human brain. To quantitatively map the nature of sleep-induced modulations in sensory responses we presented participants with auditory stimuli possessing different levels of linguistic complexity. Ten participants were scanned using functional magnetic resonance imaging (fMRI) during the waking state and after falling asleep. Sleep staging was based on heart rate measures validated independently on 20 participants using concurrent EEG and heart rate measurements and the results were confirmed using permutation analysis. Participants were exposed to three types of auditory stimuli: scrambled sounds, meaningless word sentences and comprehensible sentences. During non-rapid eye movement (NREM) sleep, we found diminishing brain activation along the hierarchy of language processing, more pronounced in higher processing regions. Specifically, the auditory thalamus showed similar activation levels during sleep and waking states, primary auditory cortex remained activated but showed a significant reduction in auditory responses during sleep, and the high order language-related representation in inferior frontal gyrus (IFG) cortex showed a complete abolishment of responses during NREM sleep. In addition to an overall activation decrease in language processing regions in superior temporal gyrus and IFG, those areas manifested a loss of semantic selectivity during NREM sleep. Our results suggest that the decreased awareness to linguistic auditory stimuli during NREM sleep is linked to diminished activity in high order processing stations.

  13. Luteal-phase ovarian stimulation increases the number of mature oocytes in older women with severe diminished ovarian reserve.

    Science.gov (United States)

    Rashtian, Justin; Zhang, John

    2018-03-22

    In older women with severe diminished ovarian response (DOR), in vitro fertilization (IVF) treatment is much less successful due to the low number of mature oocytes collected. The objective of this study was to assess whether follicular-phase stimulation (FPS) and luteal-phase stimulation (LPS) in the same menstrual cycle (double ovarian stimulation) in older women with severe DOR will produce a higher number of oocytes compared to FPS alone. Women with DOR (n = 69; mean age = 42.4) who underwent double ovarian stimulation for IVF were included. Women underwent ovarian stimulation in FPS using clomiphene citrate, letrozole, and gonadotropins followed by oocyte retrieval. The next day following oocyte retrieval, women underwent a second ovarian stimulation (LPS) using the same medications followed by a second oocyte retrieval. T-test was performed in order to compare the clinical characteristics and outcome in the same participant between FPS and LPS. Although antral follicle count at the start of FPS tended to be higher than at the start of the LPS cycle, there was no statistically significant difference between the duration of ovarian stimulation, peak estradiol levels, number of small (FPS alone. The addition of LPS to the conventional FPS increases the number of mature oocytes retrieved in the same IVF cycle, thus potentially increasing the chances of pregnancy in older women with severe DOR. AFC: antral follicle count; BMI: body mass index; DOR: diminished ovarian reserve; E2: estradiol; FPS: follicular-phase stimulation; FSH: follicle stimulating hormone; GnRH: gonadotropin-releasing hormone; HCG: human chorionic gonadotropin; IRB: institutional review board; IVF: in vitro fertilization; LH: luteinizing hormone; LPS: luteal-phase stimulation; MII: metaphase II.

  14. When will fossil fuel reserves be diminished?

    International Nuclear Information System (INIS)

    Shafiee, Shahriar; Topal, Erkan

    2009-01-01

    Crude oil, coal and gas are the main resources for world energy supply. The size of fossil fuel reserves and the dilemma that 'when non-renewable energy will be diminished' is a fundamental and doubtful question that needs to be answered. This paper presents a new formula for calculating when fossil fuel reserves are likely to be depleted and develops an econometrics model to demonstrate the relationship between fossil fuel reserves and some main variables. The new formula is modified from the Klass model and thus assumes a continuous compound rate and computes fossil fuel reserve depletion times for oil, coal and gas of approximately 35, 107 and 37 years, respectively. This means that coal reserves are available up to 2112, and will be the only fossil fuel remaining after 2042. In the Econometrics model, the main exogenous variables affecting oil, coal and gas reserve trends are their consumption and respective prices between 1980 and 2006. The models for oil and gas reserves unexpectedly show a positive and significant relationship with consumption, while presenting a negative and significant relationship with price. The econometrics model for coal reserves, however, expectedly illustrates a negative and significant relationship with consumption and a positive and significant relationship with price. Consequently, huge reserves of coal and low-level coal prices in comparison to oil and gas make coal one of the main energy substitutions for oil and gas in the future, under the assumption of coal as a clean energy source

  15. The effect of biomass concentration on polymer alginate in the immobilized biosorbent formation during the sorption processof heavy metal Cu2+

    Science.gov (United States)

    Rinanti, A.; Jonathan, D.; Silalahi, M. D. S.; Fachrul, M. F.; Hadisoebroto, R.

    2018-01-01

    A research in environmental biotechnology has been done to analysis adsorption of ion Cu2+ by biomass of microalgae (Chlorella sp, Ankistrodesmus braunii, Scenedesmus quadricauda) and Saccharomyces cerevisiae onto alginate polymeras immobilized biosorbent on laboratory scale. The purpose of this study is to achieve the optimum biomass concentration which gives the best biosorption performance. Biosorption of Cu2+ was carried out in continuous fixed-bed column reactor system, volume of 1.5 L, equipped with peristaltic pump with a flow rate of 13 mL/min. Biosorption of Cu2+ was investigated using immobilized biosorbent with concentration of (g biomass/g polymer) 0.25; 0.5; 1, at pH4,initial concentration Cu2+15 mg/L and 26°C±1. The results of this study showed that the increasing of biomass concentration (0 to 0.5 g/g) would result in better biosorption performance but soon decreased its performance at biomass concentration of 1 g/g. Biosorption capacity and highest removal efficiency of 0.1025 mg Cu2+/g biosorbent and 66.36% occurred by immobilized biosorbent with 0.5 g/g concentration. The connection between the variation of biomass concentration in alginate to the biosorption performance by immobilized biosorbent shown by breakthrough curve, total adsorbed metal mass(qtotal ), efficiency of removal (%R) and biosorption capacity at breakthrough(qe ). Excessive biomass concentrations lead to reduced porosity of the beads thus slowing down the adsorption process.

  16. Reconciling the Mitscherlich's law of diminishing returns with Liebig's law of the minimum. Some results on crop modeling.

    Science.gov (United States)

    Ferreira, Iuri E P; Zocchi, Silvio S; Baron, Daniel

    2017-11-01

    Reliable fertilizer recommendations depend on the correctness of the crop production models fitted to the data, but generally the crop models are built empirically, neglecting important physiological aspects related with response to fertilizers, or they are based in laws of plant mineral nutrition seen by many authors as conflicting theories: the Liebig's Law of the Minimum and Mitscherlich's Law of Diminishing Returns. We developed a new approach to modelling the crop response to fertilizers that reconcile these laws. In this study, the Liebig's Law is applied at the cellular level to explain plant production and, as a result, crop models compatible with the Law of Diminishing Returns are derived. Some classical crop models appear here as special cases of our methodology, and a new interpretation for Mitscherlich's Law is also provided. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Characterization of the binding capacity of mercurial species in Lactobacillus strains.

    Science.gov (United States)

    Alcántara, Cristina; Jadán-Piedra, Carlos; Vélez, Dinoraz; Devesa, Vicenta; Zúñiga, Manuel; Monedero, Vicente

    2017-12-01

    Metal sequestration by bacteria has been proposed as a strategy to counteract metal contamination in foodstuffs. Lactobacilli can interact with metals, although studies with important foodborne metals such as inorganic [Hg(II)] or organic (CH 3 Hg) mercury are lacking. Lactobacilli were evaluated for their potential to bind these contaminants and the nature of the interaction was assessed by the use of metal competitors, chemical and enzymatical treatments, and mutants affected in the cell wall structure. Lactobacillus strains efficiently bound Hg(II) and CH 3 Hg. Mercury binding by Lactobacillus casei BL23 was independent of cell viability. In BL23, both forms of mercury were cell wall bound. Their interaction was not inhibited by cations and it was resistant to chelating agents and protein digestion. Lactobacillus casei mutants affected in genes involved in the modulation of the negative charge of the cell wall anionic polymer lipoteichoic acid showed increased mercury biosorption. In these mutants, mercury toxicity was enhanced compared to wild-type bacteria. These data suggest that lipoteichoic acid itself or the physicochemical characteristics that it confers to the cell wall play a major role in mercury complexation. This is the first example of the biosorption of Hg(II) and CH 3 Hg in lactobacilli and it represents a first step towards their possible use as agents for diminishing mercury bioaccessibility from food at the gastrointestinal tract. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  18. A novel approach of utilization of the fungal conidia biomass to remove heavy metals from the aqueous solution through immobilization

    Science.gov (United States)

    Cai, Chun-Xiang; Xu, Jian; Deng, Nian-Fang; Dong, Xue-Wei; Tang, Hao; Liang, Yu; Fan, Xian-Wei; Li, You-Zhi

    2016-11-01

    The biomass of filamentous fungi is an important cost-effective biomass for heavy metal biosorption. However, use of free fungal cells can cause difficulties in the separation of biomass from the effluent. In this study, we immobilized the living conidia of the heavy metal-resistant Penicillium janthinillum strain GXCR by polyvinyl alcohol (PVA)-sodium alginate (SA) beads to remove heavy metals from an aqueous solution containing a low concentration (70 mg/L) of Cu, Pb, and Cd. The PVA-SA-conidia beads showed perfect characters of appropriate mechanical strength suitable for metal removal from the dynamic wastewater environment, an ideal settleability, easy separation from the solution, and a high metal biosorption and removal rate even after four cycles of successive sorption-desorption of the beads, overcoming disadvantages when fungal biomasses alone are used for heavy metal removal from wastewater. We also discuss the major biosorption-affecting factors, biosorption models, and biosorption mechanisms.

  19. Study of parameters that influence the process of biosorption in the removal of heavy metals; Estudo de parametros que influenciam o processo de biossorcao na remocao de metais pesados

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Albina S.; Duarte, Marcia M.L.; Nandenha, Julio; Macedo, Gorete R. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2004-07-01

    The removal of heavy metal by microbial biomass have been investigated as an alternative to the traditional methods. The removal of the heavy metals copper and iron from discarded lubricating-oil was studied using the biosorbent Sargassum sp. It was chosen a discarded lubricating-oil of a bus fleet from the city of Natal-RN-Brazil. The oil was characterized to determine and quantify the heavy metals present. The effect of biomass protonation was performed in order to increase the removal efficiency of the metals. The equilibrium time between the oil and the biomass was determined. It was found that after 10 hours the equilibrium was reached. It was also studied the influence of biomass quantity. The results showed that the biomass quantity is an important parameter to the efficiency and biosorption capacity. The protonated biomass was shown more efficient to removal of Fe and Cu, removing 37,53% and 31,63% respectively. (author)

  20. Overexpression of CRF in the BNST diminishes dysphoria but not anxiety-like behavior in nicotine withdrawing rats.

    Science.gov (United States)

    Qi, Xiaoli; Guzhva, Lidia; Yang, Zhihui; Febo, Marcelo; Shan, Zhiying; Wang, Kevin K W; Bruijnzeel, Adriaan W

    2016-09-01

    Smoking cessation leads to dysphoria and anxiety, which both increase the risk for relapse. This negative affective state is partly mediated by an increase in activity in brain stress systems. Recent studies indicate that prolonged viral vector-mediated overexpression of stress peptides diminishes stress sensitivity. Here we investigated whether the overexpression of corticotropin-releasing factor (CRF) in the bed nucleus of the stria terminalis (BNST) diminishes nicotine withdrawal symptoms in rats. The effect of nicotine withdrawal on brain reward function was investigated with an intracranial self-stimulation (ICSS) procedure. Anxiety-like behavior was investigated in the elevated plus maze test and a large open field. An adeno-associated virus (AAV) pseudotype 2/5 vector was used to overexpress CRF in the lateral BNST and nicotine dependence was induced using minipumps. Administration of the nicotinic receptor antagonist mecamylamine and cessation of nicotine administration led to a dysphoria-like state, which was prevented by the overexpression of CRF in the BNST. Nicotine withdrawal also increased anxiety-like behavior in the elevated plus maze test and large open field test and slightly decreased locomotor activity in the open field. The overexpression of CRF in the BNST did not prevent the increase in anxiety-like behavior or decrease in locomotor activity. The overexpression of CRF increased CRF1 and CRF2 receptor gene expression and increased the CRF2/CRF1 receptor ratio. In conclusion, the overexpression of CRF in the BNST prevents the dysphoria-like state associated with nicotine withdrawal and increases the CRF2/CRF1 receptor ratio, which may diminish the negative effects of CRF on mood. Published by Elsevier B.V.

  1. Mechanisms of diminished natural killer cell activity in pregnant women and neonates

    International Nuclear Information System (INIS)

    Baley, J.E.; Schacter, B.Z.

    1985-01-01

    Because alterations in natural killer (NK) activity in the perinatal period may be important in the maintenance of a healthy pregnancy, the mechanisms by which these alterations are mediated in neonates and in pregnant and postpartum women was examined. NK activity, as measured in a 4-hr 51 Cr-release assay and compared with adult controls, is significantly diminished in all three trimesters of pregnancy and in immediately postpartum women. In postpartum women, NK activity appears to be higher than in pregnant women, although this does not reach statistical significance. Pregnant and postpartum women have normal numbers of large granular lymphocytes and normal target cell binding in an agarose single cell assay but decreased lysis of the bound target cells. NK activity of mononuclear cells from postpartum women, in addition, demonstrate a shift in distribution to higher levels of resistance to gamma-irradiation. Further, sera from postpartum women cause a similar shift to increased radioresistance in mononuclear cells from adult controls. Because radioresistance is a property of interleukin 2-stimulated NK, the shift to radioresistance may represent lymphokine-mediated stimulation occurring during parturition. In contrast, cord blood cells have a more profound decrease in NK activity as determined by 51 Cr-release assay and decreases in both binding and lysis of bound target cells in the single cell assay. The resistance of NK activity in cord cells to gamma-irradiation is also increased, as seen in postpartum women. Cord blood serum, however, did not alter radioresistance or inhibit NK activity. The results suggest that the observed diminished NK activity in pregnant women and neonates arise by different mechanisms: an absence of mature NK cells in the neonate and an alteration of the NK cell in pregnancy leading to decreased killing

  2. Hypoandrogenism in association with diminished functional ovarian reserve.

    Science.gov (United States)

    Gleicher, Norbert; Kim, Ann; Weghofer, Andrea; Kushnir, Vitaly A; Shohat-Tal, Aya; Lazzaroni, Emanuela; Lee, Ho-Joon; Barad, David H

    2013-04-01

    Is diminished functional ovarian reserve (DFOR) associated with low androgen levels? Low androgen levels are associated with DFOR at all ages. Androgen supplementation via dehydroepiandrosterone (DHEA) has been reported to improve functional ovarian reserve (FOR); pregnancy rates in IVF cycles are associated with how well DHEA converts to testosterone (T); and androgen effects through the androgen receptor have been demonstrated in mice to beneficially affect early stages of follicle maturation. In a controlled cohort study we investigated consecutive women presenting to our center with two forms of DFOR, premature ovarian aging/occult primary ovarian insufficiency (POA/OPOI) and physiologic diminished ovarian reserve (DOR). As controls for POA/OPOI patients, infertile women with normal age-specific FOR were recruited. The study involved 140 women with POA/OPOI, defined as age women with DOR, defined as women age >40 years. Forty-nine control patients women early morning cortisol levels were also assessed. DHEAS marginally varied between the three groups (P = 0.04), with older women with DOR actually demonstrating higher levels than controls (P = 0.03). TT differed between the three groups more profoundly (P = 0.005), with women with POA/OPOI demonstrating significantly lower levels than controls (P = 0.009). Adjustment for body mass index, age and race in principle maintained observed differences in TT between groups, while adjustment for FMR1 (fragile X mental retardation 1) genotypes/sub-genotypes eliminated all differences. All three patient groups demonstrated low morning cortisol levels. While results support lower androgen levels in women with DOR, and even more so in women with POA/OPOI, presented data should be viewed as preliminary, considering the known variability of androgen levels and the small number of women in whom morning cortisol levels were available. Especially at young ages DFOR appears associated with significant hypoandrogenism (low T) in

  3. Poor sleep quality diminishes cognitive functioning independent of depression and anxiety in healthy young adults.

    Science.gov (United States)

    Benitez, Andreana; Gunstad, John

    2012-01-01

    Sufficient sleep is essential for optimum cognitive and psychological functioning. Diminished sleep quality is associated with depression and anxiety, but the extent to which poor sleep quality uniquely impacts attention and executive functions independent of the effects of the common underlying features of depression and anxiety requires further exploration. Here 67 healthy young adults were given the Minnesota Multiphasic Personality Inventory, second edition (MMPI-2), the Pittsburgh Sleep Quality Index (PSQI), and tests of attention and executive functions. Similar to findings from a previous study with healthy community-based older adults (Nebes, Buysse, Halligan, Houck, & Monk, 2009), participants who reported poor sleep quality on the PSQI endorsed significantly greater scores on MMPI-2 Restructured Clinical scales related to depression and anxiety (Cohen's d = 0.77-1.05). In addition, PSQI component scores indexing poor sleep quality, duration, and medication use were associated with diminished attention and executive functions, even after controlling for emotional reactivity or demoralization (rs = 0.21-0.27). These results add to the concurrent validity of the PSQI, and provide further evidence for subtle cognitive decrements related to insufficient sleep even in healthy young adults. Future extension of these findings is necessary with larger samples and clinical comparison groups, and using objective indices of sleep dysfunction such as polysomnography.

  4. Regression model, artificial neural network, and cost estimation for biosorption of Ni(II)-ions from aqueous solutions by Potamogeton pectinatus.

    Science.gov (United States)

    Fawzy, Manal; Nasr, Mahmoud; Adel, Samar; Helmi, Shacker

    2018-03-21

    This study investigated the application of Potamogeton pectinatus for Ni(II)-ions biosorption from aqueous solutions. FTIR spectra showed that the functional groups of -OH, C-H, -C = O, and -COO- could form an organometallic complex with Ni(II)-ions on the biomaterial surface. SEM/EDX analysis indicated that the voids on the biosorbent surface were blocked due to Ni(II)-ions uptake via an ion exchange mechanism. For Ni(II)-ions of 50 mg/L, the adsorption efficiency recorded 63.4% at pH: 5, biosorbent dosage: 10 g/L, and particle-diameter: 0.125-0.25 mm within 180 minutes. A quadratic model depicted that the plot of removal efficiency against pH or contact time caused quadratic-linear concave up curves, whereas the curve of initial Ni(II)-ions was quadratic-linear convex down. Artificial neural network with a structure of 5 - 6 - 1 was able to predict the adsorption efficiency (R 2 : 0.967). The relative importance of inputs was: initial Ni(II)-ions > pH > contact time > biosorbent dosage > particle-size. Freundlich isotherm described well the adsorption mechanism (R 2 : 0.974), which indicated a multilayer adsorption onto energetically heterogeneous surfaces. The net cost of using P. pectinatus for the removal of Ni(II)-ions (4.25 ± 1.26 mg/L) from real industrial effluents within 30 minutes was 3.4 $USD/m 3 .

  5. Biosorptive behaviour of Mango (Mangifera indica) and Neem (Azadirachta indica) bark for Hg2+, Cr3+ and Cd2+ toxic ions from aqueous solutions: a radiotracer study

    International Nuclear Information System (INIS)

    Tiwari, Diwakar; Mishra, Shuddhodan P.; Mishra, Manisha; Dubey, R.S.

    1999-01-01

    Biosorption of Hg 2+ and Cr 3+ on dead biomass Mango (Mangifera indica) and Neem (Azadirachta indica) bark has been assessed at micro to tracer level concentrations from aqueous solutions employing the 'radiotracer technique'. A high level of uptake of metal ions on these solid surfaces occurs within ca. 4 h of contact time reaching apparent saturation. The increase of sorptive concentration (10 -8 to 10 -2 mol dm -3 ), temperature (293-323 K) and pH (ca. 3 to 10) favoured the removal process of these ions; but in the case of Hg 2+ on Neem bark, there was seemingly no temperature effect. The uptake process follows first order rate law and obeys the Freundlich adsorption isotherm. Added anions and cations in the bulk solution inhibit to some extent the removal of these toxic ions. Similarly the inhibition in the uptake was also observed when both biomasses were irradiated by neutron and γ-rays prior to being employed as sorbents. No significant sorption of Cd 2+ was observed on these dead biomass solid surfaces under various physical-chemical conditions

  6. Northern European trees show a progressively diminishing response to increasing atmospheric carbon dioxide concentrations

    CSIR Research Space (South Africa)

    Waterhouse, JS

    2004-04-01

    Full Text Available Reviews 23 (2004) 803?810 Northern European trees show a progressively diminishing response to increasing atmospheric carbon dioxide concentrations J.S. Waterhousea,*, V.R. Switsura,b, A.C. Barkera, A.H.C. Cartera,b,{, D.L. Hemmingc, N.J. Loaderd, I..., V.R., Waterhouse, J.S., Heaton, T.H.E., Carter, A.H.C., 1998. Climatic variation andthe stable carbon isotope composition of tree ring cellulose: an intercomparison of Quercus robur, Fagus sylvatica and Pinus silvestris. Tellus 50B, 25?33. J.ggi, M...

  7. Cp/Heph mutant mice have iron-induced neurodegeneration diminished by deferiprone

    Science.gov (United States)

    Zhao, Liangliang; Hadziahmetovic, Majda; Wang, Chenguang; Xu, Xueying; Song, Ying; Jinnah, H.A.; Wodzinska, Jolanta; Iacovelli, Jared; Wolkow, Natalie; Krajacic, Predrag; Weissberger, Alyssa Cwanger; Connelly, John; Spino, Michael; Lee, Michael K.; Connor, James; Giasson, Benoit; Harris, Z. Leah; Dunaief, Joshua L.

    2016-01-01

    Brain iron accumulates in several neurodegenerative diseases and can cause oxidative damage, but mechanisms of brain iron homeostasis are incompletely understood. Patients with mutations in the cellular iron-exporting ferroxidase ceruloplasmin (Cp) have brain iron accumulation causing neurodegeneration. Here, we assessed the brains of mice with combined mutation of Cp and its homolog hephaestin. Compared to single mutants, brain iron accumulation was accelerated in double mutants in the cerebellum, substantia nigra, and hippocampus. Iron accumulated within glia, while neurons were iron deficient. There was loss of both neurons and glia. Mice developed ataxia and tremor, and most died by 9 months. Treatment with the oral iron chelator deferiprone diminished brain iron levels, protected against neuron loss, and extended lifespan. Ferroxidases play important, partially overlapping roles in brain iron homeostasis by facilitating iron export from glia, making iron available to neurons. PMID:26303407

  8. A further insight into the biosorption mechanism of Au(III by infrared spectrometry

    Directory of Open Access Journals (Sweden)

    Lin Zhongyu

    2011-10-01

    Full Text Available Abstract Background The interactions of microbes with metal ions form an important basis for our study of biotechnological applications. Despite the recent progress in studying some properties of Au(III adsorption and reduction by Bacillus megatherium D01 biomass, there is still a need for additional data on the molecular mechanisms of biosorbents responsible for their interactions with Au(III to have a further insight and to make a better exposition. Results The biosorption mechanism of Au(III onto the resting cell of Bacillus megatherium D01 biomass on a molecular level has been further studied here. The infrared (IR spectroscopy on D01 biomass and that binding Au(III demonstrates that the molecular recognition of and binding to Au(III appear to occur mostly with oxygenous- and nitrogenous-active groups of polysaccharides and proteins in cell wall biopolymers, such as hydroxyl of saccharides, carboxylate anion of amino-acid residues (side-chains of polypeptide backbone, peptide bond (amide I and amide II bands, etc.; and that the active groups must serve as nucleation sites for Au(0 nuclei growth. A further investigation on the interactions of each of the soluble hydrolysates of D01, Bacillus licheniformis R08, Lactobacillus sp. strain A09 and waste Saccharomyces cerevisiae biomasses with Au(III by IR spectrometry clearly reveals an essential biomacromolecule-characteristic that seems the binding of Au(III to the oxygen of the peptide bond has caused a significant, molecular conformation-rearrangement in polypeptide backbones from β-pleated sheet to α-helices and/or β-turns of protein secondary structure; and that this changing appears to be accompanied by the occurrence, in the peptide bond, of much unbound -C=O and H-N- groups, being freed from the inter-molecular hydrogen-bonding of the β-pleated sheet and carried on the helical forms, as well as by the alternation in side chain steric positions of protein primary structure. This might

  9. Vision-guided ocular growth in a mutant chicken model with diminished visual acuity.

    Science.gov (United States)

    Ritchey, Eric R; Zelinka, Christopher; Tang, Junhua; Liu, Jun; Code, Kimberly A; Petersen-Jones, Simon; Fischer, Andy J

    2012-09-01

    Visual experience is known to guide ocular growth. We tested the hypothesis that vision-guided ocular growth is disrupted in a model system with diminished visual acuity. We examine whether ocular elongation is influenced by form-deprivation (FD) and lens-imposed defocus in the Retinopathy, Globe Enlarged (RGE) chicken. Young RGE chicks have poor visual acuity, without significant retinal pathology, resulting from a mutation in guanine nucleotide-binding protein β3 (GNB3), also known as transducin β3 or Gβ3. The mutation in GNB3 destabilizes the protein and causes a loss of Gβ3 from photoreceptors and ON-bipolar cells (Ritchey et al., 2010). FD increased ocular elongation in RGE eyes in a manner similar to that seen in wild-type (WT) eyes. By comparison, the excessive ocular elongation that results from hyperopic defocus was increased, whereas myopic defocus failed to significantly decrease ocular elongation in RGE eyes. Brief daily periods of unrestricted vision interrupting FD prevented ocular elongation in RGE chicks in a manner similar to that seen in WT chicks. Glucagonergic amacrine cells differentially expressed the immediate early gene Egr1 in response to growth-guiding stimuli in RGE retinas, but the defocus-dependent up-regulation of Egr1 was lesser in RGE retinas compared to that of WT retinas. We conclude that high visual acuity, and the retinal signaling mediated by Gβ3, is not required for emmetropization and the excessive ocular elongation caused by FD and hyperopic defocus. However, the loss of acuity and Gβ3 from RGE retinas causes enhanced responses to hyperopic defocus and diminished responses to myopic defocus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Role of U(VI) adsorption in U(VI) Reduction by Geobacter species

    International Nuclear Information System (INIS)

    Lovely, Derrick

    2008-01-01

    Previous work had suggested that Acholeplasma palmae has a higher capacity for uranium sorption than other bacteria studied. Sorption studies were performed with cells in suspension in various solutions containing uranium, and results were used to generate uranium-biosorption isotherms. Results from this study showed that the U(VI) sorption capacity of G. uraniireducens was relatively similar in simple solutions, such as sodium chloride or bicarbonate. However, this ability to sorb uranium significantly decreased in groundwater. This suggested that certain chemicals present in the groundwater were inhibiting the ability of cell components of Geobacter to adsorb uranium. It was hypothesized that uranium removal would also be diminished in the bicarbonate solution. However, this did not seem to be the case, as uranium was as easily removed in the bicarbonate solution as in the sodium chloride solution.

  11. Isolation, identification, Pb(II) biosorption isotherms and kinetics of a lead adsorbing penicillium sp. MRF-1 from South Korean mine soil.

    Science.gov (United States)

    Velmurugan, Natarajan; Hwang, Grim; Sathishkumar, Muthuswamy; Choi, Tae Kie; Lee, Kui-Jae; Oh, Byung-Taek; Lee, Yang-Soo

    2010-01-01

    A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead (Pb) at 357 mg/kg and cyanide (CN) at 14.6 mg/kg in the soil. The experimental results showed that Penicillium sp. MRF-1 was the best lead resistant fungus among the four individual metal tolerant fungal species isolated from the soil. Molecular characterization of Penicillium sp. MRF-1 was determined using ITS regions sequences. Effects of pH, temperature and contact time on adsorption of Pb(II) by Penicillium sp. MRF-1 were studied. Favorable conditions for maximum biosportion were found at pH 4 with 3 hr contact time. Biosorption of Pb(II) gradually increased with increasing temperature. Efficient performance of the biosorbent was described using Langmuir and Freundlich isotherms. Adsorption kinetics was studied using pseudo first-order and pseudo second-order models. Biosorbent Penicillium sp. MRF-1 showed the maximum desorption in alkali conditions. Consistent adsorption/desorption potential of the biosorbent in repetitive cycles validated the efficacy of it in large scale. SEM studies given notes on surface modification of fungal biomass under metal stress and FT-IR results showed the presence of amino groups in the surface structure of the biosorbent. In conclusion, the new biosorbent Penicillium sp. MRF-1 may potentially be used as an inexpensive, easily cultivatable material for the removal of lead from aqueous solution.

  12. Removal of copper(II) ions from aqueous solutions by Azolla rongpong: batch and continuous study.

    Science.gov (United States)

    Nedumaran, B; Velan, M

    2008-01-01

    Batch and packed bed continuous biosorption studies were conducted to investigate the kinetics and isotherms of Cu(II) ions on the biomass of blue green alga Azolla rongpong. It is observed that the biosorption capacity of algae depends on initial pH and dosage. The biosorption capacity increases with increasing concentration and follows Freundlich isotherm model well with k and n values 0.06223 and 0.949 respectively. The optimum pH of 3.5 with an algae dosage of 1 g/L was observed. The results indicate that with the advantage of high metal biosorption capacity and recovery of Cu(II) ions, A. rongpong can be used as an efficient and economic biosorbent for the removal and recovery of toxic heavy metals from aqueous wastes even at higher concentration.

  13. Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters: Research updated.

    Science.gov (United States)

    Chang, Yingju; Lai, Juin-Yih; Lee, Duu-Jong

    2016-12-01

    The standard Gibbs free energy, enthalpy and entropy change data for adsorption equilibrium reported in biosorption literature during January 2013-May2016 were listed. Since the studied biosorption systems are all near-equilibrium processes, the enthalpy and entropy change data evaluated by fitting temperature-dependent free energy data using van Hoff's equation reveal a compensation artifact. Additional confusion is introduced with arbitrarily chosen adsorbate concentration unit in bulk solution that added free energy change of mixing into the reported free energy and enthalpy change data. Different standard states may be chosen for properly describing biosorption processes; however, this makes the general comparison between data from different systems inappropriate. No conclusion should be drawn based on unjustified thermodynamic parameters reported in biosorption studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Heavy metal biosorption by chitin and chitosan isolated from Cunninghamella elegans (IFM 46109 Remoção de metais pesados por quitina e quitosana isoladas de Cunninghamella elegans (IFM 46109

    Directory of Open Access Journals (Sweden)

    Luciana de Oliveira Franco

    2004-09-01

    Full Text Available Chitin and chitosan were extracted from mycelial biomass of Cunninghamella elegans and the performance for copper, lead and iron biosorption in aqueous solution was evaluated. The growth curve of C. elegans was accomplished by determination of biomass, pH, glucose and nitrogen consumption. Chitin and chitosan were extracted by alkali-acid treatment and the yields were 23.8 and 7.8%, respectively. For the adsorption analysis, the process of heavy uptake metal sorption was evaluated using polysaccharides solutions (1% w/v. The rate of metallic biosorption was dependent upon the concentration and pH of metal solutions, and the best results were observed with pH 4.0. Chitosan showed the highest affinity for copper and chitin for iron adsorption. The results suggest that C. elegans (IFM 46109 is an attractive source of production of chitin and chitosan, with a great potential of heavy metals bioremediation in polluted environments.Quitina e quitosana foram extraídas a partir da massa micelial de Cunninghamella elegans (IFM 46109 e avaliou-se a aplicação destes polissacarídeos na remoção dos metais pesados cobre, chumbo e ferro preparados em solução aquosa. O crescimento de C. elegans foi acompanhado através da determinação de biomassa, pH, consumo de glicose e de nitrogênio. A extração de quitina e quitosana realizou-se através de tratamento álcali-ácido e a produção dos polissacarídeos foi de 23,8 e 7,8 %, respectivamente. A avaliação do processo de remoção dos metais pesados foi realizada utilizando-se os polissacarídeos em solução a 1% (p/v. Os níveis de biossorção de metais foram dependentes da concentração e do pH das soluções. Os melhores resultados foram obtidos em pH 4,0. A quitosana mostrou maior índice de biossorção para o íon cobre e a quitina para o ferro. Os resultados sugerem que C.elegans pode ser considerada uma fonte atrativa para a produção alternativa de quitina e quitosana, e que demonstra

  15. Diminished stress resistance and defective adaptive homeostasis in age-related diseases.

    Science.gov (United States)

    Lomeli, Naomi; Bota, Daniela A; Davies, Kelvin J A

    2017-11-01

    Adaptive homeostasis is defined as the transient expansion or contraction of the homeostatic range following exposure to subtoxic, non-damaging, signaling molecules or events, or the removal or cessation of such molecules or events ( Mol. Aspects Med. (2016) 49, 1-7 ). Adaptive homeostasis allows us to transiently adapt (and then de-adapt) to fluctuating levels of internal and external stressors. The ability to cope with transient changes in internal and external environmental stress, however, diminishes with age. Declining adaptive homeostasis may make older people more susceptible to many diseases. Chronic oxidative stress and defective protein homeostasis (proteostasis) are two major factors associated with the etiology of age-related disorders. In the present paper, we review the contribution of impaired responses to oxidative stress and defective adaptive homeostasis in the development of age-associated diseases. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  16. Ambient groundwater flow diminishes nitrogen cycling in streams

    Science.gov (United States)

    Azizian, M.; Grant, S. B.; Rippy, M.; Detwiler, R. L.; Boano, F.; Cook, P. L. M.

    2017-12-01

    Modeling and experimental studies demonstrate that ambient groundwater reduces hyporheic exchange, but the implications of this observation for stream N-cycling is not yet clear. We utilized a simple process-based model (the Pumping and Streamline Segregation or PASS model) to evaluate N- cycling over two scales of hyporheic exchange (fluvial ripples and riffle-pool sequences), ten ambient groundwater and stream flow scenarios (five gaining and losing conditions and two stream discharges), and three biogeochemical settings (identified based on a principal component analysis of previously published measurements in streams throughout the United States). Model-data comparisons indicate that our model provides realistic estimates for direct denitrification of stream nitrate, but overpredicts nitrification and coupled nitrification-denitrification. Riffle-pool sequences are responsible for most of the N-processing, despite the fact that fluvial ripples generate 3-11 times more hyporheic exchange flux. Across all scenarios, hyporheic exchange flux and the Damkohler Number emerge as primary controls on stream N-cycling; the former regulates trafficking of nutrients and oxygen across the sediment-water interface, while the latter quantifies the relative rates of organic carbon mineralization and advective transport in streambed sediments. Vertical groundwater flux modulates both of these master variables in ways that tend to diminish stream N-cycling. Thus, anthropogenic perturbations of ambient groundwater flows (e.g., by urbanization, agricultural activities, groundwater mining, and/or climate change) may compromise some of the key ecosystem services provided by streams.

  17. Dowex anion exchanger-loaded-baker's yeast as bi-functionalized biosorbents for selective extraction of anionic and cationic mercury(II) species

    International Nuclear Information System (INIS)

    Mahmoud, Mohamed E.; Yakout, Amr A.; Osman, Maher M.

    2009-01-01

    Dowex anion exchanger-immobilized-baker's yeast [Dae-yeast] were synthesized and potentially applied as environmental friendly biosorbents to evaluate the up-take process of anionic and cationic mercury(II) species as well as other metal ions. Optimization of mass ratio of Dowex anion exchanger versus yeast (1:1-1:10) in presence of various interacting buffer solutions (pH 4.0-9.0) was performed and evaluated. Surface modification of [Dae-yeast] was characterized by scanning electron microscopy (SEM) and infrared spectroscopy. The maximum metal biosorption capacity values of [Dae-yeast] towards mercury(II) were found in the range of 0.800-0.960, 0.840-0.950 and 0.730-0.900 mmol g -1 in presence of buffer solutions pH 2.0, 4.0 and 7.0, respectively. Three possible and different mechanisms are proposed to account for the biosorption of mercury and mercuric species under these three buffering conditions based on ion exchange, ion pair and chelation interaction processes. Factors affecting biosorption of mercury from aqueous medium including the pH effect of aqueous solutions (1.0-7.0), shaking time (1-30 min) and interfering ions were searched. The potential applications of modified biosorbents for selective biosorption and extraction of mercury from different real matrices including dental filling waste materials, industrial waste water samples and mercury lamp waste materials were also explored. The results denote to excellent percentage extraction values, from nitric acid as the dissolution solvent with a pH 2.0, as determined in the range of 90.77-97.91 ± 3.00-5.00%, 90.00-93.40 ± 4.00-5.00% and 92.31-100.00 ± 3.00-4.00% for the three tested samples, respectively.

  18. and Pb(ii) by Phanerochaete chrysosporium from a binary metal ...

    African Journals Online (AJOL)

    drinie

    2001-01-01

    Jan 1, 2001 ... Kinetic studies revealed that biosorption takes place in two stages: a rapid surface adsorption, within the ... With the help of multi-metal biosorption studies, these complex ..... bioreactor for color removal from bleach effluents.

  19. Diminishing Risk for Age-Related Macular Degeneration with Nutrition: A Current View

    Directory of Open Access Journals (Sweden)

    Allen Taylor

    2013-07-01

    Full Text Available Age-related macular degeneration (AMD is the leading cause of blindness in the elderly. Clinical hallmarks of AMD are observed in one third of the elderly in industrialized countries. Preventative interventions through dietary modification are attractive strategies, because they are more affordable than clinical therapies, do not require specialists for administration and many studies suggest a benefit of micro- and macro-nutrients with respect to AMD with few, if any, adverse effects. The goal of this review is to provide information from recent literature on the value of various nutrients, particularly omega-3 fatty acids, lower glycemic index diets and, perhaps, some carotenoids, with regard to diminishing risk for onset or progression of AMD. Results from the upcoming Age-Related Eye Disease Study (AREDS II intervention trial should be particularly informative.

  20. Diminishing Risk for Age-Related Macular Degeneration with Nutrition: A Current View

    Science.gov (United States)

    Schleicher, Molly; Weikel, Karen; Garber, Caren; Taylor, Allen

    2013-01-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Clinical hallmarks of AMD are observed in one third of the elderly in industrialized countries. Preventative interventions through dietary modification are attractive strategies, because they are more affordable than clinical therapies, do not require specialists for administration and many studies suggest a benefit of micro- and macro-nutrients with respect to AMD with few, if any, adverse effects. The goal of this review is to provide information from recent literature on the value of various nutrients, particularly omega-3 fatty acids, lower glycemic index diets and, perhaps, some carotenoids, with regard to diminishing risk for onset or progression of AMD. Results from the upcoming Age-Related Eye Disease Study (AREDS) II intervention trial should be particularly informative. PMID:23820727

  1. Measuring mental illness stigma with diminished social desirability effects.

    Science.gov (United States)

    Michaels, Patrick J; Corrigan, Patrick W

    2013-06-01

    For persons with mental illness, stigma diminishes employment and independent living opportunities as well as participation in psychiatric care. Public stigma interventions have sought to ameliorate these consequences. Evaluation of anti-stigma programs' impact is typically accomplished with self-report questionnaires. However, cultural mores encourage endorsement of answers that are socially preferred rather than one's true belief. This problem, social desirability, has been circumvented through development of faux knowledge tests (KTs) (i.e., Error-Choice Tests); written to assess prejudice. Our KT uses error-choice test methodology to assess stigmatizing attitudes. Test content was derived from review of typical KTs for façade reinforcement. Answer endorsement suggests bias or stigma; such determinations were based on the empirical literature. KT psychometrics were examined in samples of college students, community members and mental health providers and consumers. Test-retest reliability ranged from fair (0.50) to good (0.70). Construct validity analyses of public stigma indicated a positive relationship with the Attribution Questionnaire and inverse relationships with Self-Determination and Empowerment Scales. No significant relationships were observed with self-stigma measures (recovery, empowerment). This psychometric evaluation study suggests that a self-administered questionnaire may circumvent social desirability and have merit as a stigma measurement tool.

  2. Diminishing self-disclosure to maintain security in partners' care.

    Science.gov (United States)

    Lemay, Edward P; Melville, Michael C

    2014-01-01

    Six studies demonstrate that perceivers' desire to bond with targets motivates perceivers to misconstrue their own self-disclosure in ways that maintain perceivers' security in targets' care and commitment. Perceivers who strongly valued relationships with targets reported high levels of global self-disclosure, consistent with many findings suggesting salutary effects of disclosure. However, these same perceivers reported low self-disclosure of needs and desires in hypothetical (Study 1) and actual (Study 2) situations characterized by targets' unresponsive behavior. Similarly, in daily report (Study 3) and behavioral observation (Study 4) studies, perceivers who valued relationships with targets perceived high levels of self-disclosure when targets were responsive, but they perceived low self-disclosure when targets were unresponsive, and these perceptions seemed partly illusory. In turn, these perceptions of low self-disclosure in situations characterized by partners' unresponsive behavior predicted decreased perceptions of diagnosticity of targets' behavior (Studies 1-3) and buffered the negative affective and interpersonal effects of unresponsive behavior (Study 4). Experimental manipulations (Studies 5 and 6) demonstrated the motivational nature of perceived self-disclosure. Collectively, the results suggest that a desire to bond with targets motivates perceivers to downplay the diagnosticity of targets' unresponsive behavior through diminishing their self-disclosure, in turn preserving perceivers' trust in targets' care and commitment.

  3. Uranium biosorption under dynamic conditions. Preliminary tests with Sargassum filipendula in real radioactive wastewater containing Ba, Cr, Fe, Mn, Pb, Ca and Mg

    International Nuclear Information System (INIS)

    Rodrigues Silva, J.I.; Melo Ferreira de, A.C.; Costa da, A.C.A

    2009-01-01

    The biosorption of uranium by the seaweed Sargassum filipendula was investigated under dynamic conditions at various bed heights. Our results indicate that a bed height of 40.0 cm (111.9 g biomass) was the most efficient for long-term operation of the continuous system. Our results also indicate that the effluent solutions produced are in accordance with Brazilian legislation for safe discharge of uranium in aqueous streams. The efficiency of the process increased with an increase in bed height from 5.0 to 40.0 cm due to changes in the transfer zone. In treatment of a real effluent contaminated with uranium, stable heavy metals and essential metals, 64% of the uranium was biosorbed, as well as the stable heavy metals chromium, lead and barium. The essential metals calcium, magnesium, iron and manganese were not biosorbed by the seaweed, in fact, their concentrations in the solution increased due to ion-exchange mechanisms with the constituent polysaccharides of the biomass. Another important result was the 85-87% reduction of mass obtained after drying and calcination of the biomass. This is a relevant indication that long-term storage of biomass loaded with radionuclides and heavy metals is possible after concentration of the contaminants. In the present work, the reduction in total mass of the loaded biomass was considerable, thus facilitating storage of the contaminated seaweed. (author)

  4. The use of biosorbents for heavy metals removal from aqueous media

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Amin, Y.

    2010-04-01

    Biomaterials, which could be adsorbed heavy metals, such bacteria, algae, yeasts, fungi and agricultural waste, is called Biomass. Recently, they are widely used for heavy metal removal from aqueous media, due to their large available quantities, low cost and good performance. The biosorbent, unlike mono functional ion exchange resins, contains variety of functional sites including carboxyl, imidazole, sulphydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide and hydroxyl moieties. In this paper, the biosorbents word widely and nationally used for heavy metal removal were reviewed. Their biosorption performance, their pretreatment and modification, aiming to improve their sorption capacity, and regeneration/reuse was introduced and evaluated. The potential application of biosorption and biosorbents was discussed. (author)

  5. REMOVAL OF ARSENIC FROM AN AQUEOUS SOLUTION BY PRETREATED WASTE TEA FUNGAL BIOMASS

    Directory of Open Access Journals (Sweden)

    S. Mamisahebei , Gh. R. Jahed Khaniki, A. Torabian, S. Nasseri, K. Naddafi

    2007-04-01

    Full Text Available Arsenic contamination in water poses a serious threat on human health. The tea fungus known as Kombucha is a waste produced during black tea fermentation. The objective of this study was to examine the main aspect of a possible strategy for the removal of arsenates employing tea fungal biomass. The pretreatment of biomass with FeCl3 was found to improve the biosorption efficiency. Arsenics uptake was found to be rapid for all concentrations and reached to 79% of equilibrium capacity of biosorption in 20 min and reached equilibrium in 90 min. The pseudo second-order and first-order models described the biosorption kinetics of As (V with good correlation coefficient (R2>0.93 and better than the other equations. The data obtained from the experiment of biosorption isotherm were analyzed using the Freundlich and Langmuir isotherm models. The equation described the isotherm of As (V biosorption with relatively high correlation coefficient (R2>0.93. According to the Langmuir model, the maximum uptake capacities (qm of tea fungal biomass for As (V were obtained 3.9810-3 mmol/gr. The effect of Na+, K+, Mg+2 and Ca+2 on equilibrium capacities of As was not significant. The variation of sorption efficiency with pH showed that optimum biosorption takes place in the pH ranges of 6 to 8. Promising results were obtained in laboratory experiments and effective As (V removals were observed.

  6. Comparison of characteristics parameters in the evaluation of wall thickness diminishing in admiralty brass tubes of the steam condenser, tested by eddy currents

    International Nuclear Information System (INIS)

    Obrutsky, Alba E.; Mendez, Jorge A.; Acosta, Cesar D.; Scopelliti, Jose D.

    1999-01-01

    This work is aimed to appraise the measure of the wall thickness diminishing in the signals evaluation obtained in the inspection of steam condenser by eddy currents. In the analysis of the obtained signals were observed in the brass tubes a great quantity of internal defects whose signal indicates that there were diminishing of the wall thickness between 80% and 100%. With all this information and analyzing the data acquired, the tubes with more important indications were selected to make a more exhaustive study of the found defectology. As first test, it was measured the thickness of the worn tubes, comparing them with the original ones that are in stock. It was verified that the tubes separated for this study presented a 30% less thickness in comparison with the new tubes. A semiquantitative chemical test (EDAX) was made to verify if it was the same material. One of the extracted tubes (066 Y1) was reinspected in order to isolate the area with indications. Once this was performed, it was decided to cut the tube to make a visual inspection and to evaluate to what type of defect corresponds to the signals obtained. In the metallography it was confirm that it was a horseshoe type defect. When performing a dimensional control test of the found real defect, it was checked that the information obtained by eddy currents regarding the diminishing of the wall thickness diminishing was valid. At a last stage of the test, it was proceed to make an study and verification of the used parameters, probes, standards and finally determine which shall be the convenient modifications to minimize errors. (author)

  7. Characterization and lead(II) ions removal of modified Punica granatum L. peels.

    Science.gov (United States)

    Ay, Çiğdem; Özcan, Asiye Safa; Erdoğan, Yunus; Özcan, Adnan

    2017-04-03

    The aim of the present study was to enhance the biosorption capacity of a waste biomass of Punica granatum L. peels (PGL) using various chemical modification agents. Among these agents, hexamethylenediamine (HMDA) indicated the best performance with regard to the improvement of lead(II) ions removal from aqueous solution. The characterization of HMDA-modified P. granatum L. peels (HMDA-PGL) was achieved by using elemental analysis, FT-IR, thermogravimetric (TG) analysis and zeta potential measurement techniques. Based on FT-IR study, the chemical modification of P. granatum L. peels take place with its carboxyl, carbonyl, hydroxyl, etc. groups and these groups are responsible for the biosorption of lead(II) ions onto modified biomass. Biosorption equilibrium and kinetic data fitted well the Langmuir isotherm and the pseudo-second-order kinetic models, respectively. The highest biosorption capacity obtained from Langmuir isotherm model was 371.36 mg g -1 . Biosorption process was spontaneous and endothermic in nature according to the thermodynamic results and it quickly reached the equilibrium within 60 minutes. The validity of kinetic models used in this study can be quantitatively tested by using a normalized standard deviation Δq(%).

  8. Characterization of uranium bioaccumulation on a fungal isolate Geotrichum sp. dwc-1 as investigated by FTIR, TEM and XPS

    International Nuclear Information System (INIS)

    Changsong Zhao; Congcong Ding; Jiali Liao; Jijun Yang; Yuanyou Yang; Jun Tang; Ning Liu; Qun Sun

    2016-01-01

    In this paper, TEM-EDX, FTIR, XPS, PIXE, and EPBS were employed to identify the uranium biosorption behavior and the potential mechanism on cells of Geotrichum sp. dwc-1, isolated from soils. These results displayed that the biosorption behavior was greatly dependent on pH and uranium was absorbed by bounding to amino, phosphate as well as carboxyl functional groups. Uranium biosorption behavior on Geotrichum sp. dwc-1 involves bioaccumulation, electrostatic interaction and ion exchange process. This work throws further light on potential fungal roles these mechanisms for elemental recovery and bioremediation. (author)

  9. Diminished adrenal sensitivity to endogenous and exogenous adrenocorticotropic hormone in critical illness: a prospective cohort study.

    Science.gov (United States)

    de Jong, Margriet F C; Molenaar, Nienke; Beishuizen, Albertus; Groeneveld, A B Johan

    2015-01-06

    Adrenal dysfunction may represent critical illness-related corticosteroid insufficiency (CIRCI), as evidenced by a diminished cortisol response to exogenous adrenocorticotropic hormone (ACTH), but this concept and its clinical significance remain highly controversial. We studied the adrenal response to exogenous ACTH as a function of the endogenous cortisol-to-ACTH ratio, a measure of adrenal sensitivity, and of clinical variables, during critical illness and recovery from the acute phase. We prospectively included 59 consecutive septic and nonseptic patients in the intensive care unit with treatment-insensitive hypotension in whom CIRCI was suspected; patients having received etomidate and prolonged corticosteroids were excluded. An ACTH test (250 μg) was performed, followed by a second test after ≥7 days in acute-phase survivors. Serum total and free cortisol, ACTH, and clinical variables were assessed. Patients were divided according to responses (delta, Δ) of cortisol to ACTH at the first and second tests. Patients with low (endogenous ACTH predicts a low increase of cortisol to exogenous ACTH, suggesting adrenal dysfunction, irrespective of the stage of disease. The data further suggest a role of disease severity and culture-positive sepsis.

  10. Arsenic transformation predisposes human skin keratinocytes to UV-induced DNA damage yet enhances their survival apparently by diminishing oxidant response

    International Nuclear Information System (INIS)

    Sun Yang; Kojima, Chikara; Chignell, Colin; Mason, Ronald; Waalkes, Michael P.

    2011-01-01

    Inorganic arsenic and UV, both human skin carcinogens, may act together as skin co-carcinogens. We find human skin keratinocytes (HaCaT cells) are malignantly transformed by low-level arsenite (100 nM, 30 weeks; termed As-TM cells) and with transformation concurrently undergo full adaptation to arsenic toxicity involving reduced apoptosis and oxidative stress response to high arsenite concentrations. Oxidative DNA damage (ODD) is a possible mechanism in arsenic carcinogenesis and a hallmark of UV-induced skin cancer. In the current work, inorganic arsenite exposure (100 nM) did not induce ODD during the 30 weeks required for malignant transformation. Although acute UV-treatment (UVA, 25 J/cm 2 ) increased ODD in passage-matched control cells, once transformed by arsenic to As-TM cells, acute UV actually further increased ODD (> 50%). Despite enhanced ODD, As-TM cells were resistant to UV-induced apoptosis. The response of apoptotic factors and oxidative stress genes was strongly mitigated in As-TM cells after UV exposure including increased Bcl2/Bax ratio and reduced Caspase-3, Nrf2, and Keap1 expression. Several Nrf2-related genes (HO-1, GCLs, SOD) showed diminished responses in As-TM cells after UV exposure consistent with reduced oxidant stress response. UV-exposed As-TM cells showed increased expression of cyclin D1 (proliferation gene) and decreased p16 (tumor suppressor). UV exposure enhanced the malignant phenotype of As-TM cells. Thus, the co-carcinogenicity between UV and arsenic in skin cancer might involve adaptation to chronic arsenic exposure generally mitigating the oxidative stress response, allowing apoptotic by-pass after UV and enhanced cell survival even in the face of increased UV-induced oxidative stress and increased ODD. - Highlights: → Arsenic transformation adapted to UV-induced apoptosis. → Arsenic transformation diminished oxidant response. → Arsenic transformation enhanced UV-induced DNA damage.

  11. COMBATING CYBERBULLYING AS STRATEGY TO DIMINISH THE STUDENTS’ AGGRESSIVENESS

    Directory of Open Access Journals (Sweden)

    Ali ABU RIA

    2018-03-01

    Full Text Available This article addresses the relationship between cyberbullying and students’ behaviors. At present, cyber security is one of the most discussed topics in most countries of the world. Cyber space is characterized by lack of borders, dynamism and anonymity, generating both opportunities for the development of the information society and risks to its functioning and its beneficiaries. Noting the noxious impact of cyberbullying on youth behaviors, we propose tackling cyberbullying as a strategy to diminish students' aggressiveness in the school.COMBATEREA BULLYING-ULUI CIBERNETIC CA STRATEGIE DE DIMINUARE A AGRESIVITĂȚII ELEVILORÎn articol este abordată relația dintre bullying-ul cibernetic și comportamentele elevilor. La etapa actuală, securitatea cibernetică este unul dintre cele mai discutate subiecte în majoritatea țărilor lumii. Spaţiul cibernetic se caracterizează prin lipsa frontierelor, dinamism şi anonimat, generând atât oportunităţi de dezvoltare a societăţii informaţionale, cât şi riscuri la adresa funcţionării acesteia și a beneficiarilor săi. Constatând impactul nociv al bullying-ului cibernetic asupra comportamentelor tinerilor, propunem abordarea combaterii bullying-ului cibernetic ca strategie de diminuare a agresi­vității elevilor în școală.

  12. Removal of remazol brilliant blue R dye from aqueous solutions using yeast biomass as biosorbent

    International Nuclear Information System (INIS)

    Barreda-Reyes, Karen L.; Ortega-López, Jocelyn; Ortega-Regules, Ana E.; Santiago-Santiago, Luis A.; Netzahuatl-Muñoz, Alma R.

    2015-01-01

    The main purpose of this study was to obtain kinetic and equilibrium parameters for the anthraquinone dye r emoval of Remazol Brilliant Blue R dye from aqueous solutions using yeast biomass as biosorbent, and identify the functional groups responsible for biosorption by infrared spectrometry. Biosorption dye kinetics at temperatures of 10 °C, 20 °C, 30 °C and 40 °C were fitted correctly by the pseudo-first and pseudo-second order models. The values of thermodynamic activation parameters indicated that the biosorption process is endothermic and no spontaneous. Sorption isotherm at 20 °C, pH 2,0 and a biomass concentration of 1,0 g L-1 was obtained, finding a value of 127,6 mg g-1 for the saturated monolayer according to the Langmuir model. Infrared studies showed that carboxyl and amide are the main functional groups responsible for dye biosorption. (author)

  13. Application of Sargassum biomass to remove heavy metal ions from synthetic multi-metal solutions and urban storm water runoff.

    Science.gov (United States)

    Vijayaraghavan, K; Teo, Ting Ting; Balasubramanian, R; Joshi, Umid Man

    2009-05-30

    The ability of Sargassum sp. to biosorb four metal ions, namely lead, copper, zinc, and manganese from a synthetic multi-solute system and real storm water runoff has been investigated for the first time. Experiments on synthetic multi-solute systems revealed that Sargassum performed well in the biosorption of all four metal ions, with preference towards Pb, followed by Cu, Zn, and Mn. The solution pH strongly affected the metal biosorption, with pH 6 being identified as the optimal condition for achieving maximum biosorption. Experiments at different biosorbent dosages revealed that good biosorption capacity as well as high metal removal efficiency was observed at 3g/L. The biosorption kinetics was found to be fast with equilibrium being attained within 50 min. According to the Langmuir isotherm model, Sargassum exhibited maximum uptakes of 214, 67.5, 24.2 and 20.2mg/g for lead, copper, zinc, and manganese, respectively in single-solute systems. In multi-metal systems, strong competition between four metal ions in terms of occupancy binding sites was observed, and Sargassum showed preference in the order of Pb>Cu>Zn>Mn. The application of Sargassum to remove four heavy metal ions in real storm water runoff revealed that the biomass was capable of removing the heavy metal ions. However, the biosorption performance was slightly lower compared to that of synthetic metal solutions. Several factors were responsible for this difference, and the most important factor is the presence of other contaminants such as anions, organics, and other trace metals in the runoff.

  14. Metabolic Evidence of Diminished Lipid Oxidation in Women With Polycystic Ovary Syndrome

    Science.gov (United States)

    Whigham, Leah D.; Butz, Daniel E.; Dashti, Hesam; Tonelli, Marco; Johnson, LuAnn K.; Cook, Mark E.; Porter, Warren P.; Eghbalnia, Hamid R.; Markley, John L.; Lindheim, Steven R.; Schoeller, Dale A.; Abbott, David H.; Assadi-Porter, Fariba M.

    2014-01-01

    Polycystic ovary syndrome (PCOS), a common female endocrinopathy, is a complex metabolic syndrome of enhanced weight gain. The goal of this pilot study was to evaluate metabolic differences between normal (n=10) and PCOS (n=10) women via breath carbon isotope ratio, urinary nitrogen and nuclear magnetic resonance (NMR)-determined serum metabolites. Breath carbon stable isotopes measured by cavity ring down spectroscopy (CRDS) indicated diminished (pglucose tolerance test showed that a transient elevation in blood glucose levels decreased circulating levels of lipid, glucose and amino acid metabolic intermediates (acetone, 2-oxocaporate, 2-aminobutyrate, pyruvate, formate, and sarcosine) in PCOS women, whereas the 2 h glucose challenge led to increases in the same intermediates in normal women. These pilot data suggest that PCOS-related inflexibility in fasting-related switching between lipid and carbohydrate/protein utilization for carbon metabolism may contribute to enhanced weight gain. PMID:24765590

  15. Diminished Economic Return of Socioeconomic Status at Birth among Black than White Youth

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2018-05-01

    Full Text Available Background: According to the Minorities’ Diminished Return theory, socioeconomic status (SES systemically generates larger gains for Whites compared to Blacks. It is, however, unknown whether the effects of baseline SES on future family income also varies between Blacks and Whites. Aims: Using a national sample, this study investigated racial variation in the effects of family SES (i.e., family structure, maternal education, and income at birth on subsequent household income at age 15. Methods: This 15-year longitudinal study used data from the Fragile Families and Child Wellbeing Study (FFCWS, which followed 1471 non-Hispanic Black or White families from the time of birth of their child for 15 years. Two family SES indicators (maternal education and income at birth were the independent variables. Family income 15 years later was the outcome. Maternal age, child gender, and family structure at baseline were covariates. Race was the focal moderator. Linear regression models were used for data analysis. Results: In the pooled sample, maternal education (b = 11.62, p < 0.001 and household income (b = 0.73, p < 0.001 at baseline were predictive of family income 15 years later. Race, however, interacted with maternal education (b = −12,073.89, p < 0.001 and household income (b = −312.47, p < 0.001 at birth on household income 15 years later, indicating smaller effects for Black compared to White families. These differential gains were independent of family structure, mother age, and child gender. Conclusions: The economic return of family SES is smaller for Black compared to White families, regardless of the SES indicator. Policies should specifically address structural barriers in the lives of racial and ethnic minorities to minimize the diminished return of SES resources across racial minority groups. Policies should also reduce extra cost of upward social mobility for racial minorities. As the likely causes are multi-level, solutions should

  16. CAN MELATONIN BE EFFECTIVELY USED TO DIMINISH SIDE EFFECTS OF VARIOUS PSYCHOTROPIC DRUGS AND ELECTROCONVULSIVE THERAPY?

    Directory of Open Access Journals (Sweden)

    Roman Aleksandrovich Bekker

    2017-10-01

    Full Text Available Purpose. To study and summarize the existing evidence base for the use of melatonin as a mean to counteract or diminish the side effects of various psychotropic drugs and electroconvulsive therapy, and to provide the reader with relevant conclusions. Methodology. The authors have searched for the scientific literature regarding the use of melatonin as a mean to counteract or diminish the side effects of various psychotropic drugs and electroconvulsive therapy, using the PubMed and Google Scholar as a search tool. Then the authors thoroughly reviewed the data they found. The resulting review is presented in this article. Results. The data we have obtained from this review of the literature indicate that melatonin can be effectively used both in monotherapy and in combination with other therapeutic means in order to reduce several different side effects of psychotropic drugs and electroconvulsive therapy. Melatonin also deserves further study in this regard. The evidence base for its use in this manner is very variable in quality for different side effects. For now, the greatest evidence base exists regarding the potential effectiveness of melatonin in the prevention and treatment of drug-induced insomnia, memory and cognitive impairment, akathisia, tardive dyskinesias, and metabolic syndrome. Practical implications. The results we have obtained can be widely applied in psychiatry, neurology and addiction medicine, as well as in all those areas of general medicine, which make use of psychotropic drugs.

  17. BIOSSORÇÃO DE Pb(II POR CASCA DE URUCUM (Bixa orellana EM SOLUÇÕES AQUOSAS: ESTUDO CINÉTICO, EQUILÍBRIO E TERMODINÂMICO

    Directory of Open Access Journals (Sweden)

    Klaiani B. Fontana

    Full Text Available This study describes the application of new and low cost biosorbent, shells of urucum (Bixa Orellana, for removal of lead ions (Pb(II from water solution. The urucum shells were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy techniques. Batch adsorption experiments were performed in order to evaluate the effect of pH, agitation speed, adsorbent dosage, contact time, temperature, presence of interfering ions and matrix effect on the adsorption of process. The kinetics of biosorption followed pseudo-second-order model. Langmuir and Freundlich isotherm models were applied to describe the biosorption of Pb(II by urucum shells. The Langmuir model showed better fit and the estimated biosorption capacity was 43.6 mg g-1. The negative Gibbs free energy, ΔG°, confirms the spontaneous nature and positive value of enthalpy, ΔH°, the endothermic character of the process. Furthermore, we also performed an evaluation of matrix and others ions effect on the biosorption process.

  18. Potential use of algae for heavy metal bioremediation, a critical review.

    Science.gov (United States)

    Zeraatkar, Amin Keyvan; Ahmadzadeh, Hossein; Talebi, Ahmad Farhad; Moheimani, Navid R; McHenry, Mark P

    2016-10-01

    Algae have several industrial applications that can lower the cost of biofuel co-production. Among these co-production applications, environmental and wastewater bioremediation are increasingly important. Heavy metal pollution and its implications for public health and the environment have led to increased interest in developing environmental biotechnology approaches. We review the potential for algal biosorption and/or neutralization of the toxic effects of heavy metal ions, primarily focusing on their cellular structure, pretreatment, modification, as well as potential application of genetic engineering in biosorption performance. We evaluate pretreatment, immobilization, and factors affecting biosorption capacity, such as initial metal ion concentration, biomass concentration, initial pH, time, temperature, and interference of multi metal ions and introduce molecular tools to develop engineered algal strains with higher biosorption capacity and selectivity. We conclude that consideration of these parameters can lead to the development of low-cost micro and macroalgae cultivation with high bioremediation potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Treatment of uranium mining and milling wastewater using biological adsorbents

    International Nuclear Information System (INIS)

    Tsezos, M.

    1983-01-01

    Selected samples of waste microbial biomass originating from various industrial fermentation processes and biological treatment plants have been screened for biosorbent properties in conjunction with uranium, thorium and radium in aqueous solutions. Biosorption isotherms were used for the evaluation of biosorptive uptake capacity of the biomass. The biomass was also compared to synthetic adsorbents such as activated carbon. Determined uranium, thorium and radium biosorption isotherms were independent of the initial solution concentrations. Solution pH affected uptake. Rhizopus arrhizus at pH 4 exhibited the highest uranium and thorium biosorptive uptake capacity in excess of 180 Mg/g. It removed about 2.5 and 3.3 times more uranium than the ion exchange resin and activated carbon tested. Penicillium chrysogenum adsorbed 50000 pCi/g radium at pH 7 and at an equilibrium radium concentration of 1000 pCi/L. The most effective biomass types studied exhibited removals in excess of 99% of the radium in solution

  20. Shifting paradigms in diminished ovarian reserve and advanced reproductive age in assisted reproduction: customization instead of conformity.

    Science.gov (United States)

    Reed, Beverly G; Babayev, Samir N; Bukulmez, Orhan

    2015-05-01

    As women are increasingly delaying childbearing into their 30s and beyond, diminished ovarian reserve (DOR) and advanced reproductive age (ARA) patients are bound to become a large proportion of all assisted reproductive technology practices. Traditional controlled ovarian stimulation (COS) protocols for DOR and/or ARA have had some limited success, but pregnancy rates are lower and cycle cancellation rates are higher than their younger counterparts with normal ovarian reserve. Though many physicians have a selection of favorite standard protocols that they use, patients with DOR may require closer monitoring and customization of the treatment cycle to address the common problems that come with low ovarian reserve. Frequent issues that surface in women with DOR and/or ARA include poor follicular response, premature luteinizing hormone surge, and poor embryo quality. Limited published evidence exists to guide treatment for DOR. However, use of minimal or mild doses of gonadotropins, avoidance of severe pituitary suppression, and consideration for luteal phase stimulation and a "freeze all" approach are possible customized treatment options that can be considered for such patients who have failed more traditional COS protocols. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  1. On the random cascading model study of anomalous scaling in multiparticle production with continuously diminishing scale

    International Nuclear Information System (INIS)

    Liu Lianshou; Zhang Yang; Wu Yuanfang

    1996-01-01

    The anomalous scaling of factorial moments with continuously diminishing scale is studied using a random cascading model. It is shown that the model currently used have the property of anomalous scaling only for descrete values of elementary cell size. A revised model is proposed which can give good scaling property also for continuously varying scale. It turns out that the strip integral has good scaling property provided the integral regions are chosen correctly, and that this property is insensitive to the concrete way of self-similar subdivision of phase space in the models. (orig.)

  2. CGG repeat length and AGG interruptions as indicators of fragile X-associated diminished ovarian reserve.

    Science.gov (United States)

    Lekovich, Jovana; Man, Limor; Xu, Kangpu; Canon, Chelsea; Lilienthal, Debra; Stewart, Joshua D; Pereira, Nigel; Rosenwaks, Zev; Gerhardt, Jeannine

    2017-12-21

    PurposeFragile X premutation (PM) carriers may experience difficulties conceiving a child probably due to fragile X-associated diminished ovarian reserve (FXDOR). We investigated which subgroups of carriers with a PM are at higher risk of FXDOR, and whether the number of AGG interruptions within the repeat sequence further ameliorates the risk.MethodsWe compared markers of ovarian reserve, including anti-Müllerian hormone, antral follicle count, and number of oocytes retrieved between different subgroups of patients with a PM.ResultsWe found that carriers with midrange repeats size (70-90 CGG) demonstrate significantly lower ovarian reserve. Additionally, the number of AGG interruptions directly correlated with parameters of ovarian reserve. Patients with longer uninterrupted CGG repeats post-AGG interruptions had the lowest ovarian reserve.ConclusionThis study connects AGG interruptions and certain CGG repeat length to reduced ovarian reserve in carriers with a PM. A possible explanation for our findings is the proposed gonadotoxicity of the FMR1 transcripts. Reduction of AGG interruptions could increase the likelihood that secondary RNA structures in the FMR1 messenger RNA are formed, which could cause cell dysfunction within the ovaries. These findings may provide women with guidance regarding their fertility potential and accordingly assist with their family planning.GENETICS in MEDICINE advance online publication, 21 December 2017; doi:10.1038/gim.2017.220.

  3. Diminished fronto-limbic functional connectivity in child sexual offenders.

    Science.gov (United States)

    Kneer, Jonas; Borchardt, Viola; Kärgel, Christian; Sinke, Christopher; Massau, Claudia; Tenbergen, Gilian; Ponseti, Jorge; Walter, Henrik; Beier, Klaus M; Schiffer, Boris; Schiltz, Kolja; Walter, Martin; Kruger, Tillmann H C

    2018-02-22

    Child sexual abuse and neglect have been related to an increased risk for the development of a wide range of behavioral, psychological, and sexual problems and increased rates of suicidal behavior. Contrary to the large amount of research focusing on the negative mental health consequences of child sexual abuse, very little is known about the characteristics of child sexual offenders and the neuronal underpinnings contributing to child sexual offending. This study investigates differences in resting state functional connectivity (rs-FC) between non-pedophilic child sexual offenders (N = 20; CSO-P) and matched healthy controls (N = 20; HC) using a seed-based approach. The focus of this investigation of rs-FC in CSO-P was put on prefrontal and limbic regions highly relevant for emotional and behavioral processing. Results revealed a significant reduction of rs-FC between the right centromedial amygdala and the left dorsolateral prefrontal cortex in child sexual offenders compared to controls. Given that, in the healthy brain, there is a strong top-down inhibitory control of prefrontal over limbic structures, these results suggest that diminished rs-FC between the amygdala and the dorsolateral prefrontal cortex and may foster sexual deviance and sexual offending. A profound understanding of these concepts should contribute to a better understanding of the occurrence of child sexual offending, as well as further development of more differentiated and effective interventions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. The relative effectiveness of extinction and counter-conditioning in diminishing children's fear.

    Science.gov (United States)

    Newall, Carol; Watson, Tiffany; Grant, Kerry-Ann; Richardson, Rick

    2017-08-01

    Two behavioural strategies for reducing learned fear are extinction and counter-conditioning, and in this study we compared the relative effectiveness of the two procedures at diminishing fear in children. Seventy-three children aged 7-12 years old (M = 9.30, SD = 1.62) were exposed to pictures of two novel animals on a computer screen during the fear acquisition phase. One of these animals was paired with a picture of a scared human face (CS+) while the other was not (CS-). The children were then randomly assigned to one of three conditions: counter-conditioning (animal paired with a happy face), extinction (animal without scared face), or control (no fear reduction procedure). Changes in fear beliefs and behavioural avoidance of the animal were measured. Counter-conditioning was more effective at reducing fear to the CS + than extinction. The findings are discussed in terms of implications for behavioural treatments of childhood anxiety disorders. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  5. Nutrient removal using biosorption activated media: preliminary biogeochemical assessment of an innovative stormwater infiltration basin

    Science.gov (United States)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Xuan, Zhemin; Harris, Willie G.

    2012-01-01

    Soil beneath a stormwater infiltration basin receiving runoff from a 22.7 ha predominantly residential watershed in central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop a prototype stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO3-/Cl-) ratios for the shallow groundwater indicate that prior to using BAM, NO3- concentrations were substantially influenced by nitrification or variations in NO3- input. In contrast, for the prototype basin utilizing BAM, NO3-/Cl- ratios indicate minor nitrification and NO3- losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest NO3- losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO43-) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO43-/Cl- ratios for shallow groundwater indicate predominantly minor increases and

  6. A short educational intervention diminishes causal illusions and specific paranormal beliefs in undergraduates.

    Science.gov (United States)

    Barberia, Itxaso; Tubau, Elisabet; Matute, Helena; Rodríguez-Ferreiro, Javier

    2018-01-01

    Cognitive biases such as causal illusions have been related to paranormal and pseudoscientific beliefs and, thus, pose a real threat to the development of adequate critical thinking abilities. We aimed to reduce causal illusions in undergraduates by means of an educational intervention combining training-in-bias and training-in-rules techniques. First, participants directly experienced situations that tend to induce the Barnum effect and the confirmation bias. Thereafter, these effects were explained and examples of their influence over everyday life were provided. Compared to a control group, participants who received the intervention showed diminished causal illusions in a contingency learning task and a decrease in the precognition dimension of a paranormal belief scale. Overall, results suggest that evidence-based educational interventions like the one presented here could be used to significantly improve critical thinking skills in our students.

  7. A short educational intervention diminishes causal illusions and specific paranormal beliefs in undergraduates.

    Directory of Open Access Journals (Sweden)

    Itxaso Barberia

    Full Text Available Cognitive biases such as causal illusions have been related to paranormal and pseudoscientific beliefs and, thus, pose a real threat to the development of adequate critical thinking abilities. We aimed to reduce causal illusions in undergraduates by means of an educational intervention combining training-in-bias and training-in-rules techniques. First, participants directly experienced situations that tend to induce the Barnum effect and the confirmation bias. Thereafter, these effects were explained and examples of their influence over everyday life were provided. Compared to a control group, participants who received the intervention showed diminished causal illusions in a contingency learning task and a decrease in the precognition dimension of a paranormal belief scale. Overall, results suggest that evidence-based educational interventions like the one presented here could be used to significantly improve critical thinking skills in our students.

  8. Diminished exercise capacity and mitochondrial bc1 complex deficiency in tafazzin-knockdown mice.

    Directory of Open Access Journals (Sweden)

    Corey ePowers

    2013-04-01

    Full Text Available The phospholipid, cardiolipin, is essential for maintaining mitochondrial structure and optimal function. Cardiolipin-deficiency in humans, Barth syndrome, is characterized by exercise intolerance, dilated cardiomyopathy, neutropenia and 3-methyl-glutaconic aciduria. The causative gene is the mitochondrial acyl-transferase, tafazzin that is essential for remodeling acyl chains of cardiolipin. We sought to determine metabolic rates in tafazzin-deficient mice during resting and exercise, and investigate the impact of cardiolipin deficiency on mitochondrial respiratory chain activities. Tafazzin knockdown in mice markedly impaired oxygen consumption rates during an exercise, without any significant effect on resting metabolic rates. CL-deficiency resulted in significant reduction of mitochondrial respiratory reserve capacity in neonatal cardiomyocytes that is likely to be caused by diminished activity of complex-III, which requires CL for its assembly and optimal activity. Our results may provide mechanistic insights of Barth syndrome pathogenesis.

  9. The pervasive crisis of diminishing radiation therapy access for vulnerable populations in the United States, part 1: African-American patients

    Directory of Open Access Journals (Sweden)

    Shearwood McClelland, III, MD

    2017-10-01

    Conclusions: African Americans in the United States have diminished access to RT compared with Caucasian patients, independent of but often in concert with low socioeconomic status. These findings underscore the importance of finding systemic and systematic solutions to address these inequalities to reduce the barriers that patient race provides in receipt of optimal cancer care.

  10. Mitigating Diminishing Manufacturing Sources Material Shortages (DMS/MS) and Obsolescence for the T-6 Canopy Fracturing Initiation System (CFIS)

    Science.gov (United States)

    2012-03-01

    the extra effort to nurse dwindling industries to sustain them becomes a case of diminishing returns. The added cost would be better spent...safety stock is not a prudent or tolerable in the current environment stressing increased efficiencies in defense procurement. Nor should this...NAVAIR, Interview by Author. Interview with NAVAIR JPATS Egress Engineer (2010). Olleros, Francisco-Javier. "Emerging industries and the burnout of

  11. Biosorptive behaviour of Mango (Mangifera indica) and Neem (Azadirachta indica) bark for Hg{sup 2+}, Cr{sup 3+} and Cd{sup 2+} toxic ions from aqueous solutions: a radiotracer study

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Diwakar; Mishra, Shuddhodan P. [Nuclear and Radiochemistry Laboratory, Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi (India); Mishra, Manisha; Dubey, R.S. [Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi (India)

    1999-04-01

    Biosorption of Hg{sup 2+} and Cr{sup 3+} on dead biomass Mango (Mangifera indica) and Neem (Azadirachta indica) bark has been assessed at micro to tracer level concentrations from aqueous solutions employing the 'radiotracer technique'. A high level of uptake of metal ions on these solid surfaces occurs within ca. 4 h of contact time reaching apparent saturation. The increase of sorptive concentration (10{sup -8} to 10{sup -2} mol dm{sup -3}), temperature (293-323 K) and pH (ca. 3 to 10) favoured the removal process of these ions; but in the case of Hg{sup 2+} on Neem bark, there was seemingly no temperature effect. The uptake process follows first order rate law and obeys the Freundlich adsorption isotherm. Added anions and cations in the bulk solution inhibit to some extent the removal of these toxic ions. Similarly the inhibition in the uptake was also observed when both biomasses were irradiated by neutron and {gamma}-rays prior to being employed as sorbents. No significant sorption of Cd{sup 2+} was observed on these dead biomass solid surfaces under various physical-chemical conditions.

  12. A biosystem for removal of metal ions from water

    Energy Technology Data Exchange (ETDEWEB)

    Kilbane, J.J. II.

    1990-01-01

    The presence of heavy metal ions in ground and surface waters constitutes a potential health risk and is an environmental concern. Moreover, processes for the recovery of valuable metal ions are of interest. Bioaccumulation or biosorption is not only a factor in assessing the environmental risk posed by metal ions; it can also be used as a means of decontamination. A biological system for the removal and recovery of metal ions from contaminated water is reported here. Exopolysaccharide-producing microorganisms, including a methanotrophic culture, are demonstrated to have superior metal binding ability, compared with other microbial cultures. This paper describes a biosorption process in which dried biomass obtained from exopolysaccharide-producing microorganisms is encapsulated in porous plastic beads and is used for metal ion binding and recovery. 22 refs., 13 figs.

  13. Mycobacterium tuberculosis has diminished capacity to counteract redox stress induced by elevated levels of endogenous superoxide.

    Science.gov (United States)

    Tyagi, Priyanka; Dharmaraja, Allimuthu T; Bhaskar, Ashima; Chakrapani, Harinath; Singh, Amit

    2015-07-01

    Mycobacterium tuberculosis (Mtb) has evolved protective and detoxification mechanisms to maintain cytoplasmic redox balance in response to exogenous oxidative stress encountered inside host phagocytes. In contrast, little is known about the dynamic response of this pathogen to endogenous oxidative stress generated within Mtb. Using a noninvasive and specific biosensor of cytoplasmic redox state of Mtb, we for first time discovered a surprisingly high sensitivity of this pathogen to perturbation in redox homeostasis induced by elevated endogenous reactive oxygen species (ROS). We synthesized a series of hydroquinone-based small molecule ROS generators and found that ATD-3169 permeated mycobacteria to reliably enhance endogenous ROS including superoxide radicals. When Mtb strains including multidrug-resistant (MDR) and extensively drug-resistant (XDR) patient isolates were exposed to this compound, a dose-dependent, long-lasting, and irreversible oxidative shift in intramycobacterial redox potential was detected. Dynamic redox potential measurements revealed that Mtb had diminished capacity to restore cytoplasmic redox balance in comparison with Mycobacterium smegmatis (Msm), a fast growing nonpathogenic mycobacterial species. Accordingly, Mtb strains were extremely susceptible to inhibition by ATD-3169 but not Msm, suggesting a functional linkage between dynamic redox changes and survival. Microarray analysis showed major realignment of pathways involved in redox homeostasis, central metabolism, DNA repair, and cell wall lipid biosynthesis in response to ATD-3169, all consistent with enhanced endogenous ROS contributing to lethality induced by this compound. This work provides empirical evidence that the cytoplasmic redox poise of Mtb is uniquely sensitive to manipulation in steady-state endogenous ROS levels, thus revealing the importance of targeting intramycobacterial redox metabolism for controlling TB infection. Copyright © 2015 The Authors. Published by

  14. Valorization of aquaculture waste in removal of cadmium from aqueous solution: optimization by kinetics and ANN analysis

    Science.gov (United States)

    Aditya, Gautam; Hossain, Asif

    2018-05-01

    Cadmium is one of the most hazardous heavy metal concerning human health and aquatic pollution. The removal of cadmium through biosorption is a feasible option for restoration of the ecosystem health of the contaminated freshwater ecosystems. In compliance with this proposition and considering the efficiency of calcium carbonate as biosorbent, the shell dust of the economically important snail Bellamya bengalensis was tested for the removal of cadmium from aqueous medium. Following use of the flesh as a cheap source of protein, the shells of B. bengalensis made up of CaCO3 are discarded as aquaculture waste. The biosorption was assessed through batch sorption studies along with studies to characterize the morphology and surface structures of waste shell dust. The data on the biosorption were subjected to the artificial neural network (ANN) model for optimization of the process. The biosorption process changed as functions of pH of the solution, concentration of heavy metal, biomass of the adsorbent and time of exposure. The kinetic process was well represented by pseudo second order ( R 2 = 0.998), and Langmuir equilibrium ( R 2 = 0.995) had better fits in the equilibrium process with 30.33 mg g-1 of maximum sorption capacity. The regression equation ( R 2 = 0.948) in the ANN model supports predicted values of Cd removal satisfactorily. The normalized importance analysis in ANN predicts Cd2+ concentration, and pH has the most influence in removal than biomass dose and time. The SEM and EDX studies show clear peaks for Cd confirming the biosorption process while the FTIR study depicts the main functional groups (-OH, C-H, C=O, C=C) responsible for the biosorption process. The study indicated that the waste shell dust can be used as an efficient, low cost, environment friendly, sustainable adsorbent for the removal of cadmium from aqueous solution.

  15. Use of agricultural waste sugar beet pulp for the removal of Gemazol turquoise blue-G reactive dye from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Aksu, Zuemriye [Hacettepe University, Department of Chemical Engineering, 06532 Beytepe, Ankara (Turkey)]. E-mail: zaksu@hacettepe.edu.tr; Isoglu, I. Alper [Hacettepe University, Department of Chemical Engineering, 06532 Beytepe, Ankara (Turkey)

    2006-09-01

    The potential use of dried sugar beet pulp, an agricultural solid waste by-product, as an biosorbent for Gemazol turquoise blue-G, a copper-pthalocyanine reactive dye commonly used in dyeing of cotton, was investigated in the present study. Batch adsorption studies were carried out to examine the influence of various parameters such as initial pH, temperature and initial dye concentration. The results indicated that adsorption was strongly pH-dependent and slightly temperature-dependent. At 800 mg l{sup -1} initial Gemazol turquoise blue-G concentration, dried sugar beet pulp exhibited the highest Gemazol turquoise blue-G uptake capacity of 234.8 mg g{sup -1} at 25 deg. C and at an initial pH value of 2.0. The Freundlich, Langmuir, Redlich-Peterson and Langmuir-Freundlich, the two and three parameters adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated depending on temperature. Both the Langmuir and Redlich-Peterson models were applicable for describing the dye biosorption by dried sugar beet pulp in the concentration (100-800 mg l{sup -1}) and temperature (25-45 deg. C) ranges studied. Simple mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of biosorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion and biosorption process. The sorption process was found to be controlled by both surface and pore diffusion with surface diffusion at the earlier stages followed by pore diffusion at the later stages. Pseudo first-order, pseudo second-order and saturation type kinetic models described the biosorption kinetics accurately at all concentrations and temperatures studied. The thermodynamic analysis indicated that the sorption process was exothermic and the biosorption of dye on dried sugar beet pulp might be physical in nature.

  16. Use of agricultural waste sugar beet pulp for the removal of Gemazol turquoise blue-G reactive dye from aqueous solution.

    Science.gov (United States)

    Aksu, Zümriye; Isoglu, I Alper

    2006-09-01

    The potential use of dried sugar beet pulp, an agricultural solid waste by-product, as an biosorbent for Gemazol turquoise blue-G, a copper-pthalocyanine reactive dye commonly used in dyeing of cotton, was investigated in the present study. Batch adsorption studies were carried out to examine the influence of various parameters such as initial pH, temperature and initial dye concentration. The results indicated that adsorption was strongly pH-dependent and slightly temperature-dependent. At 800 mg l(-1) initial Gemazol turquoise blue-G concentration, dried sugar beet pulp exhibited the highest Gemazol turquoise blue-G uptake capacity of 234.8 mg g(-1) at 25 degrees C and at an initial pH value of 2.0. The Freundlich, Langmuir, Redlich-Peterson and Langmuir-Freundlich, the two and three parameters adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated depending on temperature. Both the Langmuir and Redlich-Peterson models were applicable for describing the dye biosorption by dried sugar beet pulp in the concentration (100-800 mg l(-1)) and temperature (25-45 degrees C) ranges studied. Simple mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of biosorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion and biosorption process. The sorption process was found to be controlled by both surface and pore diffusion with surface diffusion at the earlier stages followed by pore diffusion at the later stages. Pseudo first-order, pseudo second-order and saturation type kinetic models described the biosorption kinetics accurately at all concentrations and temperatures studied. The thermodynamic analysis indicated that the sorption process was exothermic and the biosorption of dye on dried sugar beet pulp might be physical in nature.

  17. Equilibrium modeling of removal of drimarine yello HG-3GL dye from aqueous solutions by low cost agricultural waste

    International Nuclear Information System (INIS)

    Bhatti, S.N.H.N.; Sadaf, S.; Sadaf, S.; Farrukh, Z.; Noreen, S.

    2014-01-01

    Pollution control is one of the leading issues of society today. The present study was designed to remove the Drimarine Yellow HF-3GL dye from aqueous solutions through biosorption. Sugarcane bagasse was used as biosorbent in native, acetic acid treated and immobilized form. Batch study was conducted to optimize different system variables like pH of solution, medium temperature, biosorbent concentration, initial dye concentration and contact time. Maximum dye removal was observed at pH 2, biosorbent dose of 0.05 g/50 mL and 40 degree C temperature. The equilibrium was achieved in 45-90 min. Different kinetic and equilibrium models were applied to the experimental results. The biosorption kinetic data was found to follow the pseudo second order kinetic model. Freundlich adsorption isotherm model showed a better fitness to the equilibrium data. The value of Gibbs free energy revealed that biosorption of Drimarine Yellow HF-3GL dye by native and pretreated sugarcane bagasse was a spontaneous process. Presence of salt and heavy metal ions in aqueous solution enhanced the biosorption capacity while presence of surfactants decreased the biosorption potential of biosorbent. Dye was desorbed by 1M NaOH solution. Fixed bed column study of Drimarine Yellow HF-3GL was carried out to optimize different parameters like bed height, flow rate and initial dye concentration. It was observed that biosorption capacity increases with increase in initial dye concentration and bed height but decreases with the increase in flow rate. The data of column study was explained very well by BDST model. FT-IR analysis confirmed the involvement of various functional groups, mainly hydroxyl, carboxyl and amine groups. The results proved that sugarcane bagasse waste biomass can be used as a favorable biosorbent for the removal of dyes from aqueous solutions. (author)

  18. A breakthrough biosorbent in removing heavy metals: Equilibrium, kinetic, thermodynamic and mechanism analyses in a lab-scale study

    Energy Technology Data Exchange (ETDEWEB)

    Abdolali, Atefeh [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Ngo, Huu Hao, E-mail: h.ngo@uts.edu.au [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Guo, Wenshan [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Lu, Shaoyong [Chinese Research Academy of Environmental Science, Beijing 100012 (China); Chen, Shiao-Shing; Nguyen, Nguyen Cong [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd, Taipei 106, Taiwan (China); Zhang, Xinbo [Department of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384 (China); Wang, Jie; Wu, Yun [School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

    2016-01-15

    A breakthrough biosorbent namely multi-metal binding biosorbent (MMBB) made from a combination of tea wastes, maple leaves and mandarin peels, was prepared to evaluate their biosorptive potential for removal of Cd(II), Cu(II), Pb(II) and Zn(II) from multi-metal aqueous solutions. FTIR and SEM were conducted, before and after biosorption, to explore the intensity and position of the available functional groups and changes in adsorbent surface morphology. Carboxylic, hydroxyl and amine groups were found to be the principal functional groups for the sorption of metals. MMBB exhibited best performance at pH 5.5 with maximum sorption capacities of 31.73, 41.06, 76.25 and 26.63 mg/g for Cd(II), Cu(II), Pb(II) and Zn(II), respectively. Pseudo-first and pseudo-second-order models represented the kinetic experimental data in different initial metal concentrations very well. Among two-parameter adsorption isotherm models, the Langmuir equation gave a better fit of the equilibrium data. For Cu(II) and Zn(II), the Khan isotherm describes better biosorption conditions while for Cd(II) and Pb(II), the Sips model was found to provide the best correlation of the biosorption equilibrium data. The calculated thermodynamic parameters indicated feasible, spontaneous and exothermic biosorption process. Overall, this novel MMBB can effectively be utilized as an adsorbent to remove heavy metal ions from aqueous solutions. - Highlights: • A novel multi-metal binding biosorbent (MMBB) was studied. • The biosorption of Cd{sup 2+}, Cu{sup 2+}, Pb{sup 2+} and Zn{sup 2+} on MMBB was evaluated. • Hydroxyl, carbonyl and amine groups are involved in metal binding of MMBB. • Equilibrium data were presented and the best fitting models were identified. • The obtained results recommend this MMBB as potentially low-cost biosorbent.

  19. Polypogon monspeliensis waste biomass: A potential biosorbent for ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-03-20

    Mar 20, 2009 ... and initial metal concentration for Cd (II) uptake by P. monspeliensis waste biomass were 6, 0.05 g, .... Inital metal(mg/L) q. (m g. /g. ) Figure 4. Effect of initial concentration on the biosorption of Cd (II) by Polypogon monspeliensis waste biomass. Effect of initial Cd ..... Biosorption of uranium by Pseudomonas.

  20. Diminished neural responses predict enhanced intrinsic motivation and sensitivity to external incentive.

    Science.gov (United States)

    Marsden, Karen E; Ma, Wei Ji; Deci, Edward L; Ryan, Richard M; Chiu, Pearl H

    2015-06-01

    The duration and quality of human performance depend on both intrinsic motivation and external incentives. However, little is known about the neuroscientific basis of this interplay between internal and external motivators. Here, we used functional magnetic resonance imaging to examine the neural substrates of intrinsic motivation, operationalized as the free-choice time spent on a task when this was not required, and tested the neural and behavioral effects of external reward on intrinsic motivation. We found that increased duration of free-choice time was predicted by generally diminished neural responses in regions associated with cognitive and affective regulation. By comparison, the possibility of additional reward improved task accuracy, and specifically increased neural and behavioral responses following errors. Those individuals with the smallest neural responses associated with intrinsic motivation exhibited the greatest error-related neural enhancement under the external contingency of possible reward. Together, these data suggest that human performance is guided by a "tonic" and "phasic" relationship between the neural substrates of intrinsic motivation (tonic) and the impact of external incentives (phasic).

  1. Enhanced biosorption of mercury(II) and cadmium(II) by cold-induced hydrophobic exobiopolymer secreted from the psychrotroph Pseudomonas fluorescens BM07

    Energy Technology Data Exchange (ETDEWEB)

    Zamil, Sheikh Shawkat; Choi, Mun Hwan; Song, Jung Hyun; Park, Hyunju; Xu, Ju; Yoon, Sung Chul [Gyeongsang National Univ., Jinju (Korea). Nano-Biomaterials Science Lab.; Chi, Ki-Whan [Ulsan Univ. (Korea). Dept. of Chemistry

    2008-09-15

    The cells of psychrotrophic Pseudomonas fluorescens BM07 were found to secrete large amounts of exobiopolymer (EBP) composed of mainly hydrophobic (water insoluble) polypeptide(s) (as contain {proportional_to}50 mol% hydrophobic amino acids, lacking cysteine residue) when grown on fructose containing limited M1 medium at the temperatures as low as 0-10 C but trace amount at high (30 C, optimum growth) temperature. Two types of nonliving BM07 cells (i.e., cells grown at 30 C and 10 C) as well as the freeze-dried EBP were compared for biosorption of mercury (Hg(II)) and cadmium (Cd(II)). The optimum adsorption pH was found 7 for Hg(II) but 6 for Cd(II), irrespective of the type of biomass. Equilibrium adsorption data well fitted the Langmuir adsorption model. The maximum adsorption (Q{sub max}) was 72.3, 97.4, and 286.2 mg Hg(II)/g dry biomass and 18.9, 27.0, and 61.5 mg Cd(II)/g dry biomass for cells grown at 30 C and 10 C and EBP, respectively, indicating major contribution of heavy metal adsorption by cold-induced EBP. Mercury(II) binding induced a significant shift of infrared (IR) amide I and II absorption of EBP whereas cadmium(II) binding showed only a very little shift. These IR shifts demonstrate that mercury(II) and cadmium(II) might have different binding sites in EBP, which was supported by X-ray diffraction and differential scanning calorimetric analysis and sorption results of chemically modified biomasses. This study implies that the psychrotrophs like BM07 strain may play an important role in the bioremediation of heavy metals in the temperate regions especially in the inactive cold season. (orig.)

  2. Biosorption of U(VI) by the green algae Chlorella vulgaris in dependence of pH value and cell activity

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, M., E-mail: M.Vogel@fzd.de; Guenther, A.; Rossberg, A.; Li, B.; Bernhard, G.; Raff, J.

    2010-12-15

    Biosorption of uranium(VI) by the green alga Chlorella vulgaris was studied at varying uranium concentrations from 5 {mu}M to 1 mM, and in the environmentally relevant pH range of 4.4 to 7.0. Living cells bind in a 0.1 mM uranium solution at pH 4.4 within 5 min 14.3 {+-} 5.5 mg U/g dry biomass and dead cells 28.3 {+-} 0.6 mg U/g dry biomass which corresponds to 45% and 90% of total uranium in solution, respectively. During 96 h of incubation with uranium initially living cells died off and with 26.6 {+-} 2.1 mg U/g dry biomass bound similar amounts of uranium compared to dead cells, binding 27.0 {+-} 0.7 mg U/g dry biomass. In both cases, these amounts correspond to around 85% of the initially applied uranium. Interestingly, at a lower and more environmentally relevant uranium concentration of 5 {mu}M, living cells firstly bind with 1.3 {+-} 0.2 mg U/g dry biomass to 1.4 {+-} 0.1 mg U/g dry biomass almost all uranium within the first 5 min of incubation. But then algal cells again mobilize up to 80% of the bound uranium during ongoing incubation in the time from 48 h to 96 h. The release of metabolism related substances is suggested to cause this mobilization of uranium. As potential leachates for algal-bound uranium oxalate, citrate and ATP were tested and found to be able to mobilize more than 50% of the algal-bound uranium within 24 h. Differences in complexation of uranium by active and inactive algae cells were investigated with a combination of time-resolved laser-induced fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure (EXAFS) spectroscopy and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Obtained results demonstrated an involvement of carboxylic and organic/inorganic phosphate groups in the uranium complexation with varying contributions dependent on cell status, uranium concentration and pH.

  3. Biosorption of U(VI) by the green algae Chlorella vulgaris in dependence of pH value and cell activity

    International Nuclear Information System (INIS)

    Vogel, M.; Guenther, A.; Rossberg, A.; Li, B.; Bernhard, G.; Raff, J.

    2010-01-01

    Biosorption of uranium(VI) by the green alga Chlorella vulgaris was studied at varying uranium concentrations from 5 μM to 1 mM, and in the environmentally relevant pH range of 4.4 to 7.0. Living cells bind in a 0.1 mM uranium solution at pH 4.4 within 5 min 14.3 ± 5.5 mg U/g dry biomass and dead cells 28.3 ± 0.6 mg U/g dry biomass which corresponds to 45% and 90% of total uranium in solution, respectively. During 96 h of incubation with uranium initially living cells died off and with 26.6 ± 2.1 mg U/g dry biomass bound similar amounts of uranium compared to dead cells, binding 27.0 ± 0.7 mg U/g dry biomass. In both cases, these amounts correspond to around 85% of the initially applied uranium. Interestingly, at a lower and more environmentally relevant uranium concentration of 5 μM, living cells firstly bind with 1.3 ± 0.2 mg U/g dry biomass to 1.4 ± 0.1 mg U/g dry biomass almost all uranium within the first 5 min of incubation. But then algal cells again mobilize up to 80% of the bound uranium during ongoing incubation in the time from 48 h to 96 h. The release of metabolism related substances is suggested to cause this mobilization of uranium. As potential leachates for algal-bound uranium oxalate, citrate and ATP were tested and found to be able to mobilize more than 50% of the algal-bound uranium within 24 h. Differences in complexation of uranium by active and inactive algae cells were investigated with a combination of time-resolved laser-induced fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure (EXAFS) spectroscopy and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Obtained results demonstrated an involvement of carboxylic and organic/inorganic phosphate groups in the uranium complexation with varying contributions dependent on cell status, uranium concentration and pH.

  4. Evaluation of the individuality of white rot macro fungus for the decolorization of synthetic dye.

    Science.gov (United States)

    Pandey, Priyanka; Singh, Ram Praksh; Singh, Kailash Nath; Manisankar, Paramasivam

    2013-01-01

    A biosorbent was developed by simple dried Agaricus bisporus (SDAB) and effectively used for the biosorption of cationic dyes, Crystal Violet and Brilliant Green. For the evaluation of the biosorbent system, all the batch equilibrium parameters like pH, biomass dose, contact time, and temperature were optimized to determine the decolorization efficiency of the biosorbent. The maximum yields of dye removal were achieved at pH 4.0 for Crystal Violet (CV) and pH 5.0 for Brilliant Green (BG), which are closer to their natural pH also. Equilibrium was established at 60 and 40 min for CV and BG, respectively. Pseudo first-order, pseudo second-order, and intraparticle-diffusion kinetic models were studied at different temperatures. Isotherm models such as Freundlich, Langmuir, and Dubinin-Radushkevich were also studied. Biosorption processes were successfully described by Langmuir isotherm model and the pseudo second-order kinetic model. The biosorption capacity of A. bisporus over CV and BG were found as 21.74 and 12.16 mg gm(-1). Thermodynamic parameters indicated that the CV and BG dye adsorption onto A. bisporus is spontaneous and exothermic in the single and ternary systems. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used for the surface morphology, crystalline structure of biosorbent, and dye-biosorbent interaction, respectively. This analysis of the biosorption data confirmed that these biosorption processes are ecofriendly and economical. Thus, this biomass system may be useful for the removal of contaminating cationic dyes.

  5. Liquid-phase separation of reactive dye by wood-rotting fungus: a biotechnological approach.

    Science.gov (United States)

    Binupriya, Arthur R; Sathishkumar, Muthuswamy; Dhamodaran, Kavitha; Jayabalan, Rasu; Swaminathan, Krishnaswamy; Yun, Sei Eok

    2007-08-01

    The live and pretreated mycelial pellets/biomass of Trametes versicolor was used for the biosorption of a textile dye, reactive blue MR (RBMR) from aqueous solution. The parameters that affect the biosorption of RBMR, such as contact time, concentration of dye and pH, on the extent of RBMR adsorption were investigated. To develop an effective and accurate design model for removal of dye, adsorption kinetics and equilibrium data are essential basic requirements. Lagergren first-order, second-order and Bangham's model were used to fit the experimental data. Results of the kinetic studies showed that the second order kinetic model fitted well for the present experimental data. The Langmuir, Freundlich and Temkin adsorption models were used for the mathematical description of the biosorption equilibrium. The biosorption equilibrium data obeyed well for Langmuir isotherm and the maximum adsorption capacities were found to be 49.8, 51.6, 47.4 and 46.7 mg/g for live, autoclaved, acid- and alkali-pretreated biomass. The dye uptake capacity order of the fungal biomass was found as autoclaved > live > acid-treated > alkali-pretreated. The Freundlich and Temkin models were also able to describe the biosorption equilibrium on RBMR on live and pretreated fungal biomass. Acidic pH was favorable for the adsorption of dye. Studies on pH effect and desorption show that chemisorption seems to play a major role in the adsorption process. On comparison with fixed bed adsorption, batch mode adsorption was more efficient in adsorption of RBMR.

  6. Diminished facial emotion expression and associated clinical characteristics in Anorexia Nervosa.

    Science.gov (United States)

    Lang, Katie; Larsson, Emma E C; Mavromara, Liza; Simic, Mima; Treasure, Janet; Tchanturia, Kate

    2016-02-28

    This study aimed to investigate emotion expression in a large group of children, adolescents and adults with Anorexia Nervosa (AN), and investigate the associated clinical correlates. One hundred and forty-one participants (AN=66, HC= 75) were recruited and positive and negative film clips were used to elicit emotion expressions. The Facial Activation Coding system (FACES) was used to code emotion expression. Subjective ratings of emotion were collected. Individuals with AN displayed less positive emotions during the positive film clip compared to healthy controls (HC). There was no significant difference between the groups on the Positive and Negative Affect Scale (PANAS). The AN group displayed emotional incongruence (reporting a different emotion to what would be expected given the stimuli, with limited facial affect to signal the emotion experienced), whereby they reported feeling significantly higher rates of negative emotion during the positive clip. There were no differences in emotion expression between the groups during the negative film clip. Despite this individuals with AN reported feeling significantly higher levels of negative emotions during the negative clip. Diminished positive emotion expression was associated with more severe clinical symptoms, which could suggest that these individuals represent a group with serious social difficulties, which may require specific attention in treatment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Diminished physical function in older HIV-infected adults in the Southeastern U.S. despite successful antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Audrey L Khoury

    Full Text Available As antiretroviral therapy efficacy improves, HIV is gradually being recognized more as a chronic disease within the aging HIV-infected population. While these individuals are surviving into old age, they may, however, be experiencing "accelerated aging" with greater declines in physical function than that observed among comparably matched individuals free of HIV. This decline is not well understood and it remains unclear if physical decline correlates with the degree of immunosuppression based on CD4 lymphocyte nadir.In a cross-sectional study of accelerated aging in the older HIV-infected population on antiretroviral therapy (ART, physical performance evaluations were completed on a cohort of 107 HIV-infected subjects, age 50 years or older (with no HIV-1 RNA >200 copies/mL in the prior 12 months, and compared to reference ranges for age- and gender-matched HIV-uninfected persons. Physical performance testing consisted of four validated assessments: the 2.4-meter walk, 30-second chair stand, grip strength and 6-minute walk test.When compared to age- and gender-matched HIV-uninfected reference controls, older HIV-infected persons had diminished physical function. No correlation was found between physical function and degree of immunosuppression as determined by pre-ART CD4 nadir.Despite improved survival, HIV-infected adults on suppressive ART have diminished physical function compared to HIV-uninfected persons. The degree of HIV-associated immunosuppression does not correlate with the observed degree of physical function decline in older HIV-infected persons, suggesting the decline is mediated by other mechanisms.

  8. Fragile X-Associated Diminished Ovarian Reserve and Primary Ovarian Insufficiency from Molecular Mechanisms to Clinical Manifestations

    Directory of Open Access Journals (Sweden)

    Limor Man

    2017-09-01

    Full Text Available Fragile X syndrome (FXS, is caused by a loss-of-function mutation in the FMR1 gene located on the X-chromosome, which leads to the most common cause of inherited intellectual disability in males and the leading single-gene defect associated with autism. A full mutation (FM is represented by more than 200 CGG repeats within the FMR1 gene, resulting in FXS. A FM is inherited from women carrying a FM or a premutation (PM; 55–200 CGG repeats allele. PM is associated with phenotypes distinct from those associated with FM. Some manifestations of the PM are unique; fragile-X-associated tremor/ataxia syndrome (FXTAS, and fragile-X-associated primary ovarian insufficiency (FXPOI, while others tend to be non-specific such as intellectual disability. In addition, women carrying a PM may suffer from subfertility or infertility. There is a need to elucidate whether the impairment of ovarian function found in PM carriers arises during the primordial germ cell (PGC development stage, or due to a rapidly diminishing oocyte pool throughout life or even both. Due to the possibility of expansion into a FM in the next generation, and other ramifications, carrying a PM can have an enormous impact on one’s life; therefore, preconception counseling for couples carrying the PM is of paramount importance. In this review, we will elaborate on the clinical manifestations in female PM carriers and propose the definition of fragile-X-associated diminished ovarian reserve (FXDOR, then we will review recent scientific findings regarding possible mechanisms leading to FXDOR and FXPOI. Lastly, we will discuss counseling, preventative measures and interventions available for women carrying a PM regarding different aspects of their reproductive life, fertility treatment, pregnancy, prenatal testing, contraception and fertility preservation options.

  9. Fragile X-Associated Diminished Ovarian Reserve and Primary Ovarian Insufficiency from Molecular Mechanisms to Clinical Manifestations.

    Science.gov (United States)

    Man, Limor; Lekovich, Jovana; Rosenwaks, Zev; Gerhardt, Jeannine

    2017-01-01

    Fragile X syndrome (FXS), is caused by a loss-of-function mutation in the FMR1 gene located on the X-chromosome, which leads to the most common cause of inherited intellectual disability in males and the leading single-gene defect associated with autism. A full mutation (FM) is represented by more than 200 CGG repeats within the FMR1 gene, resulting in FXS. A FM is inherited from women carrying a FM or a premutation (PM; 55-200 CGG repeats) allele. PM is associated with phenotypes distinct from those associated with FM. Some manifestations of the PM are unique; fragile-X-associated tremor/ataxia syndrome (FXTAS), and fragile-X-associated primary ovarian insufficiency (FXPOI), while others tend to be non-specific such as intellectual disability. In addition, women carrying a PM may suffer from subfertility or infertility. There is a need to elucidate whether the impairment of ovarian function found in PM carriers arises during the primordial germ cell (PGC) development stage, or due to a rapidly diminishing oocyte pool throughout life or even both. Due to the possibility of expansion into a FM in the next generation, and other ramifications, carrying a PM can have an enormous impact on one's life; therefore, preconception counseling for couples carrying the PM is of paramount importance. In this review, we will elaborate on the clinical manifestations in female PM carriers and propose the definition of fragile-X-associated diminished ovarian reserve (FXDOR), then we will review recent scientific findings regarding possible mechanisms leading to FXDOR and FXPOI. Lastly, we will discuss counseling, preventative measures and interventions available for women carrying a PM regarding different aspects of their reproductive life, fertility treatment, pregnancy, prenatal testing, contraception and fertility preservation options.

  10. Intensification of the process of sorption of copper ions by yeast of Saccharomyces cerevisiae 1968 by means of a permanent magnetic field

    International Nuclear Information System (INIS)

    Gorobets, Svetlana; Gorobets, Oksana; Ukrainetz, Anatoliy; Kasatkina, Taisiya; Goyko, Irina

    2004-01-01

    Possibility to replace mechanical stirring by magnetic field-induced one was shown for intensification of yeast biosorption and cementation. Combined method of metal ion recover, including Cu ion sorption by yeast Saccharomyces cerevisiae and Cu cementation on a surface of a steel matrix, is tested in a case of magnetic field-induced stirring

  11. Smoking Through a Topography Device Diminishes Some of the Acute Rewarding Effects of Smoking.

    Science.gov (United States)

    Ross, Kathryn C; Juliano, Laura M

    2016-05-01

    Smoking topography (ST) devices are an important methodological tool for quantifying puffing behavior (eg, puff volume, puff velocity) as well as identifying puffing differences across individuals and situations. Available ST devices are designed such that the smoker's mouth and hands have direct contact with the device rather than the cigarette itself. Given the importance of the sensorimotor aspects of cigarette smoking in smoking reward, it is possible that ST devices may interfere with the acute rewarding effects of smoking. Despite the methodological importance of this issue, few studies have directly compared subjective reactions to smoking through a topography device to naturalistic smoking. Smokers (N = 58; 38% female) smoked their preferred brand of cigarettes one time through a portable topography device and one time naturalistically, in counterbalanced order across two laboratory sessions. Smoking behavior (eg, number of puffs) and subjective effects (eg, urge reduction, affect, smoking satisfaction) were assessed. Negative affect reduction was greater in the natural smoking condition relative to the topography condition, but differences were not significant on measures of urge, withdrawal, or positive affect. Self-reported smoking satisfaction, enjoyment of respiratory tract sensations, psychological reward, craving reduction, and other rewarding effects of smoking were also significantly greater in the naturalistic smoking condition. The effects of using a ST device on the smoking experience should be considered when it is used in research as it may diminish some of the rewarding effects of smoking. When considering the inclusion of a smoking topography device in one's research, it is important to know if use of that device will alter the smoker's experience. This study assessed affective and subjective reactions to smoking through a topography device compared to naturalistic smoking. We found that smoking satisfaction, psychological reward, enjoyment

  12. Rifaximin diminishes neutropenia following potentially lethal whole-body radiation.

    Science.gov (United States)

    Jahraus, Christopher D; Schemera, Bettina; Rynders, Patricia; Ramos, Melissa; Powell, Charles; Faircloth, John; Brawner, William R

    2010-07-01

    Terrorist attacks involving radiological or nuclear weapons are a substantial geopolitical concern, given that large populations could be exposed to potentially lethal doses of radiation. Because of this, evaluating potential countermeasures against radiation-induced mortality is critical. Gut microflora are the most common source of systemic infection following exposure to lethal doses of whole-body radiation, suggesting that prophylactic antibiotic therapy may reduce mortality after radiation exposure. The chemical stability, easy administration and favorable tolerability profile of the non-systemic antibiotic, rifaximin, make it an ideal potential candidate for use as a countermeasure. This study evaluated the use of rifaximin as a countermeasure against low-to-intermediate-dose whole-body radiation in rodents. Female Wistar rats (8 weeks old) were irradiated with 550 cGy to the whole body and were evaluated for 30 d. Animals received methylcellulose, neomycin (179 mg/kg/d) or variably dosed rifaximin (150-2000 mg/kg/d) one hour after irradiation and daily throughout the study period. Clinical assessments (e.g. body weight) were made daily. On postirradiation day 30, blood samples were collected and a complete blood cell count was performed. Animals receiving high doses of rifaximin (i.e. 1000 or 2000 mg/kg/d) had a greater increase in weight from the day of irradiation to postirradiation day 30 compared with animals that received placebo or neomycin. For animals with an increase in average body weight from irradiation day within 80-110% of the group average, methylcellulose rendered an absolute neutrophil count (ANC) of 211, neomycin rendered an ANC of 334, rifaximin 300 mg/kg/d rendered an ANC of 582 and rifaximin 1000 mg/kg/d rendered an ANC of 854 (P = 0.05 for group comparison). Exposure to rifaximin after near-lethal whole-body radiation resulted in diminished levels of neutropenia.

  13. Increased outdoor recreation, diminished ozone layer pose ultraviolet radiation threat to eye

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-24

    The long-term effects of ultraviolet (UV) light on the eye are of increasing concern as many people live longer and spend more of that time in outdoor recreation and as the diminishing ozone layer filters less UV light. Ultraviolet radiation is strongest at high altitude, low latitude, and open for reflective environments (sand, snow, or water). For people who lack an eye lens (aphakics), UV light is transmitted directly onto the retina. Cumulative exposure to the 300- to 400-nm range of UV light is one factor causing cataracts. Ophthalmologists say cataracts cause visual deficits for more than 3.5 million people in the United States. Cumulative UV exposure may lead to age-related macular degeneration. At a Research to Prevent Blindness conference in Arlington, VA, John S. Werner, PhD, professor of psychology and neurosciences at the University of Colorado, Boulder, described how his group demonstrated the effects of UV light on retinal cones. Different types of intraocular lenses were placed in each eye of eight patients who had undergone bilateral cataract surgery. After five years, retinal cones chronically exposured to UV radiation had less sensitivity for short wavelengths (440 nm) by a factor of 1.7.

  14. Removal of Pb (II Ions from Aqueous Solutions by Cladophora rivularis (Linnaeus Hoek

    Directory of Open Access Journals (Sweden)

    Naser Jafari

    2012-01-01

    Full Text Available Biosorption of Pb(II using Cladophora rivularis was examined as a function of initial pH heavy metal concentration and temperature. The optimum pH value for the biosorption of lead was 4.0. The adsorption equilibriums were well described by Langmuir and Freundlich isotherm models and it was implied by the results that the C. rivularis biomass is suitable for the development of efficient biosorbent in order to remove Pb(II from wastewater and to recover it. The high values of correlation coefficient (2=0.984 demonstrate equilibrium data concerning algal biomass, which is well fitted in Freundlich isotherms model equations. The dimensionless parameter RL is found in the range of 0.0639 to 0.1925 (0<<1, which confirms the favorable biosorption process. Fourier transform infra-red (FTIR spectroscopy of C. rivularis was used to reveal the main function groups of biosorption, which were hydroxyl, amine groups, C–H stretching vibrations of –CH3 and –CH2, and complexation with functional groups. All these results suggest that C. rivularis can be used effectively for removal of Pb(II.

  15. Removal of Pb (II) ions from aqueous solutions by Cladophora rivularis (Linnaeus) Hoek.

    Science.gov (United States)

    Jafari, Naser; Senobari, Zoreh

    2012-01-01

    Biosorption of Pb(II) using Cladophora rivularis was examined as a function of initial pH heavy metal concentration and temperature. The optimum pH value for the biosorption of lead was 4.0. The adsorption equilibriums were well described by Langmuir and Freundlich isotherm models and it was implied by the results that the C. rivularis biomass is suitable for the development of efficient biosorbent in order to remove Pb(II) from wastewater and to recover it. The high values of correlation coefficient (R(2) = 0.984) demonstrate equilibrium data concerning algal biomass, which is well fitted in Freundlich isotherms model equations. The dimensionless parameter R(L) is found in the range of 0.0639 to 0.1925 (0 < R(L) < 1), which confirms the favorable biosorption process. Fourier transform infra-red (FTIR) spectroscopy of C. rivularis was used to reveal the main function groups of biosorption, which were hydroxyl, amine groups, C-H stretching vibrations of -CH3 and -CH2, and complexation with functional groups. All these results suggest that C. rivularis can be used effectively for removal of Pb(II).

  16. Growth hormone secretion is diminished and tightly controlled in humans enriched for familial longevity

    DEFF Research Database (Denmark)

    van der Spoel, Evie; Jansen, Steffy W; Akintola, Abimbola A

    2016-01-01

    Reduced growth hormone (GH) signaling has been consistently associated with increased health and lifespan in various mouse models. Here, we assessed GH secretion and its control in relation with human familial longevity. We frequently sampled blood over 24 h in 19 middle-aged offspring of long......-living families from the Leiden Longevity Study together with 18 of their partners as controls. Circulating GH concentrations were measured every 10 min and insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP3) every 4 h. Using deconvolution analysis, we found that 24-h.......39-0.53)] compared with controls [0.66 (0.56-0.77)], indicating tighter control of GH secretion. No significant differences were observed in circulating levels of IGF-1 and IGFBP3 between offspring and controls. In conclusion, GH secretion in human familial longevity is characterized by diminished secretion rate...

  17. Modeling of the adsorptive removal of arsenic(III) using plant biomass: a bioremedial approach

    Science.gov (United States)

    Roy, Palas; Dey, Uttiya; Chattoraj, Soumya; Mukhopadhyay, Debasis; Mondal, Naba Kumar

    2017-06-01

    In the present work, the possibility of using a non-conventional finely ground (250 μm) Azadirachta indica (neem) bark powder [AiBP] has been tested as a low-cost biosorbent for the removal of arsenic(III) from water. The removal of As(III) was studied by performing a series of biosorption experiments (batch and column). The biosorption behavior of As(III) for batch and column operations were examined in the concentration ranges of 50-500 µg L-1 and 500.0-2000.0 µg L-1, respectively. Under optimized batch conditions, the AiBP could remove up to 89.96 % of As(III) in water system. The artificial neural network (ANN) model was developed from batch experimental data sets which provided reasonable predictive performance ( R 2 = 0.961; 0.954) of As(III) biosorption. In batch operation, the initial As(III) concentration had the most significant impact on the biosorption process. For column operation, central composite design (CCD) was applied to investigate the influence on the breakthrough time for optimization of As(III) biosorption process and evaluation of interacting effects of different operating variables. The optimized result of CCD revealed that the AiBP was an effective and economically feasible biosorbent with maximum breakthrough time of 653.9 min, when the independent variables were retained at 2.0 g AiBP dose, 2000.0 µg L-1 initial As(III) concentrations, and 3.0 mL min-1 flow rate, at maximum desirability value of 0.969.

  18. Failure to demonstrate that playing violent video games diminishes prosocial behavior.

    Science.gov (United States)

    Tear, Morgan J; Nielsen, Mark

    2013-01-01

    Past research has found that playing a classic prosocial video game resulted in heightened prosocial behavior when compared to a control group, whereas playing a classic violent video game had no effect. Given purported links between violent video games and poor social behavior, this result is surprising. Here our aim was to assess whether this finding may be due to the specific games used. That is, modern games are experienced differently from classic games (more immersion in virtual environments, more connection with characters, etc.) and it may be that playing violent video games impacts prosocial behavior only when contemporary versions are used. Experiments 1 and 2 explored the effects of playing contemporary violent, non-violent, and prosocial video games on prosocial behavior, as measured by the pen-drop task. We found that slight contextual changes in the delivery of the pen-drop task led to different rates of helping but that the type of game played had little effect. Experiment 3 explored this further by using classic games. Again, we found no effect. We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest. It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior.

  19. Increased conformity offers diminishing returns for reducing total knee replacement wear.

    Science.gov (United States)

    Fregly, Benjamin J; Marquez-Barrientos, Carlos; Banks, Scott A; DesJardins, John D

    2010-02-01

    Wear remains a significant problem limiting the lifespan of total knee replacements (TKRs). Though increased conformity between TKR components has the potential to decrease wear, the optimal amount and planes of conformity have not been investigated. Furthermore, differing conformities in the medial and lateral compartments may provide designers the opportunity to address both wear and kinematic design goals simultaneously. This study used a computational model of a Stanmore knee simulator machine and a previously validated wear model to investigate this issue for simulated gait. TKR geometries with different amounts and planes of conformity on the medial and lateral sides were created and tested in two phases. The first phase utilized a wide range of sagittal and coronal conformity combinations to blanket a physically realistic design space. The second phase performed a focused investigation of the conformity conditions from the first phase to which predicted wear volume was sensitive. For the first phase, sagittal but not coronal conformity was found to have a significant effect on predicted wear volume. For the second phase, increased sagittal conformity was found to decrease predicted wear volume in a nonlinear fashion, with reductions gradually diminishing as conformity increased. These results suggest that TKR geometric design efforts aimed at minimizing wear should focus on sagittal rather than coronal conformity and that at least moderate sagittal conformity is desirable in both compartments.

  20. Reflex peripheral vasoconstriction is diminished in older men.

    Science.gov (United States)

    Kenney, W L; Armstrong, C G

    1996-02-01

    The purpose of this study was to compare reflex control of limb blood flow in healthy young (Y; 26 +/- 2 yr) and older (O;61 +/- 2 yr) men during whole body cooling under resting conditions. To better isolate the effect of chronological age, the two age groups (n = 6 per group) were closely matched for maximal oxygen uptake, body surface area, skinfold thickness, and fat-free weight. Subjects sat in an environmentally controlled chamber clad in standardized (0.6-clo) light cotton clothing at a dry-bulb temperature (Tdb) of 28 degrees C. After 30 min, Tdb was decreased by 2 degrees C every 5 min until Tdb = 10 degrees C, where it was held constant for the remainder of the 120-min session. Esophageal and mean skin temperatures were monitored continuously. Forearm blood flow (FBF) was measured every 5 min by venous occlusion plethysmography by using a mercury-in-Silastic strain gauge while arm temperature between the wrist and elbow was clamped at 37.2 +/- 0.1 degrees C by localized warm air heating. In this way, limb vasoconstriction was driven solely by thermoregulatory reflexes and not by direct effects of localized cooling. Mean skin temperature decreased at a similar rate and to a similar extent (by approximately 6 degrees C over a 2-h period) in both age groups, whereas esophageal temperature was relatively unaffected. In response to the local heating, the Y group maintained a significantly higher FBF than did the O group during the initial 30 min but decreased FBF during the cooling phase at a greater rate and to a greater extent than did the O group, leading to a significantly lower FBF during the final 30 min (at Tdb = 10 degrees C). Because there was no age difference in the mean arterial pressure response, similar effects of age were seen on forearm vascular conductance (FBF/mean arterial pressure). It was concluded that older men have a diminished reflex limb vasoconstrictor response to skin cooling. Furthermore, this difference in control of peripheral

  1. The cytotoxicity of organobismuth compounds with certain molecular structures can be diminished by replacing the bismuth atom with an antimony atom in the molecules.

    Science.gov (United States)

    Kohri, Kumiko; Yoshida, Eiko; Yasuike, Shuji; Fujie, Tomoya; Yamamoto, Chika; Kaji, Toshiyuki

    2015-06-01

    Organic-inorganic hybrid molecules, which are composed of an organic structure and metal(s), are indispensable for synthetic chemical reactions; however, their toxicity has been incompletely understood. In the present study, we discovered two cytotoxic organobismuth compounds whose cytotoxicity diminished upon replacement of the intramolecular bismuth atom with an antimony atom. The intracellular accumulation of the organobismuth compounds was much higher than that of the organoantimony compounds with the corresponding organic structures. We also showed that both the organic structure and bismuth atom are required for certain organobismuth compounds to exert their cytotoxic effect, suggesting that the cytotoxicity of such a compound is a result of an interaction between the organic structure and the bismuth atom. The present data suggest that organobismuth compounds with certain molecular structures exhibit cytotoxicity via an interaction between the molecular structure and the bismuth atom, and this cytotoxicity can be diminished by replacing the bismuth atom with an antimony atom, resulting in lower intracellular accumulation.

  2. Comparative study on adsorption of crude oil and spent engine oil from seawater and freshwater using algal biomass.

    Science.gov (United States)

    Boleydei, Hamid; Mirghaffari, Nourollah; Farhadian, Omidvar

    2018-05-15

    Efficiency of a biosorbent prepared from the green macroalga Enteromorpha intestinalis biomass for decontamination of seawater and freshwater polluted by crude oil and engine spent oil was compared. The effect of different experimental conditions including contact time, pH, particle size, initial oil concentration, and biosorbent dose on the oil biosorption was studied in the batch method. The biosorbent was characterized by CHNOS, FTIR, and SEM analysis. The experimental data were well fitted to the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. Based on the obtained results, the adsorption of spent oil with higher viscosity was better than crude oil. The biosorption of oil hydrocarbons from seawater was more efficient than freshwater. The algal biomasses which are abundantly available could be effectively used as a low-cost and environmentally friendly adsorbent for remediation of oil spill in the marine environments or in the water and wastewater treatment.

  3. Chemical and microbial remediation of hexavalent chromium from contaminated soil and mining/metallurgical solid waste: a review.

    Science.gov (United States)

    Dhal, B; Thatoi, H N; Das, N N; Pandey, B D

    2013-04-15

    Chromium is a highly toxic non-essential metal for microorganisms and plants, and its occurrence is rare in nature. Lower to higher chromium containing effluents and solid wastes released by activities such as mining, metal plating, wood preservation, ink manufacture, dyes, pigments, glass and ceramics, tanning and textile industries, and corrosion inhibitors in cooling water, induce pollution and may cause major health hazards. Besides, natural processes (weathering and biochemical) also contribute to the mobility of chromium which enters in to the soil affecting the plant growth and metabolic functions of the living species. Generally, chemical processes are used for Cr- remediation. However, with the inference derived from the diverse Cr-resistance mechanism displayed by microorganisms and the plants including biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux, bioremediation is emerging as a potential tool to address the problem of Cr(VI) pollution. This review focuses on the chemistry of chromium, its use, and toxicity and mobility in soil, while assessing its concentration in effluents/wastes which becomes the source of pollution. In order to conserve the environment and resources, the chemical/biological remediation processes for Cr(VI) and their efficiency have been summarised in some detail. The interaction of chromium with various microbial/bacterial strains isolated and their reduction capacity towards Cr(VI) are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Assisted Hatching and Intracytoplasmic Sperm Injection are not Associated with Improved Outcomes in ART Cycles for Diminished Ovarian Reserve: An Analysis of US Cycles from 2004–2011

    Science.gov (United States)

    Butts, Samantha F.; Owen, Carter; Mainigi, Monica; Senapati, Suneeta; Seifer, David B.; Dokras, Anuja

    2014-01-01

    Objective To investigate the impact of intracytoplasmic sperm injection (ICSI) and assisted hatching (AH) on ART outcomes in cycles with diminished ovarian reserve (DOR) as the primary diagnosis. Design Retrospective cohort study of cycles from the SART-CORS database. Setting NA. Patient(s) A total of 422,949 fresh, non-donor, initial ART cycles of which 8,597 were diagnosed with only elevated FSH and 38,926 were diagnosed with only DOR according to the SART DOR categorization. Intervention(s) None. Main Outcome Measure(s) Live birth and clinical pregnancy rates. Result(s) ICSI and AH were associated with diminished odds of live birth in SART DOR only cycles (AOR, 95% CI 0.88, 0.81–0.96 for ICSI; AOR, 95% CI 0.77 0.71–0.84 for AH). No association between either ICSI or AH in Elevated FSH only cycles was observed. The combination of ICSI and AH resulted in significantly lower odds of live birth in SART DOR only cycles but not in Elevated FSH only cycles. Conclusion(s) In initial ART cycles for which the only indication relates to a diagnosis of diminished ovarian reserve, assisted hatching and ICSI are not associated with improved live birth rates. PMID:25086790

  5. Hybrid Design of Electric Power Generation Systems Including Renewable Sources of Energy

    Science.gov (United States)

    Wang, Lingfeng; Singh, Chanan

    2008-01-01

    With the stricter environmental regulations and diminishing fossil-fuel reserves, there is now higher emphasis on exploiting various renewable sources of energy. These alternative sources of energy are usually environmentally friendly and emit no pollutants. However, the capital investments for those renewable sources of energy are normally high,…

  6. Application of the Diminishing Returns Concept in the Hydroecologic Restoration of Riverscapes

    International Nuclear Information System (INIS)

    Diefenderfer, Heida L.; Johnson, Gary E.; Skalski, John R.; Breithaupt, Stephen A.; Coleman, Andre M.

    2012-01-01

    Principles for optimizing the number and placement of ecological restoration actions on rivers and coasts would be useful in project engineering design and program planning. This study demonstrated that the yield of inundated floodplain habitat area from dike breaching conforms to a diminishing returns model. The aggregate effects of establishing hydrologic connections between a tidally influenced main stem river and the floodplain were experimentally examined using a hydrodynamic model. Restoration clusters of size 1, 4, 8, and more, replicated and randomized within the landscape, yielded average wetted floodplain area conforming with an exponential rise to maximum curve2(0.99)r=. Analysis of the average incremental change in floodplain inundation produced per breach showed that opening 25 % of the channels crossing the dike provided the maximum return on investment as measured by wetted area. Midstream breaches yielded 60 % and upstream breaches 2 % of the wetted area produced by downstream breaches. Dike-breach restoration programs therefore can be optimized by strategic determination of the spatial configuration and number of demolitions, though biological factors such as the accessibility of floodplain habitat and total length of channels connected also need to be considered. These findings have implications for cost-benefit analyses in restoration program planning.

  7. Akt1 deficiency diminishes skeletal muscle hypertrophy by reducing satellite cell proliferation.

    Science.gov (United States)

    Moriya, Nobuki; Miyazaki, Mitsunori

    2018-02-14

    Skeletal muscle mass is determined by the net dynamic balance between protein synthesis and degradation. Although the Akt/mechanistic target of rapamycin (mTOR)-dependent pathway plays an important role in promoting protein synthesis and subsequent skeletal muscle hypertrophy, the precise molecular regulation of mTOR activity by the upstream protein kinase Akt is largely unknown. In addition, the activation of satellite cells has been indicated as a key regulator of muscle mass. However, the requirement of satellite cells for load-induced skeletal muscle hypertrophy is still under intense debate. In this study, female germline Akt1 knockout (KO) mice were used to examine whether Akt1 deficiency attenuates load-induced skeletal muscle hypertrophy through suppressing mTOR-dependent signaling and satellite cell proliferation. Akt1 KO mice showed a blunted hypertrophic response of skeletal muscle, with a diminished rate of satellite cell proliferation following mechanical overload. In contrast, Akt1 deficiency did not affect the load-induced activation of mTOR signaling and the subsequent enhanced rate of protein synthesis in skeletal muscle. These observations suggest that the load-induced activation of mTOR signaling occurs independently of Akt1 regulation and that Akt1 plays a critical role in regulating satellite cell proliferation during load-induced muscle hypertrophy.

  8. Characterization of Cd-, Pb-, Zn-resistant endophytic Lasiodiplodia sp. MXSF31 from metal accumulating Portulaca oleracea and its potential in promoting the growth of rape in metal-contaminated soils.

    Science.gov (United States)

    Deng, Zujun; Zhang, Renduo; Shi, Yang; Hu, Li'ao; Tan, Hongming; Cao, Lixiang

    2014-02-01

    The aim of this study was to characterize the features of a Cd-, Pb-, and Zn-resistant endophytic fungus Lasiodiplodia sp. MXSF31 and to investigate the potential of MXSF31 to remove metals from contaminated water and soils. The endophytic fungus was isolated from the stem of Portulaca oleracea growing in metal-contaminated soils. The maximum biosorption capacities of MXSF31 were 3.0 × 10(3), 1.1 × 10(4), and 1.3 × 10(4) mg kg(-1) for Cd, Pb, and Zn, respectively. The biosorption processes of Cd, Pb, and Zn by MXSF31 were well characterized with the pseudo-second-order kinetic model. The biosorption isotherm processes of Pb and Zn by the fungus were fitted better with the Langmuir model, while the biosorption processes of Cd was better fitted with the Freundlich model. The biosorption process of MXSF31 was attributed to the functional groups of hydroxyl, amino, carbonyl, and benzene ring on the cell wall. The active biomass of the strain removed more Cd, Pb, and Zn (4.6 × 10(4), 5.6 × 10(5), and 7.0 × 10(4) mg kg(-1), respectively) than the dead biomass. The inoculation of MXSF31 increased the biomass of rape (Brassica napus L.), the translocation factor of Cd, and the extraction amount of Cd by rape in the Cd+Pb-contaminated soils. The results indicated that the endophytic fungus strain had the potential to remove heavy metals from water and soils contaminated by multiple heavy metals, and plants accumulating multiple metals might harbor diverse fungi suitable for bioremediation of contaminated media.

  9. Failure to demonstrate that playing violent video games diminishes prosocial behavior.

    Directory of Open Access Journals (Sweden)

    Morgan J Tear

    Full Text Available BACKGROUND: Past research has found that playing a classic prosocial video game resulted in heightened prosocial behavior when compared to a control group, whereas playing a classic violent video game had no effect. Given purported links between violent video games and poor social behavior, this result is surprising. Here our aim was to assess whether this finding may be due to the specific games used. That is, modern games are experienced differently from classic games (more immersion in virtual environments, more connection with characters, etc. and it may be that playing violent video games impacts prosocial behavior only when contemporary versions are used. METHODS AND FINDINGS: Experiments 1 and 2 explored the effects of playing contemporary violent, non-violent, and prosocial video games on prosocial behavior, as measured by the pen-drop task. We found that slight contextual changes in the delivery of the pen-drop task led to different rates of helping but that the type of game played had little effect. Experiment 3 explored this further by using classic games. Again, we found no effect. CONCLUSIONS: We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest. It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior.

  10. Failure to Demonstrate That Playing Violent Video Games Diminishes Prosocial Behavior

    Science.gov (United States)

    Tear, Morgan J.; Nielsen, Mark

    2013-01-01

    Background Past research has found that playing a classic prosocial video game resulted in heightened prosocial behavior when compared to a control group, whereas playing a classic violent video game had no effect. Given purported links between violent video games and poor social behavior, this result is surprising. Here our aim was to assess whether this finding may be due to the specific games used. That is, modern games are experienced differently from classic games (more immersion in virtual environments, more connection with characters, etc.) and it may be that playing violent video games impacts prosocial behavior only when contemporary versions are used. Methods and Findings Experiments 1 and 2 explored the effects of playing contemporary violent, non-violent, and prosocial video games on prosocial behavior, as measured by the pen-drop task. We found that slight contextual changes in the delivery of the pen-drop task led to different rates of helping but that the type of game played had little effect. Experiment 3 explored this further by using classic games. Again, we found no effect. Conclusions We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest. It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior. PMID:23844191

  11. Educational Attainment and Smoking Status in a National Sample of American Adults; Evidence for the Blacks' Diminished Return.

    Science.gov (United States)

    Assari, Shervin; Mistry, Ritesh

    2018-04-16

    Although higher socioeconomic status (SES) indicators such as educational attainment are linked with health behaviors, the Blacks’ Diminished Return theory posits that the protective effects of SES are systemically smaller for Blacks than Whites. To explore the Black/White differences in the association between education and smoking. This cross-sectional study used the Health Information National Trends Survey (HINTS) 2017 ( n = 3217). HINTS is a national survey of American adults. The current analysis included 2277 adults who were either Whites ( n = 1868; 82%) or Blacks ( n = 409; 18%). The independent variable was educational attainment, and the dependent variables were ever and current (past 30-day) smoking. Demographic factors (age and gender) were covariates. Race was the focal moderator. In the pooled sample, higher educational attainment was associated with lower odds of ever and current smoking. Race interacted with the effects of higher educational attainment on current smoking, suggesting a stronger protective effect of higher education against current smoking for Whites than Blacks. Race did not interact with the effect of educational attainment on odds of ever smoking. In line with previous research in the United States, education is more strongly associated with health and health behaviors in Whites than Blacks. Smaller protective effects of education on health behaviors may be due to the existing racism across institutions such as the education system and labor market.

  12. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  13. Sorption and desorption of lead (II) from wastewater by green algae Cladophora fascicularis.

    Science.gov (United States)

    Deng, Liping; Su, Yingying; Su, Hua; Wang, Xinting; Zhu, Xiaobin

    2007-05-08

    Biosorption is an effective method to remove heavy metals from wastewater. In this work, adsorption features of Cladophora fascicularis were investigated as a function of time, initial pH, initial Pb(II) concentrations, temperature and co-existing ions. Kinetics and equilibria were obtained from batch experiments. The biosorption kinetics followed the pseudo-second order model. Adsorption equilibria were well described by the Langmuir and Freundlich isotherm models. The maximum adsorption capacity was 198.5 mg/g at 298K and pH 5.0. The adsorption processes were endothermic and the biosorption heat was 29.6 kJ/mol. Desorption experiments indicated that 0.01 mol/L Na(2)EDTA was an efficient desorbent for the recovery of Pb(II) from biomass. IR spectrum analysis suggested amido or hydroxy, CO and C-O could combine intensively with Pb(II).

  14. Panus tigrinus as a potential biomass source for Reactive Blue decolorization: Isotherm and kinetic study

    Directory of Open Access Journals (Sweden)

    Monawar Munjid Mustafa

    2017-03-01

    Conclusion: The biosorption process provided vital information on the process parameters required to obtain the optimum level of dye removal. The isotherm study indicated the homogeneous distribution of active sites on the biomass surface, and the kinetic study suggested that chemisorption is the rate-limiting step that controlled the biosorption process. According to the obtained results, P. tigrinus biomass can be used effectively to decolorize textile dyes and tackle the pollution problems in the environment.

  15. Studi Karakteristik Biopolimer Gracilaria Verrucosa Sebagai Bahan Penjerap

    OpenAIRE

    Ariyanti, Dessy; Nurcahyani, Intan

    2012-01-01

    The presence of heavy metals such as Cu in industrial wastewater can lead to the environment contamination. The algae Gracilaria verrucosa is intended to be the environmentally friendly polymer used in biosorption process of heavy metals Cu. In this research, the characteristics and adsorption ability of biopolymers Gracilaria verrucosa against heavy metals Cu was studied respectively. Results shown that the maximum biosorption capacity of Gracilaria verrucosa in adsorbing Cu2+ was 38.34 mg/g...

  16. The Fate of Aspen in a World with Diminishing Snowpacks

    Science.gov (United States)

    Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Kemp, K. B.

    2010-12-01

    Aspen (Populus tremuloides) productivity is tightly coupled with soil moisture. In the mountainous regions of the western USA, annual replenishment of soil moisture commonly occurs during snowmelt. Therefore, snow pack depth and duration can play an important role in sustaining aspen productivity. The presence of almost 50 years of detailed climate data across an elevational transect in the Reynolds Creek Experimental Watershed (RCEW) in southwestern Idaho offers a novel opportunity to better understand the role of shifting precipitation patterns on aspen productivity. Over the past 50 years, the proportion of the precipitation falling in the form of snow decreased by almost a factor of 2 at mid to low elevations in the RCEW, coupled with a roughly four week advance of snow ablation, and decline of large snow drifts that release moisture into the early summer. Results from growth ring increment, stable isotope analysis, sapflux and a process model (Biome BGC), will be used to determine the impact of shifting precipitation patterns on tree productivity along this transect over the past 50 years. Aspen trees located on moist microsites continue to transpire water and maintain high stomatal conductance 21 days later in the growing season relative to individuals on drier microsites. Predictions of net primary productivity (NPP) in aspen are very sensitive to precipitation patterns. NPP becomes negative as early as day 183 (90 days post budbreak) for years with little winter and spring precipitation whereas, in years with ample winter and spring precipitation, NPP remains positive until day 260 when leaf fall occurs. These results give unique insight into the conditions that deciduous tree species will encounter in a warming climate where snow water equivalent continues to diminish and soil moisture declines soon after budbreak occurs.

  17. Remediation of groundwater contaminated with the lead-phenol binary system by granular dead anaerobic sludge-permeable reactive barrier.

    Science.gov (United States)

    Faisal, Ayad A H; Abd Ali, Ziad T

    2017-10-01

    Computer solutions (COMSOL) Multiphysics 3.5a software was used for simulating the one-dimensional equilibrium transport of the lead-phenol binary system including the sorption process through saturated sandy soil as the aquifer and granular dead anaerobic sludge (GDAS) as the permeable reactive barrier. Fourier-transform infrared spectroscopy analysis proved that the carboxylic and alcohol groups are responsible for the bio-sorption of lead onto GDAS, while phosphines, aromatic and alkane are the functional groups responsible for the bio-sorption of phenol. Batch tests have been performed to characterize the equilibrium sorption properties of the GDAS and sandy soil in lead and/or phenol containing aqueous solutions. Numerical and experimental results proved that the barrier plays a potential role in the restriction of the contaminant plume migration and there is a linear relationship between longevity and thickness of the barrier. A good agreement between these results was recognized with root mean squared error not exceeding 0.04.

  18. Apoptosis inhibitor of macrophage (AIM) diminishes lipid droplet-coating proteins leading to lipolysis in adipocytes

    International Nuclear Information System (INIS)

    Iwamura, Yoshihiro; Mori, Mayumi; Nakashima, Katsuhiko; Mikami, Toshiyuki; Murayama, Katsuhisa; Arai, Satoko; Miyazaki, Toru

    2012-01-01

    Highlights: ► AIM induces lipolysis in a distinct manner from that of hormone-dependent lipolysis. ► AIM ablates activity of peroxisome proliferator-activated receptor in adipocytes. ► AIM reduces mRNA levels of lipid-droplet coating proteins leading to lipolysis. -- Abstract: Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown. Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPARγ), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPARγ-agonist or forced expression of FSP27, while it was synergized by a PPARγ-antagonist. Overall, distinct modes of lipolysis appear to take place in different physiological situations; one is a supportive response against nutritional deprivation achieved by

  19. No Spearman’s Law of Diminishing Returns for the working memory and intelligence relationship

    Directory of Open Access Journals (Sweden)

    Kroczek Bartłomiej

    2016-04-01

    Full Text Available Spearman’s Law of Diminishing Returns (SLODR holds that correlation between general (g/fluid (Gf intelligence factor and other cognitive abilities weakens with increasing ability level. Thus, cognitive processing in low ability people is most strongly saturated by g/Gf, whereas processing in high ability people depends less on g/Gf. Numerous studies demonstrated that low g is more strongly correlated with crystallized intelligence/creativity/processing speed than is high g, however no study tested an analogous effect in the case of working memory (WM. Our aim was to investigate SLODR for the relationship between Gf and WM capacity, using a large data set from our own previous studies. We tested alternative regression models separately for three types of WM tasks that tapped short-term memory storage, attention control, and relational integration, respectively. No significant SLODR effect was found for any of these tasks. Each task shared with Gf virtually the same amount of variance in the case of low- and high-ability people. This result suggests that Gf and WM rely on one and the same (neurocognitive mechanism.

  20. Aging and physiological changes of the kidneys including changes in glomerular filtration rate.

    Science.gov (United States)

    Musso, Carlos G; Oreopoulos, Dimitrios G

    2011-01-01

    In addition to the structural changes in the kidney associated with aging, physiological changes in renal function are also found in older adults, such as decreased glomerular filtration rate, vascular dysautonomia, altered tubular handling of creatinine, reduction in sodium reabsorption and potassium secretion, and diminished renal reserve. These alterations make aged individuals susceptible to the development of clinical conditions in response to usual stimuli that would otherwise be compensated for in younger individuals, including acute kidney injury, volume depletion and overload, disorders of serum sodium and potassium concentration, and toxic reactions to water-soluble drugs excreted by the kidneys. Additionally, the preservation with aging of a normal urinalysis, normal serum urea and creatinine values, erythropoietin synthesis, and normal phosphorus, calcium and magnesium tubular handling distinguishes decreased GFR due to normal aging from that due to chronic kidney disease. Copyright © 2011 S. Karger AG, Basel.

  1. Feasibility study of the application of biotechnology to nuclear waste treatment

    International Nuclear Information System (INIS)

    Ashley, N.V.; Pope, N.R.; Roach, D.J.W.

    1987-12-01

    A number of biotechnology areas applicable to the removal of radionuclides from industrial nuclear effluents were considered, namely: use of Biopolymers; Biosorption using biomass; microbial leaching and solubilisation of metal ions. The potential of biomagnetic separation technology, genetic engineering and monoclonal antibody technology was also examined. It appeared that the most appropriate technologies to develop for radionuclide removal in the short term were based on biosorptions of radionuclides by biomass and modified and unmodified biopolymers. (author)

  2. Association of diminished expression of RASSF1A with promoter methylation in primary gastric cancer from patients of central China

    Directory of Open Access Journals (Sweden)

    Zhou Feng

    2007-07-01

    Full Text Available Abstract Background Although methylation-mediated inactivation of expression of RASSF1A, a candidate tumor suppressor gene, has been observed in several human cancers, the data concerning alteration of RASSF1A expression and methylation in Chinese primary gastric cancer are scarce. Moreover, direct evidence showing the association between protein expression of RASSF1A and primary human cancers is lacking. The aim of this study was to investigate RASSF1A expression in tissue of primary gastric cancer (GC at mRNA and protein levels, and to establish the possible relationship between DNA methylation status and protein expression of RASSF1A in Chinese. Methods Fifty-four patients with primary gastric cancers were included in the study of RASSF1A mRNA expression and methylation status between the cancer tissue and the corresponding adjacent normal tissue. 20 out of 54 patients were included for study of RASSF1A protein expression. The expression of RASSF1A at mRNA and protein levels was determined by RT-PCR and Western-blotting, respectively. The RASSF1A promoter methylation was detected by methylation-specific PCR. Results RASSF1A mRNA and protein expressions in GC were reduced significantly with comparison to the corresponding normal tissues (OD value: 0.2589 ± 0.2407 vs 0.5448 ± 0.2971, P P P P Conclusion Expression of RASSF1A was reduced in tissue of GC at mRNA and protein levels. Diminished expression of RASSF1A was associated with the promoter methylation.

  3. Removal of Pb(II), Cu(II) and Cd(II) from aqueous solution by some fungi and natural adsorbents in single and multiple metal systems

    International Nuclear Information System (INIS)

    Shoaib, A.; Badar, T.; Aslam, N.

    2011-01-01

    Six fungal and 10 natural biosorbents were analyzed for their Cu(II), Cd(II) and Pb(II) uptake capacity from single, binary and ternary metal ion system. Preliminary screening biosorption of assays revealed 2 fungi (Aspergillus niger and Cunninghamella echinulata) and three natural [Cicer arietinum husk, Moringa oleifera flower and soil (clay)] adsorbents hold considerable high adsorption efficiency and capacity for 3 meta l ions amongst the adsorbents. Further biosorption trials with five elected adsorbents showed a considerable reduction in metal uptake capability of adsorbents in binary- and ternary systems as compared to singly metal system. Cd(II) manifested the highest inhibitory effect on the biosorption of other metal ions, followed by Pb(II) and Cu(II). On account of metal preference, the selectivity order for metal ion towards the studied biomass matrices was Pb(II) (40-90%) > Cd(II) (2-53%) > Cu(II) (2-30%). (author)

  4. The Efficient Removal of Heavy Metal Ions from Industry Effluents Using Waste Biomass as Low-Cost Adsorbent: Thermodynamic and Kinetic Models

    Science.gov (United States)

    Indhumathi, Ponnuswamy; Sathiyaraj, Subbaiyan; Koelmel, Jeremy P.; Shoba, Srinivasan U.; Jayabalakrishnan, Chinnasamy; Saravanabhavan, Munusamy

    2018-05-01

    The ability of green micro algae Chlorella vulgaris for biosorption of Cu(II) ions from an aqueous solution was studied. The biosorption process was affected by the solution pH, contact time, temperature and initial Cu(II) concentration. Experimental data were analyzed in terms of pseudo-first order, pseudo-second order and intra particle diffusion models. Results showed that the sorption process of Cu(II) ions followed pseudo-second order kinetics. The sorption data of Cu(II) ions are fitted to Langmuir, Freundlich, and Redlich-Peterson isotherms, and the Temkin isotherm. The thermodynamic study shows the Cu(II) biosorption was exothermic in nature. The Cu(II) ions were recovered effectively from Chlorella vulgaris biomass using 0.1 M H2SO4 with up to 90.3% recovery, allowing for recycling of the Cu. Green algae from freshwater bodies showed significant potential for Cu(II) removal and recovery from industrial wastewater.

  5. THE TREATED EGGSHELLS AS A NEW BIOSORBENT FOR ELIMINATION OF CARBARYL PESTICIDE FROM AQUEOUS SOLUTIONS: KINETICS, THERMODYNAMICS AND ISOTHERMS

    Directory of Open Access Journals (Sweden)

    ABDELHAMID BAKKA

    2016-10-01

    Full Text Available The efficiency of treated eggshells (TES for removing the carbaryl pesticide from aqueous solutions was examined by biosorption process. Batch mode experiments were conducted using various parameters such as contact time, temperature, biosorbent amount, carbaryl concentration and pH. Removal efficiency of carbaryl by the TES attained 87.35 % after 60 min of contact time, using 10 mg·L-1 of pesticide and 1.5 g·L-1 of biosorbent. The results indicate that Freundlich equation is well described with the carbaryl adsorption, with correlation coefficient R2 value of 0.99. They showed that the biosorption processes were spontaneous and exothermic. The Gibbs energy ∆G increased with increase in temperature indicating an increase in feasibility of biosorption at low temperature. These results show that treated eggshells can be employed as an alternative to commercial adsorbents in the removal of pesticides from aqueous solutions.

  6. Evaluation on diminishing effects of DNA damaging potential by humic substances using the bacillus subtilis rec-assay; Karekusakin rec-assay wo mochiita fuminsan ni yoru DNA sonshosei kaizen koka no kento

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H.; Takigami, H.; Shimizu, Y.; Matsui, S. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1998-05-22

    Antimutagenic effect of humic substances has been reported by various investigators. In this research, the diminishing effect of DNA damaging toxicity by humic acid was evaluated for the influent and effluent of activated sludge tank receiving municipal wastewater and several DNA damaging chemicals (e.g., pyrene, 1-aminopyrene and benzo(a)pyrene) using Bacillus subtilis rec-assay. The diminishing effect was not apparent for influent but observed in the effluent. Among the DNA damaging chemicals, the DNA toxicity was effectively suppressed by humic acid for pyrene and benzo(a)pyrene. However, the effect was relatively smaller for 1-aminopyrene. 19 refs., 6 figs., 6 tabs.

  7. Application of macrophytes as biosorbents for radioactive liquid waste treatment; Aplicacao de macrofitas como biossorventes no tratamento de rejeitos radioativos liquidos

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Ludmila Cabreira

    2016-07-01

    Radioactive waste as any other type of waste should be treated and disposed adequately. It is necessary to consider its physical, chemical and radiological characteristics for choosing the appropriate action for the treatment and final disposal. Many treatment techniques currently used are economically costly, often invalidating its use and favoring the study of other treatment techniques. One of these techniques is biosorption, which demonstrates high potential when applied to radioactive waste. This technology uses materials of biological origin for removing metals. Among potential biosorbents found, macrophyte aquatics are useful because they may remove uranium present in the liquid radioactive waste at low cost. This study aims to evaluate the biosorption capacity of macrophyte aquatics Pistia stratiotes, Limnobium laevigatum, Lemna sp and Azolla sp in the treatment of liquid radioactive waste. This study was divided into two stages, the first one is characterization and preparation of biosorption and the other is tests, carried out with uranium solutions and real samples. The biomass was tested in its raw form and biosorption assays were performed in polypropylene vials containing 10 ml of solution of uranium or 10ml of radioactive waste and 0.20g of biomass. The behavior of biomass was evaluated by sorption kinetics and isotherm models. The highest sorption capacities found was 162.1 mg / g for the macrophyte Lemna sp and 161.8 mg / g for the Azolla sp. The equilibrium times obtained were 1 hour for Lemna sp, and 30 minutes for Azolla sp. With the real waste, the macrophyte Azolla sp presented a sorption capacity of 2.6 mg / g. These results suggest that Azolla sp has a larger capacity of biosorption, therefore it is more suitable for more detailed studies of treatment of liquid radioactive waste. (author)

  8. Application of macrophytes as biosorbents for radioactive liquid waste treatment

    International Nuclear Information System (INIS)

    Vieira, Ludmila Cabreira

    2016-01-01

    Radioactive waste as any other type of waste should be treated and disposed adequately. It is necessary to consider its physical, chemical and radiological characteristics for choosing the appropriate action for the treatment and final disposal. Many treatment techniques currently used are economically costly, often invalidating its use and favoring the study of other treatment techniques. One of these techniques is biosorption, which demonstrates high potential when applied to radioactive waste. This technology uses materials of biological origin for removing metals. Among potential biosorbents found, macrophyte aquatics are useful because they may remove uranium present in the liquid radioactive waste at low cost. This study aims to evaluate the biosorption capacity of macrophyte aquatics Pistia stratiotes, Limnobium laevigatum, Lemna sp and Azolla sp in the treatment of liquid radioactive waste. This study was divided into two stages, the first one is characterization and preparation of biosorption and the other is tests, carried out with uranium solutions and real samples. The biomass was tested in its raw form and biosorption assays were performed in polypropylene vials containing 10 ml of solution of uranium or 10ml of radioactive waste and 0.20g of biomass. The behavior of biomass was evaluated by sorption kinetics and isotherm models. The highest sorption capacities found was 162.1 mg / g for the macrophyte Lemna sp and 161.8 mg / g for the Azolla sp. The equilibrium times obtained were 1 hour for Lemna sp, and 30 minutes for Azolla sp. With the real waste, the macrophyte Azolla sp presented a sorption capacity of 2.6 mg / g. These results suggest that Azolla sp has a larger capacity of biosorption, therefore it is more suitable for more detailed studies of treatment of liquid radioactive waste. (author)

  9. Characterization and application of Mucuna urens seed husk as novel biosorbent for sequestration of some divalent metal ions from solution

    Directory of Open Access Journals (Sweden)

    Linda Obiageli ELUKE

    2017-07-01

    Full Text Available The utilization of Horse-Eye Bean (Mucuna urens Seed Husk (HEBSH as low cost biosorbent for the abstraction of Co (II, Pb (II and Zn (II ions from water was performed. The biosorbent was characterized by the Fourier Transform Infrared (FTIR spectroscopy, X-ray diffraction (XRD and Scanning Electron Microscopy (SEM. The influence of pH, initial metal ion concentration, biosorbent dosage and contact time on the biosorption was studied. Four isotherm and four kinetic models were used to determine the mechanism of biosorption. FTIR showed the presence of some functional groups such as OH, C=O, C=C, C-O, C-Cl on the surface of HEBSH, while XRD and SEM showed amorphous and non-porous surface structure respectively. Optimum biosorption of the metal ions was obtained at pH 6.0, biosorbent dosage 0.1 g, metal concentration 400 mg/L and contact time of 30, 40, and 60 min for Co (II, Zn (II and Pb (II respectively. The Freundlich gave the best fit for the three metal ions (R2 > 0.95 than the Langmuir, Tempkin and Dubinin-Radushkevich models indicating a multilayer biosorption on a heterogenous surface of HEBSH. Kinetic analysis showed the pseudo first order model presented good fits for Zn (II and Pb (II while the pseudo second order model for Co (II. The initial sorption rate h (mg/g min was 2.35 × 10-3, 2.1 × 10-4 and 6.3 × 10-7 for Co (II, Zn (II and Pb (II ions respectively. Liquid film diffusion was found to be the diffusion mechanism of biosorption rather than the intraparticle diffusion. The experimental investigation showed that HEBSH is effective as a low cost alternative biosorbent for the sequestration of heavy metal ions from aqueous stream.

  10. Increased endothelin-1 and diminished nitric oxide levels in blister fluids of patients with intermediate cold type complex regional pain syndrome type 1

    Directory of Open Access Journals (Sweden)

    Niehof Sjoerd

    2006-11-01

    Full Text Available Abstract Background In complex regional pain syndrome type 1 (CRPS1 pro-inflammatory mediators and vascular changes play an important role in the sustained development and outcome of the disease. The aim of this study was to determine the involvement of vasoactive substances endothelin-1 (ET-1 and nitric oxide (NO during early chronic CRPS1. Methods Included were 29 patients with CRPS 1 who were diagnosed during the acute stage of their disease and observed during follow-up visits. Disease activity and impairment were determined and artificial suction blisters were made on the CRPS1 and the contralateral extremities for measurements of IL-6, TNF-α, ET-1 and nitrate/nitrite (NOx. Results The levels of IL-6, TNF-α and ET-1 in blister fluid in the CRPS1 extremity versus the contralateral extremity were significantly increased and correlated with each other, whereas NOx levels were decreased. Conclusion The NOx/ET-1 ratio appears to be disturbed in the intermediate stage of CRPS, resulting in vasoconstriction and consequently in a diminished tissue blood distribution.

  11. Clonidine, an alpha2-receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

    Science.gov (United States)

    Philbin, Kerry E; Bateman, Ryan J; Mendelowitz, David

    2010-08-06

    In hypertension, there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Presympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these presympathetic neurons are catecholaminergic. In addition to their projection to the spinal cord, many of these presympathetic neurons have axon collaterals that arborize into neighboring cardiorespiratory locations and likely release norepinephrine onto nearby neurons. Activation of alpha(2)-adrenergic receptors in the central nervous system evokes a diverse range of physiological effects, including reducing blood pressure. This study tests whether clonidine, an alpha(2)-adrenergic receptor agonist, alters excitatory glutamatergic, and/or inhibitory GABAergic or glycinergic synaptic neurotransmission to cardiac vagal neurons in the nucleus ambiguus. Cardiac vagal neurons were identified in an in vitro brainstem slice preparation, and synaptic events were recording using whole cell voltage clamp methodologies. Clonidine significantly inhibited GABAergic neurotransmission but had no effect on glycinergic or glutamatergic pathways to cardiac vagal neurons. This diminished inhibitory GABAergic neurotransmission to cardiac vagal neurons would increase parasympathetic activity to the heart, decreasing heart rate and blood pressure. The results presented here provide a cellular substrate for the clinical use of clonidine as a treatment for hypertension as well as a role in alleviating posttraumatic stress disorder by evoking an increase in parasympathetic cardiac vagal activity, and a decrease in heart rate and blood pressure. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Educational Attainment and Smoking Status in a National Sample of American Adults; Evidence for the Blacks’ Diminished Return

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2018-04-01

    Full Text Available Background: Although higher socioeconomic status (SES indicators such as educational attainment are linked with health behaviors, the Blacks’ Diminished Return theory posits that the protective effects of SES are systemically smaller for Blacks than Whites. Aims: To explore the Black/White differences in the association between education and smoking. Methods: This cross-sectional study used the Health Information National Trends Survey (HINTS 2017 (n = 3217. HINTS is a national survey of American adults. The current analysis included 2277 adults who were either Whites (n = 1868; 82% or Blacks (n = 409; 18%. The independent variable was educational attainment, and the dependent variables were ever and current (past 30-day smoking. Demographic factors (age and gender were covariates. Race was the focal moderator. Results: In the pooled sample, higher educational attainment was associated with lower odds of ever and current smoking. Race interacted with the effects of higher educational attainment on current smoking, suggesting a stronger protective effect of higher education against current smoking for Whites than Blacks. Race did not interact with the effect of educational attainment on odds of ever smoking. Conclusions: In line with previous research in the United States, education is more strongly associated with health and health behaviors in Whites than Blacks. Smaller protective effects of education on health behaviors may be due to the existing racism across institutions such as the education system and labor market.

  13. A change will do us good: threats diminish typical preferences for male leaders.

    Science.gov (United States)

    Brown, Elizabeth R; Diekman, Amanda B; Schneider, Monica C

    2011-07-01

    The current research explores role congruity processes from a new vantage point by investigating how the need for change might shift gender-based leadership preferences. According to role congruity theory, favorability toward leaders results from alignment between what is desired in a leadership role and the characteristics stereotypically ascribed to the leader. Generally speaking, these processes lead to baseline preferences for male over female leaders. In this research, the authors propose that a shift in gender-based leadership preferences will emerge under conditions of threat. Because the psychological experience of threat signals a need for change, individuals will favor candidates who represent new directions in leadership rather than consistency with past directions in leadership. Specifically, they find that threat evokes an implicit preference for change over stability (Experiment 1) and gender stereotypes align women with change but men with stability (Experiments 2a and 2b). Consequently, the typical preference for male leaders is diminished, or even reversed, under threat (Experiments 3 and 4). Moreover, the shift away from typical gender-based leadership preferences occurs especially among individuals who highly legitimize the sociopolitical system (Experiment 4), suggesting that these preference shifts might serve to protect the underlying system. © 2011 by the Society for Personality and Social Psychology, Inc

  14. Public health intervention over four decades for the children in the Australian Capital Territory: Have we reached the point of diminishing returns?

    Science.gov (United States)

    Sohal, I; Kruger, E; Tennant, M

    2017-06-01

    Most of the developed world has seen some substantial improvements in the dental health of children over the past four decades owing to advances in service access, fluoride exposure, socio-economic development and improved diets, with the DMFT score of 12 year-olds dropping from well over 10 down to around one. To examine the question of advancing dental health for children even further using the same set of tools as we have to date by asking the question: Have we come to a point of diminishing returns? The study examines the long-term, near optimum settings of the known public dental health variables in the Australian Capital Territory. Despite having the most ideal and persistent dental health optimised situation, there remains underlying dental caries at a severity level of just below 1 DMFT (12 year olds), and over the last decade the rate of diminishing incidence and prevalence of decay has slowed and arguably stopped. This suggests that rather than toiling to eliminate dental decay completely, the focus might usefully be reoriented towards those small known pockets of society with persistent higher levels of disease and looking for new ways to address these difficult clusters, while simultaneously advancing the understanding that a small residual level of decay will always exist in society. Copyright© 2017 Dennis Barber Ltd.

  15. Syndrome of diminished vasodilator reserve of the coronary microcirculation (microvascular angina or syndrome X): Diagnosis by combined atrial pacing and thallium 201 imaging--a case report

    International Nuclear Information System (INIS)

    Magarian, G.J.; Palac, R.; Reinhart, S.

    1990-01-01

    Patients with angina-like chest pain without evidence of epicardial coronary artery disease or coronary arterial vasospasm are becoming increasingly recognized. These are often related to noncardiac causes including esophageal, musculoskeletal, and hyperventilatory or panic states. However, recently a subgroup of such patients are being recognized as having true myocardial ischemia and chest pain on the basis of diminished coronary microvascular vasodilatory reserve (microvascular ischemia or Syndrome X). The authors describe such a patient who was found to have replication of anginal pain associated with a reversible ischemic defect on thallium 201 imaging during atrial pacing, suggesting ischemia in this myocardial segment. Resolution of angina and ST segment electrocardiographic changes of ischemia occurred with cessation of pacing. We believe this is the first report of a patient with this form of myocardial ischemia diagnosed by this method and should be considered in patients with anginal chest pain after significant coronary artery disease and coronary vasospasm have been excluded

  16. Role of Sulfhydryl Sites on Bacterial Cell Walls in the Biosorption, Mobility and Bioavailability of Mercury and Uranium

    Energy Technology Data Exchange (ETDEWEB)

    Myneni, Satish C. [Princeton Univ., NJ (United States); Mishra, Bhoopesh [Princeton Univ., NJ (United States); Fein, Jeremy [Princeton Univ., NJ (United States)

    2009-04-01

    The goal of this exploratory study is to provide a quantitative and mechanistic understanding of the impact of bacterial sulfhydryl groups on the bacterial uptake, speciation, methylation and bioavailability of Hg and redox changes of uranium. The relative concentration and reactivity of different functional groups present on bacterial surfaces will be determined, enabling quantitative predictions of the role of biosorption of Hg under the physicochemical conditions found at contaminated DOE sites.The hypotheses we propose to test in this investigation are as follows- 1) Sulfhydryl groups on bacterial cell surfaces modify Hg speciation and solubility, and play an important role, specifically in the sub-micromolar concentration ranges of metals in the natural and contaminated systems. 2) Sulfhydryl binding of Hg on bacterial surfaces significantly influences Hg transport into the cell and the methylation rates by the bacteria. 3) Sulfhydryls on cell membranes can interact with hexavalent uranium and convert to insoluble tetravalent species. 4) Bacterial sulfhydryl surface groups are inducible by the presence of metals during cell growth. Our studies focused on the first hypothesis, and we examined the nature of sulfhydryl sites on three representative bacterial species: Bacillus subtilis, a common gram-positive aerobic soil species; Shewanella oneidensis, a facultative gram-negative surface water species; and Geobacter sulfurreducens, an anaerobic iron-reducing gram-negative species that is capable of Hg methylation; and at a range of Hg concentration (and Hg:bacterial concentration ratio) in which these sites become important. A summary of our findings is as follows- Hg adsorbs more extensively to bacteria than other metals. Hg adsorption also varies strongly with pH and chloride concentration, with maximum adsorption occurring under circumneutral pH conditions for both Cl-bearing and Cl-free systems. Under these conditions, all bacterial species tested exhibit

  17. Confronting diminished epistemic privilege and epistemic injustice in pregnancy by challenging a "panoptics of the womb".

    Science.gov (United States)

    Freeman, Lauren

    2015-02-01

    This paper demonstrates how the problematic kinds of epistemic power that physicians have can diminish the epistemic privilege that pregnant women have over their bodies and can put them in a state of epistemic powerlessness. This result, I argue, constitutes an epistemic injustice for many pregnant women. A reconsideration of how we understand and care for pregnant women and of the physician-patient relationship can provide us with a valuable context and starting point for helping to alleviate the knowledge/power problems that are symptomatic of the current system and structure of medicine. I suggest that we can begin to confront this kind of injustice if medicine adopts a more phenomenological understanding of bodies and if physicians and patients--in this case, pregnant women--become what I call "epistemic peers." © The Author 2014. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Food image-induced brain activation is not diminished by insulin infusion.

    Science.gov (United States)

    Belfort-DeAguiar, R; Seo, D; Naik, S; Hwang, J; Lacadie, C; Schmidt, C; Constable, R T; Sinha, R; Sherwin, R

    2016-11-01

    The obesity epidemic appears to be driven in large part by our modern environment inundated by food cues, which may influence our desire to eat. Although insulin decreases food intake in both animals and humans, the effect of insulin on motivation for food in the presence of food cues is not known. Therefore, the aim of this study was to evaluate the effect of an intravenous insulin infusion on the brain response to visual food cues, hunger and food craving in non-obese human subjects. Thirty-four right-handed healthy non-obese subjects (19F/15M, age: 29±8 years.; BMI: 23.1±2.1 kg m -2 ) were divided in two groups matched by age and BMI; the insulin group (18 subjects) underwent a hyperinsulinemic-euglycemic-clamp, and the control group (16 subjects) received an intravenous saline infusion, while viewing high and low-calorie food and non-food pictures during a functional MRI scan. Motivation for food was determined via analog scales for hunger, wanting and liking ratings. Food images induced brain responses in the hypothalamus, striatum, amygdala, insula, ventromedial prefrontal cortex (PFC), dorsolateral PFC and occipital lobe (whole brain correction, Pinsulin and saline infusion groups. Hunger ratings increased throughout the MRI scan and correlated with preference for high-calorie food pictures (r=0.70; Pbrain activity nor food cravings were affected by hyperinsulinemia or hormonal status (leptin and ghrelin levels) (P=NS). Our data demonstrate that visual food cues induce a strong response in motivation/reward and cognitive-executive control brain regions in non-obese subjects, but that these responses are not diminished by hyperinsulinemia per se. These findings suggest that our modern food cue saturated environment may be sufficient to overpower homeostatic hormonal signals, and thus contribute to the current obesity epidemic.

  19. Calcium alginate as an eco-friendly supporting material for Baker’s yeast strain in chromium bioremediation

    Directory of Open Access Journals (Sweden)

    M.S. Mahmoud

    2017-12-01

    Full Text Available In this study, Baker’s yeast strain (Saccharomyces cerevisiae biomass was immobilized in alginate extract 3% forming Biomass/Polymer Matrices Beads (BPMB. These beads were investigated for chromium biosorption from aqueous solution. Factors such as solution pH, contact times, temperature values, stirring rates, BPMB dosages and initial chromium ions concentrations were experimentally tested using repeated-batch process to determine the sorption capacity for chromium (VI ions. Batch experiments were conducted at pH range from 1.5 to 7.5. The optimum pH value was 3.5 for direct chromium removal. The effect of chromium concentration was studied using different concentrations from 200 to 1000 ppm. Freundlich’s isothermal model showed better representation of data than Langmuir’s isothermal model with correlation coefficient 0.922. The maximum biosorption capacity of chromium was found to be 154 mg g−1 at initial concentration 200 ppm under optimum conditions. At the end of the experiments, BPMB were investigated for chromium biosorption from tannery effluent sample. Results showed decrease in chromium concentration up to 85%. The availability of recycling of the BPMB was also studied for three subsequent cycles. The surface sequestration of metal ions by BPMB was characterized before and after metal binding using a scanning electron microscope (SEM equipped with an energy dispersive X-ray analysis (EDXA and FTIR spectroscopy in order to determine the mechanisms of chromium biosorption.

  20. Apoptosis inhibitor of macrophage (AIM) diminishes lipid droplet-coating proteins leading to lipolysis in adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Iwamura, Yoshihiro; Mori, Mayumi; Nakashima, Katsuhiko [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mikami, Toshiyuki; Murayama, Katsuhisa [Genomic Science Laboratories, Dainippon Sumitomo Pharma Co. Ltd., 3-1-98 Kasugadenaka, Konohana-ku, Osaka 554-0022 (Japan); Arai, Satoko [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Miyazaki, Toru, E-mail: tm@m.u-tokyo.ac.jp [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer AIM induces lipolysis in a distinct manner from that of hormone-dependent lipolysis. Black-Right-Pointing-Pointer AIM ablates activity of peroxisome proliferator-activated receptor in adipocytes. Black-Right-Pointing-Pointer AIM reduces mRNA levels of lipid-droplet coating proteins leading to lipolysis. -- Abstract: Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown. Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPAR{gamma}), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPAR{gamma}-agonist or forced expression of FSP27, while it was synergized by a PPAR{gamma}-antagonist. Overall, distinct modes of lipolysis appear to take place in different physiological