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Sample records for include biosorption diminished

  1. 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.

  2. Evaluation of actinide biosorption by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Happel, A.M.

    1996-06-01

    Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

  3. 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)

  4. 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

  5. BIOSORPTION IN TREATMENT OF WASTE WATER

    Directory of Open Access Journals (Sweden)

    Lavinia Tofan

    2003-08-01

    toxic or valuable metals from diluted effluents. This fact is due to biosorption, which is more efficient in retention of cations present at low concentrations in aqueous solutions, that the conventional treatment, involving reduced energetic consumptions too.

  6. 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)

  7. A REVIEW OF BIOSORPTION OF CHROMIUM IONS BY MICROORGANISMS

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    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

  8. Characterization of Punica granatum L. peels and quantitatively determination of its biosorption behavior towards lead(II) ions and Acid Blue 40.

    Science.gov (United States)

    Ay, Ciğdem Omeroğlu; Ozcan, A Safa; Erdoğan, Yunus; Ozcan, Adnan

    2012-12-01

    In this study, a waste biomass of Punica granatum L. (P. granatum L.) peels was firstly characterized by means of Brunauer-Emmett-Teller (BET) surface area, elemental analysis, FT-IR, thermogravimetric (TG) analysis and zeta potential measurement techniques. FT-IR results indicated that the mechanism involved in the biosorption of lead(II) ions and AB40 onto biosorbent was mainly attributed to lead(II) ions and dye binding of amino, carboxylic, hydroxyl and carbonyl groups. The biosorption abilities of P. granatum L. peels for lead(II) ions and Acid Blue 40 (AB40) were then investigated. Biosorption equilibrium and kinetic data fit well by the Langmuir isotherm and the pseudo-second-order kinetic models, respectively. The maximum biosorption capacities were 193.9 mg g(-1) for lead(II) ions and 138.1 mg g(-1) for AB40. Biosorption processes were spontaneous and endothermic in nature according to the thermodynamic results and the equilibrium was attained within 50 min. The validity of used kinetic models in this study can be quantitatively checked by using a normalized standard deviation Δq(%). Finally, the biosorption procedure was adopted to treat the real and simulated wastewaters including several metal salts and dyes. The wastewater applications have shown that the biosorbent indicated a reasonable biosorption capability to remove lead(II) ions (98.07%) and AB40 (94.76%) from industrial wastewaters. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Toxicity of ionic liquids to Clostridium sp. and effects on uranium biosorption

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C., E-mail: zhangchengdong@nankai.edu.cn [College of Environmental Science and Engineering, Nankai University, Tianjin, China 300071 (China); Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07104 (United States); Malhotra, S.V. [Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07104 (United States); Francis, A.J. [Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

    2014-01-15

    Highlights: • Three ILs showed varying degrees of toxicity to Clostridium sp. • In the presence of ILs uranium biosorption by the bacteria decreased. • The decreased biosorption was due to membrane damage induced by ILs. • Intracellular accumulation of uranium was also impacted. -- Abstract: As green solvents ionic liquids (ILs) show high potential in nuclear industry for extraction and purification of actinides. However, to date relatively little information has been gained on ILs application in microbial processes, for example biosorption of radionuclides. We investigated the effects of three ILs, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF{sub 6}), N-ethylpyridinium trifluoroacetate (EtPyCF{sub 3}COO) and N-ethylpyridinium tetrafluoroborate (EtPyBF{sub 4}) on the growth and biosorption of uranium by Clostridium sp. The ILs affected the growth of the bacterium as evidenced by decreases in optical density, total gas production, and organic acids production from glucose metabolism. The IC{sub 50-48h} of three ILs decreased in the order of BMIMPF{sub 6} (8.26 mM) > EtPyBF{sub 4} (7.04 mM) > EtPyCF{sub 3}COO (4.05 mM). Uranium biosorption by the bacterial cells decreased by 75% in the presence of 1% (v/v) BMIMPF{sub 6} and by about 90% with 1% (v/v) EtPyBF{sub 4} or EtPyCF{sub 3}COO, in comparison to the control without ILs. The diminished biosorption may be attributed to the membrane damages induced by EtPyBF{sub 4} and EtPyCF{sub 3}COO, which can be visualized by Transmission Electron Microscope (TEM) analysis. Energy-dispersive X-ray spectroscopy (EDS) analysis revealed the accumulation of uranium inside peripheral membrane of the cells exposed to uranium alone or with BMIMPF{sub 6}, while little or no accumulation was observed in the presence of EtPyBF{sub 4} and EtPyCF{sub 3}COO. These results imply that potential toxicity of ILs towards microorganisms is a particularly important issue in limiting its biotechnological applications.

  10. 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 ...

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Optimization of process parameters for heavy metals biosorption onto mustard waste biomass

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    Nemeş Lăcrămioara (Negrilă

    2016-01-01

    Full Text Available Mustard waste biomass was tested as a biosorbent for the removal of Pb(II, Zn(II and Cd(II from aqueous solution. This strategy may be a sustainable option for the utilization of such wastes. The influence of the most important operating parameters of the biosorption process was analyzed in batch experiments, and optimal conditions were found to include initial solution pH 5.5, 5.0 g biosorbent/L, 2 hours of contact time and high temperature. Kinetics analyses show that the maximum of biosorption was quickly reached and could be described by a pseudo-second order kinetic model. The equilibrium data were well fitted by the Langmuir model, and the highest values of maximum biosorption capacity were obtained with Pb(II, followed by Zn(II and Cd(II. The thermodynamic parameters of the biosorption process (ΔG, ΔH and ΔS were also evaluated from isotherms. The results of this study suggest that mustard waste biomass can be used for the removal of heavy metals from aqueous media.

  18. 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)

  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 (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 ...

  1. Biosorption of hexavalent chromium from aqueous medium with Opuntia biomass.

    Science.gov (United States)

    Fernández-López, José A; Angosto, José M; Avilés, María D

    2014-01-01

    The biosorption of hexavalent chromium from aqueous solutions by Opuntia cladodes and ectodermis from cactus fruits was investigated. Both types of biomass are considered low-cost, natural, and ecofriendly biosorbents. Batch experiments were carried out to determine Cr(VI) biosorption capacity and the efficiency of the biosorption process under different pH, initial Cr(VI) concentration, and sorbent dosage. The biosorption of Cr(VI) by Opuntia biomass was highly pH dependent, favoring higher metal uptake at low pH. The higher biosorption capacity was exhibited at pH 2. The optimal conditions were obtained at a sorbent dosage of 1 g L(-1) and initial metal concentration of 10 mg L(-1). Biosorption kinetic data were properly fitted with the pseudo-second-order kinetic model. The rate constant, the initial biosorption rate, and the equilibrium biosorption capacity were determined. The experimental equilibrium data obtained were analyzed using two-parameter isotherm models (Langmuir, Freundlich, and Temkin). The Langmuir maximum monolayer biosorption capacity (q max) was 18.5 mg g(-1) for cladodes and 16.4 mg g(-1) for ectodermis. The results suggest that Opuntia biomass could be considered a promising low-cost biosorbent for the ecofriendly removal of Cr(VI) from aqueous systems.

  2. 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.

  3. 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)

  4. 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.

  5. 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)

  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 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)

  8. 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

  9. Biosorption of Hexavalent Chromium Using Bark of Cassia spectabilis

    African Journals Online (AJOL)

    Biosorption is a relatively new process that has proven very promising in the removal of heavy metal contaminants from aqueous solutions. The biosorption of Cr(VI) from aqueous solution using bark of Cassia spectabilis has been investigated in a batch system. The effect of various parameters such as pH, contact time, ...

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. Thermodynamics and adsorption isotherms for the biosorption of Cr ...

    African Journals Online (AJOL)

    The use of maize (Zea mays) cob for the biosorption of Cr(VI), Ni(II) and Cd(II) is reported. Biosorption experiments were carried out using batch process with 8g weight of adsorbent and variable adsorbate concentrations. Variations in the concentration of the different adsorbates during the adsorption process were ...

  14. 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 ...

  15. Biosorption of mercury by capsulated and slime layer- forming Gram ...

    African Journals Online (AJOL)

    ONOS

    2010-09-20

    Sep 20, 2010 ... 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.

  16. 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 ...

  17. 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.

  18. 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

  19. LEAD BIOSORPTION USING BIOMASS FROM KETAPANG LEAF

    Directory of Open Access Journals (Sweden)

    Reza Mulyawan

    2015-05-01

    Full Text Available Waste containing of lead (Pb is very dangerous for the environment. However, waste treatment process has been introduced to minimize the waste, either by precipitation process or ionic exchange resin. In addition, researchers have shown that ketapang leaves (Terminalia catappa can be potentially used in waste water treatment. It has been used as water treatment media for fresh water aquarium. Moreover, this research was aimed to find out the potential of ketapang leaves biosorption for waste treatment that has been polluted by heavy metal, such as lead, by investigating the characteristics of biosorption, kinetics and thermodynamics. Maximum conditions of pH, ketapang leaves dose, contact time, and temperature were also investigated in this research. The result showed that biomass of ketapang leaves has potential as biosorbent. Nevertheless, the absorbtion was highly affected by dependent to pH, Pb concentration, adsorbent mass, contact time, and temperature, in which the maximum limits are 3; 5 mg/L; 0.5 gram; 4 hours; 40 ºC; respectively. Reaction rate, moreover, was running on order one and was fulfilled the principle of Langmuir. Ketapan leaves have a low activation energy making it suitable to be used as an alternative adsorbent Pb absorption of waste containing Pb.

  20. 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.

  1. 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

  2. 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

  3. Biosorption of uranium by microorganisms isolated from soil

    International Nuclear Information System (INIS)

    Ding Congcong; Liu Jun; Hu Xiaolong; Liu Ning; Yang Yuanyou; Tang Jun; Yang Jijun; Liao Jiali

    2012-01-01

    The quantitative distribution of microbial species of different layers (surface layer, 1.5 m, 2.5 m, 3.5 m) isolated from intended as a low-level radioactive landfill site has been investigated using traditional plate colony count. Bio-sorption of U using two kinds of fungi isolated from 3.5 m layer is studied. Solution pH value, bio-sorption time, adsorbent dosage, U initial concentration and temperature are researched. The results showed that F1, F2 had marked absorption effect on U, but the interaction regular pattern between F1, F2 and U was different. The maximum removal rate 90% was gained for F1 at pH5, while the maximum removal rate 97% was got for F2 at pH4; The kinetics adsorption model of both F1 and F2 followed pseudo-second order model. Biosorption equilibrium of F1 was established in 2 h. While F2 needed 12 h to establish bio-sorption equilibrium; In the studied concentration range of uranium, the isotherms biosorption process of F1 conformed to Freundlich equation, while F2 fitted well to Langmuir equation. The adsorption rate of F1 presented a slow pace of decline in the range of 50-600 ℃. (authors)

  4. 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.

  5. BIOSORPTIVE REMOVAL OF CADMIUM BY TINOSPORA CORDIFOLIA (WILD GILOY).

    Science.gov (United States)

    2017-10-12

    This research reports the efficacy of Tinospora cordifolia as biosorbent for removing cadmium ions from industrial effluents. The biosorption capacity was found to be 38.91mg Cd/g and 43.06mg Cd/g at batch and column mode experiments respectively. The work included uptake capacity, equilibrium study and column study at varying pH (1-9), contact time (5-240minutes), biosorbent dosages (1-8 g) initial metal concentration (10-1000 mg/L). Both Langmuir and Freundlich isotherm model were applied to study the dose-response behavior and it was observed that the Freundlich model provided highest R2 value. The FTIR analysis indicated involvement of hydroxyl, alkane, anhydride, halide and amine functional groups. The multilayer adsorption as indicated by Freundlich adsorption model and multifunctional group interaction as identified in FTIR analysis explains the high adsorptive capacity. The biomass was successfully applied for the removal of cadmium from industrial effluents. Biosorbent also gave higher removal percentage at low pH value that was 2. The feasibility and viability of the biomass for techno-commercial utilization for effluent treatment appears high.

  6. Bio-sorption of Tl-201 radionuclide on olive pomace

    International Nuclear Information System (INIS)

    Yapici, Sinan; Eroglu, Hayrettin; Varoglu, Erhan

    2011-01-01

    This work presents an investigation on the bio-sorption of Tl-201 radionuclide used in nuclear medicine on olive pomace. The experimental parameters were chosen as temperature, the initial pH of the solution, stirring speed, bio-sorbent dose and nominal particle size of bio-sorbent. The initial pH of the solution was found to be the most effective parameter. Thermodynamic analysis gave negative values for ΔG and ΔH. The kinetics of the bio-sorption process fitted very well to the pseudo-second order rate model.

  7. Biosorption of uranium by two kinds of yeasts

    International Nuclear Information System (INIS)

    Liu Wenjuan; Xu Weichang; Wang Baoe

    2003-01-01

    The biosorption of Uranium on two kinds of yeasts from aqueous solution and the effects of the experimental conditions on the biosorption and the effects of various pretreatment procedures are investigated. The experimental results show that the yeasts are an efficient bio-sorbent, by which 99% U in aqueous solution can be adsorbed. The adsorption capacity of the yeasts is more than 162.5 mgU/g. The relationship between concentration of U in aqueous solutions and adsorption capacity of U can be described by the Langmuir and Freundlich adsorption equation. The uranium adsorbed by the yeasts can be desorbed easily by 0.1 mol/LNaHCO 3

  8. 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.

  9. Investigation of uranium biosorption from aqueous solutions by Dictyopteris polypodioides brown algae

    International Nuclear Information System (INIS)

    Bampaiti, A.; Ege University, Izmir; Yusan, S.; Aytas, S.; Pavlidou, E.; Noli, F.

    2016-01-01

    The biosorption of uranium from aqueous solutions by Dictyopteris polypodioides brown algae was investigated. The effect of pH, uranium concentration, mass of the adsorbent, temperature and contact time on the removal efficiency were studied and the results were simulated by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. Kinetics data could be satisfactorily reproduced by the pseudo-second order equation and thermodynamic parameters were determined in order to evaluate the uranium uptake behavior. SEM/EDS and FTIR were additionally used to characterize the algae and comprehend the sorption process which can be described as a combination of several mechanisms, including physical sorption, ion exchange and complexation. (author)

  10. Application of mucilage from Dicerocaryum eriocarpum plant as biosorption medium in the removal of selected heavy metal ions.

    Science.gov (United States)

    Jones, Bassey O; John, Odiyo O; Luke, Chimuka; Ochieng, Aoyi; Bassey, Bridget J

    2016-07-15

    The ability of mucilage from Dicerocaryum eriocarpum (DE) plant to act as biosorption medium in the removal of metals ions from aqueous solution was investigated. Functional groups present in the mucilage were identified using Fourier transform infrared spectroscopy (FTIR). Mucilage was modified with sodium and potassium chlorides. This was aimed at assessing the biosorption efficiency of modified mucilage: potassium mucilage (PCE) and sodium mucilage (SCE) and comparing it with non-modified deionised water mucilage (DCE) in the uptake of metal ions. FTIR results showed that the functional groups providing the active sites in PCE and SCE and DCE include: carboxyl, hydroxyl and carbonyl groups. The chloride used in the modification of the mucilage did not introduce new functional groups but increased the intensity of the already existing functional groups in the mucilage. Results from biosorption experiment showed that DE mucilage displays good binding affinity with metals ions [Zn(II), Cd(II) Ni(II), Cr(III) and Fe(II)] in the aqueous solution. Increase in the aqueous solution pH, metal ions initial concentration and mucilage concentration increased the biosorption efficiency of DE mucilage. The maximum contact time varied with each species of metal ions. Optimum pH for [Zn(II), Cd(II) Ni(II) and Fe(II)] occurred at pH 4 and pH 6 for Cr(III). Kinetic models result fitted well to pseudo-second-order with a coefficient values of R(2) = 1 for Cd(II), Ni(II), Cr(III), Fe(II) and R(2) = 0.9974 for Zn(II). Biosorption isotherms conforms best with Freundlich model for all the metal ions with correlation factors of 0.9994, 0.9987, 0.9554, 0.9621 and 0.937 for Zn(II), Ni(II), Fe(II), Cr(III) and Cd(II), respectively. Biosorption capacity of DE mucilage was 0.010, 2.387, 4.902, 0688 and 0.125 for Zn(II), Cr(III), Fe(II), Cd(II) and Ni(II) respectively. The modified mucilage was found to be highly efficient in the removal of metal ions than the unmodified mucilage

  11. Iron(III) biosorption by Polyporus squamosus | Razmovski | African ...

    African Journals Online (AJOL)

    The increases in initial concentration of metal and pH of the solutions resulted in an increase in iron uptake. The equilibrium data could be fitted by Langmuir and Freundlich isotherm equation. Both Langmuir and Freundlich sorption models adequately describe the biosorption of Fe(III) by P. squamosus. Maximum metal ...

  12. 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, ...

  13. 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

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

    African Journals Online (AJOL)

    enoh

    2012-03-01

    Mar 1, 2012 ... Lactic acid bacteria (LAB) have been reported to remove heavy metals. The removal .... El-Ahwany 4227. Table 2. Response to Plackett Burman design of 11 variables and 12 trials. Variables. Response. (Percent of biosorption). Mixing speed. ( A) ..... dead cells. The use of heat inactivated or dead biomass.

  15. Biosorptive removal of cobalt (II) ions from aqueous solution by ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-29

    Nov 29, 2010 ... African Journal of Biotechnology Vol. ... an alternative to high cost commercial adsorbent materials for the removal of Co (II) from aqueous ..... J. Hazard. Mater. 137: 865-870. Han R, Zhang J, Zou W, Xiao H, Shi J, Liu H (2005). Biosorption of copper (II) and lead (II) from aqueous solution by chaff in a fixed- ...

  16. 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 ...

  17. 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 ...

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

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    103A , 1113 Sofia, Bulgaria. ABSTRACT: 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 ...

  20. Heavy metal biosorption potential of Aspergillus and Rhizopus sp ...

    African Journals Online (AJOL)

    Two isolates belonging to the predominant genera Aspergillus and Rhizopus isolated from agricultural field treated with sewage/ industrial effluents were selected for the biosorption potential evaluation of Cr and Cd. Pretreated, dead biomass of above fungi was used for bioadsorption experiment at pH value 4.5 with the ...

  1. 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 ...

  2. Potentiometric Demonstration of Metal Biosorption by Nonliving Plants

    Science.gov (United States)

    Velazquez-Jimenez, Litza Halla; Torres-Rodriguez, Luz Maria; Garcia-de la Cruz, Ramon Fernando; Montes-Rojas, Antonio; Lopez-Arteaga, Rafael Eduardo

    2010-01-01

    An electrochemical experiment is presented to illustrate biosorption to second-year and upper-division undergraduate students. The extraction of Cd[superscript 2+], Pb[superscript 2+], and Cu[superscript 2+] by nonliving "Typha latifolia" (cattail) roots can be monitored in real time by potentiometry determinations. The open circuit potential…

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

    African Journals Online (AJOL)

    Michael Horsfall

    2Department of Chemistry, Delta State University, Abraka, Nigeria;. 3Department of Chemical Sciences, Olabisi Olabanjo University, Ago-Iwoye, Nigeria. ABSTRACT: The kinetics, equilibrium and thermodynamics of the biosorption of Cd (II) from aqueous solution by the leaf biomass of Calotropis procera popularly known in ...

  4. Biosorption of stable cesium by chemically modified biomass of Sargassum glaucescens and Cystoseira indica in a continuous flow system.

    Science.gov (United States)

    Dabbagh, R; Ebrahimi, M; Aflaki, F; Ghafourian, H; Sahafipour, M H

    2008-11-30

    Pretreatment of biosorbents have been suggested to modify the surface characteristics which could improve biosorption process. Stable cesium biosorption was studied in continuous fixed-bed column by chemically modified biosorbents. Two kinds of brown algae (Sargassum glaucescens and Cystoseira indica) were treated with chemical agents including formaldehyde (FA), glutaraldehyde (GA), potassium hexacyanoferrate (HCF), FA and HCF, and GA and HCF. The highest biosorption capacity (BC) was obtained from C. indica treated with FA (63.5 mg Cs/g biomass) and S. glaucescens treated with FA and HCF (62 mg Cs/g biomass). To study the effect of the best treatments on the BC, the concentration of each treatment agent was decreased. With decreasing FA agent for C. indica treatment, the BC dropped. Treatment of 1g S. glaucescens biomass with 2.2g FA and then 0.18 g HCF resulted in the highest BC (73.08 mg Cs/g dry biomass) which was 35.8 times higher than intact S. glaucescens.

  5. Biosorption of stable cesium by chemically modified biomass of Sargassum glaucescens and Cystoseira indica in a continuous flow system

    Energy Technology Data Exchange (ETDEWEB)

    Dabbagh, R. [Nuclear Science Research School, Nuclear Science Technology Research Institute, Tehran (Iran, Islamic Republic of)], E-mail: rdabagh@yahoo.com; Ebrahimi, M.; Aflaki, F.; Ghafourian, H.; Sahafipour, M.H. [Nuclear Science Research School, Nuclear Science Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2008-11-30

    Pretreatment of biosorbents have been suggested to modify the surface characteristics which could improve biosorption process. Stable cesium biosorption was studied in continuous fixed-bed column by chemically modified biosorbents. Two kinds of brown algae (Sargassum glaucescens and Cystoseira indica) were treated with chemical agents including formaldehyde (FA), glutaraldehyde (GA), potassium hexacyanoferrate (HCF), FA and HCF, and GA and HCF. The highest biosorption capacity (BC) was obtained from C. indica treated with FA (63.5 mg Cs/g biomass) and S. glaucescens treated with FA and HCF (62 mg Cs/g biomass). To study the effect of the best treatments on the BC, the concentration of each treatment agent was decreased. With decreasing FA agent for C. indica treatment, the BC dropped. Treatment of 1 g S. glaucescens biomass with 2.2 g FA and then 0.18 g HCF resulted in the highest BC (73.08 mg Cs/g dry biomass) which was 35.8 times higher than intact S. glaucescens.

  6. 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.

  7. Kinetics and equilibrium studies on biosorption of cadmium, lead, and nickel ions from aqueous solutions by intact and chemically modified brown algae

    Energy Technology Data Exchange (ETDEWEB)

    Montazer-Rahmati, Mohammad Mehdi, E-mail: mrahmati@ut.ac.ir [School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box: 11155-4563, Tehran 4563 (Iran, Islamic Republic of); Rabbani, Parisa; Abdolali, Atefeh [School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box: 11155-4563, Tehran 4563 (Iran, Islamic Republic of); Keshtkar, Ali Reza [Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, P.O. Box: 11365-8486, Tehran (Iran, Islamic Republic of)

    2011-01-15

    Research highlights: {yields} The present study deals with the evaluation of biosorptive removal of Cd (II), Ni (II) and Pb (II) ions by both intact and pre-treated brown marine algae: Cystoseira indica, Sargassum glaucescens, Nizimuddinia zanardini and Padina australis treated with formaldehyde (FA), glutaraldehyde (GA), polyethylene imine (PEI), calcium chloride (CaCl{sub 2}) and hydrochloric acid (HCl). From the results obtained, chemically modification leads to higher capacity of biosorption. {yields} The equilibrium experimental data were tested using the most common isotherms. The results are best fitted by the Freundlich model among two-parameter models and the Toth, Khan and Radke-Prausnitz models among three-parameter isotherm models for Cd (II), Ni (II) and Pb (II), respectively. {yields} One-way ANOVA and one sample t-tests were performed on experimental data to evaluate the statistical significance of biosorption capacities after five cycles of sorption and desorption. {yields} The kinetic data were fitted by models including pseudo-first-order and pseudo-second-order. From the results obtained, the pseudo-second-order kinetic model describes best the biosorption of cadmium, nickel and lead ions. - Abstract: The present study deals with the evaluation of biosorptive removal of Cd (II), Ni (II) and Pb (II) ions by both intact and pre-treated brown marine algae: Cystoseira indica, Sargassum glaucescens, Nizimuddinia zanardini and Padina australis treated with formaldehyde (FA), glutaraldehyde (GA), polyethylene imine (PEI), calcium chloride (CaCl{sub 2}) and hydrochloric acid (HCl). Batch shaking adsorption experiments were performed in order to examine the effects of pH, contact time, biomass concentration, biomass treatment and initial metal concentration on the removal process. The optimum sorption conditions for each heavy metal are presented. One-way ANOVA and one sample t-tests were performed on experimental data to evaluate the statistical

  8. Optimization of biosorptive removal of dye from aqueous system by cone shell of Calabrian pine.

    Science.gov (United States)

    Deniz, Fatih

    2014-01-01

    The biosorption performance of raw cone shell of Calabrian pine for C.I. Basic Red 46 as a model azo dye from aqueous system was optimized using Taguchi experimental design methodology. L9 (3(3)) orthogonal array was used to optimize the dye biosorption by the pine cone shell. The selected factors and their levels were biosorbent particle size, dye concentration, and contact time. The predicted dye biosorption capacity for the pine cone shell from Taguchi design was obtained as 71.770 mg g(-1) under optimized biosorption conditions. This experimental design provided reasonable predictive performance of dye biosorption by the biosorbent (R (2): 0.9961). Langmuir model fitted better to the biosorption equilibrium data than Freundlich model. This displayed the monolayer coverage of dye molecules on the biosorbent surface. Dubinin-Radushkevich model and the standard Gibbs free energy change proposed physical biosorption for predominant mechanism. The logistic function presented the best fit to the data of biosorption kinetics. The kinetic parameters reflecting biosorption performance were also evaluated. The optimization study revealed that the pine cone shell can be an effective and economically feasible biosorbent for the removal of dye.

  9. [Biosorption of Ag+ by heavy metals hyperresistant Bacillus cereus strain HQ-1].

    Science.gov (United States)

    Zeng, Jing-Hai; Qi, Hong-Yan; Yang, Jian-Zhou; Hu, Qing; Zhang, Hong-Xun; Zhuang, Guo-Qiang

    2008-01-01

    A newly isolated Bacillus cereus strain HQ-1 was found to possess high capability to absorb silver ions. The study showed that the biosorption process could be described well by pseudo-second-order kinetic model and Freundlich isotherm model. Higher cell concentration was favorable to the biosorption. Temperature's effect on the biosorption was not obvious. The oxygenous and nitrogenous functional groups on the cell wall played a very important role in the process of biosorption. Microdeposits were formed by interaction between silver ions and biopolymers from the cell wall (such as polysaccharides, proteins and some hydrolysis).

  10. Zinc Biosorption by Waste Streptomyces fradiae Biomass: Equilibrium and Kinetics

    Directory of Open Access Journals (Sweden)

    Gergana K. Kirova

    2015-12-01

    Full Text Available Waste Streptomyces fradiae biomass from pharmaceutical industry was successfully used for Zn(II removal from aqueous solutions. In the present study process parameters (initial pH of the solution, amount of biomass, initial metal concentration, stirring speed and contact time and their influence on Zn(II biosorption were investigated and optimized. Langmuir and Freundlich adsorption isotherms were used to describe sorption behavior between the waste biomass and the Zn ions. The biosorption process was better described by the Langmuir adsorption isotherm with 61.09 mg g-1 maximum adsorption capacity. Lagergren and Ho models were used to analyze the kinetic data. Ho model fitted better to the experimental results.

  11. 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)

  12. 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

  13. Biosorption of copper and lead ions by waste beer yeast.

    Science.gov (United States)

    Han, Runping; Li, Hongkui; Li, Yanhu; Zhang, Jinghua; Xiao, Huijun; Shi, Jie

    2006-10-11

    Locally available waste beer yeast, a byproduct of brewing industry, was found to be a low cost and promising adsorbent for adsorbing copper and lead ions from wastewater. In this work, biosorption of copper and lead ions on waste beer yeast was investigated in batch mode. The equilibrium adsorptive quantity was determined to be a function of the solution pH, contact time, beer yeast concentration, salt concentration and initial concentration of copper and lead ions. The experimental results were fitted well to the Langmuir and Freundlich model isotherms. According to the parameters of Langmuir isotherm, the maximum biosorption capacities of copper and lead ions onto beer yeast were 0.0228 and 0.0277 mmol g(-1) at 293 K, respectively. The negative values of the standard free energy change (DeltaG degrees ) indicate spontaneous nature of the process. Competitive biosorption of two metal ions was investigated in terms of sorption quantity. The amount of one metal ion adsorbed onto unit weight of biosorbent (q(e)) decreased with increasing the competing metal ion concentration. The binding capacity for lead is more than for copper. Ion exchange is probably one of the main mechanism during adsorptive process.

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. Biosorption of nickel(II) from aqueous solution by brown algae: equilibrium, dynamic and thermodynamic studies.

    Science.gov (United States)

    Pahlavanzadeh, H; Keshtkar, A R; Safdari, J; Abadi, Z

    2010-03-15

    The biosorption characteristics of nickel(II) ions using the brown algae (Cystoseria indica, Nizmuddinia zanardini, Sargassum glaucescens and Padina australis) were investigated. Experimental parameters affecting the biosorption process such as pH level, contact time, initial metal concentration and temperature were studied. The equilibrium data fitted very well to the Langmuir adsorption model in the concentration range of nickel(II) ions and at all the temperatures studied. Evaluation of the experimental data in terms of biosorption dynamics showed that the biosorption of nickel(II) onto algal biomass followed the pseudo-second-order dynamics well. The calculated thermodynamic parameters (Delta G degrees, Delta H degrees and DeltaS degrees) showed that the biosorption of nickel(II) ions were feasible, spontaneous and endothermic at the temperature ranges of 293-313 K. (c) 2009 Elsevier B.V. All rights reserved.

  18. Biosorption of copper(II) by Marrubium globosum subsp. globosum leaves powder: effect of chemical pretreatment.

    Science.gov (United States)

    Yazici, Hüseyin; Kiliç, Mehmet; Solak, Murat

    2008-03-01

    The study was aimed at determining the effect of chemical pretreatment on copper(II) biosorption by Marrubium globosum subsp. globosum leaves. The uptake capacity of the biomass was increased by chemical pretreatment when compared with the raw biomass. The results of biosorption experiments, carried out at the conditions of 50 mg l(-1) initial metal concentration and pH 5.5, showed that pretreating the biomass with alkali solutions (laundry detergent, sodium hydroxide and sodium bicarbonate, 0.5 M) improved the biosorption capacity of biomass (45.90, 45.78 and 43.91%, respectively) compared with raw biomass. Pretreatment with sulfuric and nitric acid solutions, 0.5 M, increased the biosorption capacity of biomass by 11.82 and 10.18%, respectively, while there was no considerable change in the biosorption capacity of biomass (0.35%) after pretreatment with formic acid solution, 0.5 M. Furthermore, sodium chloride and calcium chloride, 0.5 M, pretreatments resulted in the improvement in biosorption capacity of biomass (31.38 and 26.69%, respectively). FT-IR analysis revealed that hydroxyl and carboxyl functional groups were mainly responsible for copper(II) biosorption.

  19. Biosorption of manganese from groundwater by biomass of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    M. Fadel

    2017-04-01

    Full Text Available Heavy metal pollution has become one of the most serious environmental problems today. Biological methods such as biosorption or bioaccumulation strategies for the removal of metals ions may provide an attractive alternative to existing technologies. Microorganisms, as heavy metal bioadsorbents, offer a new alternative for removal of toxic or valuable metals in water. Saccharomyces cerevisiae has received increasing attention due to its unique nature and capacity for metal sorption. It is one of the most promising biosorbents capable of removing metal ions from aqueous solution. Manganese occurs naturally in many surface water and groundwater sources and in soils that may erode into this water. Eleven S. cerevisiae yeast strains in alive and dead forms were screened for biosorption and bioaccumulation of manganese from artificial aqueous solution. S. cerevisiae F-25 in alive form was found to be highly biosorbent for Mn+2 and biosorbed 22.5 mg Mn+2/gm yeast biomass. Optimization of environmental conditions reveals that optimum concentrations for maximum Mn2+ biosorption by S. cerevisiae F-25 in alive form were 4.8 mg Mn2+/l after 30 min at pH 7, agitation 150 rpm and yeast biomass concentration 0.1 gm/l at 30 °C. Competition of Mn+2 with other heavy metals shows that Mn+2 in control sample without, any other heavy metals added in solution at 4.8 mg/l of the biosorbed Mn+2 was 41.3 mg/g biomass. Addition of other heavy metals affects the percent of biosorbed Mn+2.

  20. BIOSORPTION OF CONGO RED BY HYDROGEN PEROXIDE TREATED TENDU WASTE

    Directory of Open Access Journals (Sweden)

    G. K. Nagda ، V. S. Ghole

    2009-07-01

    Full Text Available Solid wastes from agro-industrial operations can be recycled as non-conventional adsorbents if they are inert and harmless and reduce the cost of wastewater treatment. Tendu leaf Diospyros melanoxylon is the second largest forest product in India after timber and is exclusively used in making local cigarette called Bidi. Waste leaf cutting remaining after making cigarette was used in present study as a biosorbent for the removal of Congo red dye from aqueous solution. It was treated with hydrogen peroxide to obtain biosorbent with increased adsorption capacity. Batch type experiments were conducted to study the influence of different parameters such as pH, initial dye concentration and dosage of adsorbent on biosorption evaluated. The adsorption occured very fast initially and attains equilibrium within 60 min at pH= 6.2 and the equilibrium attained faster after hydrogen peroxide modification. Kinetic studies showed that the biosorption of Congo red on tendu waste followed pseudo-second-order rate equation. The data fitted well to Langmuir and Freundlich isotherm models. Comparison was done on the extent of biosorption between untreated and treated forms of the tendu waste. The maximum adsorption capacity for untreated tendu waste was found to be 46.95 mg/g, which was enhanced by 2.8 times after hydrogen peroxide treatment and was found to be 134.4 mg/g. The adsorption process was in conformity with Freundlich and Langmuir isotherms for Congo red adsorption from aqueous solution. The study demonstrated use of milder chemical treatment of tendu waste to obtain a biosorbent with enhanced dye removal capacity.

  1. 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.

  2. Equilibrium and thermodynamic studies on biosorption of Pb(II) onto Candida albicans biomass

    International Nuclear Information System (INIS)

    Baysal, Zuebeyde; Cinar, Ercan; Bulut, Yasemin; Alkan, Hueseyin; Dogru, Mehmet

    2009-01-01

    Biosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida albicans. The optimum conditions of biosorption were determined by investigating the initial metal ion concentration, contact time, temperature, biosorbent dose and pH. The extent of metal ion removed increased with increasing contact time, initial metal ion concentration and temperature. Biosorption equilibrium time was observed in 30 min. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and isotherm constants were also evaluated. The maximum biosorption capacity of Pb(II) on C. albicans was determined as 828.50 ± 1.05, 831.26 ± 1.30 and 833.33 ± 1.12 mg g -1 , respectively, at different temperatures (25, 35 and 45 deg. C). Biosorption showed pseudo second-order rate kinetics at different initial concentration of Pb(II) and different temperatures. The activation energy of the biosorption (E a ) was estimated as 59.04 kJ mol -1 from Arrhenius equation. Using the equilibrium constant value obtained at different temperatures, the thermodynamic properties of the biosorption (ΔG o , ΔH o and ΔS o ) were also determined. The results showed that biosorption of Pb(II) ions on C. albicans were endothermic and spontaneous. The optimum initial pH for Pb(II) was determined as pH 5.0. FTIR spectral analysis of Pb(II) adsorbed and unadsorbed C. albicans biomass was also discussed

  3. 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.

  4. Enhanced biosorption of transition metals by living Chlorella vulgaris immobilized in Ca-alginate beads.

    Science.gov (United States)

    Ahmad, Ashfaq; Bhat, A H; Buang, Azizul

    2018-02-01

    In this study freely suspended and Ca-alginate immobilized C. vulgaris cells were used for the biosorption of Fe(II), Mn(II), and Zn(II) ions, from the aqueous solution. Experimental data showed that biosorption capacity of algal cells was strongly dependent on the operational condition such as pH, initial metal ions concentration, dosages, contact time and temperature. The maximum biosorption of Fe(II) 43.43, Mn(II) 40.98 and Zn(II) 37.43 mg/g was achieved with Ca-alginate immobilized algal cells at optimum pH of 6.0, algal cells dosage 0.6 g/L, and contact time of 450 min at room temperature. The biosorption efficiency of freely suspended and immobilized C. vulgaris cells for heavy metals removal from the industrial wastewater was validated. Modeling of biosorption kinetics showed good agreements with pseudo-second-order. Langmuir and D-R isotherm models exhibited the best fit of experimental data. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) revealed that the biosorption of considered metal ions was feasible, spontaneous and exothermic at 25-45°C. The SEM showed porous morphology which greatly helps in the biosorption of heavy metals. The Fourier transform infrared spectrophotometer (FTIR) and X-rays Photon Spectroscopy (XPS) data spectra indicated that the functional groups predominately involved in the biosorption were C-N, -OH, COO-, -CH, C=C, C=S and -C-. These results shows that immobilized algal cells in alginate beads could potentially enhance the biosorption of considered metal ions than freely suspended cells. Furthermore, the biosorbent has significantly removed heavy metals from industrial wastewater at the optimized condition.

  5. 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.

  6. Biosorption of Lead Ions from Aqueous Solution Using Ficus benghalensis L.

    Directory of Open Access Journals (Sweden)

    Venkateswara Rao Surisetty

    2013-01-01

    Full Text Available Ficus benghalensis L., a plant-based material leaf powder, is used as an adsorbent for the removal of lead ions from aqueous solution using the biosorption technique. The effects of process parameters such as contact time, adsorbent size and dosage, initial lead ion concentration, and pH of the aqueous solution on bio-sorption of lead by Ficus benghalensis L. were studied using batch process. The Langmuir isotherm was more suitable for biosorption followed by Freundlich and Temkin isotherms with a maximum adsorption capacity of 28.63 mg/g of lead ion on the biomass of Ficus benghalensis L. leaves.

  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. Biosorption of heavy metals by red algae (Palmaria palmata).

    Science.gov (United States)

    Prasher, S O; Beaugeard, M; Hawari, J; Bera, P; Patel, R M; Kim, S H

    2004-10-01

    The biosorption of heavy metals from aqueous solutions was investigated, using a cheap and abundant dry biomass of red algae P. palmata. The Freundlich, Langmuir and Brunauer Emmer and Teller (BET) models were used to describe the uptake of lead (pb2+), copper (Cu2+), nickel (Ni2+), cadmium (Cd 2+) and zinc (Zn2+) on P. palmata. The good fits of the Langmuir and BET models to the experimental data reflected that the sorption on P. palmata was a multi-layer sorption, in which a Langmuir equation could be applied to each layer. The highest maximum sorption capacity q(max), derived from the Langmuir model was 15.17 mg g(-1) for lead and 6.65 mg g(-1) for copper (dry weight metal/dry weight biosorbent) at a pH of 5.5-6. The affinity of metals for P. palmata was found to decrease in the order: Pb2+ > Cd2+ > Cu2+ > Ni2+. The factors influencing copper and lead uptake were found to be contact time, pH, initial concentration and temperature. Biosorption of copper and lead was a rapid process, with 70% and 100% of the respective uptakes occurring within the first 10 minutes.

  9. 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.

  10. 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

  11. Biosorption of americium-241 by immobilized Rhizopus arrihizus

    Energy Technology Data Exchange (ETDEWEB)

    Liao Jiali E-mail: liaojiali@163.com; 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 {sup 241}Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting {sup 241}Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb {sup 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 {sup 241}Am was removed from {sup 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 {sup 241}Am. At this time, the total adsorption of {sup 241}Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed {sup 241}Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO{sub 3}.

  12. 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.

  13. 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.

  14. Biosorption of lead by Gram-ve capsulated and non-capsulated ...

    African Journals Online (AJOL)

    Citrobacter freundii ) or capsulated (Klebsiella pneumoniae) was characterised. Lead biosorption was found to be influenced by the pH of the solution, initial metal concentration, and amount of the dried powdered cells and contact time. Thus, the ...

  15. Biosorption of food dyes onto Spirulina platensis nanoparticles: equilibrium isotherm and thermodynamic analysis.

    Science.gov (United States)

    Dotto, G L; Lima, E C; Pinto, L A A

    2012-01-01

    The biosorption of food dyes FD&C red no. 40 and acid blue 9 onto Spirulina platensis nanoparticles was studied at different conditions of pH and temperature. Four isotherm models were used to evaluate the biosorption equilibrium and the thermodynamic parameters were estimated. Infra red analysis (FT-IR) and energy dispersive X-ray spectroscopy (EDS) were used to verify the biosorption behavior. The maximum biosorption capacities of FD&C red no. 40 and acid blue 9 were found at pH 4 and 298 K, and the values were 468.7 mg g(-1) and 1619.4 mg g(-1), respectively. The Sips model was more adequate to fit the equilibrium experimental data (R2>0.99 and AREdyes onto nanoparticles occurred by chemisorption. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. 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.

  17. 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.

  18. Kinetics and equilibrium studies on biosorption of cadmium, lead, and nickel ions from aqueous solutions by intact and chemically modified brown algae.

    Science.gov (United States)

    Montazer-Rahmati, Mohammad Mehdi; Rabbani, Parisa; Abdolali, Atefeh; Keshtkar, Ali Reza

    2011-01-15

    The present study deals with the evaluation of biosorptive removal of Cd (II), Ni (II) and Pb (II) ions by both intact and pre-treated brown marine algae: Cystoseira indica, Sargassum glaucescens, Nizimuddinia zanardini and Padina australis treated with formaldehyde (FA), glutaraldehyde (GA), polyethylene imine (PEI), calcium chloride (CaCl(2)) and hydrochloric acid (HCl). Batch shaking adsorption experiments were performed in order to examine the effects of pH, contact time, biomass concentration, biomass treatment and initial metal concentration on the removal process. The optimum sorption conditions for each heavy metal are presented. One-way ANOVA and one sample t-tests were performed on experimental data to evaluate the statistical significance of biosorption capacities after five cycles of sorption and desorption. The equilibrium experimental data were tested using the most common isotherms. The results are best fitted by the Freundlich model among two-parameter models and the Toth, Khan and Radke-Prausnitz models among three-parameter isotherm models for Cd (II), Ni (II) and Pb (II), respectively. The kinetic data were fitted by models including pseudo-first-order and pseudo-second-order. From the results obtained, the pseudo-second-order kinetic model best describes the biosorption of cadmium, nickel and lead ions. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. 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.

  20. Biosorption of Heavy Metal Ions to Brown Algae, Macrocystis pyrifera, Kjellmaniella crassiforia, and Undaria pinnatifida

    OpenAIRE

    Seki, Hideshi; Suzuki, Akira

    1998-01-01

    A fundamental study of the application of brown algae to the aqueous-phase separation of toxic heavy metals was carried out. The biosorption characteristics of cadmium and lead ions were determined with brown algae, Macrocystis pyrifera, Kjellmaniella crassiforia, and Undaria pinnatifida. A metal binding model proposed by the authors was used for the description of metal binding data. The results showed that the biosorption of bivalent metal ions to brown algae was due to bivalent binding to ...

  1. Biosorption of nonylphenol on dead biomass of Rhizopus arrhizus encapsulated in chitosan beads

    OpenAIRE

    Lang, Weeranuch; Dejma, Chomawan; Sirisansaneeyakul, Sarote; Sakairi, Nobuo

    2009-01-01

    The nonylphenol (NP) biosorption and desorption potential for fungal biomass used under batch conditions was investigated using kinetics and isotherm models. Fungal biomass of Rhizopus arrhizus TISTR 3610 exhibited preferential uptake of NP, an endocrine disrupting chemicals. Sporangiospores, asexual spores, were immobilisation in chitosan beads. The biosorption data of NP on the moist heat inactivated R. arrhizus-chitosan beads were analyzed using four popular adsorption isotherms and, by us...

  2. 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.

  3. Pleurotus ostreatus spent mushroom compost as green biosorbent for nickel (II) biosorption.

    Science.gov (United States)

    Tay, Chia-Chay; Liew, Hong-Hooi; Redzwan, Ghufran; Yong, Soon-Kong; Surif, Salmijah; Abdul-Talib, Suhaimi

    2011-01-01

    The potential of Pleurotus ostreatus spent mushroom compost (PSMC) as a green biosorbent for nickel (II) biosorption was investigated in this study. A novel approach of using the half-saturation concentration of biosorbent to rapidly determine the uptake, kinetics and mechanism of biosorption was employed together with cost per unit uptake analysis to determine the potential of this biosorbent. Fifty per cent nickel (II) biosorption was obtained at a half-saturation constant of 0.7 g biosorbent concentration, initial pH in the range of 4-8, 10 min contact time, 50 mL 50 mg/L nickel (II) initial concentration. The experimental data were well fitted with the Langmuir isotherm model and the maximum nickel (II) biosorption was 3.04 mg/g. The results corresponded well to a second pseudo order kinetic model with the coefficient of determination value of 0.9999. Based on FTIR analysis, the general alkyl, hydroxyl or amino, aliphatic alcohol and carbonyl functional groups of biosorbent were involved in the biosorption process. Therefore, biosorption of nickel (II) must involve several mechanisms simultaneously such as physical adsorption, chemisorption and ion exchange. Cost comparison for PSMC with Amberlite IRC-86 ion exchange resin indicates that the biosorbent has the potential to be developed into a cost effective and environmentally friendly treatment system.

  4. Comparison of uranium biosorption between scytalidium acidophilum and rhizopus arrhizus. Mineral sciences laboratories division report

    International Nuclear Information System (INIS)

    Salley, J.; McCready, R.G.L.; Cuif, J.P.

    1989-03-01

    Biosorption of uranium from the mine biolixiviant and from complex synthetic uranium solutions by the extremely acid-tolerant fungus Scytalidium acidophilum was studies. Uranium uptake at pH 4 was shown to be three times greater than uptake at pH 2.5. Kinetics of biosorption at different ceg[ centrations were conducted to evaluate the biosorptive capacities of the fungus at pH 4. An uptake of 42 mgU/g was reached within 10 min for a cell concentration of 1.0 g/l. Kinetic studies showed that biosorption is slower and less efficient with mine water compared to synthetic U solution, due to the higher concentrations of competitive ions present in mine water. Uranium biosorption by S. acidophilum was also evaluated with biosorption isotherms and compared to another fungus, Rhizopus arrhizus. At pH 4, R. arrhizus always showed greater uranium uptake than S. acidophilum for both mine water and complex synthetic solution. Uranium uptake was greater than 37 mgU/g and 51 mgU/g with min water for S. acidophilum and R. arrhizus respectively, and 65 mgU/g and 122 mgU/g with complex synthetic uranium solution. (author). 21 refs., 1 tab., 8 figs

  5. Examination of Pb2+ bio-sorption onto Rhodotorula mucilaginosa using response surface methodology.

    Science.gov (United States)

    Jiang, Bin-hui; Zhao, Yan; Zhao, Xin; Hu, Xiao-min; Li, Li

    2015-01-01

    With the rapid industrial development, wastewater has been a risk for environmental contamination. We aimed to explore the optimum condition and mechanism of Pb2+ bio-sorption onto Rhodotorula mucilaginosa WT6-5. Optimization of initial concentration of Pb2+, initial pH, and adsorption time for Pb2+ bio-sorption onto R. mucilaginosa WT6-5 was performed using response surface methodology. Field emission scanning electron microscopy, energy dispersive X-ray detection, X-ray fluorescence and Fourier transform infrared spectroscopy were used to analyze the mechanisms and characteristics of Pb2+ bio-sorption. A maximum Pb2+ bio-sorption capacity of 1.45 mg/g was obtained under the optimal conditions of initial concentration of Pb2+ (30 mg/L), initial pH (5.45) and adsorption time (25 minutes). Some Pb2+ remained after adsorption, and the -OH, -C=O and C-O functional groups were primarily involved in Pb2+ bio-sorption onto R. mucilaginosa WT6-5. The mechanism of Pb2+ bio-sorption involved chemical and biological actions, ion exchange and functional groups effects.

  6. KINETIC AND EQUILIBRIUM STUDIES OF LEAD AND CADMIUM BIOSORPTION FROM AQUEOUS SOLUTIONS BY SARGASSUM SPP. BIOMASS

    Directory of Open Access Journals (Sweden)

    R. Nabizadeh, K. Naddafi, R. Saeedi, A. H. Mahvi, F. Vaezi, K. Yaghmaeian and S. Nazmara

    2005-07-01

    Full Text Available Contamination of the aqueous environment by heavy metals is a worldwide environmental problem. Biosorption of lead (II and cadmium (II from aqueous solutions by brown algae Sargassum spp.biomass was studied in a batch system. The heavy metals uptake was found to be rapid and reached to 88-96% of equilibrium capacity of biosorption in 15min. The pseudo second-order and saturation rate equations were found in the best fitness with the kinetic data (R2 > 0.99. The data obtained from experiments of single-component biosorption isotherm were analyzed using the Freundlich, Langmuir, Freundlich-Langmuir and Redlich-Peterson isotherm models. The Redlich-Peterson equation described the biosorption isotherm of Pb2+ and Cd2+ with high correlation coefficient (R2 > 0.99 and better than the other equations. The effect of Na+, K+, Mg2+ and Ca2+ on the biosorption of Pb2+ was not significant, but the metal ions affected the biosorption of Cd2+ considerably. According to the Langmuir model, the maximum uptake capacities (qm of Sargassum spp. for Pb2+ and Cd2+ were obtained as 1.70 and 1.02mmol/g, respectively. Although the Sargassum spp. used in this study can be classified as an efficient biosorbent.

  7. [Biosorption of lead ions on dried waste beer yeast and the analysis by FTIR].

    Science.gov (United States)

    Dai, Qun-Wei; Dong, Fa-Qin; Zhang, Wei

    2009-07-01

    The biosorption of lead ions on dried waste beer yeast was investigated with respect to the adsorption conditions and the biosorption mechanism was analyzed with the instruments of AAS, SEM/EDS and FTIR. The results show that the metal uptake value obtained was 47.6 mg x g(-1) and the adsorptive efficiency was above 90%. Under our experiment conditions, the biosorption of Pb2+ on dried waste beer yeast is a fast process. The biosroption quantity of Pb2+ on beer yeast cells was 47.6 mg x g(-1) and the adsorption efficiency obtained was 91.6% in fisrt 30 min, then the metal uptake value obtained was 48.8 mg x g(-1) and the adsorptive efficiency was above 94% at 90 min. The cells cracking and breaking off were seen after the biosorption of lead ions on beer yeast through SEM analysis, and the cytoplasts from yeast cell should be responsible for the last period biosorption of lead ions. EDS analysis also proved that lead ions were absorbed on the yeast cells. FTIR analysis showed that the infrared spectrograms are different at different pH and biosorption time, especially hydroxyl groups, carboxylate groups and amide groups have obviously changed. Amylase and amide of protein were considered as main components to participate the chemical absorption of lead ions on yeast cells. Consequently, dried waste beer yeast is an inexpensive, readily available adsorbent for metals and especially has a high adsorption capacity for lead ions.

  8. 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.

  9. Chromium Biosorption from Cr(VI) Aqueous Solutions by Cupressus lusitanica Bark: Kinetics, Equilibrium and Thermodynamic Studies

    Science.gov (United States)

    Netzahuatl-Muñoz, Alma Rosa; Cristiani-Urbina, María del Carmen; Cristiani-Urbina, Eliseo

    2015-01-01

    The present study investigated the kinetics, equilibrium and thermodynamics of chromium (Cr) ion biosorption from Cr(VI) aqueous solutions by Cupressus lusitanica bark (CLB). CLB total Cr biosorption capacity strongly depended on operating variables such as initial Cr(VI) concentration and contact time: as these variables rose, total Cr biosorption capacity increased significantly. Total Cr biosorption rate also increased with rising solution temperature. The pseudo-second-order model described the total Cr biosorption kinetic data best. Langmuir´s model fitted the experimental equilibrium biosorption data of total Cr best and predicted a maximum total Cr biosorption capacity of 305.4 mg g-1. Total Cr biosorption by CLB is an endothermic and non-spontaneous process as indicated by the thermodynamic parameters. Results from the present kinetic, equilibrium and thermodynamic studies suggest that CLB biosorbs Cr ions from Cr(VI) aqueous solutions predominantly by a chemical sorption phenomenon. Low cost, availability, renewable nature, and effective total Cr biosorption make CLB a highly attractive and efficient method to remediate Cr(VI)-contaminated water and wastewater. PMID:26352933

  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. Using ICP-OES and SEM-EDX in biosorption studies.

    Science.gov (United States)

    Michalak, Izabela; Chojnacka, Katarzyna; Marycz, Krzysztof

    2011-02-01

    We have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution.FigureThe advantages and disadvantages of ICP-OES and SEM-EDX techniques ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00604-010-0468-0) contains supplementary material, which is available to authorized users.

  12. 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

  13. Study of thermodynamics and dynamics of removing Cu(II) by biosorption membrane of Penicillium biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, College of Life Science and Technology, Beijing 100029 (China); Su, Haijia, E-mail: suhj@mail.buct.edu.cn [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, College of Life Science and Technology, Beijing 100029 (China); Tan, Tianwei; Xiao, Gang [Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, College of Life Science and Technology, Beijing 100029 (China)

    2011-10-15

    Based on the integration of biosorption and membrane-separation, a novel biosorption membrane with good mechanical property was prepared by immobilizing Penicillium biomass with cross-linked chitosan on fabric. The ability of the low cost biosorption membrane to remove Cu(II) ions from a solution was studied through batch and continuous experiments. Langmuir adsorption isotherm models were found to accurately fit the batch experimental data (R{sup 2} > 0.99) indicating that sorption was of monolayer-mode. The uptake of Cu(II) could reach 38 mg/g at its initial concentration of 200 mg/L in the solution. Continuous biosorption was investigated in a column and the effects of the height, flow rate and initial concentration of Cu(II) were studied. The Bed Depth Service Time model (BDST) was applied to simulate column adsorption data. The breakthrough time at different flow rates and initial concentrations was accurately predicted by the model (error < 8%). The uptake of Cu(II) could reach 38.3 mg/g at height 30 cm, flow rate 5 mL/min, initial concentration of Cu(II) 200 mg/L. The biosorption membrane was regenerated by washing with 0.05 mol/L solution of HCl, and breakthrough curves remained fairly unchanged after 10 cycles of adsorption-desorption.

  14. 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.

  15. Biosorption of textile dye reactive blue 221 by capia pepper (Capsicum annuum L.) seeds.

    Science.gov (United States)

    Gürel, Levent

    2017-04-01

    Peppers are very important foodstuffs in the world for direct and indirect consumption, so they are extensively used. The seeds of these peppers are waste materials that are disposed of from houses and factories. To evaluate the performance of this biomass in the treatment of wastewaters, a study was conducted to remove a textile dye, reactive blue 221, which is commercially used in textile mills. Raw seed materials were used without any pre-treatment. The effects of contact time, initial concentration of dye, pH and dose of biosorbent were studied to determine the optimum conditions for this biomass on color removal from wastewaters. The optimum pH value for dye biosorption was found to be 2.0. At an initial dye concentration of 217 mg L -1 , treatment efficiency and biosorption capacity were 96.7% and 95.35 mg g -1 , respectively. A maximum biosorption capacity of 142.86 mg g -1 was also obtained. Equilibrium biosorption of dye by capia seeds was well described by the Langmuir isotherm with a correlation coefficient above 99%. The biosorption process was also successfully explained with the pseudo-second order kinetic model. This biomass was found to be effective in terms of textile dye removal from aqueous solutions.

  16. Biosorption of B-aflatoxins Using Biomasses Obtained from Formosa Firethorn [Pyracantha koidzumii (Hayata Rehder

    Directory of Open Access Journals (Sweden)

    Rosa Adriana Ramales-Valderrama

    2016-07-01

    Full Text Available Mycotoxin adsorption onto biomaterials is considered as a promising alternative for decontamination without harmful chemicals. In this research, the adsorption of B-aflatoxins (AFB1 and AFB2 using Pyracantha koidzumii biomasses (leaves, berries and the mixture of leaves/berries from aqueous solutions was explored. The biosorbent was used at 0.5% (w/v in samples spiked with 100 ng/mL of B-aflatoxin standards and incubated at 40 °C for up to 24 h. A standard biosorption methodology was employed and aflatoxins were quantified by an immunoaffinity column and UPLC methodologies. The biosorbent-aflatoxin interaction mechanism was investigated from a combination of zeta potential (ζ, Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. The highest aflatoxin uptakes were 86% and 82% at 6 h using leaves and the mixture of leaves/berries biomasses, respectively. A moderate biosorption of 46% was attained when using berries biomass. From kinetic studies, the biosorption process is described using the first order adsorption model. Evidence from FTIR spectra suggests the participation of hydroxyl, amine, carboxyl, amide, phosphate and ketone groups in the biosorption and the mechanism was proposed to be dominated by the electrostatic interaction between the negatively charged functional groups and the positively charged aflatoxin molecules. Biosorption by P. koidzumii biomasses has been demonstrated to be an alternative to conventional systems for B-aflatoxins removal.

  17. Biosorption of {sup 241}Am by Rhizopus arrihizus: preliminary investigation and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Liu Ning E-mail: 5416507@mail.sc.cninfo.net; Yang Yuanyou; Luo Shunzhong; Zhang Taiming; Jin Jiannan; Liao Jiali; Hua Xifeng

    2002-08-01

    The biosorption of {sup 241}Am from solution by a fungus--Rhizopus Arrihizus (R. arrihizus), and the effect of experimental conditions on the adsorption were investigated. The preliminary results showed that the biosorption of {sup 241}Am by R. arrihizus is very efficient. An average of more than 99% of the total {sup 241}Am was removed by R. arrihizus of 1.3 g/l (dry weight) from {sup 241}Am solutions of 5.6-111 MBq/l (44.3-877.2 {mu}g/l) (C{sub 0}), with adsorption capacities (W) of 4.2-79.4 MBq/g biomass (dry weight) (33.2-627.5 {mu}g/g). The biosorption equilibrium was achieved within 1 h and the optimum pH ranged from 1 to 3. No significant differences in {sup 241}Am biosorption were observed at 10-45 deg. C, or in solutions containing Au{sup 3+} or Ag{sup +}, even 2000 times above {sup 241}Am concentration. The relationship between concentrations and adsorption capacities of {sup 241}Am indicated that the {sup 241}Am biosorption by R. arrihizus obeys the Freundlich adsorption equation.

  18. 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.

  19. 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.

  20. 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.

  1. Equilibrium and kinetics studies of heavy metal ions biosorption on green algae waste biomass.

    Science.gov (United States)

    Bulgariu, Dumitru; Bulgariu, Laura

    2012-01-01

    The biosorption of Pb(II), Cd(II), and Co(II), respectively, from aqueous solution on green algae waste biomass was investigated. The green algae waste biomass was obtained from marine green algae after extraction of oil, and was used as low-cost biosorbent. Batch shaking experiments were performed to examine the effects of initial solution pH, contact time and temperature. The equilibrium biosorption data were analyzed using two isotherm models (Langmuir and Freundlich) and two kinetics models (pseudo-first order and pseudo-second order). The results indicate that Langmuir model provide best correlation of experimental data, and the pseudo-second order kinetic equation could best describe the biosorption kinetics of considered heavy metals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. The effect of dodecyltrimethilammoniumbromide on Ni biosorption property of white rod fungi

    Science.gov (United States)

    Gül, Ülküye Dudu; Silah, Hülya

    2017-04-01

    Industrial waste water contains abundant amount of heavy metals, therefore the treatment of heavy metals have gained importance. The effect of Dodecylthrimetylammonium bromide (DTAB) on biological treatment of heavy metal called Nickel by white rot fungus Trametes versicolor was examined in this study. In biosorption experiments, the effects of DTAB, pH and contact time on removal of Nickel by dried T. versicolor were investigated. The results of Nickel removal experiments showed that after 4 hours of incubation Nickel biosorption was 14.95% and 24.81% in the absence and peresence of DTAB, respectively. The addition of surfactant had contribution on metal biosorption. The results of research finding showed that the biolgical heavy metal treatment capacity of fungus was enhanced by using surfactants.

  3. 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.

  4. Lead, copper and zinc biosorption from bicomponent systems modelled by empirical Freundlich isotherm

    Energy Technology Data Exchange (ETDEWEB)

    Sag, Y.; Kaya, A.; Kutsal, T. [Dept. of Chemical Engineering, Hacettepe Univ., Beytepe, Ankara (Turkey)

    2000-07-01

    The biosorption of lead, copper and zinc ions on Rhizopus arrhizus has been studied for three single-component and two binary systems. The equilibrium data have been analysed using the Freundlich adsorption model. The characteristic parameters for the Freundlich adsorption model have been determined and the competition coefficients for the competitive biosorption of Pb(II)-Cu(II) at pH 4.0 and 5.0, and Pb(II)-Zn(II) at pH 5.0 have been calcualted. For the individual single-component isotherms, lead has the highest biosorption capacity followed by copper, then zinc. The capacity of lead in the two binary systems is always significantly greater than those of the other metal ions, in agreement with the single-component data. Only a partial selectivity for copper ions has been obtained at pH 4.0. (orig.)

  5. 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.

  6. 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

  7. Biosorption of copper ions from aqueous solutions by Spirulina platensis biomass

    Directory of Open Access Journals (Sweden)

    Ali A. Al-Homaidan

    2014-01-01

    Full Text Available In this study, the economically important micro-alga (cyanobacterium Spirulina platensis was used as biosorbent for the removal of copper from aqueous solutions. The cyanobacterium was exposed to various concentrations of copper and adsorption of copper by the biomass was evaluated under different conditions that included pH, contact time, temperature, concentration of adsorbate and the concentration of dry biomass. Increased adsorption of copper by the non-living biomass was recorded with gradually increasing pH, and a maximal uptake by the biomass was observed at pH 7. The adsorption of copper was found to increase gradually along with decrease in biomass concentration. Biosorption was found to be at a maximum (90.6%, in a solution containing 100 mg copper/L, at pH 7, with 0.050 g dry biomass and at 37 °C with 90 min of contact time. Analysis of the spectrum obtained with atomic absorption spectrophotometer (AAS, indicated that the adsorbent has a great potential to remove copper from aqueous media contributing to an eco-friendly technology for efficient bioremediation in the natural environment.

  8. The research progress in mechanism and influence of biosorption between lactic acid bacteria and Pb(II): A review.

    Science.gov (United States)

    Lin, Derong; Ji, Ran; Wang, Dan; Xiao, Mengshi; Zhao, Jingjing; Zou, Jinpeng; Li, Yutong; Qin, Tao; Xing, Baoshan; Chen, Yuan; Liu, Peng; Wu, Zhijun; Wang, Lilin; Zhang, Qing; Chen, Hong; Qin, Wen; Wu, Dingtao; Liu, Yuntao; Liu, Yaowen; Li, Suqing

    2017-09-08

    Currently, due to high surface to volume ratio; large availability, rapid kinetics of adsorption and desorption and low cost, the exploitation of microbial biosorption of heavy metals is regarded as a reliable alternative compared to the conventional bioremediation approaches. In parallel with the increasing attractiveness of biosorption research, its pace of advance is also boosted. The barrier that prevent biosorption as an effective method from being applied into wastewater purification is listed, (1) There is not enough data on multi-component biosorption, (2) It remains to be seen that physical-chemical characteristics of different biomasses. (3) Studies on surface modification of strains for enhancement of heavy metals removal efficiency is lack. And extensive literatures involving the mechanism and model of biosorption for particular metal and microbial strains are not available. The present literatures lack systematization, the theory on interaction between lactic acid bacteria and Pb is far from complete. Therefore, the review tries to give a comprehensive explanation about the mechanism of Pb removal from Lactic acid bacteria and provide a brief overview of distinction between biosorption and bioaccumulation, biosorption technology, highlight the underlying features of biosorption and the various affecting factors such as pH, dose required, initial concentration, temperature, and treatment performance as a reference. Biosorption mechanisms can be briefly generalized into several pathways, which are ion exchange, complexation, precipitation, reduction and chelation. Many views holds that complexation is the major absorption mechanisms of Pb. Biosorption mechanisms can be roughly classified as biosorption and bioaccumulation, which have great differences between each other. Biosorption is metabolism-independent but fast, while bioaccumulation is metabolism-dependent but slow. The slight advantages of the bioaccumulation are the metabolite (lactic acid

  9. 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.

  10. Equilibrium, kinetic and thermodynamic studies on aluminum biosorption by a mycelial biomass (Streptomyces rimosus)

    International Nuclear Information System (INIS)

    Tassist, Amina; Lounici, Hakim; Abdi, Nadia; Mameri, Nabil

    2010-01-01

    This work focused on kinetic, equilibrium and thermodynamic studies on aluminum biosorption by Streptomyces rimosus biomass. Infrared spectroscopy analysis shows that S. rimosus present some groups: hydroxyl, methyl, carboxyl, amine, thiol and phosphate. The maximum biosorption capacity of S. rimosus biomass was found to be 11.76 mg g -1 for the following optimum conditions: particle size,]250-560] μm, pH 4-4.25, biomass content of 25 g L -1 , agitation of 250 rpm and temperature of 25 deg. C. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherms at free pH (pH i 4) and fixed pH (pH f 4). Langmuir model is the most adequate. With fixed pH, the maximum biosorption capacity is enhanced from 6.62 mg g -1 to 11.76 mg g -1 . The thermodynamic parameters (ΔG o , ΔH o and ΔS o ) showed the feasibility, endothermic and spontaneous nature of the biosorption at 10-80 deg. C. The activation energy (Ea) was determined as 52.18 kJ mol -1 using the Arrhenius equation and the rate constant of pseudo-second-order model (the most adequate kinetic model). The mean free energy was calculated as 12.91 kJ mol -1 using the D-R isotherm model. The mechanism of Al(III) biosorption on S. rimosus could be a chemical ion exchange and carboxyl groups are mainly involved in this mechanism.

  11. 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.

  12. Biosorption behavior and mechanism of thorium on Streptomyces sporoverrucosus dwc-3

    International Nuclear Information System (INIS)

    Congcong Ding; Sichuan University, Chengdu; Su Feng; Wencai Cheng; Jie Zhang; Xiaolong Li; Jiali Liao; Yuanyou Yang; Zhu An; Jijun Yang; Jun Tang

    2014-01-01

    To understand the impact of microorganisms on the fate of thorium in soils, we have investigated the thorium biosorption behavior and mechanism on the living and dead cells of Streptomyces sporoverrucosus dwc-3, isolated from soils in China. The living cells need more time (24 h) to reach equilibrium than dead cells (24 h). The biosorption is greatly dependent on pH and ionic strength for the two kinds of cells. SEM and TEM indicate that thorium initially bind with the cell surface which is probably controlled by ion-exchange, evidence by PIXE, and inner-sphere complexation mechanism and then accumulated in the cytoplasm. (author)

  13. Comparison of nickel biosorption properties of living and dead Rhizopus arrhizus biosorbent

    Science.gov (United States)

    Silah, Hülya; Gül, Ülküye Dudu

    2017-04-01

    The passive removal of commonly used heavy metal Ni(II), from aqueous solutions by inexpensive biomaterial, fungi Rhizopus arrhizus biomass, termed biosorption, was studied in this study. The effects of biomass type (living and dead) and pH (2-6) on metal removal by fungus were investigated. The dead biomass (44.2%) exhibited higher uptake ability of Ni(II) than living biomass (40.5%) at 100 mg/L heavy metal after 6 h. Optimal pH for biosorption was 6.

  14. 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)

  15. 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)

  16. 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

  17. Biosorption behavior and mechanism of heavy metals by the fruiting body of jelly fungus (Auricularia polytricha) from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haiwei; Wan, Yuxuan; Zhang, Renduo [Sun Yat-sen Univ., Guangzhou (China). School of Environmental Science and Engineering; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou (China); Cao, Lixiang; Wang, Wenfeng [Sun Yat-sen Univ., Guangzhou (China). School of Life Sciences

    2012-11-15

    The aim of this study was to investigate the biosorption characteristics of Cd{sup 2+}, Cu{sup 2+}, and Pb{sup 2+} by the fruiting body of jelly fungus Auricularia polytricha. Batch experiments were conducted to characterize the kinetics, equilibrium, and mechanisms of the biosorption process. Optimum values of pH 5, biomass dosage 4 g L{sup -1}, and contact time 60 min provided maximum biosorption capacities of A. polytricha for Cd{sup 2+}, Cu{sup 2+}, and Pb{sup 2+} of 63.3, 73.7, and 221 mg g{sup -1}, respectively. The maximum desorption was achieved using 0.05 mol L{sup -1} HNO{sub 3} as an elute. The fruiting body was reusable at least for six cycles of operations. The pseudo-second-order model was the best to describe the biosorption processes among the three kinetic models tested. Freundlich and Dubinin-Radushkevich models fitted the equilibrium data well, indicating a heterogeneous biosorbent surface and the favorable chemisorption nature of the biosorption process. A Fourier transform infrared spectroscopy analysis indicated that carboxyl, amine/hydroxyl, amino, phosphoryl, and C-N-C were the main functional groups to affect the biosorption process. Synergistic ion exchange and surface complexation were the dominant mechanisms in the biosorption process. The present work revealed the potential of jelly fungus (fruiting body of A. polytricha) to remove toxic heavy metals from contaminated water. (orig.)

  18. EQUILIBRIUM MODELLING AND SPECTROSCOPIC STUDIES FOR THE BIOSORPTION OF ZN+2 IONS FROM AQUEOUS SOLUTION USING IMMOBILIZED SPIRULINA PLATENSIS

    Directory of Open Access Journals (Sweden)

    N. Gaur ، R. Dehankhar

    2009-01-01

    Full Text Available Biosorption equilibrium of zinc ions to Spirulina platensis both in free and immobilized forms were studied in batch system with respect to pH, metal ion concentration, algal dosages and time. The maximum adsorption was observed at pH=8, optimum metal ion concentration and algal dose were 100 mg/L and 1g/100mL, respectively. Biosorption equilibrium was established in 90 minutes. The maximum attainable biosorption was found to be 97.1% for Spirulina platensis. The equilibrium adsorption capacities of adsorbents used for zinc ions were measured and extrapolated using Langmuir and Freundlich isotherms models. Langmuir model was found to be in better correlation with experimental data. The maximum Langmuir constants Q◦ (mg/g and b were 92.93 and 0.0012, respectively for Spirulina platensis embedded in calcium alginate matrix. The immobilized Spirulina platensis in calcium of alginate matrix was the best biosorbent. 0.1 M EDTA was used as an eluant, which allowed the reuse of biomass in three biosorption-desorption cycles without considerable loss in biosorption capacity. 89-95 % zinc ions were desorbed with EDTA. The functional groups involved in zinc biosorption were identified by using Fourier Transform Infra Red spectroscopy. Spectroscopic analysis of algae revealed the presence of carboxyl, hydroxyl, amino, amide and imine groups, which were responsible for biosorption of zinc ions.

  19. Characterization and lead(II), cadmium(II), nickel(II) biosorption of dried marine brown macro algae Cystoseira barbata.

    Science.gov (United States)

    Yalçın, Sibel; Sezer, Semih; Apak, Reşat

    2012-09-01

    The objectives of this research are to identify the functional groups and determine corresponding pK (a) values of the acidic sites on dried brown algae Cystoseira barbata using FTIR and potentiometric titrations, and to investigate the biosorption ability of biomass towards divalent nickel, cadmium, and lead ions. Adsorption was studied as a function of solution pH and contact time, and experimental data were evaluated by the Langmuir isotherm model. CaCl(2) pretreatment was applied to the sorbent for enhancing the metal uptake capacity. The effect of solution pH on biosorption equilibrium was investigated in the pH range of 1.5-5.0. Individual as well as competitive adsorption capacity of the sorbent were studied for metal cations and mixtures. The retention of the tested metal ions was mostly influenced from pH in the range of 1.5-2.5, then stayed almost constant up to 5.0, while Ni(II) uptake showed the highest variation with pH. Potentiometric titrations were performed to find the number of strong and weak acidic groups and their acidity constants. The density of strong and weak acidic functional groups in the biomass were found to be 0.9 and 2.26 mmol/g, respectively. The FTIR spectra of the sorbent samples indicated various functionalities on the biomass surface including carboxyl, hydroxyl, and amino and sulphonate groups which are responsible for the binding of metal ions. The capacity of the biomass for single metal ions (around 1 mmol/g) was increased to 1.3 mmol/g in competitive adsorption, Pb(II) showing the highest Langmuir intensity constant. Considering its extremely high abundance and low cost, C. barbata may be potentially important in metal ion removal from contaminated water and industrial effluents.

  20. Biosorption of Cr (VI), Cr (III), Pb (II) and Cd (II) from aqueous solutions by Sargassum wightii and Caulerpa racemosa algal biomass

    Science.gov (United States)

    Tamilselvan, Narayanaswamy; Saurav, Kumar; Kannabiran, Krishnan

    2012-03-01

    Heavy metal pollution is one of the most important environmental problems today. Biosorption is an innovative technology that employs biological materials to accumulate heavy metals from waste water through metabolic process or physicochemical pathways of uptake. Even though several physical and chemical methods are available for removal of heavy metals, currently many biological materials such as bacteria, algae, yeasts and fungi have been widely used due to their good performance, low cost and large quantity of availability. The aim of the present study is to explore the biosorption of toxic heavy metals, Cr(VI), Cr(III), Pb(II) and Cd(II) by algal biomass obtained from algae Sargassum wightii (brown) and Caulerpa racemosa (green). Biosorption of algal biomass was found to be biomass concentration- and pH-dependent, while the maximal biosorption was found at pH 5.0 and with the metal concentration of 100 mg L-1. S. wightii showed the maximal metal biosorption at the biomass concentration of 25 g L-1, followed by C. racemosa with the maximal biosorption at 30 g L-1. S. wightii showed 78% biosorption of Cr(VI), Cr(III), Pb(II) and Cd(II) ions. C. racemosa exhibited 85% biosorption of Cd(II) and Cr(VI), and 50% biosorption of Cr(III) and Pb(II). The results of our study suggest that seaweed biomass can be used efficiently for biosorption of heavy metals.

  1. 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)

  2. 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)

  3. Mechanisms for biosorption of chromium(III), copper(II) and mercury ...

    African Journals Online (AJOL)

    This shows that the softer metal ions, copper(II) and mercury(II), form complexes with oxygen and/or nitrogen donor ligands in the MO extracts, while the harder and more highly charged chromium(III) ion becomes hydrolysed. The study therefore suggests that the successful biosorption of heavy metals by Moringa, ...

  4. 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.

  5. 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.

  6. 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.

  7. Biosorption of Cr (III) from aqueous solution by the leaf biomass of ...

    African Journals Online (AJOL)

    Michael Horsfall

    initial metal ion concentration and temperature were also found to influence the biosorption process. Both. Langmuir and Freundlich isotherms .... or adsorb metallic macromolecules and therefore expected to sorb heavy metals from ..... active sites on the biosorbent surface due to bond ruptures (Meena et al., 2005; Sari ...

  8. 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.

  9. The effect of silica concentration on the biosorption of Cu2+ and ...

    African Journals Online (AJOL)

    2009-10-26

    Oct 26, 2009 ... exchange, oxidation, reduction and reverse osmosis (Bueno et al., 2008). Metal uptake by biosorption is complex and may involve the contribution of diffusion, adsorption, chelation, complexa- tion, coordination and microprecipitation mechanisms, depend- ing on the specific biomass or substrate (Veglio ...

  10. Biosorption of aquatic copper (II) by mushroom biomass Pleurotus eryngii: kinetic and isotherm studies.

    Science.gov (United States)

    Kan, Shi-Hong; Sun, Bai-Ye; Xu, Fang; Song, Qi-Xue; Zhang, Sui-Fang

    2015-01-01

    Biosorption is an effective method for removing heavy metals from effluent. This work mainly aimed to evaluate the adsorption performance of the widely cultivated novel mushroom, Pleurotus eryngii, for the removal of Cu(II) from single aqueous solutions. Kinetics and equilibria were obtained using a batch technique. The sorption kinetics follows the pseudo-second-order model, whereas the adsorption equilibria are best described by the Langmuir model. The adsorption process is exothermic because both the Langmuir-estimated biosorption capacity and the heat of adsorption estimated from the Temkin model decreased with increasing tested temperature. Based on the adsorption intensity estimated by the Freundlich model and the mean adsorption free energy estimated by the Dubinin-Radushkevich model, the type of adsorption is defined as physical adsorption. The biomass of the macro-fungus P. eryngii has the potential to remove Cu(II) from a large-scale wastewater contaminated by heavy metals, because of its favorable adsorption, short biosorption equilibrium time of 20 min and remarkable biosorption capacity (15.19 mg g⁻¹ as calculated by the Langmuir model). The adsorbed metal-enriched mushroom is a high-quality bio-ore by the virtue of its high metal content of industrial mining grade and easy metal extractability.

  11. Biosorption of lead using Bacillus badius AK strain isolated from compost of green waste (water hyacinth).

    Science.gov (United States)

    Vishan, Isha; Sivaprakasam, Senthilkumar; Kalamdhad, Ajay

    2017-07-01

    The bacterial strain Bacillus badius AK isolated from water hyacinth compost was investigated for biosorption characteristics in Pb(II) removal. Batch mode experiments depicted the optimum conditions for biosorption as pH at 4, the temperature of 30°C, 150 rpm of the rotational speed at biomass concentration of 20 mL with 1.7 × 10 16  colony forming unit per milliliter (CFU/mL) value, at 100-150 mg/L concentration of Pb(II). The bacterial biomass was used in its native and non-pretreated state, unlike the dried, freeze-dried or chemically treated biomass. The biosorption followed pseudo-second-order kinetics and isotherm fitted well to the Langmuir model. Maximum Pb(II) biosorption was observed at 1.7 × 10 16  CFU/mL. Influence of Pb(II) on the growth of bacterial biomass was examined by fitting the monod's model. Specific growth rate and maximum specific growth rate of B. badius AK was observed as 0.05 and 2.54 h -1 , respectively; biomass yield coefficient was 11.81. The results indicated that bacterial biomass was efficient, robust and cheaper biosorbent for removal of Pb(II).

  12. 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 ...

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

    African Journals Online (AJOL)

    Conventional water treatment technologies for the removal of fluoride ion may not be feasible for developing countries due to their high investment and operational costs. The aim of this study was therefore, to investigate the fluoride biosorption potential of the seeds of the cabbage tree (Moringa stenopetala). The influence ...

  14. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption.

    Science.gov (United States)

    Andreazza, R; Pieniz, S; Okeke, B C; Camargo, F A O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09'53.92″S and 51°31'39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29'43.48″S and 53'32'37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L(-1) in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  15. 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)

  16. selection of biosorbents for biosorption of three heavy metals in a ...

    African Journals Online (AJOL)

    eobe

    affecting biosorption capacity also known as metal uptake capacity also known as metal uptake capacity ... initial ion concentration of heavy metals, mass of biosorbent and contact time were investigated. The removal stigated. The removal ..... metals: accumulation of uranium by Saccharamyces cervisea and Pseudomonas ...

  17. 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)

  18. Study of the removal of paraquat from aqueous solution by biosorption onto Ayous (Triplochiton schleroxylon) sawdust

    Energy Technology Data Exchange (ETDEWEB)

    Nanseu-Njiki, Charles Peguy; Dedzo, Gustave Kenne [Laboratoire de Chimie Analytique, Faculte des Sciences, Universite de Yaounde I, B.P. 812 Yaounde (Cameroon); Ngameni, Emmanuel, E-mail: engameni@yahoo.fr [Laboratoire de Chimie Analytique, Faculte des Sciences, Universite de Yaounde I, B.P. 812 Yaounde (Cameroon)

    2010-07-15

    This study concerns the batch biosorption of paraquat on Ayous (Triplochiton schleroxylon) sawdust; the study centers on the evolution of biosorption parameters during the process. It appears that paraquat forms a monolayer on the sawdust surface as evidenced by the good correlation between the experimental data and the Langmuir model. The biosorption which is rather fast (the equilibrium was reached after ten minutes) follows a pseudo-second-order kinetic model and does not obey to the intra-particle diffusion model. According to the mathematical kinetic modeling, pore and surface mass transfer well describe the phenomenon. NaCl reduces the adsorption capacity of the material but has no significant effect on the kinetics. Alkaline solutions enhance the accumulation of the pollutant, the reverse being observed for acidic media. According to the thermodynamic data, this biosorption is a spontaneous and exothermic process. From these results we concluded that the adsorption of the pollutant is mainly due to cation exchange as indicated by the adsorption energy determined by the Dubinin-Radushkevich model (E = 12.0736 kJ mol{sup -1}); some other interactions resulting from the affinity through organophilic interactions between paraquat and sawdust have also been pointed out. Desorption experiments conducted in HCl and HNO{sub 3} solutions confirmed the proposed mechanism.

  19. Study of the removal of paraquat from aqueous solution by biosorption onto Ayous (Triplochiton schleroxylon) sawdust

    International Nuclear Information System (INIS)

    Nanseu-Njiki, Charles Peguy; Dedzo, Gustave Kenne; Ngameni, Emmanuel

    2010-01-01

    This study concerns the batch biosorption of paraquat on Ayous (Triplochiton schleroxylon) sawdust; the study centers on the evolution of biosorption parameters during the process. It appears that paraquat forms a monolayer on the sawdust surface as evidenced by the good correlation between the experimental data and the Langmuir model. The biosorption which is rather fast (the equilibrium was reached after ten minutes) follows a pseudo-second-order kinetic model and does not obey to the intra-particle diffusion model. According to the mathematical kinetic modeling, pore and surface mass transfer well describe the phenomenon. NaCl reduces the adsorption capacity of the material but has no significant effect on the kinetics. Alkaline solutions enhance the accumulation of the pollutant, the reverse being observed for acidic media. According to the thermodynamic data, this biosorption is a spontaneous and exothermic process. From these results we concluded that the adsorption of the pollutant is mainly due to cation exchange as indicated by the adsorption energy determined by the Dubinin-Radushkevich model (E = 12.0736 kJ mol -1 ); some other interactions resulting from the affinity through organophilic interactions between paraquat and sawdust have also been pointed out. Desorption experiments conducted in HCl and HNO 3 solutions confirmed the proposed mechanism.

  20. 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 ...

  1. 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

  2. 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

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

    Science.gov (United States)

    Sun, Xiang-Yu; Zhao, Yu; 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. Biosorption of diazinon by a pre-treated alimentary industrial waste: equilibrium and kinetic modeling

    Science.gov (United States)

    Yeddou Mezenner, N.; Lagha, H.; Kais, H.; Trari, M.

    2017-11-01

    This study explores the feasibility of pre-treated coffee waste (PCW) as biosorbent for the removal of diazinon. The effect of the pesticide concentration (6-20 mg L-1), contact time, adsorbent dose (0.2-1.2 g L-1), solution pH (3-11.5), temperature (15-40 °C) and co-existing inorganic ions (H2PO4 -, NO3 -) on the diazinon biosorption over PCW is investigated. The experimental results indicate an optimal pH of 7.3 for the diazinon elimination on PCW (1 g L-1). The Langmuir model describes well the isotherm data with a high regression coefficient ( R 2 > 0.990) and a maximum monolayer biosorption capacity of 18.52 mg g-1 at 15 °C. It is also observed that the intra-particle diffusion is not the rate-controlling step. A comparison is evaluated between the pseudo-second-order and intra-particle diffusion kinetic models; the experimental data are well fitted by the pseudo-second-order kinetic model. The biosorption capacity decreases with increasing temperature for a diazinon concentration of 10 mg L-1. The negative enthalpy Δ H° (-63.57 kJ/mol) indicates that the diazinon biosorption onto PCW is exothermic. Under optimal conditions, the biosorption reaches 95% after 90 min. The removal efficiency decreases from 95 to 65.67 and 48.9% for the diazinon alone and in the presence of NO3 - and H2PO4 - (100 mg L-1), respectively.

  9. 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. (author)

  10. Diminished aversive classical conditioning in pathological gamblers.

    Science.gov (United States)

    Brunborg, Geir Scott; Johnsen, Bjørn Helge; Mentzoni, Rune Aune; Myrseth, Helga; Molde, Helge; Lorvik, Ingjerd Meen; Bu, Eli Torild Hellandsjø; Pallesen, Ståle

    2012-09-01

    Impaired ability to form associations between negative events in gambling and aversive somatic reactions may be a predisposing factor for pathological gambling. The current study investigated whether a group of pathological gamblers and a control group differed in aversive classical conditioning. A differential aversive classical conditioning paradigm, which consisted of three phases. In the habituation phase, one 850-Hz tone stimulus and one 1500-Hz tone stimulus were presented three times each in random order. In the acquisition phase, the two tones were presented 10 times each in random order, and one was always followed by a 100-dB burst of white noise. In the extinction phase the two tones were presented three times each without the white noise. University laboratory testing facilities and out-patient treatment facilities. Twenty pathological gamblers and 20 control participants. Duration of seven cardiac interbeat-intervals (IBIs) following tone offset, gambling severity, tobacco and alcohol use, anxiety and depression. No group differences were found in the habituation and acquisition phases. However, a significant group × stimuli × trials × IBIs interaction effect was found in the extinction phase (P classical conditioning, but that the control group did. Pathological gamblers have a diminished capacity to form associations between aversive events and stimuli that predict aversive events. Aversion learning is likely to be an ineffective treatment for pathological gamblers. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

  11. 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.

  12. Equilibrium and kinetic studies of Cd²⁺ biosorption by the brown algae Sargassum fusiforme.

    Directory of Open Access Journals (Sweden)

    Hui-Xi Zou

    Full Text Available A fundamental investigation of the biosorption of Cd2+ from aqueous solution by the edible seaweed Sargassum fusiforme was performed under batch conditions. The influences of experimental parameters, such as the initial pH, sorption time, temperature, and initial Cd2+ concentration, on Cd2+ uptake by S. fusiforme were evaluated. The results indicated that the biosorption of Cd2+ depended on the initial Cd2+ concentration, as well as the pH. The uptake of Cd2+ could be described by the Langmuir isotherm model, and both the Langmuir biosorption equilibrium constant and the maximum biosorption capacity of the monolayer decreased with increasing temperature, thereby confirming the exothermic character of the sorption process. The biosorption kinetics follows the pseudo-second-order kinetic model, and intraparticle diffusion is the sole rate-limiting step for the entire biosorption period. These fundamental equilibrium and kinetic results can support further studies to the removal of cadmium from S. fusiforme harvested from cadmium-polluted waters.

  13. Equilibrium and kinetic studies of Cd²⁺ biosorption by the brown algae Sargassum fusiforme.

    Science.gov (United States)

    Zou, Hui-Xi; Li, Nan; Wang, Li-Hua; Yu, Ping; Yan, Xiu-Feng

    2014-01-01

    A fundamental investigation of the biosorption of Cd2+ from aqueous solution by the edible seaweed Sargassum fusiforme was performed under batch conditions. The influences of experimental parameters, such as the initial pH, sorption time, temperature, and initial Cd2+ concentration, on Cd2+ uptake by S. fusiforme were evaluated. The results indicated that the biosorption of Cd2+ depended on the initial Cd2+ concentration, as well as the pH. The uptake of Cd2+ could be described by the Langmuir isotherm model, and both the Langmuir biosorption equilibrium constant and the maximum biosorption capacity of the monolayer decreased with increasing temperature, thereby confirming the exothermic character of the sorption process. The biosorption kinetics follows the pseudo-second-order kinetic model, and intraparticle diffusion is the sole rate-limiting step for the entire biosorption period. These fundamental equilibrium and kinetic results can support further studies to the removal of cadmium from S. fusiforme harvested from cadmium-polluted waters.

  14. Biosorptive removal of mercury(II) from aqueous solution using lichen (Xanthoparmelia conspersa) biomass: Kinetic and equilibrium studies

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa; Sari, Ahmet; Mendil, Durali [Department of Chemistry, Gaziosmanpasa University, 60250, Tokat (Turkey); Soylak, Mustafa, E-mail: soylak@erciyes.edu.tr [Department of Chemistry, Erciyes University, 38039, Kayseri (Turkey)

    2009-09-30

    The potential use of the lichen biomass (Xanthoparmelia conspersa) to remove mercury(II) ions from aqueous solution by biosorption was evaluated using the batch method. Effects of pH, contact time, biomass concentration and temperature on the removal of Hg(II) ions were studied. The Langmuir isotherm models defined the equilibrium data precisely compared to Freundlich model and the maximum biosorption capacity obtained was 82.8 mg g{sup -1}. From the D-R isotherm model, the mean free energy was calculated as 9.5 kJ mol{sup -1}. It shows that the biosorption of Hg(II) ions onto X. conspersa biomass was taken place by chemical ion-exchange. Experimental data were also performed to the pseudo-first-order and pseudo-second-order kinetic models. The results indicated that the biosorption of Hg(II) on the lichen biomass followed well the second-order kinetics. Thermodynamic parameters, {Delta}G{sup o}, {Delta}H{sup o} and {Delta}S{sup o} indicated the Hg(II) sorption to be exothermic and spontaneous with decreased randomness at the solid-solution interface. Furthermore, the lichen biomass could be regenerated using 1 M HCl, with up to 85% recovery, which allowed the reuse of the biomass in ten biosorption-desorption cycles without any considerable loss of biosorptive removal capacity.

  15. 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.

  16. Influence of pH value on Cu (II biosorption by lignocellulose peach shell waste material

    Directory of Open Access Journals (Sweden)

    Lopičić Zorica R.

    2013-01-01

    Full Text Available In the last decade, the pollution made by anthropogenic sources has reached large amounts with special attention on heavy metals because of their high toxicity, persistence and bioaccumulation tendency. Since the conventional methods for their removing are either too expensive or create large quantities of toxic sludge, the great attention has been paid to the new technologies such as biosorption, technology that use cheap, abundant, organic waste for sequestering pollutants from contaminated mediums. Among the other factors that affect biosorption process, pH value is one the most important because it directs both the metal solution chemistry as well as the activity of the biomass functional groups. In this paper the influence of pH value on biosorption of Cu (II by unmodified low-cost lignocellulose biosorbent - peach shell (PS particles, have been studied. The chemical composition of PS, point of zero charge (pHPZC as well as its surface morphology is also presented. Results have showed that this biosorbent contains mainly cellulose and lignin, the components that carry the functional groups responsible for metal binding. Its multilayer surface contains many pores and channels that help diffusion in deeper layers and force biosorption process. Point of zero charge determination was performed with three different KNO3 ionic strengths: 0,1M, 0,01M and 0,001M. The obtained value for pHPZC was 4,75±0,1 and showed that this biosorbent is non-sensitive to ionic strength of electrolyte applied. Biosorption experiments were done with peach shell particles whose diameter was -0,5+0,1mm at 25oC . The initial copper (II concentration was 50 mg/dm3 while the biosorbent concentration was 10g/dm3. Experiments were done with and without keeping pH constant. The influence of pH on biosorption process was examined in 2-6 pH range. The percentage of Cu (II removed by PS, reaches its maximum at pH 6, with the 90,43% removing but this percentage can also be

  17. Electronic Tongue-FIA system for the Monitoring of Heavy Metal Biosorption Processes

    Science.gov (United States)

    Wilson, D.; Florido, A.; Valderrama, C.; de Labastida, M. Fernández; Alegret, S.; del Valle, M.

    2011-09-01

    An automated flow injection potentiometric (FIP) system with electronic tongue detection (ET) was used for the monitoring of biosorption processes of heavy metals on waste biomaterial. Grape stalk wastes were used as biosorbent to remove Cu2+ ions in a fixed-bed column setup. For the monitoring, the used ET employed a sensor array formed by Cu2+ and Ca2+ selective electrodes and two generic heavy-metal electrodes. The subsequent cross-response obtained was processed by a multilayer artificial neural network (ANN) model in order to resolve the concentrations of the monitored species. The coupling of the electronic tongue with the automation features of the flow-injection system (ET-FIP) allowed us to accurately characterize the biosorption process, through obtaining its breakthrough curves. In parallel, fractions of the extract solution were analyzed by atomic absorption spectroscopy in order to validate the results obtained with the reported methodology.

  18. 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.

  19. Biosorption of lead by filamentous fungal biomass-loaded TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bakircioglu, Yasemin, E-mail: ybakircioglu@trakya.edu.tr [Trakya University, Faculty of Art and Science, Department of Chemistry, 22030 Edirne (Turkey); Bakircioglu, Dilek [Trakya University, Faculty of Art and Science, Department of Chemistry, 22030 Edirne (Turkey); Akman, Suleyman [Istanbul Technical University, Faculty of Art and Science, Department of Chemistry, Maslak, Istanbul (Turkey)

    2010-06-15

    In this study filamentous fungal biomass-loaded TiO{sub 2} nanoparticles were used for the biosorption of lead(II) ions by flow-injection system coupled to flame atomic absorption spectrometry. The effects of pH, sample volume, loading and elution flow rates, eluent type and volume on the recovery of lead were investigated. Lead ions were sorbed on a biosorbent minicolumn at pH 4.0 followed by an elution step using 288 {mu}L of 1.0 mol/L hydrochloric acid solution. The limit of detection was 0.78 {mu}g/L. The validation of the described procedure was performed by the analysis of certified reference material (NRC-CNRC NASS-5 seawater). Finally, the presented biosorption procedure was applied to the determination of lead in tap water and seawater samples.

  20. Biosorption of copper(II) by nonliving lichen biomass of Cladonia rangiformis hoffm

    Energy Technology Data Exchange (ETDEWEB)

    Ekmekyapar, Fatma [Engineering Faculty, Department of Environmental Engineering, Atatuerk University, Erzurum 25240 (Turkey)]. E-mail: fyapar@atauni.edu.tr; Aslan, Ali [Education Faculty, Department of Biology, Atatuerk University, Erzurum 25240 (Turkey); Bayhan, Y. Kemal [Engineering Faculty, Department of Environmental Engineering, Atatuerk University, Erzurum 25240 (Turkey); Cakici, Avni [Engineering Faculty, Department of Environmental Engineering, Atatuerk University, Erzurum 25240 (Turkey)

    2006-09-01

    Biosorption of heavy metals can be an effective process for the removal of heavy metal ions from aqueous solutions. In this study, the adsorption properties of lichen biomass of Cladonia rangiformis hoffm. for copper(II) were investigated by using batch adsorption techniques. The effects of initial metal ion concentration, initial pH, biosorbent concentration, stirring speed and contact time on biosorption efficiency were studied. In the experiments the optimum pH value was found out 5.0 which was the native pH value of solution. The experimental adsorption data were fitted to the Langmuir adsorption model. The highest metal uptake was calculated from Langmuir isotherm and found to be 7.6923 mg Cu(II)/g inactivated lichen at 15 deg. C. The results indicated that the biomass of C. rangiformis is a suitable biosorbent for removing Cu(II) from aqueous solutions.

  1. 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

  2. Biosorption of heavy metals by marine algae Ulva rigida, Cystoseira barbata and C. crinita

    Directory of Open Access Journals (Sweden)

    A. Simeonova

    2007-06-01

    Full Text Available Adsorption properties of three different marine algae (Ulva rigida (green algae; Cystoseira barbata (brown algae and Cystoseira crinita (brown algae were investigated. They were collected from the Black Sea coastal area in Varna region, Bulgaria. Kinetics were studied to evaluate the ability of the three algae to sequester Cu (II, Zn (II, Pb (II, Ni (II, Cd (II from aqueous solution. The maximum biosorption capacity obtained was 2.84 mgeq Ni2+/g for Cystoseira crinita and 2.28 mgeq Cu2+/g for Cystoseira barbata at a solution pH of 5 ± 0.5. The influence of pH of the solution and algae mass on the heavy metal sorption was investigated either. Desorption using 0.05 M HNO3 was carried out and was determined that regeneration of biomass for use in multiple cycles of Cd (II biosorption –desorption should be feasible.

  3. Modeling of chromium (VI) biosorption by immobilized Spirulina platensis in packed column.

    Science.gov (United States)

    Gokhale, S V; Jyoti, K K; Lele, S S

    2009-10-30

    This study describes biosorption of chromium (VI) by immobilized Spirulina platensis, in calcium alginate beads. Three aspects viz. optimization of bead parameters, equilibrium conditions and packed column operation were studied and subsequently modeled. Under optimized bead diameter (2.6mm), calcium alginate concentration (2%, w/v) and biomass loading (2.6%, w/v) maximum biosorption was achieved. 140 g l(-1) loading of optimized beads resulted in 99% adsorption of chromium (VI) ions from an aqueous solution containing 100 mg l(-1) of chromium (VI). The quantitative chromium (VI) uptake was effectively described by Freundlich adsorption isotherm. The immobilized S. platensis beads were further used in a packed bed column wherein the effects of bed height, feed flow rate, inlet chromium (VI) ion concentration were studied by assessing breakthrough time. The performance data were tested for various models fitting in order to predict scale up-design parameters such as breakthrough time and column height. Results were encouraging.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mata, Y.N. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid s/n, Madrid 28040 (Spain); Blazquez, M.L. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid s/n, Madrid 28040 (Spain)], E-mail: mlblazquez@quim.ucm.es; Ballester, A.; Gonzalez, F.; Munoz, J.A. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid s/n, Madrid 28040 (Spain)

    2008-10-30

    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 {approx} 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.

  5. 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.

  6. Selective biosorption of thorium (IV) from aqueous solutions by ginkgo leaf

    Science.gov (United States)

    Huang, Yaoyao; Hu, Yang; Chen, Lvcun; Yang, Tao; Huang, Hanfang; Shi, Runping; Lu, Peng

    2018-01-01

    Low–cost biosorbents (ginkgo leaf, osmanthus leaf, banyan leaf, magnolia leaf, holly leaf, walnut shell, and grapefruit peel) were evaluated in the simultaneous removal of La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Yb3+, Lu3+, UO22+, Th4+, Y3+, Co2+, Zn2+, Ni2+, and Sr2+ from aqueous solutions. In single metal systems, all adsorbents exhibited good to excellent adsorption capacities toward lanthanides and actinides. In a simulated multicomponent mixed solution study, higher selectivity and efficiency were observed for Th4+ over other metal cations, with ginkgo leaves providing the highest adsorptivity (81.2%) among the seven biosorbents. Through optimization studies, the selectivity of Th4+ biosorption on ginkgo leaf was found to be highly pH–dependent, with optimum Th4+ removal observed at pH 4. Th4+ adsorption was found to proceed rapidly with an equilibrium time of 120 min and conform to pseudo–second–order kinetics. The Langmuir isotherm model best described Th4+ biosorption, with a maximum monolayer adsorption capacity of 103.8 mg g–1. Thermodynamic calculations indicated that Th4+ biosorption was spontaneous and endothermic. Furthermore, the physical and chemical properties of the adsorbent were determined by scanning electron microscopy, Brunauer–Emmett–Teller, X-ray powder diffraction, and Fourier transform infrared analysis. The biosorption of Th from a real sample (monazite mineral) was studied and an efficiency of 90.4% was achieved from nitric acid at pH 4 using ginkgo leaves. PMID:29509801

  7. Biosorption of Cu(II) ions from aqueous effluents by blackgram bran (BGB).

    Science.gov (United States)

    Nadeem, Raziya; Hanif, Muhammad Asif; Mahmood, Abid; Jamil, Muhammad Salman; Ashraf, Muhammad

    2009-09-15

    Biosorption of Cu(II) ions onto blackgram bran (BGB) waste biomass in a well stirred batch system was investigated and optimum conditions were determined. The maximum Cu(II) uptake capacity of BGB was 107.65 mg L(-1) at pH 5, biosorbent dose 0.025 g/100mL, biosorbent particle size BGB biomass proved to be an excellent material of bioorigin for accumulating Cu(II) ions from aqueous solutions.

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

    OpenAIRE

    D. Sivakumar

    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 pH, fungi biomass and chromium(VI) concentration (dilution ratio).  The results of this study indicated that the order of ...

  9. 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.

  10. 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.

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

    International Nuclear Information System (INIS)

    Vimala, R.; Das, Nilanjana

    2009-01-01

    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 max 34.96 mg/g) whereas A. bisporus exhibited maximum potential for lead (q 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.

  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 anionic textile dyes from aqueous solution by yeast slurry from brewery

    Directory of Open Access Journals (Sweden)

    Ketinny Camargo de Castro

    2017-05-01

    Full Text Available ABSTRACT This study investigated the biosorption of the anionic textile dyes: Reactive Red 239 (RR239, Reactive Black B (RBB and Direct Blue 85 (DB85 according to pH, biomass dosage, contact time and dye concentration onto waste beer yeast slurry. The kinetics and isotherm of the removal of dyes were also studied. The equilibrium of biosorption reaction was reached after 30 min for the reactive dyes and after 60 min for the direct dye. Optimum decolorization was observed at pH 2 and 0.63 g/L of biomass dosage. The kinetic data of the three dyes were better described by the pseudo second-order model. The adsorption process followed the Langmuir isotherm model and the biosorption capacity being estimated to be 152.9, 162.7 and 139.2 mg/g for RR239, RBB and DB85, respectively. Our findings indicated that the waste beer yeast slurry was an attractive low-cost biosorbent for the removal of anionic textile dyes from aqueous solution.

  14. 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.

  15. 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

  16. The antipsychiatry movement: dead, diminishing, or developing?

    Science.gov (United States)

    Whitley, Rob

    2012-10-01

    It has been argued recently that the antipsychiatry movement has transmogrified into a patient-based consumer movement. Instead, the author suggests, various activities and ideas that legitimately could be described as antipsychiatry, or, at least, as highly critical of psychiatry, are burgeoning. These activities include the works of intellectual scholars, such as disgruntled psychiatrists, critical social scientists, and humanistic psychologists; the analyses and writings of high-profile and prominent investigative journalists; blogs, Web sites, and social media that communicate a disdain for psychiatry among citizen Internet activists; and the ongoing, well-documented critique of followers of Scientology. The author concludes that a renewed yet amorphous critique of psychiatry is emerging, even though the tarnished name of antipsychiatry is studiously avoided by all. This critique may intensify, given the likely media and public interest surrounding the upcoming release of DSM-5.

  17. 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.

  18. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Science.gov (United States)

    Yao, Chunxiang; Behring, Jessica B; Shao, Di; Sverdlov, Aaron L; Whelan, Stephen A; Elezaby, Aly; Yin, Xiaoyan; Siwik, Deborah A; Seta, Francesca; Costello, Catherine E; Cohen, Richard A; Matsui, Reiko; Colucci, Wilson S; McComb, Mark E; Bachschmid, Markus M

    2015-01-01

    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.

  19. 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.

  20. Global smoothness preservation and the variation-diminishing property

    Directory of Open Access Journals (Sweden)

    Gavrea Ioan

    1999-01-01

    Full Text Available In the center of our paper are two counterexamples showing the independence of the concepts of global smoothness preservation and variation diminution for sequences of approximation operators. Under certain additional assumptions it is shown that the variation-diminishing property is the stronger one. It is also demonstrated, however, that there are positive linear operators giving an optimal pointwise degree of approximation, and which preserve global smoothness, monotonicity and convexity, but are not variation-diminishing.

  1. A study on biosorption of copper ions by fungal chitosan: an alternative to shrimp chitosan

    Directory of Open Access Journals (Sweden)

    Sanaz Behnam

    2015-02-01

    Full Text Available   Introduction : One of the main applications of chitosan is for heavy metals removal from waste waters. Industrially, chitosan is produced through deacetylation of chitin present in shellfish waste. Another source of chitosan is the cell wall of zygomycetes fungi with several advantages over shellfish wastes .   Materials and method s: Fungal chitosan purified from biomass of Mucor indicus and shrimp chitosan were applied and compared for removal of copper ions from aqueous solution. The effects of pH (3 to 5.5, copper ion concentration (5 to 52 mg l-1, the amount of chitosan (200 to 3000 mg l-1, adsorption time, temperature, and presence of other metal ions on the biosorption of Cu2+ were investigated .   Results : Maximum adsorption capacities for fungal and shrimp chitosans were 58.5 and 60.7 mg g-1, respectively. T he rate of copper adsorption by the fungal chitosan was significantly higher than that by the shrimp chitosan. Among p seudo-first order, pseudo-second order, intra-particle diffusion, and Elovich models, Ho’s pseudo-second order model was the best model for fitting the kinetic data. The adsorption capacity increased for both types of chitosans by increasing the solution pH. However, temperature and presence of other ions did not show significant effects on the biosorption capacity of copper. The isotherm data were very well described by Langmuir, Freundlich, and Redlich-Peterson models .   Discussion and conclusion : Both fungal and shrimp chitosans can effectively be used for removal of copper ions from aqueous solutions. Adsorption process for fungal chitosan is fast, while the process is slower for the shrimp chitosan. Therefore, from the kinetics point of view, the fungal chitosan is preferable compared with the shrimp chitosan . Key words: Biosorption, Copper, Fungal chitosan, Shrimp chitosan, Water treatment .

  2. 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.

  3. 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

  4. 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.

  5. 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...

  6. 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.

  7. 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; 2NMR, Institute for Biological Interfaces 4 and Institute for Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, Adenauerring 20b, 76131 Karlsruhe (Germany))" data-affiliation=" (Pro2NMR, Institute for Biological Interfaces 4 and Institute for Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, Adenauerring 20b, 76131 Karlsruhe (Germany))" >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 3 O 4 -NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe 3 O 4 -NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe 3 O 4 -NP at short contact times (5 min) in flow cells and complementary, scFe 3 O 4 -NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe 3 O 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 3 O 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 3 O 4 -NP, but less on the contact time. Most scFe 3 O 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 3 O 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

  8. 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.

  9. 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.

  10. Biosorption of Cr(VI), Ni(II) and Fe(II) by maize ( zea mays ) cob ...

    African Journals Online (AJOL)

    The experimental results for the biosorption of Cr(VI), Ni(II) and Fe(II) onto maize cob were reported. The adsorbents efficiency on the bioremediation of these metals was estimated from the change in the percent adsorbate removal with (i) adsorbent dosage (ii) adsorbate initial concentration, (iii) variation in pH of the ...

  11. 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

  12. 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

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, Ayla [University of Mersin, Department of Chemical Engineering, 33343 Ciftlikkoey-Mersin (Turkey)]. E-mail: ayozer@mersin.edu.tr; Akkaya, Goenuel [University of Mersin, Department of Chemical Engineering, 33343 Ciftlikkoey-Mersin (Turkey); Turabik, Meral [University of Mersin, Higher Vocational School of Mersin, Chemical Prog., Ciftlikkoey-Mersin (Turkey)

    2006-07-31

    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.

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

    Science.gov (United States)

    Ozer, Ayla; Akkaya, Gönül; Turabik, Meral

    2006-07-31

    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 degrees C and 3.0, 25 degrees 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.

  16. TREATMENT OF ACID MINE DRAINAGE: I. EQUILIBRIUM BIOSORPTION OF ZINC AND COPPER ON NON-VIABLE ACTIVATED SLUDGE

    Science.gov (United States)

    Biosorption is potentially attractive technology for treament of acid mine drainage for separation/recovery of metal ions and mitigation of their toxicity to sulfate reducing bacteria. This study describes the equilibrium biosorptio of Zn(II) and CU(II) by nonviable activated slu...

  17. 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

  18. Assessment of Biosorption Activated Media Under Roadside Swales for the Removal of Phosphorus from Stormwater

    Directory of Open Access Journals (Sweden)

    Andrew Hood

    2013-01-01

    Full Text Available Stormwater runoff from highways is a source of pollution to surface water bodies and groundwater. Excess loadings of phosphorus in stormwater discharged to surface water bodies can result in eutrophication. Treatment of stormwater for phosphorus is necessary in order to sustain ecological and economical benefits related to aquatic resources. If phosphorus is removed, the water can be sustained for other uses, such as irrigation and industrial applications. The data presented in this paper is used to evaluate the treatment performance of a roadside biosorption activated media system with regards to the removal of total phosphorus and soluble reactive phosphorus from highway runoff. The evaluation also compares removal efficiencies and effluent concentrations using biosorption activated media (BAM to that with sandy soil commonly found in the Florida area. The results presented in this paper indicate that BAM bio-filtration systems are a feasible treatment method for removing phosphorus from highway runoff. A discussion concerning the additional treatment and reuse of water by harvesting, as part of a Bio-filtration & Harvesting Swale System, is also presented in the paper.

  19. Biosorption of metal ions from aqueous solution and tannery effluent by Bacillus sp. FM1.

    Science.gov (United States)

    Masood, Farhana; Malik, Abdul

    2011-01-01

    The metal binding capacity of Bacillus sp. FM1 isolated from soil irrigated with tannery effluent was assessed using synthetic metal solutions and tannery wastewater. Biosorption of Cr(VI) and Cu(II) ions from aqueous solutions using Bacillus was investigated as a function of pH, initial metal ion concentration and contact time. The optimum adsorption pH value observed for Cr(VI) and Cu(II) ions was 2 and 5, respectively. Metal ion uptake increased with increasing initial metal concentration but no significant difference was observed by increasing the time after 60 min. Maximum uptake capacity of chromium was estimated as 64.102 mg g(-1), and of copper to 78.125 mg g(-1). Equilibrium data were well described by the Langmuir and Freundlich adsorption relations. The presence of functional groups on the cell wall surface of the biomass that may interact with the metal ion was confirmed by Fourier Transform Infrared (FTIR) spectroscopy. The application of Bacillus to remove Cr(VI) and Cu(II) in tannery effluent revealed that the biomass was capable of removing both the metal ions. However, the biosorption performance was slightly lower compared to that of synthetic metal solutions. Several factors may be responsible for this difference. However, the most important factor appears to be the presence of other contaminants such as anions, organics, and other trace metals in the effluent.

  20. Potentiometric electronic tongue-flow injection analysis system for the monitoring of heavy metal biosorption processes.

    Science.gov (United States)

    Wilson, D; del Valle, M; Alegret, S; Valderrama, C; Florido, A

    2012-05-15

    An automated flow injection potentiometric (FIP) system with electronic tongue detection (ET) is used for the monitoring of biosorption processes of heavy metals on vegetable wastes. Grape stalk wastes are used as biosorbent to remove Cu(2+) ions in a fixed-bed column configuration. The ET is formed by a 5-sensor array with Cu(2+) and Ca(2+)-selective electrodes and electrodes with generic response to heavy-metals, plus an artificial neural network response model of the sensor's cross-response. The real-time monitoring of both the Cu(2+) and the cation exchanged and released (Ca(2+)) in the effluent solution is performed by using flow-injection potentiometric electronic tongue system. The coupling of the electronic tongue with automation features of the flow-injection system allows us to accurately characterize the Cu(2+) ion-biosorption process, through obtaining its breakthrough curves, and the profile of the Ca(2+) ion release. In parallel, fractions of the extract solution are analysed by spectroscopic techniques in order to validate the results obtained with the reported methodology. The sorption performance of grape stalks is also evaluated by means of well-established sorption models. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. 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.

  2. Biosorption of nonylphenol on dead biomass of Rhizopus arrhizus encapsulated in chitosan beads.

    Science.gov (United States)

    Lang, Weeranuch; Dejma, Chomawan; Sirisansaneeyakul, Sarote; Sakairi, Nobuo

    2009-12-01

    The nonylphenol (NP) biosorption and desorption potential for fungal biomass used under batch conditions was investigated using kinetics and isotherm models. Fungal biomass of Rhizopus arrhizus TISTR 3610 exhibited preferential uptake of NP, an endocrine disrupting chemicals. Sporangiospores, asexual spores, were immobilised in chitosan beads. The biosorption data of NP on the moist heat inactivated R. arrhizus-chitosan beads were analyzed using four popular adsorption isotherms and, by using non-linear least-regression with the solver add-in in Microsoft Excel, correlated in order with the Fritz-Schluender>Redlich-Peterson>Freundlich>Langmuir isotherms. The pseudo first-order kinetics was found to have the best fit with the experimental data. The diffusivity of NP in the R. arrhizus-chitosan beads was calculated using the shrinking core model, and the diffusivity values were in the ranges of 2.3736x10(-4)-1.8950x10(-4) cm(2) s(-1). Desorption to recover the adsorbed NP from the beads was performed in methanol and was best described using a pseudo second-order kinetic model.

  3. 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.)

  4. 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.

  5. 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.

  6. Biosorption of Cadmium and Manganese Using Free Cells of Klebsiella sp. Isolated from Waste Water

    Science.gov (United States)

    Hou, Yunnan; Cheng, Keke; Li, Zehua; Ma, Xiaohui; Wei, Yahong; Zhang, Lei; Wang, Yao

    2015-01-01

    In the present study, we evaluated a bacterium that was isolated from waste water for its ability to take up cadmium and manganese. The strain, identified both biochemically and by its 16S rRNA gene sequence as Klebsiella, was named Yangling I2 and was found to be highly resistant to heavy metals. Surface characterization of the bacterium via SEM revealed gross morphological changes, with cells appearing as biconcave discs after metal exposure rather than their typical rod shape. The effects of pH, temperature, heavy metal concentration, agitation and biomass concentration on the uptake of Cd(II) and Mn(II) was measured using atomic absorption spectrophotometry. The results showed that the biosorption was most affected by pH and incubation temperature, being maximized at pH 5.0 and 30°C, with absorption capacities of 170.4 and 114.1 mg/g for Cd(II) and Mn(II), respectively. Two models were investigated to compare the cells’ capacity for the biosorption of Cd and Mn, and the Langmuir model based on fuzzy linear regression was found to be close to the observed absorption curves and yield binding constants of 0.98 and 0.86 for Cd and Mn, respectively. This strain of Klebsiella has approximately ten times the absorption capacity reported for other strains and is promising for the removal of heavy metals from waste water. PMID:26505890

  7. 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.)

  8. Potential of Live Spirulina platensis on Biosorption of Hexavalent Chromium and Its Conversion to Trivalent Chromium.

    Science.gov (United States)

    Colla, Luciane Maria; Dal'Magro, Clinei; De Rossi, Andreia; Thomé, Antônio; Reinehr, Christian Oliveira; Bertolin, Telma Elita; Costa, Jorge Alberto Vieira

    2015-01-01

    Microalga biomass has been described worldwide according their capacity to realize biosorption of toxic metals. Chromium is one of the most toxic metals that could contaminate superficial and underground water. Considering the importance of Spirulina biomass in production of supplements for humans and for animal feed we assessed the biosorption of hexavalent chromium by living Spirulina platensis and its capacity to convert hexavalent chromium to trivalent chromium, less toxic, through its metabolism during growth. The active biomass was grown in Zarrouk medium diluted to 50% with distilled water, keeping the experiments under controlled conditions of aeration, temperature of 30°C and lighting of 1,800 lux. Hexavalent chromium was added using a potassium dichromate solution in fed-batch mode with the aim of evaluate the effect of several additions contaminant in the kinetic parameters of the culture. Cell growth was affected by the presence of chromium added at the beginning of cultures, and the best growth rates were obtained at lower metal concentrations in the medium. The biomass removed until 65.2% of hexavalent chromium added to the media, being 90.4% converted into trivalent chromium in the media and 9.6% retained in the biomass as trivalent chromium (0.931 mg.g(-1)).

  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. 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)

  11. Biosorption of heavy metals by Bacillus thuringiensis strain OSM29 originating from industrial effluent contaminated north Indian soil.

    Science.gov (United States)

    Oves, Mohammad; Khan, Mohammad Saghir; Zaidi, Almas

    2013-04-01

    The study was navigated to examine the metal biosorbing ability of bacterial strain OSM29 recovered from rhizosphere of cauliflower grown in soil irrigated consistently with industrial effluents. The metal tolerant bacterial strain OSM29 was identified as Bacillus thuringiensis following 16S rRNA gene sequence analysis. In the presence of the varying concentrations (25-150 mgl(-1)) of heavy metals, such as cadmium, chromium, copper, lead and nickel, the B. thuringiensis strain OSM29 showed an obvious metal removing potential. The effect of certain physico-chemical factors such as pH, initial metal concentration, and contact time on biosorption was also assessed. The optimum pH for nickel and chromium removal was 7, while for cadmium, copper and lead, it was 6. The optimal contact time was 30 min. for each metal at 32 ± 2 °C by strain OSM29. The biosorption capacity of the strain OSM29 for the metallic ions was highest for Ni (94%) which was followed by Cu (91.8%), while the lowest sorption by bacterial biomass was recorded for Cd (87%) at 25 mgl(-1) initial metal ion concentration. The regression coefficients obtained for heavy metals from the Freundlich and Langmuir models were significant. The surface chemical functional groups of B. thuringiensis biomass identified by Fourier transform infrared (FTIR) were amino, carboxyl, hydroxyl, and carbonyl groups, which may be involved in the biosorption of heavy metals. The biosorption ability of B. thuringiensis OSM29 varied with metals and was pH and metal concentration dependent. The biosorption of each metal was fairly rapid which could be an advantage for large scale treatment of contaminated sites.

  12. 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)

  13. 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.

  14. 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...

  15. 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

  16. 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 ...

  17. 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.

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

    African Journals Online (AJOL)

    Incidental finding of hypertension and diminished femoral pulses: short-segment stenosis of the aorta just distal to the origin of the left subclavian artery. ... Young patients may present within the first few weeks of life with poor feeding, tachypnea and lethargy. They usually progress to overt congestive heart failure and shock.

  19. Is proprioception diminished in patients with patellar tendinopathy?

    NARCIS (Netherlands)

    Groot, H.E.; van der Worp, H.; Nijenbanning, L.; Diercks, R.L.; Zwerver, J.; van den Akker-Scheek, I.

    2016-01-01

    PURPOSE: Patellar tendinopathy is a highly prevalent overuse injury, and most treatments are only effective to some extent. This persistence of complaints could be linked to changed proprioception. One study showed diminished proprioception in athletes with lateral epicondylitis. Aim of this study

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

    Directory of Open Access Journals (Sweden)

    D. Sivakumar

    2016-03-01

    Full Text Available 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 pH, 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 andan initial chromium(VI concentration of 18.125 mg/L (dilution ratio 4is 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/Lin 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  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 pH level of the medium, to achieve the highest reduction of any toxic metals from any contaminated water, wastewater and soil environment.

  1. 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.

  2. 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.

  3. Biosorption of lead (II ion from aqueous solution using dum palm kernel

    Directory of Open Access Journals (Sweden)

    Babagana Gutti

    2015-06-01

    Full Text Available Biosorption of the lead ions from aqueous solutions using dum palm kernel was studied, the lead ion removal depends on the contact time, pH and adsorbent dosage. The optimum contact time, pH and adsorbent mass with in the experimental limit of this work were 100 minutes, 6-7, and 2.5g/L respectively. The maximum percentage of lead ions removed was 87%. The data fitted well with Temkin and Langmuir models, the regression correlation were obtained to be 0.9660 and 0.8667, respectively. The biosorbent may be economical if developed further for industrial wastewater and natural contaminated water treatment. DOI: http://dx.doi.org/10.3126/ije.v4i2.12625 International Journal of Environment Vol.4(2 2015: 68-75

  4. BIOSORPTION OF METHYLENE BLUE FROM AN AQUEOUS SOLUTION BY IRON OXIDE-COATED CYSTOSEIRA BARBATA

    Directory of Open Access Journals (Sweden)

    Yeliz Ozudogru

    2016-10-01

    Full Text Available In this study, Cystoseira barbata was coated with iron oxide (Fe3O4 to obtain magnetic biomaterial and used as a sorbent material for the removal of methylene blue from aqueous solution. This biosorbent was characterized by Scanning Electron Microscopy (SEM and Fourier Transform Infrared spectroscopy (FTIR. Batch adsorption was investigated as functions of pH, contact time, initial methylene blue concentration and different temperature on biosorption. The equilibrium data was analyzed with Langmuir and Freundlich isotherms. The results showed that the maximum adsorption capacities were reached at 300 min at pH 2 and found to be 5.74 mg/g and 1.08 mg/g at 25 ºC and 45 ºC, respectively.

  5. 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

  6. 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.

  7. Cationic surfactant-modified biosorption of anionic dyes by dried Rhizopus arrhizus.

    Science.gov (United States)

    Kodal, Süheyla Pınar; Aksu, Zümriye

    2017-10-01

    The biosorption of an anionic dye Remazol Black B onto a filamentous, dried fungus, Rhizopus arrhizus, was studied in the presence of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB), which was used as a pH shifter. Without surfactant, the maximum dye uptake capacity was achieved at pH 2.0 and was 434.0 mg dye g -1 dried fungal biomass. Again, without surfactant, the highest dye uptake capacity, 27.8 mg dye g -1 dried biomass, occurred at pH 8.0 calculated from the Langmuir adsorption model. Addition of CTAB changed the pH at which the highest dye uptake was obtained. At an initial pH of 8.0 with different CTAB concentrations, the dye uptake capacity increased from 27.8 to 500.0 mg dye g -1 dried biomass. Furthermore, when 200 mg L -1 surfactant was added to the biosorption medium at pH 8.0, the amount of dye removed increased significantly. Four equilibrium adsorption models were applied to the results. The applicability of each isotherm was determined using regression correlation and fitting curves. According to the Langmuir model, without surfactant, the highest dye removal capacity at pH 8.0 was found to be 27.8 mg dye g -1 dried biomass, rising to 500.0 mg g -1 dried biomass with 200 mg L -1 CTAB.

  8. On the Issue of Age Diminished Responsibility in Criminal Law

    Directory of Open Access Journals (Sweden)

    Kuznetsova I. A.

    2014-04-01

    Full Text Available The analysis of standards of the criminal law regulating questions of age diminished responsibility is presented in article. The points of view of scientists in the field of criminal law and criminology are analysed. The problem question of a ratio of provisions of Art. 20 and Art. 22 of the criminal code of Russian Federation is designated. The option of permission of a problem question is offered

  9. Literature of Diminishment: American Regionalism and the Writing of Nature

    OpenAIRE

    Chow, Juliana

    2015-01-01

    Literature of Diminishment redefines regionalism as a philosophical approach that prefers a partial view of oneself and of others, whether human or nonhuman, rather than the comprehensive view pursued by nineteenth-century science. I show how American regionalist writings from the 1820s to 1910s adapt scientific techniques of observation to the aesthetics of the regionalist sketch. Their "sketchy" view of Nature highlights the deficiencies of knowing and nonetheless opens out to a view of bio...

  10. Metabolic reprogramming induced by ketone bodies diminishes pancreatic cancer cachexia.

    Science.gov (United States)

    Shukla, Surendra K; Gebregiworgis, Teklab; Purohit, Vinee; Chaika, Nina V; Gunda, Venugopal; Radhakrishnan, Prakash; Mehla, Kamiya; Pipinos, Iraklis I; Powers, Robert; Yu, Fang; Singh, Pankaj K

    2014-01-01

    Aberrant energy metabolism is a hallmark of cancer. To fulfill the increased energy requirements, tumor cells secrete cytokines/factors inducing muscle and fat degradation in cancer patients, a condition known as cancer cachexia. It accounts for nearly 20% of all cancer-related deaths. However, the mechanistic basis of cancer cachexia and therapies targeting cancer cachexia thus far remain elusive. A ketogenic diet, a high-fat and low-carbohydrate diet that elevates circulating levels of ketone bodies (i.e., acetoacetate, β-hydroxybutyrate, and acetone), serves as an alternative energy source. It has also been proposed that a ketogenic diet leads to systemic metabolic changes. Keeping in view the significant role of metabolic alterations in cancer, we hypothesized that a ketogenic diet may diminish glycolytic flux in tumor cells to alleviate cachexia syndrome and, hence, may provide an efficient therapeutic strategy. We observed reduced glycolytic flux in tumor cells upon treatment with ketone bodies. Ketone bodies also diminished glutamine uptake, overall ATP content, and survival in multiple pancreatic cancer cell lines, while inducing apoptosis. A decrease in levels of c-Myc, a metabolic master regulator, and its recruitment on glycolytic gene promoters, was in part responsible for the metabolic phenotype in tumor cells. Ketone body-induced intracellular metabolomic reprogramming in pancreatic cancer cells also leads to a significantly diminished cachexia in cell line models. Our mouse orthotopic xenograft models further confirmed the effect of a ketogenic diet in diminishing tumor growth and cachexia. Thus, our studies demonstrate that the cachectic phenotype is in part due to metabolic alterations in tumor cells, which can be reverted by a ketogenic diet, causing reduced tumor growth and inhibition of muscle and body weight loss.

  11. Organizational Friction: Urban Crime Control Diminish Effect Theory

    Science.gov (United States)

    2010-12-10

    titled, the Urban Crime Control Diminish Effect Theory v ACKNOWLEDGMENTS I acknowledge the almighty God the steward of all guidance. I thank my...able to use impersonators to infiltrate the Police Department simply by gaining access to their uniform. He further commented that with his... impersonate a genuine member of the police department for a considerable period of time. An opinion poll was conducted following the discovery of the

  12. Fabrication of core-shell structured magnetic nanocellulose base polymeric ionic liquid for effective biosorption of Congo red dye.

    Science.gov (United States)

    Beyki, Mostafa Hossein; Bayat, Mehrnoosh; Shemirani, Farzaneh

    2016-10-01

    Ionic liquids are considered to be a class of environmentally friendly compounds as combination of them with bioresource polymeric substances such as; cellulose, constitute emerging coating materials. Biosorption by polymeric ionic liquids exhibits an attractive green way that involves low cost and irrespective of toxicity. As a result, a novel polymeric ionic liquid has been developed by the reaction of one step synthesized Fe3O4-cellulose nanohybrid, epichlorohydrin and 1-methylimidazole and employed as a green sorbent for efficient biosorption of Congo red dye. Effective parameters on dye removing as well as their interactions were determined with response surface methodology (RSM). Congo red adsorption showed fast equilibrium time (11min) with maximum uptake of 131mgg(-1). Isotherm study revealed that Langmuir adsorption model can better describe dye adsorption behavior. Regeneration of the sorbent was performed with a mixture of methanol-acetone-NaOH (3.0molL(-1)) solution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Role of HSAB concept in understanding biosorptive behaviour of various metal ions employing green biosorbent - Dry Cow Dung Powder

    Science.gov (United States)

    Bagla, Hemlata; Khilnani, Roshan

    2016-04-01

    Hard & Soft Acid Base concept, HSAB theory given by Pearson, elucidates the crucial role of HSAB characteristics of both pollutants as well as the aqueous milieu. This theory can also explain the biosorptive behaviour of Dry Cow dung Powder, which helps in governing the success of process. The various metal ionic species exhibit a preference for the ligand binding on the biomass based on its chemical coordination characteristics. A comparative batch equilibration biosorptive assay has been carried out employing radiotracer technique for uptake of Cr(III), Cr(VI), Cd(II), Hg(II), Sr(II), Cs(I) and Co(II) at optimum biosorption parameters. To study the effect of interference of different salts on the percentage biosorption of metal ions on DCP, different organic as well as inorganic salts with varying proportion of 10 mg, 25 mg, 50 mg and 100 mg have been studied. The dynamics of the biosorption in terms of the order of the rate constant was studied applying different kinetic models. The best fitting model was Lagergren pseudo second order model. DCP, an eco-friendly humiresin, enriched with minerals, carbohydrates, fats, proteins, bile pigments, aliphatic - aromatic species such as 'Humic acid', Fulvic acid and many naturally present functional group such as carboxyl, phenols, quinols, amide etc. of both hard and soft nature, making it 'combo' in nature sorbs both concerned metal ions as well as ligands present in the system. Thus the ligands which were masking the biosorption process of heavy metal ions in this study were treated by mere increase in the dose of DCP, which successfully solves the problem without affecting efficiency of the process. This is exemplified by three very basic interactions happening in multicomponent system i.e. Synergism: Mutual enhancement; Antagonism: Mutual decrement; Non-interaction: Neutral effect. Thus DCP has a great potential in the field of water decontamination, industrial water treatment and in abatement of water pollution. So

  14. A comparative review towards potential of microbial cells for heavy metal removal with emphasis on biosorption and bioaccumulation.

    Science.gov (United States)

    Hansda, Arti; Kumar, Vipin; Anshumali

    2016-10-01

    The threat of heavy metal pollution to environmental health is getting worldwide attention due to their persistence and non-biodegradable nature. Ineffectiveness of various physicochemical methods due to economical and technical constraints resulted in the search for a cost-effective and eco-friendly biological technique for heavy metal removal from the environment. The two effective biotic methods used are biosorption and bioaccumulation. A comparison between these two processes demonstrated that biosorption is a better heavy metal removal process than bioaccumulation. This is due to the intoxication of heavy metal by inhibiting their entry into the microbial cell. Genes and enzymes related to bioremoval process are also discussed. On comparing the removal rate, bacteria are surpassed by algae and fungi. The aim of this review is to understand the biotic processes and to compare their metal removal efficiency.

  15. A model to describe Cr(VI) kinetics biosorption.

    Science.gov (United States)

    Poch, Jordi; Villaescusa, Isabel

    2010-03-15

    In this work, the effect of pH control on kinetics of Cr(VI) sorption onto grape stalks has been studied. A set of experiments were performed at a constant pH 3+/-0.1 which was assured by means of a Programmable Logic Controller (PLC). In a second set of experiments the initial pH was adjusted to pH 3 and then pH was allowed to freely evolve during the sorption process. Both sets of experiments were carried out at different temperatures within the range 5-50 degrees C. Constant temperature was assured by water recirculation from a thermostatic bath. Results demonstrated that pH has high influence on kinetics only at the lowest temperatures studied. A model based on a complex reaction sequence which takes into account Cr(VI) sorption, reduction of Cr(VI) to Cr(III), sorption of the formed Cr(III) which includes the pH variation during the sorption process has been proposed to model Cr(VI) kinetics sorption onto grape stalk waste. Furthermore, the robustness of the model has been tested. (c) 2009 Elsevier B.V. All rights reserved.

  16. Fiberotomy enhances orthodontic tooth movement and diminishes relapse in a rat model.

    Science.gov (United States)

    Young, L; Binderman, I; Yaffe, A; Beni, L; Vardimon, A D

    2013-08-01

    Accelerated orthodontic tooth movement is triggered by procedures that include mucoperiosteum flap surgery and surgical scarring of cortical bone. Our aim was to test whether fiberotomy by itself will accelerate orthodontic tooth movement and diminish relapse. In 34 Wistar rats, alveolar bone resorption and molar tooth movement were measured after fiberotomy, apical full-thickness flap without detachment of gingiva from the roots, or no surgery. Orthodontic appliance was installed at time of surgery and activated for 14 days, generating movement of the first maxillary molar buccal and then removed. Percent of sections in which alveolar bone resorption was detected was significantly higher (p accelerated orthodontic tooth movement and diminished relapse. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

    Science.gov (United States)

    Kelly, Christopher R; Grinband, Jack; Hirsch, Joy

    2007-12-05

    Media depictions of violence, although often claimed to induce viewer aggression, have not been shown to affect the cortical networks that regulate behavior. 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. 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.

  18. 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.

  19. Molecular genetic identification and metal biosorption by a Geobacillus genospecies IRKM1 isolated from Deeymand hot spring, Kerman, Iran

    Directory of Open Access Journals (Sweden)

    Asieh Dokhani

    2012-01-01

    Conclusions: The above results showed that the isolate was a member of Geobacillus spp. and the thermophilic bacteria was moderately resistant to Cu and Ni metals even though there was not any previous contamination of that biological niche. The organism exhibited highest biosorption of Cu 2+ at 65°C and Ni 2+ at 27°C. No plasmid was detected in the Geobacillus isolate.

  20. 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.

  1. 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

  2. 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.

  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. 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.

  5. 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.

  6. Immobilization of Trichosporon cutaneum R 57 Cells onto Methylcellulose/SiO2 Hybrids and Biosorption of Cadmium and Copper Ions

    Directory of Open Access Journals (Sweden)

    Georgieva N.

    2009-12-01

    Full Text Available Methylcellulose/Silica (MC/SiO2 hybrids were synthesized via poly step sol-gel method. SiO2 was included into the hybrids from two silica precursors - methyltriethoxysilane (MTES and ethyltrimethoxysilane (ETMS with different quantity of organic part-5, 20 and 50 wt.%. The filamentous yeasts Trichosporon cutaneum strain R 57 was immobilized onto the synthesized MC/SiO2 hybrids. After immobilization the hybrid materials were used in the processes of sorption of cadmium and copper ions. The obtained results of protein content analysis indicated that the amount of protein increased with increasing of MC in the hybrids. It was established that the maximal efficiency of copper and cadmium removal were observed for hybrid materials containing MTES and 50 wt.% MC - 66% and 26% respectively. For ETMS and 50 wt.% MC a high value of copper removal was 56% and for cadmium - 45% removal, respectively. FTIR analysis of free and immobilized cells with metal ions was conducted. SEM images showed successful immobilization of the yeasts cells. Second order model was employed in order to investigate the kinetics of copper and cadmium biosorption.

  7. Automatic needle insertion diminishes pain during growth hormone injection

    DEFF Research Database (Denmark)

    Main, K M; Jørgensen, J T; Hertel, N T

    1995-01-01

    Non-compliance in children receiving growth hormone (GH) treatment is often caused by pain on injection and difficulties in administration of GH. It has been suggested that automatic needle insertion diminishes pain perception. We quantitatively measured pain intensity on injection with two...... prototype pens for GH administration, providing either manual or automatic sc needle insertion, using a combined visual analogue/facial scale and a five-item scale in 18 children. With the automatic pen there was a significantly lower maximum pain score compared with the manual pen (median 28.5 versus 52.......0 mm) as well as a lower mean pain score (mean 13.7 versus 23.5 mm). The five-item scale revealed that automatic needle insertion was significantly less painful than manual insertion and 13 patients chose to continue treatment with the automatic pen. In conclusion, pain during GH injection can...

  8. Comparative biosorption of mercuric ions from aquatic systems by immobilized live and heat-inactivated Trametes versicolor and Pleurotus sajur-caju.

    Science.gov (United States)

    Arica, M Y; Arpa, C; Kaya, B; Bektaş, S; Denizli, A; Genç, O

    2003-09-01

    Trametes versicolor and Pleurotus sajur-caju mycelia immobilized in Ca-alginate beads were used for the removal of mercuric ions from aqueous solutions. The sorption of Hg(II) ions by alginate beads and both immobilized live and heat-killed fungal mycelia of T. versicolor and P. sajur-caju was studied in the concentration range of 0.150-3.00 mmol dm(-3). The biosorption of Hg(II) increased as the initial concentration of Hg(II) ions increased in the medium. Maximum biosorption capacities for plain alginate beads were 0.144+/-0.005 mmol Hg(II)/g; for immobilized live and heat-killed fungal mycelia of T. versicolor were 0.171+/-0.007 mmol Hg(II)/g and 0.383+/-0.012 mmol Hg(II)/g respectively; whereas for live and heat-killed P. sajur-caju, the values were 0.450+/-0.014 mmol Hg(II)/g and 0.660+/-0.019 mmol Hg(II)/g respectively. Biosorption equilibrium was established in about 1 h and the equilibrium adsorption was well described by Langmuir and Freundlich adsorption isotherms. Between 15 and 45 degrees C the biosorption capacity was not affected and maximum adsorption was observed between pH 4.0 and 6.0. The alginate-fungus beads could be regenerated using 10 mmol dm(-3) HCl solution, with up to 97% recovery. The biosorbents were reused in five biosorption-desorption cycles without a significant loss in biosorption capacity. Heat-killed T. versicolor and P. sajur-caju removed 73% and 81% of the Hg(II) ions, respectively, from synthetic wastewater samples.

  9. 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.

  10. 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.

  11. Kinetics and mechanisms of mercury biosorption by an exopolysaccharide producing marine isolateBacillus licheniformis.

    Science.gov (United States)

    Upadhyay, Kinjal H; Vaishnav, Avni M; Tipre, Devayani R; Patel, Bhargav C; Dave, Shailesh R

    2017-10-01

    Eight exopolysaccharide (EPS) producing metal-removing marine bacteria were screened for mercury (Hg) sorption. Bacillus licheniformis with the highest MIC values and Hg sorption ability was selected for further study. Biosorption of Hg from aqueous solution by Bacillus licheniformis was studied with respect to the metal concentration, adsorbent concentration, pH, different contact times, and in the presence of other metal ions. Under optimum conditions, more than 70% mercury was removed by 25 mg dried biomass of Bacillus licheniformis at pH 7.0 after 1 h of contact time. Freundlich adsorption isotherm was acceptable at studied Hg concentrations as compared to Langmuir isotherm model. Pseudo-second-order kinetic model was found to be more suitable for data presentation in contrast to pseudo-first-order kinetic model. Involvement of external mass transfer was prominent as compared to intraparticle diffusion model. Desorption of Hg was more effective with acids from all the studied eluents, showing 49.36 and 33.8% eluting capacity for 0.1 N HCL and 0.1 N HNO 3, respectively. Scanning electron microscopy exhibited altered cell surface morphology of the cells under the influence of mercury. The spectral images of energy dispersive spectroscopy showed the presence of metal ions on the surface of cells.

  12. Decolorization of Congo Red by Phanerochaete chrysosporium: the role of biosorption and biodegradation.

    Science.gov (United States)

    Bosco, Francesca; Mollea, Chiara; Ruggeri, Bernardo

    2017-10-01

    The degradation of Congo Red by means of Phanerochaete chrysosporium BKM-F-1767 is reported in this work. Solid and liquid cultures have been prepared to evaluate in vivo biodegradation as well as the role of biosorption phenomena on mycelium. Moreover, in vitro tests have been performed to define the influence of MnP on dye decolorization. P. chrysosporium, cultivated on Malt Extract Agar in the presence of Congo Red 0.005% (w/v), has shown good growth and the ability to decolorize the dye in the 25-39°C temperature range. It has also been cultivated in a low NMM liquid medium with the aforementioned dye concentration in immobilized stationary cultures inducted for Lignin Peroxidase (LiP) and Manganese Peroxidase (MnP) production. Congo Red was absorbed on the biomass and then decolorized (93% and 85% for the LiP and MnP cultures, respectively). The cultures with added Congo Red have shown a higher MnP synthesis rate than a control without the dye. The enzymatic degradation of Congo Red has also been investigated by means of the extracellular fluid for different MnP activities (0-300 IU/l); the decolorization percentage has been found to be clearly related to the enzyme concentration up to a value of about 200 IU/l.

  13. Tertiary-treatment of oil-field brine in a biosorption system with granulated activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Dalmacija, B.; Tamas, Z.; Karlovic, E.; Miskovic, D. [Institute of Chemistry, Novisad (Yugoslavia). Faculty of Science

    1996-05-01

    This work describes the possibility of application of a biosorption system with granulated activated carbon (GAG) for the tertiary treatment of oil-field brine. In addition to the dissolved and dispersed oil, the oil-field brine contained about 29 g/l of mineral matter, mainly NaCl. The investigation was carried out on two columns, each containing 300 g of GAG. To form the biofilm on GAC use was made of the microorganisms from the setup for the purification of refinery wastewaters by activated sludge procedure. The wastewater flow-rate through the columns was 40, 70, 95 and 130 l/d. It was found that the activated carbon in the columns was capable of removing 2.6 times more organic matter than was its adsorption capacity, and its adsorption power was not thus exhausted. The results indicate that the microorganisms present in the biofilm on activated carbon oxidize the adsorbed pollutants and thus regenerate the carbon surface. The procedure employed was very efficient - the organic matter content in the effluent did not exceed 2.5 mg/l (BOD5). (UK)

  14. 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.

  15. Biosorption of cadmium ions from aqueous solution onto non-living lichen ramalina fraxinea biomass

    Energy Technology Data Exchange (ETDEWEB)

    Candan, Mehmet [Anadolu University, Faculty of Science, Department of Biology, Eskisehir (Turkey); Erdem, Murat; Cimen, Yasemin; Tuerk, Hayrettin [Anadolu University, Faculty of Science, Department of Chemistry, Eskisehir (Turkey); Tay, Turgay

    2009-03-15

    Living lichens are known to accumulate metals across their surface. In this study, the biosorption of cadmium ions (Cd{sup 2+}) by the lichen Ramalina fraxinea was investigated in aqueous solution in a batch system with respect to pH, contact time, temperature, initial cadmium ion concentration and size of biomass. The adsorption data appear to fit both the Langmuir and Freundlich adsorption models. The maximum adsorption capacity of the lichen R. fraxinea was found to be 7.00 mg/g at pH 6. The kinetic data were analyzed using the pseudo-first-order and pseudo-second-order equations. Kinetic parameters such as rate constants, equilibrium adsorption capacities and correlation coefficients for each kinetic model were calculated and discussed. The adsorption process of cadmium ions onto the R. fraxinea biomass fitted well the pseudo-second-order kinetic model. It appears that R. fraxinea adsorbs cadmium ions moderately compared to some biosorbents. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  16. Biosorption of lead ions by cyanobacteria Spirulina platensis: kinetics, equilibrium and thermodynamic study

    Directory of Open Access Journals (Sweden)

    Zinicovscaia Inga

    2017-12-01

    Full Text Available The potential use of dry Spirulina platensis biomass to remove lead ions from aqueous solution was investigated. Effects of various parameters such as contact time, temperature, dosage of biosorbent, initial pH, and initial concentration of lead were investigated in the batch adsorption mode. The highest lead removal of 5.7 mg/g was obtained at pH 5, biomass dosage of 0.5 g, initial lead concentration of 60 mg/L. The Langmuir and Freundlich models fit the experimental data (R2 > 0.99, while the kinetic data was best described using the pseudo second-order kinetic model (R2 > 0.99. FTIR spectra indicated that the metal removal takes place through binding to OH, C=O and P=O groups. Lead was efficiently recovered from biomass by mineral acids, while using CH3COOH and NaOH as eluents the biomass maintained high biosorption capacity during three cycles. This study demonstrates the potential of using Spirulina platensis as biosorbent to remove lead from industrial wastewater.

  17. 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

  18. Biosorption of Cr(III) using in natura and chemically treated tropical peats

    International Nuclear Information System (INIS)

    Batista, A.P.S.; Romao, L.P.C.; Arguelho, M.L.P.M.; Garcia, C.A.B.; Alves, J.P.H.; Passos, E.A.; Rosa, A.H.

    2009-01-01

    The physicochemical characteristics of three Brazilian peats were investigated using elemental analysis, scanning electron microscopy (SEM), X-ray diffractometry (XRD) and studies of Cr(III) biosorption based on adsorption isotherms. Adsorption of Cr(III) by in natura peat from Santo Amaro das Brotas (Sergipe State) was much greater than by peats from either Ribeirao Preto (Sao Paulo State) or Itabaiana (Sergipe State), with adsorption capacities (q) of 4.90 ± 0.01, 1.70 ± 0.01 and 1.40 ± 0.01 mg g -1 , respectively. Pre-treatments with HCl and NaOH + HCl reduced adsorption by the Santo Amaro das Brotas peat, showing that adsorption efficiency was associated with the amount of organic matter present. Conversely, increase in the mineral content following pre-treatment increased adsorption of Cr(III) by the Ribeirao Preto and Itabaiana peats. Highest adsorption (retention >95.0%) was achieved at equilibrium pH 4.0 using the Santo Amaro das Brotas peat. Experimental data for the adsorption of Cr(III) from aqueous solution onto this peat were fitted to the Langmuir equation, from which an equilibrium adsorption capacity, q max , of 5.60 mg g -1 was obtained, which was close to the experimentally determined value

  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. Biosorption characteristics of phosphates from aqueous solution onto Phoenix dactylifera L. date palm fibers.

    Science.gov (United States)

    Riahi, Khalifa; Thayer, Béchir Ben; Mammou, Abdallah Ben; Ammar, Aouatef Ben; Jaafoura, Mohamed Habib

    2009-10-30

    Phosphates are very important basic materials in agricultural and other industrial applications. The removal of phosphates from surface waters is generally necessary to avoid problems, such as eutrophication, particularly near urban areas. This paper is focused on the sorption of PO4(3-) ions from aqueous solution onto date palm fibers as a raw, natural and abundantly materials. A series of batch tests were conducted and the influence of contact time, initial phosphate concentration, pH of the solution and adsorbent dosage on PO4(3-) specie removal was investigated. FT-IR spectroscopy, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) analysis of the date palm fibers before and after phosphates biosorption and desorption studies were investigated to confirm the mechanism of the retention of phosphates. Results indicate that PO4(3-) uptake increased with increased initial phosphate concentration and decreased with increased pH values. The results showed that the highest phosphates adsorption capacity (4.35 mg/g) was found at pH 6.8, for an adsorbent dosage of 6g/L, initial phosphate concentration of 50mg/L, under a constant temperature of 18 degrees C+/-02, and the equilibrium state was reached within 120 min of exposure time. The relatively low cost and high capabilities of date palm fibers make them potentially attractive adsorbents for the removal of phosphate from aqueous solution.

  1. 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.

  2. Biosorption characteristics of phosphates from aqueous solution onto Phoenix dactylifera L. date palm fibers

    International Nuclear Information System (INIS)

    Riahi, Khalifa; Thayer, Bechir Ben; Mammou, Abdallah Ben; Ammar, Aouatef Ben; Jaafoura, Mohamed Habib

    2009-01-01

    Phosphates are very important basic materials in agricultural and other industrial applications. The removal of phosphates from surface waters is generally necessary to avoid problems, such as eutrophication, particularly near urban areas. This paper is focused on the sorption of PO 4 3- ions from aqueous solution onto date palm fibers as a raw, natural and abundantly materials. A series of batch tests were conducted and the influence of contact time, initial phosphate concentration, pH of the solution and adsorbent dosage on PO 4 3- specie removal was investigated. FT-IR spectroscopy, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) analysis of the date palm fibers before and after phosphates biosorption and desorption studies were investigated to confirm the mechanism of the retention of phosphates. Results indicate that PO 4 3- uptake increased with increased initial phosphate concentration and decreased with increased pH values. The results showed that the highest phosphates adsorption capacity (4.35 mg/g) was found at pH 6.8, for an adsorbent dosage of 6 g/L, initial phosphate concentration of 50 mg/L, under a constant temperature of 18 deg. C ± 02, and the equilibrium state was reached within 120 min of exposure time. The relatively low cost and high capabilities of date palm fibers make them potentially attractive adsorbents for the removal of phosphate from aqueous solution.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Use of Forestry Wastes for Biosorption of Dyes and Cr (VI

    Directory of Open Access Journals (Sweden)

    Nariye Berraksu

    2013-01-01

    Full Text Available The pine cone and oak cups pulp were used as low-cost adsorbents for the removal of basic (Basic Red 18 and acidic (Acid Red 111 dyes and Cr (VI from aqueous solutions. The adsorbents were modified by HNO3 to improve their biosorption capacity. The adsorbents were characterized using scanning electron microscopy and FTIR spectroscopy. The zeta potential was determined as a function of the pH, in order to explain the effect of pH on electrostatic adsorption ability of biosorbent. Modification of adsorbents with nitric acid led to an increase in accessibility of some functional groups on the surface or a decrease in negativity of surface charge. The modification of pine cone increased its adsorption capacity for the basic dye, whereas the modification of oak cups pulp decreased the adsorption ability for basic dye to some extent. The adsorption isotherms fitted the Langmuir model. The adsorption capacities were found to be 142.85, 158.73, and 156.20 mg g-1 for modified and raw pine cone and oak cups pulp, respectively. The acidic dye and Cr (VI adsorptions were much lower compared to basic dye on all tested adsorbents. The results indicated that the forest wastes (pine cone and oak cups pulp were an attractive candidate for basic dyes from aqueous solution.

  8. Study of nickel and copper biosorption on brown algae Sargassum angustifolium: application of response surface methodology (RSM).

    Science.gov (United States)

    Ahmady-Asbchin, Salman; Tabaraki, Reza; Jafari, Naser; Allahverdi, Abdollah; Azhdehakoshpour, Ashkan

    2013-01-01

    This study has been focused on the batch culture removal of Cu2+ and Ni2+ ions from the aqueous solution using marine brown algae Sargassum angustifolium. Influences of parameters like pH, initial metal ions concentration and biosorbent dosage on nickel and copper adsorption were also examined using the Box-Behnken design matrix. For biosorption of Cu2+ the optimum pH value was determined as 5.0, optimum biosorbent concentration to 1.0 g/L and optimum initial concentration 0.15 mmol/L. For the biosorption of Ni2+, the optimal condition was the same but the optimum pH value was determined as 6.0. Desorption experiments indicated that CH3COOH and EDTA were efficient desorbents for recovery from Cu2+ and Ni2+. The Langmuir isotherm model was applied to describe the biosorption of the Cu2+ and Ni2+ into S. angustifolium. The maximum uptake of Cu2+ and Ni2+ ions by the S. angustifolium biomass under the optimal conditions was approximately 0.94 and 0.78 mmol/g dry alga, respectively. Response surface models showed that the data were adequately fitted to a second-order polynomial model. Analysis of variance showed a high coefficient of determination value (R2 = 0.993 for Cu2+ and 0.991 for Ni2+) and a satisfactory second-order regression model was derived. In addition, results reported in this research demonstrated the feasibility of employing S. angustifolium as biosorbent for Ni2+ and Cu2+ removal.

  9. 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.

  10. Green and efficient biosorptive removal of methylene blue by Abelmoschus esculentus seed: Process optimization and multi-variate modeling.

    Science.gov (United States)

    Nayak, Ashish Kumar; Pal, Anjali

    2017-09-15

    The present work explores, for the first time, the adsorptive removal of methylene blue (MB) dye from aqueous solution using different parts of abundantly available agricultural product, Abelmoschus esculentus (lady's finger), and the processed seed powder (designated as LFSP) was found as the best. The aforesaid biosorbent was characterized using field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and pH ZPC analyses. The biosorption performance was evaluated using batch studies at 303 K, at varying operating conditions such as solution pH, biosorbent dosage, initial dye concentration and contact time. The pseudo-second order kinetic model was followed during the adsorption, and it was also found that intra-particle diffusion played a prominent role in the rate-controlling step. Langmuir and Temkin isotherms were followed the best, as was evident from the lower % non-linear error values and higher degree of determination coefficients. Thermodynamic investigations revealed that the biosorption processes were spontaneous and endothermic. Using the response surface methodology (RSM), a central composite design was developed, and subsequently applied as an input for the artificial neural network (ANN) approach in order to further analyze the interactive term effects between the significant process parameters, on the maximum biosorption capacity for MB dye removal by LFSP. The non-linear error functions and linear regression coefficients on the RSM model showed its dominance behaviour over ANN model for both data fitting and estimation capabilities. Using the statistical optimization, the maximum uptake capacity was found to be 205.656 mg/g. Experiments were conducted to regenerate the adsorbent and to recover the adsorbed dye using the eluent 0.5 M HCl. Cost analysis showed that, LFSP was 7 times cheaper than commercially available activated carbons. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. A Comparative Study on the Biosorption of Cd2+ onto Paecilomyces lilacinus XLA and Mucoromycote sp. XLC

    Directory of Open Access Journals (Sweden)

    Lu Xia

    2015-07-01

    Full Text Available The filamentous fungi XLA and XLC isolated from Cd-contaminated soil were identified morphologically and phylogenetically as Paecilomyces lilacinus and Mucoromycote sp., respectively. The minimum inhibitory concentrations (MICs of Cd2+, Co2+, Cu2+, Zn2+, Cr3+ and Cr6+ in minimum mineral (MM medium agar plates were 29,786, 2945, 9425, 5080, 1785 and 204 mg·L−1 for XLA and 11,240, 884, 9100, 2540, 3060 and 51 mg·L−1 for XLC, respectively. Favorable biosorption conditions for adsorption of Cd2+ by the tested fungi were investigated. Efficient performances of the biosorbents were described using Langmuir isotherm model, and the predicted maximum biosorption capacities for Cd2+ were 77.61 mg·g−1 of XLA and 79.67 mg·g−1of XLC. Experiments on desorption potential of biosorbents validated their efficacy at a large scale. Results showed that XLA obtained a desorption rate of 84.7% by 2% EDTA and XLC gained a desorption rate of 78.9% by 0.1 M HCl. Analysis by Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS and X-ray photoelectron spectroscopy (XPS suggested that groups of C–N, COO– for XLA and C–N, CH2 and phosphate for XLC were the dominant binding sites for Cd2+ biosorption. Our results indicated that the fungus XLA, rather than XLC, could potentially be used as an inexpensive, eco-friendly and effective bioremediation agent for the removal of Cd2+ from wastewater.

  12. Antioxidative enzyme profiling and biosorption ability of Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 under cadmium stress.

    Science.gov (United States)

    Shamim, Saba; Rehman, Abdul

    2015-03-01

    Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 were used as cadmium (Cd)-resistant and -sensitive bacteria, respectively, to study their biosorption ability and their antioxidative enzymes. The minimal inhibitory concentration of C. metallidurans CH34 for Cd was found to be 30 mM, and for P. putida mt2 it was 1.25 mM. The tube dilution method revealed the heavy-metal resistance pattern of C. metallidurans CH34 as Ni(2+) (10 mM)>Zn(2+) (4 mM)>Cu(2+) (2 mM)>Hg(2+) (1 mM)>Cr(2+) (1 mM)>Pb(2+) (0 mM), whereas P. putida mt2 was only resistant to Zn(2+) (1 mM). Under Cd stress, the induction of GSH was higher in C. metallidurans CH34 (0.359 ± 0.010 mM g(-1)  FW) than in P. putida mt2 (0.286 ± 0.005 mM g(-1)  FW). Glutathione reductase was more highly expressed in the mt2 strain, in contrast to non-protein thiols and peroxidase. Unlike dead bacterial cells, live cells of both bacteria showed significant Cd biosorption, i.e. more than 80% at 48 h. C. metallidurans CH34 used only catalase, whereas P. putida mt2 used superoxide dismutase and ascorbate peroxidase to combat Cd stress. This study investigated the Cd biosorption ability and enzymes involved in the Cd detoxification mechanisms of C. metallidurans CH34 and P. putida mt2. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Biosorption Behavior of Basic Red 46 and Violet 3 by Dead Pleurotus mutilus from Single- and Multicomponent Systems

    OpenAIRE

    Yeddou Mezenner, N.; Hamadi, A.; Kaddour, S.; Bensaadi, Z.; Bensmaili, A.

    2013-01-01

    The performance of nonviable P. mutilus for removal of Crystal Violet (CV) and Basic Red 46 (BR46) was investigated in single and binary systems. Batch kinetic studies were carried out as a function of pH, temperature, biomass amount, and dye concentration to determine the decolorization efficiency of biosorbent. In single system, the biosorption capacities of P. M. reached 166 and 76.92 mg/g for CV and BR46, respectively. A comparison of kinetic models applied to the adsorption of basic dyes...

  14. Biosorption of Cr(III), Cr(VI), Cu(II) ions by intact cells of Spirulina platensis

    OpenAIRE

    Gelagutashvili, E.; Bagdavadze, N.; Rcheulishvili, A.

    2017-01-01

    The absorption characteristics of Cr(III), Cr(VI), Cu(II) ions on intact living cells Spirulina platensis (pH9.6) were studied by using a UV-VIS spectrophotometer. Also biosorption of these ions with cyanobacteria Spirulina platensis were studied using equilibrium dialysis and atomic absorption analysis.It was shown, that the absorption intensity of Spirulina platensis decreases, when Cr(III), Cr(VI), Cu(II) ions are added. Significant difference between the absorption intensity for Cu(II) Sp...

  15. Night sweats, sleep disturbance, and depression associated with diminished libido in late menopausal transition and early postmenopause

    Science.gov (United States)

    Reed, Susan D.; Newton, Katherine M.; LaCroix, Andrea Z.; Grothaus, Lou C.; Ehrlich, Kelly

    2007-01-01

    Objective To evaluate the association of depression, sleep disturbance and menopausal symptoms with diminished libido. Study Design Data from a 2001-2002 baseline survey of 341 peri- and postmenopausal women, ages 45-55, participating in a randomized trial was analyzed. Eligibility included at least two hot flashes and/or night sweats per day and no hormone therapy for at least the prior 3 months. The survey evaluated sexual function, depression, sleep and vasomotor symptoms. We examined the association between these factors, using multivariate regression models. Results Of 341 women, 64% had diminished libido, 18% had moderate-severe depression, and 43% had poor sleep quality. Women averaged 4.6 hot flashes and 1.9 night sweats per day. Depressive symptoms (P=0.003), poor sleep (P=0.02), and night sweats (P=0.04), were significantly associated with diminished libido. Conclusions Factors associated with diminished libido in midlife are complex but include depression, disturbed sleep and night sweats, all common symptoms of the menopausal transition and early menopause. PMID:17547910

  16. Changes in Global Monsoon Circulations: Evidence of a diminishing global hydrological cycle?

    Science.gov (United States)

    Chase, T. N.; Knaff, J. A.; Pielke, R. A.

    2001-05-01

    We examined changes in several independent intensity indices of four major tropical monsoonal circulations from approximately 1950-1998. These intensity indices included upper-level divergence at several standard levels, land surface precipitation in the monsoon regions and ocean surface pressure. These values were averaged seasonally over appropriate regions of southeastern Asian, western Africa, eastern Africa and Australia/Maritime continent and adjacent ocean areas. As a consistency check we also examined two secondary indices: mean sea level pressure trends averaged over each monsoon region and low level convergence at several levels both from the NCEP reanalysis. We find that in each of the four regions examined, a consistent picture emerges indicating significantly diminished monsoonal circulations over the period of record, evidence of a diminished global hydrological cycle since 1950. Trends since 1978, the period of strongest surface warming, are insignificant and uncorrelated with the surface warming. When strong ENSO years are removed from the time series the trends still show a general, significant reduction of monsoon intensity indicating that ENSO variability is not the direct cause for the observed weakening. A comparison with general circulation model simulations of the effects of rising CO2 shows an increase in monsoonal activity with rising global surface temperature except in the case of the Australian/Maritime continent monsoon. When the effects of aerosols are included the simulated southeastern Asian summer monsoon is also reduced in intensity.

  17. Overeducation and depressive symptoms: diminishing mental health returns to education.

    Science.gov (United States)

    Bracke, Piet; Pattyn, Elise; von dem Knesebeck, Olaf

    2013-11-01

    In general, well-educated people enjoy better mental health than those with less education. As a result, some wonder whether there are limits to the mental health benefits of education. Inspired by the literature on the expansion of tertiary education, this article explores marginal mental health returns to education and studies the mental health status of overeducated people. To enhance the validity of the findings we use two indicators of educational attainment - years of education and ISCED97 categories - and two objective indicators of overeducation (the realised matches method and the job analyst method) in a sample of the working population of 25 European countries (unweighted sample N = 19,089). Depression is measured using an eight-item version of the CES-D scale. We find diminishing mental health returns to education. In addition, overeducated people report more depression symptoms. Both findings hold irrespective of the indicators used. The results must be interpreted in the light of the enduring expansion of education, as our findings show that the discussion of the relevance of the human capital perspective, and the diploma disease view on the relationship between education and modern society, is not obsolete. © 2013 The Authors. Sociology of Health & Illness © 2013 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

  18. 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.

  19. 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.

  20. Is proprioception diminished in patients with patellar tendinopathy?

    Science.gov (United States)

    Groot, H E; van der Worp, H; Nijenbanning, L; Diercks, R L; Zwerver, J; van den Akker-Scheek, I

    2016-03-01

    Patellar tendinopathy is a highly prevalent overuse injury, and most treatments are only effective to some extent. This persistence of complaints could be linked to changed proprioception. One study showed diminished proprioception in athletes with lateral epicondylitis. Aim of this study was to determine differences in proprioception, by measuring threshold to detect passive motion (TTDPM) between recreational athletes diagnosed with patellar tendinopathy and healthy controls. The TTDPM as measure of proprioception was determined in 22 recreational athletes with patellar tendinopathy and 22 healthy recreational athletes using a validated instrument. Amount of knee flexion and extension before the movement was noticed by the subject was determined. 80 measurements per athlete (left and right leg, towards extension and flexion and with two starting angles of 20° and 40° flexion) were performed. Mean TTDPM was compared between groups and among the injured recreational athletes between the affected and unaffected knee. No significant difference in TTDPM was found between recreational athletes with patellar tendinopathy and healthy controls. We did find a significant difference between the injured and non-injured knee in recreational athletes with patellar tendinopathy; mean TTDPM was 0.02° higher in the injured knee (p=0.044). No difference was found in proprioception between recreational athletes with patellar tendinopathy and healthy recreational athletes. It is unclear whether such a small difference in TTDPM between affected and unaffected knee is important in clinical setting. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Normal aging selectively diminishes alpha lateralization in visual spatial attention.

    Science.gov (United States)

    Hong, Xiangfei; Sun, Junfeng; Bengson, Jesse J; Mangun, George R; Tong, Shanbao

    2015-02-01

    EEG studies of cue-induced visual alpha power (8-13 Hz) lateralization have been conducted on young adults without examining differences that may develop as a consequence of normal aging. Here, we examined age-related differences in spatial attention by comparing healthy older and younger adults. Our key finding is that cue-induced alpha power lateralization was observed in younger, but not older adults, even though both groups exhibited classic event-related potential signatures of spatial orienting. Specifically, both younger and older adults showed significant early directing-attention negativity (EDAN), anterior directing-attention negativity (ADAN), late directing-attention positivity (LDAP) and contingent negative variation (CNV). Furthermore, target-evoked sensory components were enhanced for attended relative to unattended targets in both younger and older groups. This pattern of results suggests that although older adults can successfully allocate spatial attention, they do so without the lateralization of alpha power that is commonly observed in younger adults. Taken together, our findings demonstrate that younger and older adults might engage different neural mechanisms for attentional orienting, and that alpha power lateralization during visual spatial attention is a phenomenon that diminishes during normal aging. Copyright © 2014 Elsevier Inc. All rights reserved.

  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. 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.

  4. 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

  5. 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

  6. 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)

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

    Science.gov (United States)

    Liu, Mingxue; Dong, Faqin; Zhang, Wei; Nie, Xiaoqin; Sun, Shiyong; Wei, Hongfu; Luo, Lang; Xiang, Sha; Zhang, Gege

    2016-08-15

    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 SrSO4 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Biosorption of Lead (II–containing Sasirangan Textile Wastewater using Nanocomposites of Eleocharis dulcis Fibers with Iron (III Nanoparticles as Adsorbent

    Directory of Open Access Journals (Sweden)

    Irawan Chairul

    2018-01-01

    Full Text Available This research focuses on the study of biocomposite nanoparticles of Eleocharis dulcis (ED as potentials biosorbent to reduce the concentration of lead (II ion containing Sasirangan textile industry wastewater. Eleocharis dulcis, locally named as Purun Tikus, has been developing becomes the biocomposites nanomaterial and valuables material in this research. Batch experiments were carried out to considering the kinetic of biosorption of lead onto the adsorbent, evaluating the effects of lead ion equilibrium concentration, equilibrium pH, and temperature on the adsorption of lead (II. Kinetic data of lead (II biosorption onto EDB and EDB-MH revealed that equilibrium time was reached within 2 h, and the isotherm data showed that the Langmuir maximum adsorption capacity of the EDB-M and EDB-MH at pHe of 6±0.2, room temperature were 150.43 mg/g and 180.92 mg/g, respectively. The thermodynamic of lead (II biosorption onto the adsorbent implied the biosorption was spontaneous and endothermic indicating by increased in temperature would increased in adsorption capacity.

  9. Comparative study of chromium biosorption by red, green and brown seaweed biomass.

    Science.gov (United States)

    Murphy, V; Hughes, H; McLoughlin, P

    2008-01-01

    Dried biomass of the macroalgae Fucus vesiculosus and Fucus spiralis (brown), Ulva spp. (comprising Ulva linza, Ulva compressa and Ulva intestinalis) and Ulva lactuca (green), Palmaria palmata and Polysiphonia lanosa (red) were studied in terms of their chromium biosorption performance. Metal sorption was highly pH dependent with maximum Cr(III) and Cr(VI) sorption occurring at pH 4.5 and pH 2, respectively. Extended equilibrium times were required for Cr(VI) binding over Cr(III) binding (180 and 120min, respectively) thus indicating possible disparities in binding mechanism between chromium oxidation states. The red seaweed P. palmata revealed the highest removal efficiency for both Cr(III) and Cr(VI) at low initial concentrations. However, at high initial metal concentrations F. vesiculosus had the greatest removal efficiency for Cr(III) and performed almost identically to P. lanosa in terms of Cr(VI) removal. The Langmuir Isotherm mathematically described chromium binding to the seaweeds where F. vesiculosus had the largest q(max) for Cr(III) sorption (1.21mmol g(-1)) and P. lanosa had the largest Cr(VI) uptake (0.88mmol g(-1)). P. palmata had the highest affinity for both Cr(III) and Cr(VI) binding with b values of 4.94mM(-1) and 8.64mM(-1), respectively. Fourier transform infrared analysis revealed interactions of amino, carboxyl, sulphonate and hydroxyl groups in chromium binding to Ulva spp. The remaining seaweeds showed involvement of these groups to varying degrees as well as ether group participation in the brown seaweeds and for Cr(VI) binding to the red seaweeds.

  10. 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

  11. 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.

  12. Loneliness in older adults is associated with diminished cortisol output.

    Science.gov (United States)

    Schutter, N; Holwerda, T J; Stek, M L; Dekker, J J M; Rhebergen, D; Comijs, H C

    2017-04-01

    Loneliness in older adults has been associated with increased mortality and health problems. One of the assumed underlying mechanisms is dysregulation of the hypothalamic-pituitary-adrenocortical axis (HPA-axis). The purpose of this study was to investigate whether loneliness in older adults is associated with HPA-axis dysregulation and whether this association differs between depressed and non-depressed persons. Cross-sectional data of 426 lonely and non-lonely older adults in the Netherlands Study of Depression in Older Persons (NESDO) were used. Linear regression analyses and multinominal logistic regression analyses were performed to examine the association between loneliness and morning cortisol, cortisol awakening response, diurnal slope and dexamethasone suppression ratio. In all analyses, confounders were introduced. In order to examine whether the association between loneliness and cortisol measures is different in depressed versus non-depressed persons, an interaction term for loneliness x depression diagnosis was tested. Cortisol output in the first hour after awakening and dexamethasone suppression ratio was lower in lonely participants. There were no significant interactions between loneliness and depression diagnosis in the association with the cortisol measures. This study is the first to investigate the association between the HPA-axis and loneliness in a large group of older adults aged 60-93years. We found lower cortisol output in the first hour after awakening and lower dexamethasone suppression ratio in lonely older depressed and non-depressed adults. Whether diminished cortisol output is the underlying mechanism that leads to health problems in lonely older adults is an interesting object for further study. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. 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.

  14. Biosorption of uranium(VI) from aqueous solutions by Ca-pretreated Cystoseira indica alga: breakthrough curves studies and modeling.

    Science.gov (United States)

    Ghasemi, Morteza; Keshtkar, Ali Reza; Dabbagh, Reza; Jaber Safdari, S

    2011-05-15

    Uranium(VI) biosorption from aqueous solutions containing 60 mg l(-1) metal concentration by Ca-pretreated Cystoseira indica alga was studied in a packed bed column with 1.5 cm internal diameter. The effect of bed height and flow rate on biosorption process was investigated and the experimental breakthrough curves were obtained. Results showed that by increasing the bed height, the breakthrough and exhaustion times increased and the slope of breakthrough curves decreased. Also, it was observed that the controlled-rate step shifted from external to internal mass transfer limitations, as the flow rate increased. The maximum uptake capacity, 318.15 mg g(-1), and total metal removal, 59.32%, were obtained at flow rate of 2.3 ml min(-1) and bed height of 6 cm. The column was regenerated using 0.1M HCl solution and sorption-desorption studies were carried out for three cycles. The obtained results confirmed that reusability of this biosorbent is possible. The results obtained agreed well with the bed depth service time model. In addition, for estimations of the parameters necessary for the design of a large-scale packed bed column, the experimental data were also fitted to the Thomas, Yan and Belter models and were found to agree with the experimental data fairly well. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Biosorption of uranium(VI) from aqueous solutions by Ca-pretreated Cystoseira indica alga: Breakthrough curves studies and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Morteza [Faculty of Nuclear Engineering, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Keshtkar, Ali Reza, E-mail: akeshtkar@aeoi.org.ir [Nuclear Fuel Cycle School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Dabbagh, Reza [Nuclear Science Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Jaber Safdari, S. [Nuclear Fuel Cycle School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2011-05-15

    Uranium(VI) biosorption from aqueous solutions containing 60 mg l{sup -1} metal concentration by Ca-pretreated Cystoseira indica alga was studied in a packed bed column with 1.5 cm internal diameter. The effect of bed height and flow rate on biosorption process was investigated and the experimental breakthrough curves were obtained. Results showed that by increasing the bed height, the breakthrough and exhaustion times increased and the slope of breakthrough curves decreased. Also, it was observed that the controlled-rate step shifted from external to internal mass transfer limitations, as the flow rate increased. The maximum uptake capacity, 318.15 mg g{sup -1}, and total metal removal, 59.32%, were obtained at flow rate of 2.3 ml min{sup -1} and bed height of 6 cm. The column was regenerated using 0.1 M HCl solution and sorption-desorption studies were carried out for three cycles. The obtained results confirmed that reusability of this biosorbent is possible. The results obtained agreed well with the bed depth service time model. In addition, for estimations of the parameters necessary for the design of a large-scale packed bed column, the experimental data were also fitted to the Thomas, Yan and Belter models and were found to agree with the experimental data fairly well.

  16. 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.

  17. Cadmium biosorption by ozonized activated sludge: The role of bacterial flocs surface properties and mixed liquor composition

    International Nuclear Information System (INIS)

    Laurent, Julien; Casellas, Magali; Pons, Marie-Noelle; Dagot, Christophe

    2010-01-01

    Cadmium uptake by activated sludge was studied following modifications of sludge composition and surface properties induced by ozone treatment. Ozone leads to the solubilization of sludge compounds as well as their mineralization, especially humic like substances. Small particles were formed following floc disintegration, leading to a decrease of average floc size. The study of surface properties underlined the mineralization as the number of surface binding sites decreased with the increase of ozone dose. Depending on ozone dose, cadmium uptake by activated sludge flocs was either increased or decreased. Different mechanisms were involved: below 10 mg O 3 /g TS, the increase of floc specific surface area following floc size decrease as well as the release of phosphate ions yielded an increase by 75% of cadmium uptake, due to the better availability of biosorption sites and the increase of precipitation. Inversely, at higher ozone doses, the number of biosorption sites decreased due to oxidation by ozone. Moreover, dissolved organic matter concentration increased and provided ligands for metal complexation. Cadmium uptake was therefore limited for ozone doses ranging from 10 to 16.8 mg O 3 /g TS.

  18. 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)

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

    International Nuclear Information System (INIS)

    Das, Devlina; Das, Nilanjana; Mathew, Lazar

    2010-01-01

    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 deg. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Das, Devlina [School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu (India); Das, Nilanjana, E-mail: nilanjana00@lycos.com [School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu (India); Mathew, Lazar [School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu (India)

    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{sup -1} of biomass at pH 6.0 in the presence of 200 mg L{sup -1} Ag(I) at 20 deg. 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 ({Delta}G, {Delta}H and {Delta}S) 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.

  1. Biosorption Behavior of Basic Red 46 and Violet 3 by Dead Pleurotus mutilus from Single- and Multicomponent Systems

    Directory of Open Access Journals (Sweden)

    N. Yeddou Mezenner

    2013-01-01

    Full Text Available The performance of nonviable P. mutilus for removal of Crystal Violet (CV and Basic Red 46 (BR46 was investigated in single and binary systems. Batch kinetic studies were carried out as a function of pH, temperature, biomass amount, and dye concentration to determine the decolorization efficiency of biosorbent. In single system, the biosorption capacities of P. M. reached 166 and 76.92 mg/g for CV and BR46, respectively. A comparison of kinetic models applied to the adsorption of basic dyes onto P. Mutilus was evaluated for the pseudo-second-order and intraparticle diffusion kinetics models. The experimental data fitted very well the pseudo-second-order kinetic model, whereas diffusion is not only the rate-controlling step. The thermodynamic study indicates that the adsorption of dyes is spontaneous and endothermic process. In binary system, the biosorption capacities of P. Mutilus for both dyes decreased significantly compared to that in single system. Competitive coefficients calculated on a concentration basis using Sheindorf-Rebhun-Sheintuch (SRS equation were useful for describing the degree of competitive interaction in P. M.

  2. Process optimization of batch biosorption of lead using Lactobacillius bulgaricus in an aqueous phase system using response surface methodology.

    Science.gov (United States)

    Sedighi, Mehdi; Ghasemi, Mostafa; Hassan, Sedky H A; Daud, Wan Ramli Wan; Ismail, Manal; Abdallah, Elgorban

    2012-05-01

    Response surface methodology (RSM) based on central composite rotatable design was used to investigate the effects of operating variable, mainly, pH, weight of biomass, and initial lead ion concentration on the lead adsorption capacity at ambient temperature using dried cells of Lactobacillius bulgaricus. Using RSM, quadratic polynomial equation was obtained for predicting the percent of lead ion removal. Analysis of variance showed that the effects of pH and weight of dried biomass were concluded to be the key factors influencing the capacity of lead ion removal. At pH lower than 2 (high acidic condition) and in alkaline condition, there is no significant biosorption. The optimum percent of lead ion removal was found at pH of 6.78, biomass concentration of 6.58 g/l and initial lead concentration 36.22 ppm. In this condition, percent of lead ion removal was 86.21%. This study showed RSM effectiveness for modeling of biosorption process.

  3. 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.

  4. 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.

  5. 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.

  6. Optimization with Response Surface Methodology of biosorption conditions of Hg(II ions from aqueous media by Polyporus Squamosus fungi as a new biosorbent

    Directory of Open Access Journals (Sweden)

    Uzun Yusuf

    2017-06-01

    Full Text Available Removal of mercury(II (Hg(II from aqueous media by a new biosorbent was carried out. Natural Polyporus squamosus fungus, which according to the literature has not been used for the purpose of Hg(II biosorption before, was utilized as a low-cost biosorbent, and the biosorption conditions were analyzed by response surface methodology (RSM. Medium parameters which were expected to affect the biosorption of Hg(II were determined to be initial pH, initial Hg(II concentration (Co, temperature (T (°C, and contact time (min. All experiments were carried out in a batch system using 250 mL fl asks containing 100 mL solution with a magnetic stirrer. The Hg(II concentrations remaining in fi ltration solutions after biosorption were analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. Based on the RSM results, the optimal conditions were found to be 5.30, 47.39 mg/L, 20°C and 254.9 min for pH, Co, T (°C, and contact time, respectively. Under these optimal conditions, the maximum biosorbed amount and the biosorption yield were calculated to be 3.54 mg/g and 35.37%, respectively. This result was confi rmed by experiments. This result shows that Polyporus squamosus has a specifi c affi nity for Hg ions. Under optimal conditions, by increasing the amount of Polyporus squamosus used, it can be concluded that all Hg ions will be removed

  7. How to diminish calcium loss and muscle atrophy in space

    Science.gov (United States)

    Gorgolewski, S.

    perfect relaxation when asleep or awake. We have to check in space if we can thus diminish the use of medicaments or even eliminate them. Slow Yoga exercises decrease also the amount on food required because life is not so energy demanding in space as it is here under the earth's gravitation. We can stay lean and healthy with such static yet most effective physical exercises. In addition it gives us for free a vegetarian life style, just another benefit so useful in space travel.

  8. Diminished Baroreflex Control of Forearm Vascular Resistance Following Training

    Science.gov (United States)

    Mack, G. W.; Thompson, C. A.; Doerr, D. F.; Nadel, E. R.; Convertino, V. A.

    1991-01-01

    The stimulus-response characteristics of cardiopulmonary baroreflex control of forearm vascular resistance (FVR units in mm Hg x min x I00 ml/ml) were studied in 14 volunteers before and after 10 wk of endurance training. We assessed the relationship betaleen reflex stimulus (changes in central venous pressure, CVP) and response (FVR) during unloading of cardiopulmonary baroreceptors with lower body negative pressure (LBNP, 0 to - 2O mm Hg). Changes in CVP during LBNP were estimated from pressure changes in a large peripheral vein in the dependent arm of the subject in the right lateral decubitus position. Maximal oxygen uptake (VO(sub 2max)) and total blood volume increased with endurance training from 37.8 +/- 1.4 ml/min x kg and 63.6 +/- 2.1 ml/kg to 45.3 +/- 1.4 ml/ min x kg and 69.3 +/- 2.8 ml/kg respectively (P less than 0.05). Reflex forearm vasoconstriction occurred in response to a reduction in estimated CVP, and the absolute change in FVR per unit of CVP was reduced from -5.96 +/- 0.79 to -4.06 +/- 0.52 units x mm/ Hg (P less than 0.05) following exercise training but was unchanged from -6.10 to 0.57 to -6.22 +/- 0.94 units x mm/ Hg for the time control group (N = 7). Resting values for FVR were similar before and after exercise training; however, resting estimated CVP was elevated from 9.5 +/- 0.5 mm x Hg before training to 11.3 +/- 0.6 mm x Hg after training. The reduction in sensitivity of the cardiopulmonary baroreflex control of FVR was linearly related to the increase in blood volume (r = 0.65, P less than 0.05). suggesting that diminished cardiopulmonary baroreflex control of FVR in physically fit individuals is related, in part, to a training-induced blood volume expansion.

  9. 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

  10. A Biosorption Isotherm Model for the Removal of Reactive Azo Dyes by Inactivated Mycelia of Cunninghamella elegans UCP542

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    Galba M. Campos-Takaki

    2012-01-01

    Full Text Available The biosorption of three reactive azo dyes (red, black and orange II found in textile effluents by inactive mycelium of Cunninghamella elegans has been investigated. It was found that after 120 hours of contact the adsorption led to 70%, 85%, 93% and 88% removal of reactive orange II, reactive black, reactive red and a mixture of them, respectively. The mycelium surface was found to be selective towards the azo dyes in the following order: reactive red > reactive black > orange II. Dye removal from a mixture solution resulted in 48.4 mg/g retention by mycelium and indicated a competition amongst the dyes for the cellular surface. A Freundlich adsorption isotherm model exhibited a better fit, thus suggesting the presence of heterogeneous binding sites. Electrondense deposits observed on the mycelium ultrastructure suggest that the dyes are mainly retained under the cellular surface of the inactive biomass of C. elegans.

  11. 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.

  12. Biosorption of uranium(VI) by a mangrove endophytic fungus Fusarium sp. ZZF51 from the South China Sea

    International Nuclear Information System (INIS)

    Yang, H.B.; Tan, N.; Wu, F.J.; Liu, H.J.; Sun, M.; She, Z.G.; Lin, Y.C.

    2012-01-01

    The uranium(VI) accumulation was studied in detail by using the biomass of mangrove endophytic fungus Fusarium sp. ZZF51 from the South China Sea. The uranium(VI) biosorption process onto the tested fungus powders was optimized at pH 4.0, adsorption time 60 min, and uranium(VI) initial concentration 50 mg L -1 with 61.89% of removal efficiency. According to Fourier transform infrared spectra for the tested fungus before and after loaded with uranium(VI), the results showed that both of hydroxyl and carboxyl groups acted as the important roles in the adsorption process. In addition, the experimental data were analyzed by using parameter and kinetic models, and it was obtained that the Langmuir isotherm model and the pseudo-second-order kinetic model provided better correlation with the experimental data for adsorption of uranium(VI). (author)

  13. Simultaneous and automated monitoring of the multimetal biosorption processes by potentiometric sensor array and artificial neural network.

    Science.gov (United States)

    Wilson, D; del Valle, M; Alegret, S; Valderrama, C; Florido, A

    2013-09-30

    In this communication, a new methodology for the simultaneous and automated monitoring of biosorption processes of multimetal mixtures of polluting heavy metals on vegetable wastes based on flow-injection potentiometry (FIP) and electronic tongue detection (ET) is presented. A fixed-bed column filled with grape stalks from wine industry wastes is used as the biosorption setup to remove the metal mixtures from the influent solution. The monitoring system consists in a computer controlled-FIP prototype with the ET based on an array of 9 flow-through ion-selective electrodes and electrodes with generic response to divalent ions placed in series, plus an artificial neural network response model. The cross-response to Cu(2+), Cd(2+), Zn(2+), Pb(2+) and Ca(2+) (as target ions) is used, and only when dynamic treatment of the kinetic components of the transient signal is incorporated, a correct operation of the system is achieved. For this purpose, the FIA peaks are transformed via use of Fourier treatment, and selected coefficients are used to feed an artificial neural network response model. Real-time monitoring of different binary (Cu(2+)/ Pb(2+)), (Cu(2+)/ Zn(2+)) and ternary mixtures (Cu(2+)/ Pb(2+)/ Zn(2+)), (Cu(2+)/ Zn(2+)/ Cd(2+)), simultaneous to the release of Ca(2+) in the effluent solution, are achieved satisfactorily using the reported system, obtaining the corresponding breakthrough curves, and showing the ion-exchange mechanism among the different metals. Analytical performance is verified against conventional spectroscopic techniques, with good concordance of the obtained breakthrough curves and modeled adsorption parameters. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. 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.

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

    Science.gov (United States)

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

    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 (qmax 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 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 1mM 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 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.

  17. 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.

  18. Evidence for Diminished Multisensory Integration in Autism Spectrum Disorders

    Science.gov (United States)

    Stevenson, Ryan A.; Siemann, Justin K.; Woynaroski, Tiffany G.; Schneider, Brittany C.; Eberly, Haley E.; Camarata, Stephen M.; Wallace, Mark T.

    2014-01-01

    Individuals with autism spectrum disorders (ASD) exhibit alterations in sensory processing, including changes in the integration of information across the different sensory modalities. In the current study, we used the sound-induced flash illusion to assess multisensory integration in children with ASD and typically-developing (TD) controls.…

  19. 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

  20. T151. APATHY AND DIMINISHED EXPRESSION ARE NOT ASSOCIATED WITH VENTRAL OR DORSAL STRIATUM VOLUME IN SCHIZOPHRENIA

    Science.gov (United States)

    Burrer, Achim; Kirschner, Matthias; Seifritz, Erich; Stefan, Kaiser

    2018-01-01

    Abstract Background Negative symptoms are core features of schizophrenia and can be grouped into two domains. These are apathy including anhedonia, avolition and asocialty as well as diminished expression including blunted affect and alogia. A large body of research found that ventral striatal hypoactivation is linked to negative symptoms. In particular, it has been shown that this neural correlate is specific for apathy but not diminished expression. Here, we investigated whether this dissociation can also be found in ventral striatum volume. Methods We included brain structural T1 MRI data of 60 patients diagnosed with schizophrenia (SZ) and 58 healthy controls (HC). Negative symptoms in these groups have been assessed using the Brief Negative Symptom Scale (BNSS). We performed voxel-based morphometry (VBM) using the statistical parametric mapping package (SPM 12; Wellcome Trust Centre for Neuroimaging, London). We performed a region of interest (ROI) analysis of ventral and dorsal striatal volume between patients with schizophrenia and healthy controls. Furthermore, we analyzed the correlation of right and left ventral striatal volume with apathy and diminished expression in patients with schizophrenia. Moreover, we analyzed potential group differences in gray matter volume in an exploratory whole-brain analysis. Finally, we performed an exploratory whole-brain linear regression to identify potential correlations between the two negative symptom dimensions and gray matter volume. (cluster-defining threshold of p < 0.001, cluster-level pFWE < 0.05) Results Patients with schizophrenia showed no differences in ventral striatal volume compared to healthy controls. Apathy or diminished expression did not correlate with ventral or dorsal striatal gray matter volume in patients with schizophrenia. In the exploratory whole-brain analysis we found significant less gray matter volume in the right insula of schizophrenia patients compared to healthy controls (cluster

  1. Biosorption of Reactive Red-120 dye from aqueous solution by native and modified fungus biomass preparations of Lentinus sajor-caju.

    Science.gov (United States)

    Arica, M Yakup; Bayramoğlu, Gülay

    2007-10-22

    The capacities and mechanisms of native and treated white-rot fungus "Lentinus sajur-caju" biomass preparations in removing of textile dye (i.e. Reactive Red-120) from aqueous solution was investigated with different parameters, such as adsorbent dosage, pH, temperature and ionic strength. In the batch system, the maximum dye uptake on all the tested fungal biomass preparations was observed at pH 3.0, and the dye uptake capacities of the biosorbents (at 800 mg/l dye concentration) were found to be 117.8, 182.9, 138.6 and 57.2mg/g for native and heat-, acid- and base-treated dry fungal preparations, respectively. The uptake capacities order of the fungal preparations for the dye were found as heat-treated>acid-treated>native>base-treated. The Langmuir, Freundlih and Temkin adsorption models were used for the mathematical description of the biosorption equilibrium. The Freundlich and Temkin models were able to describe the biosorption equilibrium of Reactive Red-120 on the fungal biomass preparations. The dye biosorption on the fungal biomass preparations followed second-order kinetic model and equation.

  2. 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.

  3. 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.

  4. FIR Filter Implementation Based on the RNS with Diminished-1 Encoded Channel

    Directory of Open Access Journals (Sweden)

    Dragana Uros Zivaljevic

    2013-03-01

    Full Text Available A technique, based on the residue number system (RNS with diminished-1 encoded channel, has being used for implementing a finite impulse response (FIR digital filter. The proposed RNS architecture of the filter consists of three main blocks: forward and reverse converter and arithmetic processor for each channel. Architecture for residue to binary (reverse convertor with diminished-1 encoded channel has been proposed. Besides, for all RNS channels, the systolic design is used for the efficient  realization of FIR filter. A numerical example illustrates the principles of diminished-1 residue arithmetic, signal processing, and decoding for FIR filters.

  5. High dispersity of carbon nanotubes diminishes immunotoxicity in spleen.

    Science.gov (United States)

    Lee, Soyoung; Khang, Dongwoo; Kim, Sang-Hyun

    2015-01-01

    From the various physiochemical material properties, the chemical functionalization order of single-walled carbon nanotubes (swCNTs) has not been considered as a critical factor for modulating immunological responses and toxicological aspects in drug delivery applications. Although most nanomaterials, including carbon nanotubes, are specifically accumulated in spleen, few studies have focused on spleen immunotoxicity. For this reason, this study demonstrated that the dispersity of swCNTs significantly influenced immunotoxicity in vitro and in vivo. For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages. In the in vivo study, female BALB/c mice were intravenously administered with 1 mg/kg/day of swCNTs for 2 weeks. The body weight, organ weight, hematological change, reverse-transcription polymerase chain reaction, and lymphocyte population were evaluated. Different orders of chemical functionalization of swCNTs controlled immunotoxicity. In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity. This study clarified that increasing carboxyl groups on swCNTs significantly mitigated immunotoxicity in vitro and in vivo. Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

  6. Tolerance for cougars diminished by high perception of risk

    Directory of Open Access Journals (Sweden)

    Aliah Adams Knopff

    2016-12-01

    Full Text Available In North America, both human and cougar populations are expanding and increasingly sharing the same space, including modified landscapes viewed by people as their "backyard." Low tolerance for cougars in modified landscapes has been identified as a key factor that could restrict continued cougar range expansion in North America, or even reverse some of the gains made by cougar populations in recent decades. To better understand factors influencing tolerance and identify opportunities to improve conservation prospects for cougars, we implemented a questionnaire in west-central Alberta, where both human and cougar populations have increased over the past 20 years and where we had developed a resource selection function for cougars from telemetry data. Respondents overestimated risk from cougars, and more than half believed cougars posed the same or greater risk as driving a car, even though only one Albertan has been killed by a cougar in the last century and hundreds die in car accidents each year. Although respondents valued cougars highly, they indicated that cougars belonged in the wilderness and not near their homes. We predicted that tolerance for cougars would be negatively correlated with increased probability of cougar selection near the respondent's home, but our prediction was not supported. Although such correlations have been reported at broader spatial scales, we suggest they may break down at finer scales. Other factors, such as education, were important drivers of tolerance for cougars in Alberta. Our results suggest that education undertaken to improve large carnivore conservation should focus on accurately defining the risks and ecological benefits resulting from maintaining cougars on the landscape. Education may also need to focus on the importance of nonwilderness habitats (i.e., the rapidly expanding backyard as an important part of long-term conservation and continued range expansion and repatriation of adaptable large

  7. Cerebellar damage diminishes long-latency responses to multijoint perturbations

    Science.gov (United States)

    Trautman, Paxson; Rasquinha, Russell J.; Bhanpuri, Nasir H.; Scott, Stephen H.; Bastian, Amy J.

    2013-01-01

    Damage to the cerebellum can cause significant problems in the coordination of voluntary arm movements. One prominent idea is that incoordination stems from an inability to predictively account for the complex mechanical interactions between the arm's several joints. Motivated by growing evidence that corrective feedback control shares important capabilities and neural substrates with feedforward control, we asked whether cerebellar damage impacts feedback stabilization of the multijoint arm appropriate for the arm's intersegmental dynamics. Specifically, we tested whether cerebellar dysfunction impacts the ability of posterior deltoid to incorporate elbow motion in its long-latency response (R2 = 45–75 ms and R3 = 75–100 ms after perturbation) to an unexpected torque perturbation. Healthy and cerebellar-damaged subjects were exposed to a selected pattern of shoulder-elbow displacements to probe the response pattern from this shoulder extensor muscle. The healthy elderly subjects expressed a long-latency response linked to both shoulder and elbow motion, including an increase/decrease in shoulder extensor activity with elbow flexion/extension. Critically, cerebellar-damaged subjects displayed the normal pattern of activity in the R3 period indicating an intact ability to rapidly integrate multijoint motion appropriate to the arm's intersegmental dynamics. However, cerebellar-damaged subjects had a lower magnitude of activity that was specific to the long-latency period (both R2 and R3) and a slightly delayed onset of multijoint sensitivity. Taken together, our results suggest that the basic motor pattern of the long-latency response is housed outside the cerebellum and is scaled by processes within the cerebellum. PMID:23390311

  8. Pelvic radiography in ATLS algorithms: A diminishing role?

    Directory of Open Access Journals (Sweden)

    Buggy Donald J

    2008-03-01

    Full Text Available Abstract Background Pelvic x-ray is a routine part of the primary survey of polytraumatized patients according to Advanced Trauma Life Support (ATLS guidelines. However, pelvic CT is the gold standard imaging technique in the diagnosis of pelvic fractures. This study was conducted to confirm the safety of a modified ATLS algorithm omitting pelvic x-ray in hemodynamically stable polytraumatized patients with clinically stable pelvis in favour of later pelvic examination by CT scan. Methods We conducted a retrospective analysis of all polytraumatized patients in our emergency room between 01.07.2004 and 31.01.2006. Inclusion criteria were blunt abdominal trauma, initial hemodynamic stability and a stable pelvis on clinical examination. We excluded patients requiring immediate intervention because of hemodynamic instability. Results We reviewed the records of n = 452 polytraumatized patients, of which n = 91 fulfilled inclusion criteria (56% male, mean age = 45 years. The mechanism of trauma included 43% road traffic accidents, 47% falls. In 68/91 (75% patients, both a pelvic x-ray and a CT examination were performed; the remainder had only pelvic CT. In 6/68 (9% patients, pelvic fracture was diagnosed by pelvic x-ray. None of these 6 patients was found having a false positive pelvic x-ray, i.e. there was no fracture on pelvic CT scan. In 3/68 (4% cases a fracture was missed in the pelvic x-ray, but confirmed on CT (false negative on x-ray. None of the diagnosed fractures needed an immediate therapeutic intervention. 5 (56% were classified type A fractures, and another 4 (44% B 2.1 in computed tomography (AO classification. One A 2.1 fracture was found in a clinically stable patient who only received CT scan (1/23. Conclusion While pelvic x-ray is an integral part of ATLS assessment, this retrospective study suggests that in hemodynamically stable patients with clinically stable pevis, its sensitivity is only 67% and it may safely be omitted in

  9. Increased Surface Wind Speeds Follow Diminishing Arctic Sea Ice

    Science.gov (United States)

    Mioduszewski, J.; Vavrus, S. J.; Wang, M.; Holland, M. M.; Landrum, L.

    2017-12-01

    Projections of Arctic sea ice through the end of the 21st century indicate the likelihood of a strong reduction in ice area and thickness in all seasons, leading to a substantial thermodynamic influence on the overlying atmosphere. This is likely to have an effect on winds over the Arctic Basin, due to changes in atmospheric stability and/or baroclinicity. Prior research on future Arctic wind changes is limited and has focused mainly on the practical impacts on wave heights in certain seasons. Here we attempt to identify patterns and likely mechanisms responsible for surface wind changes in all seasons across the Arctic, particularly those associated with sea ice loss in the marginal ice zone. Sea level pressure, near-surface (10 m) and upper-air (850 hPa) wind speeds, and lower-level dynamic and thermodynamic variables from the Community Earth System Model Large Ensemble Project (CESM-LE) were analyzed for the periods 1971-2000 and 2071-2100 to facilitate comparison between a present-day and future climate. Mean near-surface wind speeds over the Arctic Ocean are projected to increase by late century in all seasons but especially during autumn and winter, when they strengthen by up to 50% locally. The most extreme wind speeds in the 90th percentile change even more, increasing in frequency by over 100%. The strengthened winds are closely linked to decreasing lower-tropospheric stability resulting from the loss of sea ice cover and consequent surface warming (locally over 20 ºC warmer in autumn and winter). A muted pattern of these future changes is simulated in CESM-LE historical runs from 1920-2005. The enhanced winds near the surface are mostly collocated with weaker winds above the boundary layer during autumn and winter, implying more vigorous vertical mixing and a drawdown of high-momentum air.The implications of stronger future winds include increased coastal hazards and the potential for a positive feedback with sea ice by generating higher winds and

  10. Reducing the Polluting Emissions. A Source for Diminishing the Climate Changes

    Directory of Open Access Journals (Sweden)

    Emilian M. DOBRESCU

    2009-06-01

    Full Text Available The USA and the Western Europe are responsible for 2/3 of the CO2 emissions accumulated until today. On the other hand, Africa has produced only 3% of polluting emission since 1900 until today, by burning mineral fuels. Since 1992, the most industrialized countries have promised to help ôthe most vulnerable nations face the adverse consequences of climate changesö by supporting the costs of adaptation. The commitment was included in the convention frame that gave birth to the Kyoto Treaty, which was rejected by the George W. Bush Administration, even though the initial document, issued in 1992, had been signed by George Bush. The industrialized countries that signed the Kyoto Treaty have decided to create a special fund for ôclimate adaptationö. Hundreds of millions of dollars had to be used in order to diminish the impact of the global warming in the most exposed areas.Lately, maybe because the CO2 emissions increase due to human activities, the planet climate has changed for worse. 2007 was a key year in evaluating the reply the planet would give to the global overheating, mainly caused by the green-house effect and worsen by El Nino oceanic stream. This superposition of climate factors made 2007 to be one of the warmest years ever registered.

  11. Estudo do equilíbrio e cinética da biossorção do pb2+ por saccharomyces cerevisiae Equilibrium and kinetic study of pb2+ biosorption by saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Joelma Morais Ferreira

    2007-10-01

    Full Text Available The biosorption, based on the use of biomass for removal of ions is distinguished as an innovative and promising technology when compared with the traditional methods. In this context, the aim of the present work is to use Saccharomyces cerevisiae as biosorbent for the retention of Pb2+ metal ions. Factorial design was used for evaluation of the process. The observed equilibrium data were well described by Langmuir and Freundlich adsorption isotherms. The maximum adsorption capacity was 1486.88 mg/g. The results indicated that Saccharomyces cerevisiae is suitable for biosorption of Pb2+ metal ions.

  12. Characterization of copper-resistant rhizosphere bacteria from Avena sativa and Plantago lanceolata for copper bioreduction and biosorption.

    Science.gov (United States)

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Camargo, Flávio A O

    2012-04-01

    Copper is a toxic heavy metal widely used to microbial control especially in agriculture. Consequently, high concentrations of copper residues remain in soils selecting copper-resistant organisms. In vineyards, copper is routinely used for fungi control. This work was undertaken to study copper resistance by rhizosphere microorganisms from two plants (Avena sativa L. and Plantago lanceolata L.) common in vineyard soils. Eleven rhizosphere microorganisms were isolated, and four displayed high resistance to copper. The isolates were identified by 16S rRNA gene sequence analysis as Pseudomonas putida (A1), Stenotrophomonas maltophilia (A2) and Acinetobacter sp. (A6), isolated from Avena sativa rhizosphere, and Acinetobacter sp. (T5), isolated from Plantago lanceolata rhizosphere. The isolates displayed high copper resistance in the temperature range from 25°C to 35°C and pH in the range from 5.0 to 9.0. Pseudomonas putida A1 resisted as much as 1,000 mg L(-1) of copper. The isolates showed similar behavior on copper removal from liquid medium, with a bioremoval rate of 30% at 500 mg L(-1) after 24 h of growth. Speciation of copper revealed high copper biotransformation, reducing Cu(II) to Cu(I), capacity. Results indicate that our isolates are potential agents for copper bioremoval and bacterial stimulation of copper biosorption by Avena sativa and Plantago lanceolata.

  13. Biosorption kinetic studies of heavy metal ions from aqueous solution by a mixture of vegetable waste (abstract)

    International Nuclear Information System (INIS)

    Mahmood, A.; Firdous, A.U.; Gill, R.

    2011-01-01

    Biosorption potential of a new bio sorbent prepared from vegetable waste composed of mixture of potato and carrot peels for the removal of heavy metals such as Ni (II) and Cu (II) from aqueous solution was determined. Batch experiments were conducted to optimize parameters i.e. initial pH, temperature, contact time, initial metal concentration and bio sorbent dose and it was observed that maximum adsorption of nickel (78%) was achieved by stirring the contents for 75 min at pH 4 and 35 deg. C by using 3.0 g of bio sorbent while in the case of copper maximum removal of copper occurred at pH 2, temperature of 50 deg. C, contact time of 45 minutes, metal concentration of 30 ppm and bio sorbent dose of 2.5 g. Kinetic studies of these reactions showed that they follow a pseudo-second order reaction, while these systems fit well in the Langmuir isotherm model and Freundlich isotherm model for Ni (II) and Cu (II) ions respectively. Both neat and metal loaded bio sorbent samples were analyzed using FT-IR spectrophotometer and X-Ray Florescence spectrometer in order to confirm the bio sorption of Ni (II) and Cu (II) and results have revealed that the metals are present in the spent bio sorbent. (author)

  14. Mass transfer kinetics of biosorption of nitrogenous matter from palm oil mill effluent by aerobic granules in sequencing batch reactor.

    Science.gov (United States)

    Fulazzaky, Mohamad Ali; Nuid, Maria; Aris, Azmi; Muda, Khalida

    2017-07-13

    Understanding of mass transfer kinetics is important for biosorption of nitrogen compounds from palm oil mill effluent (POME) to gain a mechanistic insight into future biological processes for the treatment of high organic loading wastewater. In this study, the rates of global and sequential mass transfer were determined using the modified mass transfer factor equations for the experiments to remove nitrogen by aerobic granular sludge accumulation in a sequencing batch reactor (SBR). The maximum efficiencies as high as 97% for the experiment run at [k L a] g value of 1421.8 h -1 and 96% for the experiment run at [k L a] g value of 9.6 × 10 37  h -1 were verified before and after the addition of Serratia marcescens SA30, respectively. The resistance of mass transfer could be dependent on external mass transfer that controls the transport of nitrogen molecule along the experimental period of 256 days. The increase in [k L a] g value leading to increased performance of the SBR was verified to contribute to the future applications of the SBR because this phenomenon provides new insight into the dynamic response of biological processes to treat POME.

  15. 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

  16. Night sweats, sleep disturbance, and depression associated with diminished libido in late menopausal transition and early postmenopause: baseline data from the Herbal Alternatives for Menopause Trial (HALT).

    Science.gov (United States)

    Reed, Susan D; Newton, Katherine M; LaCroix, Andrea Z; Grothaus, Lou C; Ehrlich, Kelly

    2007-06-01

    The objective of the study was to evaluate the association of depression, sleep disturbance, and menopausal symptoms with diminished libido. Data from a 2001-2002 baseline survey of 341 peri- and postmenopausal women, aged 45-55 years, participating in a randomized trial, was analyzed. Eligibility included at least 2 hot flashes and/or night sweats per day and no hormone therapy for at least the prior 3 months. The survey evaluated sexual function, depression, sleep, and vasomotor symptoms. We examined the association between these factors, using multivariate regression models. Of 341 women, 64% had diminished libido, 18% had moderate to severe depression, and 43% had poor sleep quality. Women averaged 4.6 hot flashes and 1.9 night sweats per day. Depressive symptoms (P = .003), poor sleep (P = .02), and night sweats (P = .04) were significantly associated with diminished libido. Factors associated with diminished libido in midlife are complex but include depression, disturbed sleep, and night sweats, all common symptoms of the menopausal transition and early menopause.

  17. Division of Work and Fragmented Information: An Explanation for the Diminishing Marginal Product of Labor

    OpenAIRE

    Harashima, Taiji

    2014-01-01

    In this paper, an explanation for the diminishing marginal product of labor is demonstrated in a model that incorporates the concept of entropy from information theory. First, I introduce the concept of “division of work” and argue that the division of work (i.e., the allocation of tasks in the production process) and not the division of labor (i.e., worker specialization) is the source of the diminishing marginal product of labor. Division of work results in a fragmentation of the informatio...

  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. 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

  20. 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

  1. Diminished Wastewater Treatment: Evaluation of Septic System Performance Under a Climate Change Scenario

    Science.gov (United States)

    Cooper, J.; Loomis, G.; Kalen, D.; Boving, T. B.; Morales, I.; Amador, J.

    2015-12-01

    The effects of climate change are expected to reduce the ability of soil-based onsite wastewater treatment systems (OWTS), to treat domestic wastewater. In the northeastern U.S., the projected increase in atmospheric temperature, elevation of water tables from rising sea levels, and heightened precipitation will reduce the volume of unsaturated soil and oxygen available for treatment. Incomplete removal of contaminants may lead to transport of pathogens, nutrients, and biochemical oxygen demand (BOD) to groundwater, increasing the risk to public health and likelihood of eutrophying aquatic ecosystems. Advanced OWTS, which include pre-treatment steps and provide unsaturated drainfields of greater volume relative to conventional OWTS, are expected to be more resilient to climate change. We used intact soil mesocosms to quantify water quality functions for two advanced shallow narrow drainfield types and a conventional drainfield under a current climate scenario and a moderate climate change scenario of 30 cm rise in water table and 5°C increase in soil temperature. While no fecal coliform bacteria (FCB) was released under the current climate scenario, up to 109 CFU FCB/mL (conventional) and up to 20 CFU FCB/mL (shallow narrow) were released under the climate change scenario. Total P removal rates dropped from 100% to 54% (conventional) and 71% (shallow narrow) under the climate change scenario. Total N removal averaged 17% under both climate scenarios in the conventional, but dropped from 5.4% to 0% in the shallow narrow under the climate change scenario, with additional leaching of N in excess of inputs indicating release of previously held N. No significant difference was observed between scenarios for BOD removal. The initial data indicate that while advanced OWTS retain more function under the climate change scenario, all three drainfield types experience some diminished treatment capacity.

  2. Upper gastrointestinal dysmotility after spinal cord injury: Is diminished vagal sensory processing one culprit?

    Directory of Open Access Journals (Sweden)

    Gregory M Holmes

    2012-07-01

    Full Text Available Despite the widely recognized prevalence of gastric, colonic and anorectal dysfunction after SCI, significant knowledge gaps persist regarding the mechanisms leading to post-SCI gastrointestinal (GI impairments. Briefly, the regulation of GI function is governed by a mix of parasympathetic, sympathetic and enteric neurocircuitry. Unlike the intestines, the stomach is dominated by parasympathetic (vagal control whereby gastric sensory information is transmitted via the afferent vagus nerve to neurons of the nucleus tractus solitarius (NTS. The NTS integrates this sensory information with signals from throughout the CNS. Glutamatergic and GABAergic NTS neurons project to other nuclei, including the preganglionic parasympathetic neurons of the dorsal motor nucleus of the vagus (DMV. Finally, axons from the DMV project to gastric myenteric neurons, again, through the efferent vagus nerve. SCI interrupts descending input to the lumbosacral spinal cord neurons that modulate colonic motility and evacuation reflexes. In contrast, vagal neurocircuitry remains anatomically intact after injury. This review presents evidence that unlike the post-SCI loss of supraspinal control which leads to colonic and anorectal dysfunction, gastric dysmotility occurs as an indirect or secondary pathology following SCI. Specifically, emerging data points toward diminished sensitivity of vagal afferents to GI neuroactive peptides, neurotransmitters and, possibly, macronutrients. The neurophysiological properties of rat vagal afferent neurons are highly plastic and can be altered by injury or energy balance. A reduction of vagal afferent signaling to NTS neurons may ultimately bias NTS output toward unregulated GABAergic transmission onto gastric-projecting DMV neurons. The resulting gastroinhibitory signal may be one mechanism leading to upper GI dysmotility following SCI.

  3. 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…

  4. 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

  5. Can Using Human Examples Diminish the Number of Misconceptions Held Concerning Mendelian Genetics Concepts?

    Science.gov (United States)

    Moore, John M.

    2000-01-01

    Explores high school biology and the teaching of genetics. The question is asked, Can the use of relevant, meaningful human genetics concepts diminish the number of misconceptions formed between new and existing concepts? Can the application of the Ausubelian learning theory also decrease the acquisition of misconceptions? (SAH)

  6. 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

  7. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  8. Biosorptive uptake of arsenic(V) by steam activated carbon from mung bean husk: equilibrium, kinetics, thermodynamics and modeling

    Science.gov (United States)

    Mondal, Sandip; Aikat, Kaustav; Halder, Gopinath

    2017-12-01

    The present investigation emphasizes on the biosorptive removal of toxic pentavalent arsenic from water using steam activated carbon prepared from mung bean husk (SAC-MBH). Characterization of the synthesized sorbent was done using different instrumental techniques, i.e., SEM, BET and point of zero charge. Sorptive uptake of As(V) over steam activated MBH as a function of pH (3-9), agitation speed (40-200 rpm), dosage (50-1000 mg) and temperature (298-313 K) was studied by batch process at arsenic concentration of 2 mg L-1. Lower pH increases the arsenic removal over the pH range of 3-9. Among three adsorption isotherm models examined, Langmuir model was observed to show superior results over Freundlich model. The mean sorption energy (E) estimated by Dubinin-Radushkevich model suggested that the process of adsorption was chemisorption. Thermodynamic parameters confer that the sorption process was spontaneous, exothermic and feasible in nature. The pseudo-second-order rate kinetics of arsenic gave better correlation coefficients as compared to pseudo-first-order kinetics equation. Three process parameters, viz. adsorbent dosage, agitation speed and pH were opted for optimizing As(V) elimination using central composite design matrix of response surface methodology (RSM). The identical design setup was used for artificial neural network (ANN) for comparing its prediction capability with RSM towards As(V) removal. Maximum arsenic removal was observed to be 98.75% at sorbent dosage 0.75 gm L-1, pH 3.0, agitation speed 160 rpm and temperature 308 K. The study concluded that SAC-MBH could be a competent adsorbent for As(V) removal and ANN model was better in arsenic removal predictability results than RSM model.

  9. Biosorption of chromium(III) by two Brown algae macrocystis pyrifera and undaria pinnatifida: equilibrium and kinetic study

    Energy Technology Data Exchange (ETDEWEB)

    Cazon, Josefina Plaza H.; Benitez, Leonardo; Donati, Edgardo; Viera, Marisa [Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 47 y 115 (1900) La Plata (Argentina)

    2012-02-15

    Two brown algae, Macrocystis pyrifera and Undaria pinnatifida, were employed to remove Cr(III) from aqueous solutions. Both seaweeds were characterized in terms of alginate yields. The alginate contents were 20 and 30% of the dry weight for M. pyrifera and U. pinnatifida, respectively. Kinetics experiments were carried out at different initial pH values. Cr(III) biosorption was affected by the solution pH. The highest metal uptake was found at pH 4 for both biosorbents. Different models were applied to elucidate the rate-controlling mechanism: pseudo-first-order, pseudo-second-order, external mass transfer and intra-particle diffusion. The application of Langmuir, Freundlich and Dubinin-Radushkevich models to the equilibrium data showed a better fitting to the first model. The maximum Cr(III) sorption capacity (q{sub m}) and the affinity coefficient (b) were very similar for both biosorbents: 0.77 mmol/g and 1.20 L/mmol for M. pyrifera and 0.74 mmol/g and 1.06 L/mmol for U. pinnatifida. The free energy of the sorption process was estimated using the Dubinin-Radushkevich isotherm. The values indicate that the processes are chemical sorptions. To evaluate the significance of the ion-exchange mechanism, the light metals (Ca{sup 2+}, Na{sup +}, Mg{sup 2+} and K{sup +}) and pH were measured during the experiments. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Optical modulator including grapene

    Science.gov (United States)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  11. 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.

  12. Rapid bioremediation of Alizarin Red S and Quinizarine Green SS dyes using Trichoderma lixii F21 mediated by biosorption and enzymatic processes.

    Science.gov (United States)

    Adnan, Liyana Amalina; Sathishkumar, Palanivel; Yusoff, Abdull Rahim Mohd; Hadibarata, Tony; Ameen, Fuad

    2017-01-01

    In this study, a newly isolated ascomycete fungus Trichoderma lixii F21 was explored to bioremediate the polar [Alizarin Red S (ARS)] and non-polar [Quinizarine Green SS (QGSS)] anthraquinone dyes. The bioremediation of ARS and QGSS by T. lixii F21 was found to be 77.78 and 98.31 %, respectively, via biosorption and enzymatic processes within 7 days of incubation. The maximum biosorption (ARS = 33.7 % and QGSS = 74.7 %) and enzymatic biodegradation (ARS = 44.1 % and QGSS = 23.6 %) were observed at pH 4 and 27 °C in the presence of glucose and yeast extract. The laccase and catechol 1,2-dioxygenase produced by T. lixii F21 were involved in the molecular conversions of ARS and QGSS to phenolic and carboxylic acid compounds, without the formation of toxic aromatic amines. This study suggests that T. lixii F21 may be a good candidate for the bioremediation of industrial effluents contaminated with anthraquinone dyes.

  13. 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

  14. Diminishing Marginal Returns From Genomic Selection As More Selection Candidates Are Phenotyped

    DEFF Research Database (Denmark)

    Okeno, Tobias O; Henryon, Mark; Sørensen, Anders Christian

    We used stochastic simulation to test hypotheses that, (i) phenotyping proportion of high ranking selection candidates based on estimated breeding values (EBV) before genotyping could realize as much genetic gains as phenotyping all candidates, and (ii) there is diminishing return to selection...... as more candidates are phenotyped in genomic breeding programs. Three phenotyping criteria, namely, random (RS), EBV and true breeding value (TBV) were investigated under two schemes (across-population and within-litter) using traditional-BLUP and genomic-BLUP models. The EBV ranked above RS and realized...... maximum achievable gains in the breeding program at 80% phenotyping. There was diminishing return to selection as more candidates were phenotyped; indicating that information content is not so large in the last candidate compared to the first candidate phenotyped. These findings demonstrate the need...

  15. 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.

  16. Diminished levels of the soluble form of RAGE are related to poor survival in malignant melanoma.

    Science.gov (United States)

    Wagner, Nikolaus B; Weide, Benjamin; Reith, Maike; Tarnanidis, Kathrin; Kehrel, Coretta; Lichtenberger, Ramtin; Pflugfelder, Annette; Herpel, Esther; Eubel, Jana; Ikenberg, Kristian; Busch, Christian; Holland-Letz, Tim; Naeher, Helmut; Garbe, Claus; Umansky, Viktor; Enk, Alexander; Utikal, Jochen; Gebhardt, Christoffer

    2015-12-01

    RAGE is a central driver of tumorigenesis by sustaining an inflammatory tumor microenvironment. This study links the soluble forms of RAGE (sRAGE and esRAGE) with clinical outcome of melanoma patients. Moreover, tissue expression of RAGE was analyzed using immunohistochemistry on two independent tissue microarrays (TMA) containing 35 or 257 primary melanomas, and 41 or 22 benign nevi, respectively. Serum concentrations of sRAGE and esRAGE were measured in 229 Stage III-IV patients using ELISA and plasma concentrations of sRAGE were analyzed in an independent second cohort with 173 samples of Stage I-IV patients. In this cohort, three well-described SNPs in the RAGE gene were analyzed. RAGE protein expression was highly upregulated in primary melanomas compared to benign nevi in the two TMA (p melanomas (p = 0.046). sRAGE and esRAGE were identified as prognostic markers for survival as diminished sRAGE (p = 0.034) and esRAGE (p = 0.012) serum levels correlated with poor overall survival (OS). Multivariate Cox regression analysis showed that diminished serum sRAGE was independently associated with poor survival (p = 0.009). Moreover, diminished sRAGE was strongly associated with impaired OS in the second cohort (p forms of RAGE and variants in its genetic locus are prognostic markers for survival in melanoma patients with high risk for progression. © 2015 UICC.

  17. 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

  18. CNGB3-Achromatopsia Clinical Trial With CNTF: Diminished Rod Pathway Responses With No Evidence of Improvement in Cone Function

    Science.gov (United States)

    Zein, Wadih M.; Jeffrey, Brett G.; Wiley, Henry E.; Turriff, Amy E.; Tumminia, Santa J.; Tao, Weng; Bush, Ronald A.; Marangoni, Dario; Wen, Rong; Wei, Lisa L.; Sieving, Paul A.

    2014-01-01

    Purpose. Ciliary neurotrophic factor (CNTF) protects rod photoreceptors from retinal degenerative disease in multiple nonhuman models. Thus far, CNTF has failed to demonstrate rod protection in trials for human retinitis pigmentosa. Recently, CNTF was found to improve cone photoreceptor function in a canine CNGB3 achromatopsia model. This study explores whether this finding translates to humans with CNGB3 achromatopsia. Methods. A five-subject, open-label Phase I/II study was initiated by implanting intraocular microcapsules releasing CNTF (nominally 20 ng/d) into one eye each of CNGB3 achromat participants. Fellow eyes served as untreated controls. Subjects were followed for 1 year. Results. Pupil constriction in treated eyes gave evidence of intraocular CNTF release. Additionally, scotopic ERG responses were reduced, and dark-adapted psychophysical absolute thresholds were increased, attributable to diminished rod or rod pathway activity. Optical coherence tomography revealed that the cone-rich fovea underwent structural changes as the foveal hyporeflective zone (HRZ) became diminished in CNTF-treated eyes. No objectively measurable enhancement of cone function was found by assessments of visual acuity, mesopic increment sensitivity threshold, or the photopic ERG. Careful measurements of color hue discrimination showed no change. Nonetheless, subjects reported beneficial changes of visual function in the treated eyes, including reduced light sensitivity and aversion to bright light, which may trace to decreased effective ambient light from the pupillary constriction; further they noted slowed adaptation to darkness, consistent with CNTF action on rod photoreceptors. Conclusions. Ciliary neurotrophic factor did not measurably enhance cone function, which reveals a species difference between human and canine CNGB3 cones in response to CNTF. (ClinicalTrials.gov number, NCT01648452.) PMID:25205868

  19. Diffusion mechanism and the kinetics of biosorption of textile dye by ...

    African Journals Online (AJOL)

    Chemical modification of adsorbent efficacy was performed on poultry waste impregnated with H3PO4 and ZnCl2. The thermo-chemical activation process was carried out at different dwell time. Two simplified kinetic models, including the intra particle diffusion model were selected to follow the adsorption process. Sorption ...

  20. The TP73 gene polymorphism (rs4648551, A>G is associated with diminished ovarian reserve.

    Directory of Open Access Journals (Sweden)

    Laura Diniz Vagnini

    Full Text Available It's known that the members of the TP53 family are involved in the regulation of female reproduction. Studies in mice showed that the TP73 gene (member of this family plays a role in the size of follicular pool, ovulation rate and maintenance of genomic stability. In the present study we analyzed data from 605 patients with ≤ 37 years attending their first intracytoplasmic sperm injection (ICSI. The association between the TP73 polymorphism (rs4648551, A>G and the following parameters related to ovarian reserve, like age, antral follicular count (AFC, anti-Mullerian hormone levels (AMH and ovarian response prediction index (ORPI was evaluated. Our results showed an association of the AA genotype with diminished ovarian reserve (AMH <1, AFC ≤9. Women presenting the AA genotype had a 2.0-fold increased risk for having AMH <1 and AFC ≤9 (OR 2.0, 95% CI 1.23-3.31, P = 0.005. Patients presenting AA genotype had the lowest levels of AMH (P = 0.02, the lowest number of antral follicles (P = 0.01 and the lowest ORPI (P = 0.007. Analyzing the alleles, we can see an enrichment of the A allele in the group of diminished ovarian reserve (OR 1.4, 95%CI 1.02-1.83, P = 0.04. To the best of our knowledge, the present study is the first to analyze this polymorphism in humans for assessing the numbers of ovarian follicles and AMH levels and, therefore, the ovarian reserve. Our findings can contribute to the use of this polymorphism as a potential marker of diminished ovarian reserve.

  1. Diminished functional connectivity on the road to child sexual abuse in pedophilia.

    Science.gov (United States)

    Kärgel, Christian; Massau, Claudia; Weiß, Simone; Walter, Martin; Kruger, Tillmann H C; Schiffer, Boris

    2015-03-01

    Pedophilia is a disorder recognized for its impairment to the individual and for the harm it may cause to others. However, the neurobiology of pedophilia and a possible propensity to sexually abuse children are not well understood. In this study, we thus aimed at providing new insights in how functional integration of brain regions may relate to pedophilia or child sexual abuse (CSA). By using functional magnetic resonance imaging (fMRI) technique, we compared functional connectivity at rest (RSFC) between pedophiles who engaged (P+CSA; N = 12) or did not engage (P-CSA; N = 14) in CSA and healthy controls (HCs; N = 14) within two networks: (i) the default mode network and (ii) the limbic network that has been linked to pedophilia before. Pedophiles who engaged in CSA show diminished RSFC in both networks compared with HC and P-CSA. Most importantly, they showed diminished RSFC between the left amygdala and orbitofrontal as well as anterior prefrontal regions. Though significant age differences between groups could not be avoided, correlation control analysis did not provide evidence for the assumption that the RSFC effects were related to age differences. We found significantly diminished RSFC in brain networks critically involved in widespread motivational and socio-emotional processes. These results extend existing models of the functional neuroanatomy of pedophilia and CSA as altered RSFC between these regions were related to CSA rather than pedophilia and thus may account for an increased propensity to engage in CSA in people suffering from pedophilia. © 2015 International Society for Sexual Medicine.

  2. Symptoms of Diminished Autonomy over Cigarettes with Non-Daily Use

    Directory of Open Access Journals (Sweden)

    Judith A. Savageau

    2008-12-01

    Full Text Available Data from a nationally representative sample of smokers (ages 12-22 years, n=2,091 was examined to investigate the prevalence of symptoms of diminished autonomy over cigarettes. Six symptoms were assessed: failed cessation, smoking despite a desire to quit, and a need or urge to smoke, irritability, restlessness, or disrupted concentration attributed to nicotine withdrawal. One or more of the six symptoms were present in 18.9% of subjects who smoked less often than once per week. Among subjects who had not smoked 20 cigarettes in their lifetime, 12.6% had symptoms of nicotine withdrawal, and 25% had made an unsuccessful quit attempt.

  3. Comparative Study on Biosorption of Zn(II, Cu(II and Cr(VI from Textile Dye Effluent Using Sawdust and Neem Leaves Powder

    Directory of Open Access Journals (Sweden)

    K. Gopalakrishnan

    2010-01-01

    Full Text Available The performance of the low cost adsorbents such as sawdust and neem leaves powder in removing the heavy metals like Zn(II, Cu(II and Cr(VI from textile dye effluent are reported. Adsorbent dosage, pH and contact time were taken as parameters for biosorption study. Removal of heavy metal ions from the textile dye effluent increases with increase in adsorbent dosage. The influence of pH and contact time was maximum for removal of heavy metal ions. The presence of the decreased heavy metal toxicity in the treated textile dye effluent was evaluated through the percentage of seed germination of Vigna mungo L. On comparison, sawdust was found to be good adsorbent compared to neem leaves powder.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. When is diminishment a form of enhancement? Rethinking the enhancement debate in biomedical ethics

    Science.gov (United States)

    Earp, Brian D.; Sandberg, Anders; Kahane, Guy; Savulescu, Julian

    2014-01-01

    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 should be considered 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. PMID:24550792

  10. Ski diminishes TGF-β1-induced myofibroblast phenotype via up-regulating Meox2 expression.

    Science.gov (United States)

    Chen, Zhaowei; Li, Wenjing; Ning, Yan; Liu, Tong; Shao, Jingxiang; Wang, Yaojun

    2014-12-01

    The aim of the present work was to investigate the mechanism of transforming growth factor (TGF)-β1 and Sloan-Kettering Institute (Ski) in the pathogenesis of hypertrophic scars (HS). Wound healing is an inherent process, but the aberrant wound healing of skin injury may lead to HS. There has been growing evidence suggesting a role for TGF-β1 and Ski in the pathogenesis of fibrosis. The MTT assay was used to detect the cell proliferation induced by TGF-β1. The Ski gene was transduced into cells with an adenovirus, and then the function of Ski in cell proliferation and differentiation was observed. Ski mRNA levels were measured by RT-PCR. Western blotting was used to detect the protein expression of α-SMA, E-cadherin, Meox1, Meox2, Zeb1 and Zeb2. TGF-β1 can promote human skin fibroblast (HSF) cell proliferation in a time-dependent manner, but the promoting effect could be suppressed by Ski. TGF-β1 also induces the formation of the myofibroblast phenotype and the effect of TGF-β1 could be diminished by Ski. Also, Ski modulates the cardiac myofibroblast phenotype and function through suppression of Zeb2 by up-regulating the expression of Meox2. Ski diminishes the myofibroblast phenotype induced by TGF-β1 through the suppression of Zeb2 by up-regulating the expression of Meox2. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. 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.

  12. 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.

  13. 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.

  14. Effect of functional groups on sludge for biosorption of reactive dyes.

    Science.gov (United States)

    Cai, Junxiong; Cui, Longzhe; Wang, Yanxin; Liu, Chengfu

    2009-01-01

    The sludge, which was collected from a biological coke wastewater treatment plant, was used as a low-cost adsorbent in the removal of reactive dyes (Methylene Blue (MB) and Reactive Red 4 (RR4)) from aqueous solution. The pH of dye solution played an important role on the dye uptake. With the solution pH increase, the MB uptake increased; whereas the RR4 uptake decreased. The maximum uptake of RR4 by protonated sludge was 73.7 mg/g at pH 1, and the maximum uptake of MB by sludge was 235.3 mg/g at pH 9. Three functional groups, including carboxyl, phosphonate, and amine group, were identified by potentiometric titration, fourier transform infrared (FT-IR) spectrometry, and X-ray photoelectron spectroscopy (XPS). The anionic functional groups, phosphonate and carboxyl group, were identified as the binding sites for the cationic MB. Amine groups were identified to bind RR4. The main mechanism of the reactive dyestuffs adsorption is electrostatic interaction.

  15. Biosorption behaviors of uranium (VI) from aqueous solution by sunflower straw and insights of binding mechanism

    International Nuclear Information System (INIS)

    Lian Ai; Xuegang Luo; Xiaoyan Lin; Sizhao Zhang

    2013-01-01

    Uranium (VI)-containing water has been recognized as a potential longer-term radiological health hazard. In this work, the sorptive potential of sunflower straw for U (VI) from aqueous solution was investigated in detail, including the effect of initial solution pH, adsorbent dosage, temperature, contact time and initial U (VI) concentration. A dose of 2.0 g L -1 of sunflower straw in an initial U (VI) concentration of 20 mg L -1 with an initial pH of 5.0 and a contact time of 10 h resulted in the maximum U (VI) uptake (about 6.96 mg g -1 ) at 298 K. The isotherm adsorption data was modeled best by the nonlinear Langmuir-Freundlich equation. The equilibrium sorption capacity of sunflower straw was observed to be approximately seven times higher than that of coconut-shell activated carbon as 251.52 and 32.37 mg g -1 under optimal conditions, respectively. The positive enthalpy and negative free energy suggested the endothermic and spontaneous nature of sorption, respectively. The kinetic data conformed successfully to the pseudo-second-order equation. Furthermore, energy dispersive X-ray, fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated that U (VI) adsorption onto sunflower straw was predominantly controlled by ion exchange as well as complexation mechanism. The study revealed that sunflower straw could be exploited for uranium remediation of aqueous streams as a promising adsorbent. (author)

  16. 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.)

  17. 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.

  18. Diminished neural resources allocation to time processing in Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Anna Lambrechts

    2018-01-01

    Results: Our results suggest that compared to TDC individuals, individuals with ASD are less able to predict the duration of the standard tone accurately, affecting the sensitivity of the comparison process. In addition, contrary to TDC individuals who allocate resources at different times depending on the nature of the task (pitch or duration discrimination, individuals with ASD seem to engage less resources for the Duration task than for the Pitch task regardless of the context. Although individuals with ASD showed top-down adaptation to the context of the task, this neuronal strategy reflects a bias in the readiness to perform different types of tasks, and in particular a diminished allocation of resources to duration processing which could have cascading effect on learning and development of other cognitive functions.

  19. 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.

  20. Acute hyperinsulinemia decreases plasma osteoprotegerin with diminished effect in type 2 diabetes and obesity

    DEFF Research Database (Denmark)

    Jørgensen, Gitte Maria; Vind, Birgitte; Nybo, Mads

    2009-01-01

    the acute effects of insulin on plasma OPG concentrations in individuals with type 2 diabetes and obese individuals compared with lean controls. DESIGN: The study population consisted of ten type 2 diabetic, ten obese subjects, and ten lean subjects with no family history of diabetes. METHODS: All subjects...... infusion decreased plasma OPG concentrations in all groups (Pobese and type 2 diabetic individuals (P=0.007). Baseline OPG correlated with fasting insulin, baseline lactate, and low density lipoprotein cholesterol in the diabetic group, and with baseline FFA...... in the lean group. The relative change of OPG in response to insulin correlated inversely with HbA1c and baseline FFA in the lean group. CONCLUSIONS: Acute hyperinsulinemia decreases plasma OPG, but with diminished effect in individuals with type 2 diabetes and obesity. Increased levels of OPG in arteries...

  1. SAT predicts GPA better for high ability subjects: Implications for Spearman's Law of Diminishing Returns.

    Science.gov (United States)

    Coyle, Thomas; Snyder, Anissa; Pillow, David; Kochunov, Peter

    2011-04-01

    This research examined the predictive validity of the SAT (formerly, the Scholastic Aptitude Test) for high and low ability groups. SAT scores and college GPAs were obtained from the 1997 National Longitudinal Survey of Youth. Subjects were classified as high or low ability by g factor scores from the Armed Services Vocational Aptitude Battery. SAT correlations with GPA were higher for high than low ability subjects. SAT g loadings (i.e., SAT correlations with g) were equivalent for both groups. This is the first study to show that the predictive validity of the SAT varies for ability groups that differ in g. The results contradict a presumption, based on Spearman's Law of Diminishing Returns, that a test's predictive validity should be lower for high ability subjects. Further research is needed to identify factors that contribute to the predictive validity of the SAT for groups that differ in g.

  2. 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.

  3. 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

  4. Use of the radio mutagenesis gamma to diminish the germinative periods of the seeds

    International Nuclear Information System (INIS)

    Ramos Espinosa, K.A.; Damera Martinez, A.; Benito Zamora, E.; Vazquez Hernandez, L.

    2001-01-01

    Among the nuclear techniques that have been used in Cuba in to feasible way for their it lives it uses in the agriculture it dog think about that the radio mutagenesis is that of advance it lives. In this address the fundamental problem consists in that to the being to casuistically method forces to uses to great initial population. The Fruit Bomb Net Maradol was studied and it was obtained to diminish its germination period in 12 days without affecting the quality of the cultivation. The seeds were irradiated with an irradiator with source of Co-60, originator of radiations a (gamma) with to power of dose of 2,76 kGy/h and to half energy of 1,25 MeV. The dose range applied to the seeds was among 50 - 250 Gy

  5. Characterizing and Diminishing Autofluorescence in Formalin-fixed Paraffin-embedded Human Respiratory Tissue

    Science.gov (United States)

    Davis, A. Sally; Richter, Anke; Becker, Steven; Moyer, Jenna E.; Sandouk, Aline; Skinner, Jeff

    2014-01-01

    Tissue autofluorescence frequently hampers visualization of immunofluorescent markers in formalin-fixed paraffin-embedded respiratory tissues. We assessed nine treatments reported to have efficacy in reducing autofluorescence in other tissue types. The three most efficacious were Eriochrome black T, Sudan black B and sodium borohydride, as measured using white light laser confocal Λ2 (multi-lambda) analysis. We also assessed the impact of steam antigen retrieval and serum application on human tracheal tissue autofluorescence. Functionally fitting this Λ2 data to 2-dimensional Gaussian surfaces revealed that steam antigen retrieval and serum application contribute minimally to autofluorescence and that the three treatments are disparately efficacious. Together, these studies provide a set of guidelines for diminishing autofluorescence in formalin-fixed paraffin-embedded human respiratory tissue. Additionally, these characterization techniques are transferable to similar questions in other tissue types, as demonstrated on frozen human liver tissue and paraffin-embedded mouse lung tissue fixed in different fixatives. PMID:24722432

  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. 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.

  8. Diminished macrophage apoptosis and reactive oxygen species generation after phorbol ester stimulation in Crohn's disease.

    Directory of Open Access Journals (Sweden)

    Christine D Palmer

    2009-11-01

    Full Text Available Crohn's Disease (CD is a chronic relapsing disorder characterized by granulomatous inflammation of the gastrointestinal tract. Although its pathogenesis is complex, we have recently shown that CD patients have a systemic defect in macrophage function, which results in the defective clearance of bacteria from inflammatory sites.Here we have identified a number of additional macrophage defects in CD following diacylglycerol (DAG homolog phorbol-12-myristate-13-acetate (PMA activation. We provide evidence for decreased DNA fragmentation, reduced mitochondrial membrane depolarization, impaired reactive oxygen species production, diminished cytochrome c release and increased IL-6 production compared to healthy subjects after PMA exposure. The observed macrophage defects in CD were stimulus-specific, as normal responses were observed following p53 activation and endoplasmic reticulum stress.These findings add to a growing body of evidence highlighting disordered macrophage function in CD and, given their pivotal role in orchestrating inflammatory responses, defective apoptosis could potentially contribute to the pathogenesis of CD.

  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. Accelerated Osteogenic Orthodontics™ for retreatment of a patient with diminished root length and absence of the maxillary central incisor

    Directory of Open Access Journals (Sweden)

    Armando Montesinos F

    2015-10-01

    Full Text Available An 18-year-old female patient visited a university orthodontics department with a chief complaint of an unesthetic appearance of her teeth, including a protruded upper central incisor and unsatisfactory results from previous orthodontic treatment. Pretreatment records showed a Class II skeletal and dental relation with proclined upper and lower incisors, replacement of an absent upper left central incisor with the left upper cuspid, presence of the upper left deciduous cuspid, mild crowding, and 4 mm of overbite and overjet. The panoramic radiograph showed shortened roots of multiple teeth. Accelerated Osteogenic Orthodontics™ (AOO™ was recommended as an approach to reduce the treatment time and the risk of further root shortening. Despite being more expensive and requiring a surgical procedure, this treatment option was very attractive to the patient. The overall treatment time was 14 months. Facial balance was improved, and good occlusal relationships were achieved from the functional and esthetic perspectives. In conclusion, surgically facilitated orthodontics (specifically, AOO™ is an efficient and safe therapeutic tool for treating or retreating orthodontic patients with diminished root length.

  11. Accelerated Osteogenic Orthodontics™ for retreatment of a patient with diminished root length and absence of the maxillary central incisor.

    Science.gov (United States)

    Montesinos F, Armando; Linares T, Silvana; Pérez-Gasque B, Marisol

    2015-10-01

    An 18-year-old female patient visited a university orthodontics department with a chief complaint of an unesthetic appearance of her teeth, including a protruded upper central incisor and unsatisfactory results from previous orthodontic treatment. Pretreatment records showed a Class II skeletal and dental relation with proclined upper and lower incisors, replacement of an absent upper left central incisor with the left upper cuspid, presence of the upper left deciduous cuspid, mild crowding, and 4 mm of overbite and overjet. The panoramic radiograph showed shortened roots of multiple teeth. Accelerated Osteogenic Orthodontics™ (AOO™) was recommended as an approach to reduce the treatment time and the risk of further root shortening. Despite being more expensive and requiring a surgical procedure, this treatment option was very attractive to the patient. The overall treatment time was 14 months. Facial balance was improved, and good occlusal relationships were achieved from the functional and esthetic perspectives. In conclusion, surgically facilitated orthodontics (specifically, AOO™) is an efficient and safe therapeutic tool for treating or retreating orthodontic patients with diminished root length.

  12. 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.

  13. 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.

  14. 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

  15. Vitamin D Levels in Patients with Autoimmune Thyroiditis with Diminished Thyroid Function

    Directory of Open Access Journals (Sweden)

    V.V. Povoroznyuk

    2014-08-01

    Full Text Available The study examined vitamin D levels in 75 patients with autoimmune thyroiditis (AIT with diminished thyroid function. The objective of the study — to determine the content of 25(OHD in patients with overt and subclinical hypothyroidism on the background of AIT. Materials and Methods. 75 patients (59 women and 16 men and 25 apparently healthy subjects (matched for age and sex were followed. The levels of thyroid stimulating hormone (TSH, free thyroxine (fT4, free triiodothyronine (fT3, antibodies to thyroid peroxidase (TPO, and the content of 25(OHD in the blood serum were determined. Results. Patients with AІT were divided according to the levels of TSH and thyroid hormones into the group with subclinical (n = 21 and overt (n = 54 hypothyroidism. TSH level was significantly higher in the group with subclinical (6.80 ± 1.84 mcU/ml and overt hypothyroidism (11.38 ± 2.16 mcU/ml compared with the control group (2.11 ± 0.37 mcU/ml (p < 0.05. The level of antibodies to TPO was 312.83 ± 7.19 U/ml in subclinical hypothyroidism and 546.29 ± 9.81 U/ml — in overt hypothyroidism. 25(OHD level in blood serum was significantly lower in subclinical (18.8 ± 1.2 nmol/l and overt hypothyroidism (21.7 ± 1.3 nmol/l compared with the control group (27.3 ± 1.4 nmol/l (p < 0.05. Highly reliable negative correlation was established between the level of TSH, antibodies to TPO and vitamin D (p < 0.001. Also highly reliable positive correlation was established between the levels of serum 25(OHD and fT4 content (p < 0.001, between TSH and TPO antibody levels (p < 0.05. Conclusions. Vitamin D deficiency is combined with the presence of AIT with diminished thyroid function (in subclinical and overt hypothyroidism. Further studies are needed to determine vitamin D deficiency as a causal factor of AIT.

  16. Biosorption and Biomineralization of U(VI by the marine bacterium Idiomarina loihiensis MAH1: effect of background electrolyte and pH.

    Directory of Open Access Journals (Sweden)

    Fernando Morcillo

    Full Text Available The main goal of this study is to compare the effects of pH, uranium concentration, and background electrolyte (seawater and NaClO4 solution on the speciation of uranium(VI associated with the marine bacterium Idiomarina loihiensis MAH1. This was done at the molecular level using a multidisciplinary approach combining X-ray Absorption Spectroscopy (XAS, Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS, and High Resolution Transmission Electron Microscopy (HRTEM. We showed that the U(VI/bacterium interaction mechanism is highly dependent upon pH but also the nature of the used background electrolyte played a role. At neutral conditions and a U concentration ranging from 5·10(-4 to 10(-5 M (environmentally relevant concentrations, XAS analysis revealed that uranyl phosphate mineral phases, structurally resembling meta-autunite [Ca(UO22(PO42 2-6H2O] are precipitated at the cell surfaces of the strain MAH1. The formation of this mineral phase is independent of the background solution but U(VI luminescence lifetime analyses demonstrated that the U(VI speciation in seawater samples is more intricate, i.e., different complexes were formed under natural conditions. At acidic conditions, pH 2, 3 and 4.3 ([U] = 5·10(-4 M, background electrolyte  = 0.1 M NaClO4, the removal of U from solution was due to biosorption to Extracellular Polysaccharides (EPS and cell wall components as evident from TEM analysis. The LIII-edge XAS and TRLFS studies showed that the biosorption process observed is dependent of pH. The bacterial cell forms a complex with U through organic phosphate groups at pH 2 and via phosphate and carboxyl groups at pH 3 and 4.3, respectively. The differences in the complexes formed between uranium and bacteria on seawater compared to NaClO4 solution demonstrates that the actinide/microbe interactions are influenced by the three studied factors, i.e., the pH, the uranium concentration and the chemical composition of the

  17. 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.

  18. 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.

  19. 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.

  20. Application of the Diminishing Returns Concept in the Hydroecologic Restoration of Riverscapes

    Energy Technology Data Exchange (ETDEWEB)

    Diefenderfer, Heida L.; Johnson, Gary E.; Skalski, John R.; Breithaupt, Stephen A.; Coleman, Andre M.

    2012-03-17

    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.

  1. 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.

  2. Do online reviews diminish physician authority? The case of cosmetic surgery in the U.S.

    Science.gov (United States)

    Menon, Alka V

    2017-05-01

    This article analyzes the substance and perception of online physician reviews, which are qualitative and quantitative assessments of physicians written and shared by patients, in the case of U.S. cosmetic surgery. Like other cash-pay medical specialties, cosmetic surgery is elective and paid for largely out of pocket, with patients having latitude in their choice of surgeon. Drawing on qualitative data from interviews, observations of an American Society of Aesthetic Plastic Surgery professional meeting, and online reviews from the platforms RealSelf and Yelp, I identify two interdependent contributors to physician authority: reputation and expertise. I argue that surgeons see reviews overwhelmingly as a threat to their reputation, even as actual review content often positively reinforces physician expertise and enhances physician reputation. I show that most online reviews linked to interview participants are positive, according considerable deference to surgeons. Reviews add patients' embodied and consumer expertise as a circumscribed supplement to surgeons' technical expertise. Moreover, reviews change the doctor-patient relationship by putting it on display for a larger audience of prospective patients, enabling patients and review platforms to affect physician reputation. Surgeons report changing how they practice to establish and maintain their reputations. This research demonstrates how physician authority in medical consumerist contexts is a product of reputation as well as expertise. Consumerism changes the doctor-patient relationship and makes surgeons feel diminished authority by dint of their reputational vulnerability to online reviews. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Estrogen receptor diminishes DNA-binding activities of chicken GATA-1 and CACCC-binding proteins.

    Science.gov (United States)

    Holth, L T; Sun, J M; Coutts, A S; Murphy, L C; Davie, J R

    1997-12-01

    The estrogen receptor (ER) repressed erythroid differentiation and erythroid-specific gene expression. In this study, we investigated the effect of ER alpha (referred to throughout as ER) on DNA-binding activities of transcription factors involved in regulating the expression of erythroid-specific genes, and, in particular, the histone H5 gene. Using electrophoretic mobility shift assays, we found that in the presence of rabbit reticulocyte lysate, human ER reduced the binding activities of chicken immature erythrocyte nuclear extracted proteins to GATA and CACCC sites in the H5 promoter and enhancer. In contrast, the binding activities of NF1 and Sp1 were not affected by ER. Binding of ER to an estrogen response element was enhanced by addition of rabbit reticulocyte lysate. This lysate was also necessary for ER to diminish the DNA-binding activity of GATA-1. These results suggest that additional factor(s) are necessary for full ER function. Both GATA-1 and CACCC-binding proteins are critical for the developmentally regulated expression of erythroid-specific genes. We hypothesize that interference in DNA-binding activities of GATA-1 and CACCC-binding proteins is the mechanism by which the ER inhibits regulation of these genes.

  4. 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

  5. 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.

  6. Recovery of diminished mealtime-associated anticipatory behavior by aniracetam in aged rats.

    Science.gov (United States)

    Tanaka, Y; Kurasawa, M; Nakamura, K

    2000-08-01

    Disease- or age-related neuropsychiatric symptoms and cognitive and chronobiological impairments greatly aggravate the activities of daily living (ADL) in patients. The present study evaluates the effects of aniracetam on a decline in mealtime-associated anticipatory behavior in aged rats, as an animal model of temporally regulated behaviors or habitual daily activities. Aged rats showed a lower but typical nocturnal motor activity rhythm than young rats when the animals were fed ad lib. Mealtime-associated anticipatory behavior emerged in young rats when the rats were fed at a fixed time for 6 days, but the activity in aged rats was diminished. Repeated administration of aniracetam (100 mg/kg PO) or physostigmine (0.1 mg/kg SC) for 7 days ameliorated the impaired anticipatory behavior in aged rats. Nefiracetam (10 mg/kg PO) was ineffective. All compounds tested had no effect on appetite or motor ability. These results indicate that aging disturbs the timing or temporal regulation of anticipatory behavior, probably resulting from dysfunction in a food-entrainable oscillator linked to central cholinergic systems. The restoration of the time-keeping ability by aniracetam may be mediated by the facilitation of reticulothalamic cholinergic neurotransmission, and the action may lead to the improvement of declined ADL in stroke patients.

  7. Ambient groundwater flow diminishes nitrate processing in the hyporheic zone of streams

    Science.gov (United States)

    Azizian, Morvarid; Boano, Fulvio; Cook, Perran L. M.; Detwiler, Russell L.; Rippy, Megan A.; Grant, Stanley B.

    2017-05-01

    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. Here we utilize 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 Damköhler 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.

  8. Inhibition of the Pim1 oncogene results in diminished visual function.

    Directory of Open Access Journals (Sweden)

    Jun Yin

    Full Text Available Our objective was to profile genetic pathways whose differential expression correlates with maturation of visual function in zebrafish. Bioinformatic analysis of transcriptomic data revealed Jak-Stat signalling as the pathway most enriched in the eye, as visual function develops. Real-time PCR, western blotting, immunohistochemistry and in situ hybridization data confirm that multiple Jak-Stat pathway genes are up-regulated in the zebrafish eye between 3-5 days post-fertilisation, times associated with significant maturation of vision. One of the most up-regulated Jak-Stat genes is the proto-oncogene Pim1 kinase, previously associated with haematological malignancies and cancer. Loss of function experiments using Pim1 morpholinos or Pim1 inhibitors result in significant diminishment of visual behaviour and function. In summary, we have identified that enhanced expression of Jak-Stat pathway genes correlates with maturation of visual function and that the Pim1 oncogene is required for normal visual function.

  9. 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.

  10. Diminished osmotic fragility of mouse erythrocytes following intravenous injection of polymeric plutonium

    International Nuclear Information System (INIS)

    Joshima, Hisamasa; Kashima, Masatoshi; Matsuoka, Osamu

    1984-01-01

    Changes in the osmotic fragility and the mean corpuscular diameter of erythrocytes in CFNo.1/Nrs male mice caused by internal irradiation with polymeric 239 Pu at the dose levels of 15 μCi/kg, 10 μCi/kg and 5 μCi/kg were studied at 28 and 56 days after intravenous injection of plutonium. At 56 days after injection of plutonium, osmotic fragility curves were found to shift toward lower NaCl concentration in proportion to the amount of plutonium injected, which indicated the reduction of osmotic fragility. The size distribution curves of erythrocytes were slightly shifted toward larger size, depending on the amount of plutonium injected. Mean corpuscular diameter of erythrocytes in the highest dose group was significantly larger than that of control group. Mean corpuscular thickness of erythrocytes in plutonium injected groups was not different from that of control group. The increase in the mean corpuscular diameter-to-thickness ratio might allow the erythrocyte to accumulate a larger volume of water in a hypotonic environment before reaching the critical hemolytic volume. In the present study, it was concluded that the increased diameter-to-thickness ratio of erythrocytes could be related to the diminished osmotic fragility of erythrocytes in animals given polymeric plutonium. (author)

  11. 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.

  12. 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 (p<0.030) lipid use as a metabolic substrate during overnight fasting in PCOS compared to normal women. Accompanying urinary analyses showed a trending correlation (p<0.057) between overnight total nitrogen and circulating testosterone in PCOS women, alone. Serum analyzed by NMR spectroscopy following overnight, fast and at 2 h following an oral glucose 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

  13. The addition of body armor diminishes dynamic postural stability in military soldiers.

    Science.gov (United States)

    Sell, Timothy C; Pederson, Jonathan J; Abt, John P; Nagai, Takashi; Deluzio, Jennifer; Wirt, Michael D; McCord, Larry J; Lephart, Scott M

    2013-01-01

    Poor postural stability has been identified as a risk factor for lower extremity musculoskeletal injury. The additional weight of body armor carried by Soldiers alters static postural stability and may predispose Soldiers to lower extremity musculoskeletal injuries. However, static postural stability tasks poorly replicate the dynamic military environment, which places considerable stress on the postural control system during tactical training and combat. Therefore, the purpose of this study was to examine the effects of body armor on dynamic postural stability during single-leg jump landings. Thirty-six 101st Airborne Division (Air Assault) Soldiers performed single-leg jump landings in the anterior direction with and without wearing body armor. The dynamic postural stability index and the individual stability indices (medial-lateral stability index, anterior-posterior stability index, and vertical stability index) were calculated for each condition. Paired sample t-tests were performed to determine differences between conditions. Significant differences existed for the medial-lateral stability index, anterior-posterior stability index, vertical stability index, and dynamic postural stability index (p armor resulted in diminished dynamic postural stability, which may result in increased lower extremity injuries. Training programs should address the altered dynamic postural stability while wearing body armor in attempts to promote adaptations that will result in safer performance during dynamic tasks.

  14. 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).

  15. 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

  16. Diminished epinephrine response to hypoglycemia despite enlarged adrenal medulla in trained rats

    DEFF Research Database (Denmark)

    Stallknecht, B; Kjaer, M; Mikines, K J

    1990-01-01

    Studies in humans have indicated that trained athletes compared with sedentary subjects have an increased capacity to secrete epinephrine. To investigate whether this is due to an adaptation induced by physical training or a selection phenomenon, rats were swim trained (T) 10 wk for 6 h/day or se...... nervous system to reduced blood glucose levels induced by repeated exercise bouts, the epinephrine response to insulin-induced hypoglycemia is markedly diminished after training.......)]. Cold stress or sham swim training did not increase adrenal weight or volume of adrenal medulla (P greater than 0.05). To stimulate adrenal medulla secretion, rats had an insulin-induced hypoglycemia. Insulin dose needed to suppress plasma glucose below 4.0 mM was four times greater in sedentary...... compared with trained rats. During hypoglycemia the epinephrine response was much smaller in trained than in untrained rats (P less than 0.05). In conclusion, in rats strenuous endurance training causes an enlargement of the adrenal medulla. However, possibly reflecting an adaptation within the central...

  17. Diminished whole-brain but enhanced peri-sylvian connectivity in absolute pitch musicians.

    Science.gov (United States)

    Jäncke, Lutz; Langer, Nicolas; Hänggi, Jürgen

    2012-06-01

    Several anatomical studies have identified specific anatomical features within the peri-sylvian brain system of absolute pitch (AP) musicians. In this study we used graph theoretical analysis of cortical thickness covariations (as indirect indicator of connectivity) to examine whether AP musicians differ from relative pitch musicians and nonmusicians in small-world network characteristics. We measured "local connectedness" (local clustering = γ), "global efficiency of information transfer" (path length = λ), "small-worldness" (σ = γ/λ), and "degree" centrality as measures of connectivity. Although all groups demonstrated typical small-world features, AP musicians showed significant small-world alterations. "Degree" as a measure of interconnectedness was globally significantly decreased in AP musicians. These differences let us suggest that AP musicians demonstrate diminished neural integration (less connections) among distant brain regions. In addition, AP musicians demonstrated significantly increased local connectivity in peri-sylvian language areas of which the planum temporale, planum polare, Heschl's gyrus, lateral aspect of the superior temporal gyrus, STS, pars triangularis, and pars opercularis were hub regions. All of these brain areas are known to be involved in higher-order auditory processing, working or semantic memory processes. Taken together, whereas AP musicians demonstrate decreased global interconnectedness, the local connectedness in peri-sylvian brain areas is significantly higher than for relative pitch musicians and nonmusicians.

  18. 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.

  19. Marriage of scintillator and semiconductor for synchronous radiotherapy and deep photodynamic therapy with diminished oxygen dependence.

    Science.gov (United States)

    Zhang, Chen; Zhao, Kuaile; Bu, Wenbo; Ni, Dalong; Liu, Yanyan; Feng, Jingwei; Shi, Jianlin

    2015-02-02

    Strong oxygen dependence and limited penetration depth are the two major challenges facing the clinical application of photodynamic therapy (PDT). In contrast, ionizing radiation is too penetrative and often leads to inefficient radiotherapy (RT) in the clinic because of the lack of effective energy accumulation in the tumor region. Inspired by the complementary advantages of PDT and RT, we present herein the integration of a scintillator and a semiconductor as an ionizing-radiation-induced PDT agent, achieving synchronous radiotherapy and depth-insensitive PDT with diminished oxygen dependence. In the core-shell Ce(III)-doped LiYF4@SiO2@ZnO structure, the downconverted ultraviolet fluorescence from the Ce(III)-doped LiYF4 nanoscintillator under ionizing irradiation enables the generation of electron-hole (e(-)-h(+)) pairs in ZnO nanoparticles, giving rise to the formation of biotoxic hydroxyl radicals. This process is analogous to a type I PDT process for enhanced antitumor therapeutic efficacy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. 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.

  1. A diminished aortic-cardiac reflex during hypotension in aerobically fit young men

    Science.gov (United States)

    Shi, X.; Crandall, C. G.; Potts, J. T.; Williamson, J. W.; Foresman, B. H.; Raven, P. B.

    1993-01-01

    We compared the aortic-cardiac baroreflex sensitivity in eight average fit (AF: VO2max = 44.7 +/- 1.3 ml.kg-1 x min-1) and seven high fit (HF: VO2max = 64.1 +/- 1.7 ml.min-1 x kg-1) healthy young men during hypotension elicited by steady state sodium nitroprusside (SN) infusion. During SN mean arterial pressure (MAP) was similarly decreased in AF (-12.6 +/- 1.0 mm Hg) and HF (-12.1 +/- 1.1 mm Hg). However, the increases in heart rate (HR) were less (P 0.05) was applied to counteract the decreased carotid sinus transmural pressure during SN, thereby isolating the aortic baroreceptors, the increased HR remained less (P baroreflex sensitivity (i.e., the gain difference between the stage SN and SN + NS) was not different between AF (0.7 +/- 0.2 bpm.mm Hg-1) and HF (0.6 +/- 0.1 bpm.mm Hg-1). These data indicated that the aortic-cardiac baroreflex sensitivity during hypotension was significantly diminished with endurance exercise training.

  2. A legal-ethical analysis of reproductive endocrinologists' right to refuse ovulation induction to patients with diminished ovarian reserve.

    Science.gov (United States)

    Karipcin, Fethiye Sinem; Hossain, Amjad; Phelps, John Y

    2011-11-01

    Review of the legal and ethical basis for reproductive endocrinologists to refuse ovulation induction to patients with diminished ovarian reserve. The Lexis-Nexis search engine was used to perform a legal review pertaining to refusal of treatment. Ethical opinions of medical organizations were also reviewed. Federal antidiscrimination laws provide legal recourse for patients with diminished ovarian reserve who are denied ovulation induction. However, the same laws also permit refusal of care when there is bona fide medical justification to decline services. In addition, the codes of ethics for relevant professional organizations support physicians' decisions to refuse treatment when treatment is futile. Although it is ethically and legally permissible to deny ovulation induction to patients with diminished ovarian reserve when medically justified, refusal may invite retaliatory litigation. Counseling remains a cornerstone in directing these patients to options with more potential for success, such as donor eggs and adoption.

  3. 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.

  4. Efficient biosorption of lead(II) and cadmium(II) ions from aqueous solutions by functionalized cell with intracellular CaCO3 mineral scaffolds.

    Science.gov (United States)

    Ma, Xiaoming; Cui, Weigang; Yang, Lin; Yang, Yuanyuan; Chen, Huifeng; Wang, Kui

    2015-06-01

    The functionalized Saccharomyces cerevisiae cell with biogenic intracellular CaCO3 mineral scaffold, synthesized via a simple and environmentally friendly approach, was efficient for removing lead (II) and cadmium (II) ions from aqueous solutions. The CaCO3 mineral scaffold could promote the uptake of the heavy metal ions and increase the biosorption capabilities of the adsorbent. Compared with the Freundlich isotherm, Langmuir model more fitted the equilibrium data. The maximum removal capacity of functionalized cells for Pb(II) and Cd(II) was 116.69 and 42.63mgg(-1), respectively. Further investigation showed that the adsorbent had high removal efficiency for trace amount of heavy metal ions. Adsorption data were modeled using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetics equations. The results indicated that pseudo-second-order kinetic equation and intra-particle diffusion model could better describe the adsorption kinetics. The heavy metal ions might be removed by functionalized cells via membrane transport of metal ions and precipitation transformation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. 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)

  6. 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.

  7. Biosorption of Pb (II) from aqueous solution by extracellular polymeric substances extracted from Klebsiella sp. J1: Adsorption behavior and mechanism assessment

    Science.gov (United States)

    Wei, Wei; Wang, Qilin; Li, Ang; Yang, Jixian; Ma, Fang; Pi, Shanshan; Wu, Dan

    2016-08-01

    The adsorption performance and mechanism of extracellular polymeric substances (EPS) extracted from Klebsiella sp. J1 for soluble Pb (II) were investigated. The maximum biosorption capacity of EPS for Pb (II) was found to be 99.5 mg g-1 at pH 6.0 and EPS concentration of 0.2 g/L. The data for adsorption process satisfactorily fitted to both Langmuir isotherm and pseudo-second order kinetic model. The mean free energy E and activation energy Ea were determined at 8.22- 8.98 kJ mol-1 and 42.46 kJ mol-1, respectively. The liquid-film diffusion step might be the rate-limiting step. The thermodynamic parameters (ΔGo, ΔHo and ΔSo) revealed that the adsorption process was spontaneous and exothermic under natural conditions. The interactions between EPS system and Pb (II) ions were investigated by qualitative analysis methods (i.e Zeta potential, FT-IR and EDAX). Based on the strong experimental evidence from the mass balance of the related elements participating in the sorption process, an ion exchange process was identified quantitatively as the major mechanism responsible for Pb (II) adsorption by EPS. Molar equivalents of both K+ and Mg2+ could be exchanged with Pb2+ molar equivalents in the process and the contribution rate of ion exchange to adsorption accounted for 85.72% (Δmequiv = -0.000541).

  8. 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)

  9. Diminished Alternative Reinforcement as a Mechanism Underlying Socioeconomic Disparities in Adolescent Substance Use

    Science.gov (United States)

    Leventhal, Adam M.; Bello, Mariel S.; Unger, Jennifer B.; Strong, David R.; Kirkpatrick, Matthew G.; Audrain-McGovern, Janet

    2015-01-01

    OBJECTIVE This study examined socioeconomic disparities in adolescent substance use utilizing a behavioral economic theoretical framework. We tested the hypothesis that teens of lower (vs. higher) socioeconomic status (SES) are vulnerable to substance use because they engage in fewer pleasurable substance-free activities that provide reinforcement and may deter substance use. METHOD In a cross-sectional correlational design, 9th grade students (N=2,839; mean age=14.1 years) in Los Angeles, California, USA completed surveys in Fall 2013 measuring SES (i.e., parental education), alternative reinforcement (engagement in pleasurable substance-free activities, e.g., hobbies), substance use susceptibility, initiation, and frequency, and other factors. RESULTS For multi-substance composite outcomes, lower parental education was associated with greater likelihood of substance use initiation in the overall sample, frequency of use among lifetime substance users, and susceptibility to substance use in never users. Substance-specific analyses revealed that lower parental education was associated with higher likelihood of initiating cigarettes, alcohol, and marijuana use as well as greater susceptibility to use cigarettes in never smokers. Each inverse association between parental education and substance-related outcomes was statistically mediated by diminished alternative reinforcement; lower parental education was associated with lower engagement in alternative reinforcers, which, in turn, was associated with greater substance use susceptibility, initiation, and frequency. CONCLUSION These results point to a behavioral economic interpretation for socioeconomic disparities in adolescent substance use. Replication and extension of these findings would suggest that prevention programs that increase access to and engagement in healthy and fun activities may reduce youth socioeconomic health disparities related to substance use. PMID:26051200

  10. 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.

  11. Exposure to Porphyromonas gingivalis LPS during macrophage polarisation leads to diminished inflammatory cytokine production.

    Science.gov (United States)

    Belfield, Louise A; Bennett, Jon H; Abate, Wondwossen; Jackson, Simon K

    2017-09-01

    The objective of the present study was to determine the effects of concurrent LPS and cytokine priming, reflective of the in vivo milieu, on macrophage production of key periodontitis associated cytokines TNF, IL-1β and IL-6. THP-1 cells were pre-treated with combinations of Porphyromonas gingivalis and Escherichia coli lipopolysaccharide (LPS), concurrently with polarising cytokines IFNγ and IL-4, or PMA as a non-polarised control. Production of key periodontitis associated cytokines in response to subsequent LPS challenge were measured by enzyme - linked immunosorbent assay. Compared with cells incubated with IFNγ or IL-4 alone in the "polarisation" phase, macrophages that were incubated with LPS during the first 24h displayed a down-regulation of TNF and IL-1β production upon secondary LPS treatment in the "activation" phase. In all three macrophage populations (M0, M1 and M2), pre-treatment with P. gingivalis LPS during the polarisation process led to a significant decrease in TNF production in response to subsequent activation by LPS (p=0.007, p=0.002 and p=0.004, respectively). Pre-treatment with E. coli LPS also led to a significant down-regulation in TNF production in all three macrophage populations (pLPS during polarisation also led to the down-regulation of IL-1β in the M1 population (pLPS challenge, whereby production of key periodontitis associated cytokines TNF and IL-1β is reduced after exposure to LPS during the polarisation phase, even in the presence of inflammatory polarising cytokines. This diminished cytokine response may lead to the reduced ability to clear infection and transition to chronic inflammation seen in periodontitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Diminished neural resources allocation to time processing in Autism Spectrum Disorders.

    Science.gov (United States)

    Lambrechts, Anna; Falter-Wagner, Christine M; van Wassenhove, Virginie

    2018-01-01

    Interval timing, the ability to judge the duration of short events, has been shown to be compromised in Autism Spectrum Disorders (ASD). Timing abilities are ubiquitous and underlie behaviours as varied as sensory integration, motor coordination or communication. It has been suggested that atypical temporal processing in ASD could contribute to some of the disorder's symptoms, in particular motor clumsiness and difficulties in social interaction and communication. Recent behavioural investigations have suggested that interval timing in ASD is characterised by intact sensitivity but reduced precision in duration judgements. In this study we investigated the processing of duration as compared to pitch in a group of high-functioning individuals with ASD using magnetoencephalography (MEG). 18 adolescents and adults with ASD and 18 age- and IQ-matched typically-developing control (TDC) individuals compared two consecutive tones according to their duration or pitch in separate experimental blocks. The analysis was carried out exclusively on physically identical stimuli (500 Hz tones lasting 600 ms), which served, according to instruction, as standard or probe in a Duration or Pitch task respectively. Our results suggest that compared to TDC individuals, individuals with ASD are less able to predict the duration of the standard tone accurately, affecting the sensitivity of the comparison process. In addition, contrary to TDC individuals who allocate resources at different times depending on the nature of the task (pitch or duration discrimination), individuals with ASD seem to engage less resources for the Duration task than for the Pitch task regardless of the context. Although individuals with ASD showed top-down adaptation to the context of the task, this neuronal strategy reflects a bias in the readiness to perform different types of tasks, and in particular a diminished allocation of resources to duration processing which could have cascading effect on learning and

  13. Diminished telomeric 3' overhangs are associated with telomere dysfunction in Hoyeraal-Hreidarsson syndrome.

    Directory of Open Access Journals (Sweden)

    Noa Lamm

    Full Text Available BACKGROUND: Eukaryotic chromosomes end with telomeres, which in most organisms are composed of tandem DNA repeats associated with telomeric proteins. These DNA repeats are synthesized by the enzyme telomerase, whose activity in most human tissues is tightly regulated, leading to gradual telomere shortening with cell divisions. Shortening beyond a critical length causes telomere uncapping, manifested by the activation of a DNA damage response (DDR and consequently cell cycle arrest. Thus, telomere length limits the number of cell divisions and provides a tumor-suppressing mechanism. However, not only telomere shortening, but also damaged telomere structure, can cause telomere uncapping. Dyskeratosis Congenita (DC and its severe form Hoyeraal-Hreidarsson Syndrome (HHS are genetic disorders mainly characterized by telomerase deficiency, accelerated telomere shortening, impaired cell proliferation, bone marrow failure, and immunodeficiency. METHODOLOGY/PRINCIPAL FINDINGS: We studied the telomere phenotypes in a family affected with HHS, in which the genes implicated in other cases of DC and HHS have been excluded, and telomerase expression and activity appears to be normal. Telomeres in blood leukocytes derived from the patients were severely short, but in primary fibroblasts they were normal in length. Nevertheless, a significant fraction of telomeres in these fibroblasts activated DDR, an indication of their uncapped state. In addition, the telomeric 3' overhangs are diminished in blood cells and fibroblasts derived from the patients, consistent with a defect in telomere structure common to both cell types. CONCLUSIONS/SIGNIFICANCE: Altogether, these results suggest that the primary defect in these patients lies in the telomere structure, rather than length. We postulate that this defect hinders the access of telomerase to telomeres, thus causing accelerated telomere shortening in blood cells that rely on telomerase to replenish their telomeres

  14. Diminished Telomeric 3′ Overhangs Are Associated with Telomere Dysfunction in Hoyeraal-Hreidarsson Syndrome

    Science.gov (United States)

    Lamm, Noa; Ordan, Elly; Shponkin, Rotem; Richler, Carmelit; Aker, Memet; Tzfati, Yehuda

    2009-01-01

    Background Eukaryotic chromosomes end with telomeres, which in most organisms are composed of tandem DNA repeats associated with telomeric proteins. These DNA repeats are synthesized by the enzyme telomerase, whose activity in most human tissues is tightly regulated, leading to gradual telomere shortening with cell divisions. Shortening beyond a critical length causes telomere uncapping, manifested by the activation of a DNA damage response (DDR) and consequently cell cycle arrest. Thus, telomere length limits the number of cell divisions and provides a tumor-suppressing mechanism. However, not only telomere shortening, but also damaged telomere structure, can cause telomere uncapping. Dyskeratosis Congenita (DC) and its severe form Hoyeraal-Hreidarsson Syndrome (HHS) are genetic disorders mainly characterized by telomerase deficiency, accelerated telomere shortening, impaired cell proliferation, bone marrow failure, and immunodeficiency. Methodology/Principal Findings We studied the telomere phenotypes in a family affected with HHS, in which the genes implicated in other cases of DC and HHS have been excluded, and telomerase expression and activity appears to be normal. Telomeres in blood leukocytes derived from the patients were severely short, but in primary fibroblasts they were normal in length. Nevertheless, a significant fraction of telomeres in these fibroblasts activated DDR, an indication of their uncapped state. In addition, the telomeric 3′ overhangs are diminished in blood cells and fibroblasts derived from the patients, consistent with a defect in telomere structure common to both cell types. Conclusions/Significance Altogether, these results suggest that the primary defect in these patients lies in the telomere structure, rather than length. We postulate that this defect hinders the access of telomerase to telomeres, thus causing accelerated telomere shortening in blood cells that rely on telomerase to replenish their telomeres. In addition, it

  15. Associations between postpartum depressive symptoms and childhood asthma diminish with child age.

    Science.gov (United States)

    Kozyrskyj, A L; Letourneau, N L; Kang, L J; Salmani, M

    2017-03-01

    Affecting 19% of women, postpartum depression is a major concern to the immediate health of mothers and infants. In the long-term, it has been linked to the development of early-onset asthma at school entry, but only if the depression persists beyond the postnatal period. No studies have tested whether associations with postpartum depressive symptoms and early-onset asthma phenotypes persist into later school age. To determine associations between maternal postpartum depressive symptoms and childhood asthma between the ages of 5-10 by using a nested longitudinal design. Data were drawn from the 1994-2004 administrations of the Canadian National Longitudinal Survey of Children and Youth, which tracks the health of a nationally representative sample of children in Canada. Child asthma was diagnosed by a health professional, and maternal depressive symptoms were assessed by the Centre for Epidemiological Studies Depression scale. Analyses were conducted by using a multilevel modelling approach, in which longitudinal assessments of asthma in 1696 children were nested within the exposure of postpartum depression. Postpartum depressive symptoms had a 1.5-fold significant association with childhood asthma between the ages 6-8. This was independent of male sex, maternal asthma, non-immigrant status, low household socioeconomic status, being firstborn, low birthweight, low family functioning and urban-rural residence, of which the first 4 covariates elevated the risk of asthma. Statistical significance was lost at age 8 when maternal prenatal smoking replaced urban-rural residence as a covariate. At ages 9-10, an association was no longer evident. Women affected by postpartum depressive symptoms are concerned about long-term health effects of their illness on their infants. Although postpartum depressive symptoms were associated with school-age asthma at ages 6 and 7, this association diminished later. Both home and school life stress should be considered in future studies

  16. Diminishing returns from increased percent Bt cotton: the case of pink bollworm.

    Directory of Open Access Journals (Sweden)

    Yunxin Huang

    Full Text Available Regional suppression of pests by transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of Bt crops. Here we address this issue by analyzing 16 years of field data on pink bollworm (Pectinophora gossypiella population density and percentage of Bt cotton in the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We find that as the percent Bt cotton increased over the years, the cross-year growth rate of pink bollworm from the last generation of one year to the first generation of the next year decreased. However, as the percent Bt cotton increased, the within-year growth rate of pink bollworm from the first to last generation of the same year increased, with a slope approximately opposite to that of the cross-year rates. As a result, we did not find a statistically significant decline in the annual growth rate of pink bollworm as the percent Bt cotton increased over time. Consistent with the data, our modeling analyses predict that the regional average density of pink bollworm declines as the percent Bt cotton increases, but the higher the percent Bt cotton, the slower the decline in pest density. Specifically, we find that 95% Bt cotton is predicted to cause only 3% more reduction in larval density than 80% Bt cotton. The results here suggest that density dependence can act against the decline in pest density and diminish the net effects of Bt cotton on suppression of pink bollworm in the study region. The findings call for more studies of the interactions between pest density-dependence and Bt crops.

  17. Diminished androgen and estrogen receptors and aromatase levels in hypogonadal diabetic men: reversal with testosterone.

    Science.gov (United States)

    Ghanim, Husam; Dhindsa, Sandeep; Abuaysheh, Sanaa; Batra, Manav; Kuhadiya, Nitesh D; Makdissi, Antoine; Chaudhuri, Ajay; Dandona, Paresh

    2018-03-01

    One-third of males with type 2 diabetes (T2DM) have hypogonadism, characterized by low total and free testosterone concentrations. We hypothesized that this condition is associated with a compensatory increase in the expression of androgen receptors (AR) and that testosterone replacement reverses these changes. We also measured estrogen receptor and aromatase expression. This is a randomized double-blind placebo-controlled trial. Thirty-two hypogonadal and 32 eugonadal men with T2DM were recruited. Hypogonadal men were randomized to receive intramuscular testosterone or saline every 2 weeks for 22 weeks. We measured AR, ERα and aromatase expression in peripheral blood mononuclear cells (MNC), adipose tissue and skeletal muscle in hypogonadal and eugonadal males with T2DM at baseline and after 22 weeks of treatment in those with hypogonadism. The mRNA expression of AR, ERα (ESR1) and aromatase in adipose tissue from hypogonadal men was significantly lower as compared to eugonadal men, and it increased significantly to levels comparable to those in eugonadal patients with T2DM following testosterone treatment. AR mRNA expression was also significantly lower in MNC from hypogonadal patients compared to eugonadal T2DM patients. Testosterone administration in hypogonadal patients also restored AR mRNA and nuclear extract protein levels from MNC to that in eugonadal patients. In the skeletal muscle, AR mRNA and protein expression are lower in men with hypogonadism. Testosterone treatment restored AR expression levels to that comparable to levels in eugonadal men. We conclude that, contrary to our hypothesis, the expression of AR, ERα and aromatase is significantly diminished in hypogonadal men as compared to eugonadal men with type 2 diabetes. Following testosterone replacement, there is a reversal of these deficits. © 2018 European Society of Endocrinology.

  18. The diminished expression of proangiogenic growth factors and their receptors in gastric ulcers of cirrhotic patients.

    Science.gov (United States)

    Luo, Jiing-Chyuan; Peng, Yen-Ling; Hou, Ming-Chih; Huang, Kuang-Wei; Huang, Hui-Chun; Wang, Ying-Wen; Lin, Han-Chieh; Lee, Fa-Yauh; Lu, Ching-Liang

    2013-01-01

    The pathogenesis of the higher occurrence of peptic ulcer disease in cirrhotic patients is complex. Platelets can stimulate angiogenesis and promote gastric ulcer healing. We compared the expressions of proangiogenic growth factors and their receptors in the gastric ulcer margin between cirrhotic patients with thrombocytopenia and those of non-cirrhotic patients to elucidate possible mechanisms. Eligible cirrhotic patients (n = 55) and non-cirrhotic patients (n = 55) who had gastric ulcers were enrolled. Mucosa from the gastric ulcer margin and non-ulcer areas were sampled and the mRNA expressions of the proangiogenic growth factors (vascular endothelial growth factor [VEGF], platelet derived growth factor [PDGF], basic fibroblast growth factor [bFGF]) and their receptors (VEGFR1, VEGFR2, PDGFRA, PDGFRB, FGFR1, FGFR2) were measured and compared. Platelet count and the expressions of these growth factors and their receptors were correlated with each other. The two groups were comparable in terms of gender, ulcer size and infection rate of Helicobacter pylori. However, the cirrhotic group were younger in age, had a lower platelet count than those in the non-cirrhotic group (pexpressions of PDGFB, VEGFR2, FGFR1, and FGFR2 in gastric ulcer margin when compared with those of the non-cirrhotic patients (pexpressions of PDGFB and VEGFR2, FGFR1, and FGFR2 were well correlated with the degree of thrombocytopenia in these cirrhotic patients (ρ>0.5, pimplied that diminished activity of proangiogenic factors and their receptors may contribute to the pathogenesis of gastric ulcers in cirrhotic patients.

  19. Lentinan diminishes apoptotic bodies in the ileal crypts associated with S-1 administration.

    Science.gov (United States)

    Suga, Yasuyo; Takehana, Kenji

    2017-09-01

    S-1 is an oral agent containing tegafur (a prodrug of 5-fluorouracil) that is used to treat various cancers, but adverse effects are frequent. Two pilot clinical studies have suggested that lentinan (LNT; β-1,3-glucan) may reduce the incidence of adverse effects caused by S-1 therapy. In this study, we established a murine model for assessment of gastrointestinal toxicity associated with S-1 and studied the effect of LNT. S-1 was administered orally to BALB/c mice at the effective dose (8.3mg/kg, as tegafur equivalent) once daily (5days per week) for 3weeks. Stool consistency and intestinal specimens were examined. We investigated the effect of combined intravenous administration of LNT at 0.1mg, which is an effective dose in murine tumor models. We also investigated the effect of a single administration of S-1. During long-term administration of S-1, some mice had loose stools and an increase in apoptotic bodies was observed in the ileal crypts. An increase in apoptotic bodies was also noted after a single administration of S-1 (15mg/kg). Prior or concomitant administration of LNT inhibited the increase in apoptotic bodies in both settings. Administration of LNT also increased the accumulation of CD11b + TIM-4 + cells in the ileum, while depletion of these cells by liposomal clodronate diminished the inhibitory effect of LNT on S-1 toxicity. Combined administration of LNT with S-1 led to a decrease in apoptotic bodies in the ileal crypts, possibly because LNT promoted phagocytosis of damaged cells by CD11b + TIM-4 + cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Achievement of the charge exchange work diminishing of an internal combustion engine in part load

    Directory of Open Access Journals (Sweden)

    Stefan POSTRZEDNIK

    2012-01-01

    Full Text Available Internal combustion engines, used for driving of different cars, occurs not only at full load, but mostly at the part load. The relative load exchange work at the full (nominal engine load is significantly low. At the part load of the IC engine its energy efficiency ηe is significantly lower than in the optimal (nominal field range of the performance parameters. One of the numerous reasons of this effect is regular growing of the relative load exchange work of the IC engine. It is directly connected with the quantitative regulation method commonly used in the IC engines. From the thermodynamic point of view - the main reason of this effect is the throttling process (causing exergy losses occurring in the inlet and outlet channels. The known proposals for solving of this problem are based on applying of the fully electronic control of the motion of inlet, outlet valves and new reference cycles.The idea presented in the paper leads to diminishing the charge exchange work of the IC engines. The problem can be solved using presented in the paper a new concept of the reference cycle (called as eco-cycle of IC engine. The work of the engine basing on the eco-cycle occurs in two 3-stroke stages; the fresh air is delivered only once for both stages, but in range of each stage a new portion of fuel is burned. Normally the charge exchange occurs once during each engine cycle realized. Elaborated proposition bases on the elimination of chosen charge exchange processes and through this the dropping of the charge exchange work can be achieved.

  1. Ageing diminishes the modulation of human brain responses to visual food cues by meal ingestion.

    Science.gov (United States)

    Cheah, Y S; Lee, S; Ashoor, G; Nathan, Y; Reed, L J; Zelaya, F O; Brammer, M J; Amiel, S A

    2014-09-01

    Rates of obesity are greatest in middle age. Obesity is associated with altered activity of brain networks sensing food-related stimuli and internal signals of energy balance, which modulate eating behaviour. The impact of healthy mid-life ageing on these processes has not been characterised. We therefore aimed to investigate changes in brain responses to food cues, and the modulatory effect of meal ingestion on such evoked neural activity, from young adulthood to middle age. Twenty-four healthy, right-handed subjects, aged 19.5-52.6 years, were studied on separate days after an overnight fast, randomly receiving 50 ml water or 554 kcal mixed meal before functional brain magnetic resonance imaging while viewing visual food cues. Across the group, meal ingestion reduced food cue-evoked activity of amygdala, putamen, insula and thalamus, and increased activity in precuneus and bilateral parietal cortex. Corrected for body mass index, ageing was associated with decreasing food cue-evoked activation of right dorsolateral prefrontal cortex (DLPFC) and precuneus, and increasing activation of left ventrolateral prefrontal cortex (VLPFC), bilateral temporal lobe and posterior cingulate in the fasted state. Ageing was also positively associated with the difference in food cue-evoked activation between fed and fasted states in the right DLPFC, bilateral amygdala and striatum, and negatively associated with that of the left orbitofrontal cortex and VLPFC, superior frontal gyrus, left middle and temporal gyri, posterior cingulate and precuneus. There was an overall tendency towards decreasing modulatory effects of prior meal ingestion on food cue-evoked regional brain activity with increasing age. Healthy ageing to middle age is associated with diminishing sensitivity to meal ingestion of visual food cue-evoked activity in brain regions that represent the salience of food and direct food-associated behaviour. Reduced satiety sensing may have a role in the greater risk of

  2. Diminished metal accumulation in riverine fishes exposed to acid mine drainage over five decades.

    Directory of Open Access Journals (Sweden)

    Ross A Jeffree

    Full Text Available Bony bream (Nematalosa erebi and black catfish (Neosilurus ater were sampled from the fresh surface waters of the Finniss River in tropical northern Australia, along a metal pollution gradient draining the Rum Jungle copper/uranium mine, a contaminant source for over five decades. Paradoxically, populations of both fish species exposed to the highest concentrations of mine-related metals (cobalt, copper, lead, manganese, nickel, uranium and zinc in surface water and sediment had the lowest tissue (bone, liver and muscle concentrations of these metals. The degree of reduction in tissue concentrations of exposed populations was also specific to each metal and inversely related to its degree of environmental increase above background. Several explanations for diminished metal bioaccumulation in fishes from the contaminated region were evaluated. Geochemical speciation modeling of metal bioavailability in surface water showed no differences between the contaminated region and the control sites. Also, the macro-nutrient (calcium, magnesium and sodium water concentrations, that may competitively inhibit metal uptake, were not elevated with trace metal contamination. Reduced exposure to contaminants due to avoidance behavior was unlikely due to the absence of refugial water bodies with the requisite metal concentrations lower than the control sites and very reduced connectivity at time of sampling. The most plausible interpretation of these results is that populations of both fish species have modified kinetics within their metal bioaccumulation physiology, via adaptation or tolerance responses, to reduce their body burdens of metals. This hypothesis is consistent with (i reduced tissue concentrations of calcium, magnesium and sodium (macro-nutrients, in exposed populations of both species, (ii experimental findings for other fish species from the Finniss River and other contaminated regions, and (iii the number of generations exposed to likely

  3. Diminished Neural Processing of Aversive and Rewarding Stimuli During Selective Serotonin Reuptake Inhibitor Treatment

    Science.gov (United States)

    McCabe, Ciara; Mishor, Zevic; Cowen, Philip J.; Harmer, Catherine J.

    2010-01-01

    Background Selective serotonin reuptake inhibitors (SSRIs) are popular medications for anxiety and depression, but their effectiveness, particularly in patients with prominent symptoms of loss of motivation and pleasure, has been questioned. There are few studies of the effect of SSRIs on neural reward mechanisms in humans. Methods We studied 45 healthy participants who were randomly allocated to receive the SSRI citalopram, the noradrenaline reuptake inhibitor reboxetine, or placebo for 7 days in a double-blind, parallel group design. We used functional magnetic resonance imaging to measure the neural response to rewarding (sight and/or flavor of chocolate) and aversive stimuli (sight of moldy strawberries and/or an unpleasant strawberry taste) on the final day of drug treatment. Results Citalopram reduced activation to the chocolate stimuli in the ventral striatum and the ventral medial/orbitofrontal cortex. In contrast, reboxetine did not suppress ventral striatal activity and in fact increased neural responses within medial orbitofrontal cortex to reward. Citalopram also decreased neural responses to the aversive stimuli conditions in key “punishment” areas such as the lateral orbitofrontal cortex. Reboxetine produced a similar, although weaker effect. Conclusions Our findings are the first to show that treatment with SSRIs can diminish the neural processing of both rewarding and aversive stimuli. The ability of SSRIs to decrease neural responses to reward might underlie the questioned efficacy of SSRIs in depressive conditions characterized by decreased motivation and anhedonia and could also account for the experience of emotional blunting described by some patients during SSRI treatment. PMID:20034615

  4. Diminishing returns from increased percent Bt cotton: the case of pink bollworm.

    Science.gov (United States)

    Huang, Yunxin; Wan, Peng; Zhang, Huannan; Huang, Minsong; Li, Zhaohua; Gould, Fred

    2013-01-01

    Regional suppression of pests by transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of Bt crops. Here we address this issue by analyzing 16 years of field data on pink bollworm (Pectinophora gossypiella) population density and percentage of Bt cotton in the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We find that as the percent Bt cotton increased over the years, the cross-year growth rate of pink bollworm from the last generation of one year to the first generation of the next year decreased. However, as the percent Bt cotton increased, the within-year growth rate of pink bollworm from the first to last generation of the same year increased, with a slope approximately opposite to that of the cross-year rates. As a result, we did not find a statistically significant decline in the annual growth rate of pink bollworm as the percent Bt cotton increased over time. Consistent with the data, our modeling analyses predict that the regional average density of pink bollworm declines as the percent Bt cotton increases, but the higher the percent Bt cotton, the slower the decline in pest density. Specifically, we find that 95% Bt cotton is predicted to cause only 3% more reduction in larval density than 80% Bt cotton. The results here suggest that density dependence can act against the decline in pest density and diminish the net effects of Bt cotton on suppression of pink bollworm in the study region. The findings call for more studies of the interactions between pest density-dependence and Bt crops.

  5. Spearman's "law of diminishing returns" and the role of test reliability investigated in a large sample of Danish military draftees

    DEFF Research Database (Denmark)

    Teasdale, Thomas William; Hartmann, P.

    2005-01-01

    The present article investigates Spearman's "Law of Diminishing Returns" (SLODR), which hypothesizes that the g saturation for cognitive tests is lower for high ability subjects than for low ability subjects. This hypothesis was tested in a large sample of Danish military draftees (N = 6757) who ...

  6. Kangaroo mother care diminishes pain from heel lance in very preterm neonates: A crossover trial

    Directory of Open Access Journals (Sweden)

    McNaughton Kathryn

    2008-04-01

    Full Text Available Abstract Background Skin-to-skin contact, or kangaroo mother care (KMC has been shown to be efficacious in diminishing pain response to heel lance in full term and moderately preterm neonates. The purpose of this study was to determine if KMC would also be efficacious in very preterm neonates. Methods Preterm neonates (n = 61 between 28 0/7 and 31 6/7 weeks gestational age in three Level III NICU's in Canada comprised the sample. A single-blind randomized crossover design was employed. In the experimental condition, the infant was held in KMC for 15 minutes prior to and throughout heel lance procedure. In the control condition, the infant was in prone position swaddled in a blanket in the incubator. The primary outcome was the Premature Infant Pain Profile (PIPP, which is comprised of three facial actions, maximum heart rate, minimum oxygen saturation levels from baseline in 30-second blocks from heel lance. The secondary outcome was time to recover, defined as heart rate return to baseline. Continuous video, heart rate and oxygen saturation monitoring were recorded with event markers during the procedure and were subsequently analyzed. Repeated measures analysis-of-variance was employed to generate results. Results PIPP scores at 90 seconds post lance were significantly lower in the KMC condition (8.871 (95%CI 7.852–9.889 versus 10.677 (95%CI 9.563–11.792 p CI 103–142 versus 193 seconds (95%CI 158–227. Facial actions were highly significantly lower across all points in time reaching a two-fold difference by 120 seconds post-lance and heart rate was significantly lower across the first 90 seconds in the KMC condition. Conclusion Very preterm neonates appear to have endogenous mechanisms elicited through skin-to-skin maternal contact that decrease pain response, but not as powerfully as in older preterm neonates. The shorter recovery time in KMC is clinically important in helping maintain homeostasis. Trial Registration (Current

  7. Furosemide diminishes {sup 18}F-fluoroethylcholine uptake in prostate cancer in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Rischke, H.C. [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany); University of Freiburg, Department of Nuclear Medicine, Freiburg (Germany); Beck, Teresa; Wieser, Gesche; Meyer, Philipp T. [University of Freiburg, Department of Nuclear Medicine, Freiburg (Germany); Vach, Werner [University of Freiburg, Department of Clinical Epidemiology, Department of Medical Biometry and Medical Informatics, Freiburg (Germany); Grosu, Anca L. [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany); Schultze-Seemann, Wolfgang; Jilg, Cordula A. [University of Freiburg, Department of Urology, Freiburg (Germany)

    2014-11-15

    choline uptake in tumour lesions, especially significant in pelvic lymph node metastases. Although furosemide administration improved image quality, optimal image quality may also be obtained by adequate hydration without the risk of diminishing choline uptake in PCa lesions. Therefore a controlled hydration protocol seems more appropriate than administration of furosemide. (orig.)

  8. Diminished forearm vasomotor response to central hypervolemic loading in aerobically fit individuals

    Science.gov (United States)

    Shi, X.; Gallagher, K. M.; SMith, S. A.; Bryant, K. H.; Raven, P. B.; Blomqvist, C. G. (Principal Investigator)

    1996-01-01

    The aim of this study was to test the hypothesis that cardiopulmonary baroreflex control of forearm vascular resistance (FVR) during central hypervolemic loading was less sensitive in exercise trained high fit individuals (HF) compared to untrained average fit individuals (AF). Eight AF (age: 24 +/- 1 yr and weight: 78.9 +/- 1.7 kg) and eight HF (22 +/- 1 yr 79.5 +/- 2.4 kg) voluntarily participated in the investigation. Maximal aerobic power (determined on a treadmill), plasma volume and blood volume (Evans blue dilution method) were significantly greater in the HF than AF (60.8 +/- 0.7 vs. 41.2 +/- 1.9 ml.kg-1.min-1, 3.96 +/- 0.17 vs 3.36 +/- 0.08 1, and 6.33 +/- 0.23 vs 5.28 +/- 0.13 1). Baseline heart rate (HR), central venous pressure (CVP), mean arterial pressure (MAP, measured by an intraradial catheter or a Finapres finger cuff), forearm blood flow (FBF, plethysmography), and FVR, calculated from the ratio (MAP-CVP)/FBF, were not different between the HF and the AF. Lower body negative pressure (LBNP, -5, -10, -15, and -20 torr) and passive leg elevation (LE, 50 cm) combined with lower body positive pressure (LBPP, +5, +10, and +20 torr) were utilized to elicit central hypovolemia and hypervolemia, respectively. Range of CVP (from LBNP to LE+LBPP) was similar in the AF (from -3.9 to +1.9 mm Hg) and HF (from -4.0 to +2.2 mm Hg). However, FVR/CVP was significantly less in the HF (-1.8 +/- 0.1 unit.mm Hg-1) than AF (-34 +/- 0.1 unit.mm Hg-1). The FVR decrease in response to increase in CVP was significantly diminished in the HF (-1.46 +/- 0.45 unit.mm Hg-1) compared to the AF (-4.40 +/- 0.97 unit.mm Hg-1), and during LBNP induced unloading the FVR/CVP of the HF (-2.01 +/- 0.49 unit.mm Hg-1) was less (P training.

  9. Thyroid Ultrasonography Consistently Identifies Goiter in Adults Over the Age of 30 Years Despite a Diminished Response with Aging of the Thyroid Gland to the Effects of Goitrogenesis

    Directory of Open Access Journals (Sweden)

    Sheela R. Brahmbhatt

    2001-01-01

    Full Text Available Iodine deficiency is a national health problem in India and we have recently reported on the severity of IDD in adults and children in Gujarat province. The aim of this study was to determine the utility of thyroid ultrasonography to detect goiter in adults from an iodine-deficient population of Gujarat. We studied 472 adults selected by random household surveys. Data were collected on height, body weight, mid-upper arm circumference, thigh circumference, triceps skinfold thickness, thyroid size (palpation and ultrasonography, and diet. Casual urine samples for iodine (UI and blood spots for TSH estimation were obtained. Endemic goiter is a major public health problem in Gujarat State, India and is probably caused by multiple factors including iodine deficiency, malnutrition, and other dietary goitrogens. These results indicate that thyroid US consistently detects goiter in adults despite a diminished thyroidal response to variable goitrogenic stimuli.

  10. 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.)

  11. Applications of Box–Behnken experimental design coupled with artificial neural networks for biosorption of low concentrations of cadmium using Spirulina (Arthrospira spp.

    Directory of Open Access Journals (Sweden)

    R.R. Siva Kiran

    2017-03-01

    Full Text Available The present study deals with the application of artificial intelligence techniques coupled with Box–Behnken (BB design to model the process parameters for biosorption of cadmium using live Spirulina (Arthrospira spp. as adsorbent in open race way pond with Zarrouk medium. The biomass concentration of Spirulina spp. decreased to half at 4 ppm Cd (II after 8 days. Based on the LCt50 values, 3.69 ppm (8th day, Spirulina (Arthospira maxima showed maximum tolerance. Considerable growth and bioaccumulation of Spirulina spp. is observed below 1 ppm and tolerant up to 3 ppm. The cadmium adsorption on Spirulina spp. showed good correlation (R2 = 0.99 when applied to Freundlich equation and data fit into pseudo second order kinetics. A four factorial, three blocks and three level Box–Behnken design with initial concentration (1 ppb to 5 ppb, biosorbant dosage (0.1 gdw to 0.2 gdw, agitation speed (12 rpm to 16 rpm and pH (6 to 8 as independent variables and percentage adsorption as dependent variable were selected for study. The data were further processed using artificial neural network model and DIRECT algorithm for better optimization. The final Cd (II concentration of <0.5 ppb was achieved with 1 ppb initial concentration under optimal conditions. A continuous desorption process was also developed for removal of cadmium from Spirulina (Arthrospira sp.

  12. 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.

  13. 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

    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 Fractional arteriovenous glucose...... 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 blood flow response to adenosine and acetylcholine with or without insulin stimulation...... did not differ between groups. Whole-body glucose uptake was lower in LBW than controls (8.7 +/- 0.5 and 9.1 +/- 0.6 mg x min(-1) x kg(-1) lean body mass); however, this was not significant. CONCLUSIONS: Forearm blood flow response to insulin is impaired in LBW, whereas the response to adenosine...

  14. Chronic treatment with Tempol during acquisition or withdrawal from CPP abolishes the expression of cocaine reward and diminishes oxidative damage

    OpenAIRE

    Beiser, Tehila; Numa, Ran; Kohen, Ron; Yaka, Rami

    2017-01-01

    In previous studies, we reported that pretreatment with the antioxidant Tempol attenuated the development and expression of cocaine-induced psychomotor sensitization in rats and diminished cocaine-induced oxidative stress (OS) in the prefrontal cortex (PFC) and nucleus accumbens (NAc), suggesting a potential role for Tempol in interfering with cocaine-related psychomotor sensitization. The aim of the current study was to examine the role of Tempol in reward and reinforcement using the conditi...

  15. 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

    2018-01-14

    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 conduct problems with alcohol or combustible cigarette use were not mediated by 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.

  16. Diet-related modification of cuticular hydrocarbon profiles of the Argentine ant, Linepithema humile, diminishes intercolony aggression.

    Science.gov (United States)

    Buczkowski, Grzegorz; Kumar, Ranjit; Suib, Steven L; Silverman, Jules

    2005-04-01

    Territorial boundaries between conspecific social insect colonies are maintained through a highly developed nestmate recognition system modulated by heritable and, in some instances, nonheritable cues. Argentine ants, Linepithema humile, use both genetic and environmentally derived cues to discriminate nestmates from nonnestmates. We explored the possibility that intraspecific aggression in the Argentine ant might diminish when colonies shared a common diet. After segregating recently field-collected colony pairs into high or moderate aggression categories, we examined the effect of one of three diets: two hydrocarbon-rich insect prey, Blattella germanica and Supella longipalpa, and an artificial (insect-free) diet, on the magnitude of aggression loss. Aggression diminished between colony pairs that were initially moderately aggressive. However, initially highly aggressive colony pairs maintained high levels of injurious aggression throughout the study, independent of diet type. Each diet altered the cuticular hydrocarbon profile by contributing unique, diet-specific cues. We suggest that acquisition of common exogenous nestmate recognition cues from shared food sources may diminish aggression and promote fusion in neighboring colonies of the Argentine ant.

  17. Biossorção de cobre, manganês e cádmio por biomassas de Saprolegnia subterranea (Dissmann R.L. Seym. e Pythium torulosum Coker & P. Patt. (Oomycetes Copper, manganese and cadmium biosorption by Saprolegnia subterranea (Dissmann R.L. Seym. and Pythium torulosum Coker & P. Patt. (Oomycetes biomass

    Directory of Open Access Journals (Sweden)

    José Ivanildo de Souza

    2008-03-01

    Full Text Available As biomassas secas dos fungos zoospóricos Saprolegnia subterranea e Pythium torulosum foram avaliadas quanto a biossorção de cobre, manganês e cádmio de soluções aquosas por meio da determinação dos índices "q" (mg de metal adsorvido por g de biomassa e "R%" (remoção percentual. Os mais elevados índices q foram obtidos quando as biomassas foram colocadas em contato com elevadas concentrações de metais, enquanto que os maiores índices R% foram obtidos em condições de baixas concentrações (pDried biomass of the zoosporic fungi Saprolegnia subterranea and Pythium torulosum was evaluated for copper, manganese and cadmium biosorption from aqueous solutions using the "q" (mg of adsorbed metal per g of biomass and the "R%" (percent removal indices. The highest q values were observed when the biomass was placed in contact with high metal concentrations, whereas the highest R% values were observed at low concentrations (p<0.05. S. subterranea SPC 1244 biomass surpassed the others for copper biosorption (q = 7.48 mg/g; R% = 49.03, P. torulosum SPC 1425 biomass was the best for manganese biosorption (q = 4.13 mg/g; R% = 26.71, and S. subterranea SPC 1431 biomass was the best for cadmium biosorption (q = 6.75 mg/g; R% = 42.26. This is the first report on copper, manganese and cadmium biosorption by the biomass of these zoosporic fungi, indicating the potential to remove ions from diluted solutions.

  18. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.

  19. Malignant lymphomas (including myeloproliferative disorders)

    International Nuclear Information System (INIS)

    Todd, I.D.H.

    1985-01-01

    This chapter deals with the radiotherapy and cytotoxic chemotherapy of the malignant lymphomas. Included within this group are Hodgkin's disease, non-Hodgkin's lymphoma, mycosis fungoides, and chronic lymphatic leukaemia. A further section deals with the myeloproliferative disorders, including granulocytic leukaemia, polycythaemia vera, and primary thrombocythaemia. Excluded are myeloma and reticulum cell sarcoma of bone and acute leukaemia. With regard to Hodgkin's disease, the past 25 years have seen general recognition of the curative potential of radiotherapy, at least in the local stages, and, more recently, awareness of the ability to achieve long-term survival after combination chemotherapy in generalised or in recurrent disease. At the same time the importance of staging has become appreciated and the introduction of procedures such as lymphography, staging laparotomy, and computer tomography (CT) has enormously increased its reliability. Advances have not been so dramatic in the complex group of non-Hodgkins's lymphomas, but are still very real

  20. Embodied Identities: Using Kinesiology Programming Methods to Diminish the Hegemony of the Normal

    Science.gov (United States)

    Block, Betty A.; Weatherford, Gwendolyn M.

    2013-01-01

    The concept of embodiment and the reintroduction of the body into the disability movement debate is the focus of this investigation. This paper will include arguments from scholars from philosophy, disability studies, adapted physical education, counseling, nursing, and sociology who recognize that a dualistic approach to dealing with embodied…

  1. The Diminished Use of Tamil in South Africa | Mncwango | Lwati: A ...

    African Journals Online (AJOL)

    These include German, Greek, Gujarati, Hindi, Portuguese, Tamil, Telegu and Urdu, as well as languages used for religious purposes in South Africa, like Arabic, Hebrew, Sanskrit and others. The article argues that, while Tamil is a minority language, it serves very important functions among Tamil speakers and should, ...

  2. Early-life stress diminishes the increase in neurogenesis after exercise in adult female mice

    NARCIS (Netherlands)

    Abbink, M.R.; Naninck, E.F.G.; Lucassen, P.J.; Korosi, A.

    Exposure to early-life stress (ES) has long-lasting consequences for later cognition and hippocampal plasticity, including adult hippocampal neurogenesis (AHN), i.e., the generation of new neurons from stem/progenitor cells in the adult hippocampal dentate gyrus. We had previously demonstrated a

  3. Pyruvate diminishes the cytotoxic activity of ascorbic acid in several tumor cell lines in vitro.

    Science.gov (United States)

    Rodemeister, Sandra; Hill, Katharina

    2017-11-25

    The anticancer potential of ascorbic acid (AA) has been controversially discussed for decades. Although the cytotoxic effect of pharmacologic concentrations of ascorbic acid has already been successfully demonstrated in numerous studies in vitro, it could not be verified to the same extent in vivo. We propose that the ubiquitous metabolite pyruvate diminishes the effect of AA by reacting with its presumable cytotoxic mediator hydrogen peroxide (H 2 O 2 ). MTT assays confirm that co-incubation with 1.4 mM pyruvate abolishes the cytotoxic effect of pharmacologic concentrations of AA in all cancer cell lines tested (human melanoma (WM451-Lu), breast (MCF-7) and hypopharyngeal cancer cells (FaDu)). We further investigated whether pyruvate diminishes the anticancer effect of AA by interfering with the generation of H 2 O 2 . Therefore, we analyzed the concentration of AFR, a proposed intermediate in the AA-dependent formation of H 2 O 2, by electron paramagnetic resonance spectroscopy, during incubation with AA and pyruvate in WM451-Lu cells as a model system. In addition, we measured H 2 O 2 concentration by indirect detection with Clark-type oxygen electrode. AFR concentration was not significantly influenced by pyruvate, whereas H 2 O 2 concentration was significantly reduced. In parallel, pyruvate concentrations of the stimulation medium declined with increasing AA and consequently H 2 O 2 concentrations. In summary, pyruvate diminishes the cytotoxic activity of ascorbic acid in vitro. The AFR concentration measured remains unaffected by pyruvate whereas the H 2 O 2 concentration is reduced; confirming that pyruvate directly reacts with AA-induced H 2 O 2 , without influencing its formation. However, further experiments are needed to elucidate the complex mechanisms being responsible for the reduced efficacy of AA in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. 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.

  5. Circularity bias in abusive head trauma studies could be diminished with a new ranking scale

    DEFF Research Database (Denmark)

    Högberg, Göran; Colville-Ebeling, Bonnie; Högberg, Ulf

    2016-01-01

    Causality in abusive head trauma has never been fully established and hence no gold standard exists for the diagnosis. Implications hereof include bias introduced by circular reasoning and a shift from a trustful doctor patient relationship to a distrustful one when the caregiver statement...... is questioned. In this paper we examine seven recent abusive head trauma studies including 476 diagnosed abuse cases for circular reasoning as well as the role of the caregiver statement in the diagnosis. Secondly, we present a novel ranking scale for the diagnosis of abusive head trauma designed to minimize...... to the abuse cases showed that the demands of our ranking scale were not fulfilled in 440 (92%) cases. We conclude that most abuse cases in the studies were, to some extent, diagnosed on criteria based on circular reasoning. The caregiver statement was one of the most frequently used diagnostic items...

  6. Damage Tolerance Predictions for Spar Web Cracking in a Diminishing Stress Field

    Science.gov (United States)

    2011-12-01

    rounds a second of High-Explosive Incendiary (HEI) or Armor Piercing Incendiary (API) rounds. Furthermore, the sturdy airframe design enables the A...10 to operate from austere airfields and take battle damage without degrading capability. Examples of its survivability include self -sealing fuel...2024-T3511 aluminum end caps riveted to stiffened 7075-T6 sheet metal aluminum webs. The cap-to-web attachment consisted of a double row of MS20470D8

  7. GILT expression in B cells diminishes cathepsin S steady-state protein expression and activity

    OpenAIRE

    Phipps-Yonas, Hannah; Semik, Vikki; Hastings, Karen Taraszka

    2012-01-01

    MHC class II-restricted Ag processing requires protein degradation in the endocytic pathway for the activation of CD4+ T cells. Gamma-interferon-inducible lysosomal thiol reductase (GILT) facilitates Ag processing by reducing protein disulfide bonds in this compartment. Lysosomal cysteine protease cathepsin S (CatS) contains disulfide bonds and mediates essential steps in MHC class II-restricted processing, including proteolysis of large polypeptides and cleavage of the invariant chain. We so...

  8. Device including a contact detector

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a probe for determining an electrical property of an area of a surface of a test sample, the probe is intended to be in a specific orientation relative to the test sample. The probe may comprise a supporting body defining a first surface. A plurality of cantilever...... of cantilever arms (12) contacting the surface of the test sample when performing the movement....... arms (12) may extend from the supporting body in co-planar relationship with the first surface. The plurality of cantilever arms (12) may extend substantially parallel to each other and each of the plurality of cantilever arms (12) may include an electrical conductive tip for contacting the area...

  9. Potencial de biossorção do zinco pela macrófita egeria densa Biosorption potential of zinc by egeria densa macrophytes

    Directory of Open Access Journals (Sweden)

    Aparecido Nivaldo Módenes

    2009-12-01

    Full Text Available Neste trabalho, foi estudada a capacidade de biossorção da macrófita aquática Egeria densa seca na remoção do íon zinco. Os testes cinético e de equilíbrio foram realizados em sistema de batelada com temperatura, agitação e pH controlados. Os resultados obtidos na cinética de biossorção demonstram uma rápida remoção do zinco (II, com tempo de equilíbrio em torno de 45 minutos e taxa de remoção superior a 70%. O modelo cinético de pseudo-segunda ordem foi o que melhor representou os dados experimentais. No estudo do equilíbrio, verificou-se que o modelo de Langmuir ajustou-se melhor aos dados experimentais, com capacidade máxima de sorção de 0,92 mequiv g-1 e razão entre as taxas de sorção e dessorção de 0,829 L g-1 em pH 5. Os resultados obtidos demonstram que a macrófita E. densa tem potencial para ser utilizada em sistemas de tratamento de efluentes industriais.In this paper, the removal potential on Zn ion by macrophyte Egeria densa has been studied. The influence of the metal solution pH, the plant drying and the metal solution temperature, and biosorbent grain size was previously studied in batch systems. Adsorption kinetic and equilibrium experiments of metals onto E. densa were performed under controlled temperature and permanent shaking. In adsorption kinetic tests for Zn (II the equilibrium time was around 45 min. The biosorption kinetic data were well fitted by a pseudo-second order model. The equilibrium data at pH 5 were described a rather better by the Langmuir isotherm than the Freundlich one, with an adsorption rate and maximum metal content values of 0,829L g-1and 0,92 mequiv g-1, respectively, for Langmuir model. The macrophytes E. densa could be used as biosorbent material in industrial effluent treatment system.

  10. Higher energy prices are associated with diminished resources, performance and safety in Australian ambulance systems.

    Science.gov (United States)

    Brown, Lawrence H; Chaiechi, Taha; Buettner, Petra G; Canyon, Deon V; Crawford, J Mac; Judd, Jenni

    2013-02-01

    To evaluate the impact of changing energy prices on Australian ambulance systems. Generalised estimating equations were used to analyse contemporaneous and lagged relationships between changes in energy prices and ambulance system performance measures in all Australian State/Territory ambulance systems for the years 2000-2010. Measures included: expenditures per response; labour-to-total expenditure ratio; full-time equivalent employees (FTE) per 10,000 responses; average salary; median and 90th percentile response time; and injury compensation claims. Energy price data included State average diesel price, State average electricity price, and world crude oil price. Changes in diesel prices were inversely associated with changes in salaries, and positively associated with changes in ambulance response times; changes in oil prices were also inversely associated with changes in salaries, as well with staffing levels and expenditures per ambulance response. Changes in electricity prices were positively associated with changes in expenditures per response and changes in salaries; they were also positively associated with changes in injury compensation claims per 100 FTE. Changes in energy prices are associated with changes in Australian ambulance systems' resource, performance and safety characteristics in ways that could affect both patients and personnel. Further research is needed to explore the mechanisms of, and strategies for mitigating, these impacts. The impacts of energy prices on other aspects of the health system should also be investigated. © 2013 The Authors. ANZJPH © 2013 Public Health Association of Australia.

  11. Diminished production of TWEAK by the peripheral blood mononuclear cells is associated with vascular involvement in patients with systemic sclerosis.

    Directory of Open Access Journals (Sweden)

    Otylia Kowal-Bielecka

    2010-02-01

    Full Text Available Widespread vasculopathy and profound fibrosis are key features of the pathogenesis of systemic sclerosis (SSc. We hypothesized that the TNF-like weak inducer of apoptosis (TWEAK, a recently recognized multifunctional cytokine which regulates angiogenesis and tissue remodeling, may play a role in the development of SSc. The production of TWEAK by the peripheral blood mononuclear cells (PBMC was investigated, by means of ELISA, in 24 SSc patients and 14 healthy subjects. Moreover, production of TWEAK was correlated with clinical features of SSc. PBMC were isolated using density gradient centrifugation on Histopaque and were cultured in FCS supplemented RPMI medium at 37 degrees C under 5% CO2. Production of TWEAK by PBMC was significantly diminished in patients with more severe microvascular damage, as indicated by the presence of "active" capillaroscopic pattern, compared with SSc patients with less pronounced microangiopathy ("slow" pattern, and healthy subjects. Moreover production of TWEAK correlated inversely with duration of Raynaud's phenomenon. PBMC from patients with scleroderma-related interstitial lung disease tended to produce lower amounts of TWEAK compared with SSc patients without lung involvement but the difference was not significant. The results of our study suggest that diminished production of TWEAK might play a role in the pathogenesis of vascular injury in SSc patients. Whether TWEAK may represent a new therapeutic target in SSc requires further studies.

  12. Novel Indium Arsenide double gate and gate all around nanowire MOSFETs for diminishing the exchange correlation effect: A quantum study

    Science.gov (United States)

    Orouji, Ali A.; Nejaty, Mohammad; Mohtasham, Alireza

    2014-09-01

    In this paper we present novel double gate (DG) metal oxide semiconductor field effect transistor (MOSFET) and gate all around (GAA) nanowire metal oxide semiconductor field effect transistor (NWT) with a diminished exchange-correlation (Ex-Corr) effect. The key idea in this work is to use Indium Arsenide (InAs) semiconductor instead of Si. We have evaluated and compared different parameters of DG-MOSFET and GAA-NWTs such as threshold voltage, sub-threshold slope, drain induced barrier lowering and ON and OFF state currents from quantum view. Quantum mechanical transport approach based on non-equilibrium green's function (NEGF) has been performed in the frame work of effective mass theory in consideration with Ex-Corr effect. This simulation method consists of three dimensional Poisson's equation in which a Schrodinger equation is first solved in each slice of the device to find Eigen energies and Eigen functions. Then, a transport equation of electrons moving in the sub-bands is solved. This fully quantum method treats such effects as source-to-drain tunneling, ballistic transport, and quantum confinement on equal footing. The results show that only a few lowest Eigen sub-bands are occupied and the upper sub-bands can be safely neglected. Also, the interaction between electrons and Ex-Corr effect is diminished in the proposed structure.

  13. Chronic treatment with Tempol during acquisition or withdrawal from CPP abolishes the expression of cocaine reward and diminishes oxidative damage.

    Science.gov (United States)

    Beiser, Tehila; Numa, Ran; Kohen, Ron; Yaka, Rami

    2017-09-11

    In previous studies, we reported that pretreatment with the antioxidant Tempol attenuated the development and expression of cocaine-induced psychomotor sensitization in rats and diminished cocaine-induced oxidative stress (OS) in the prefrontal cortex (PFC) and nucleus accumbens (NAc), suggesting a potential role for Tempol in interfering with cocaine-related psychomotor sensitization. The aim of the current study was to examine the role of Tempol in reward and reinforcement using the conditioned place preference (CPP) paradigm. We found that administration of Tempol during the conditioning session abolished the expression of cocaine-induced CPP. We also found that OS was significantly elevated following the establishment of CPP, and that cocaine-induced OS was significantly diminished by pretreatment with Tempol during conditioning. Furthermore, we found that repeated, but not single, administration of Tempol for seven days during withdrawal from CPP resulted in significant attenuation in the expression of CPP. Moreover, Tempol did not affect the expression of food reward. Taken together, these findings provide evidence for the involvement of Tempol in regulating cocaine rewarding properties without affecting natural rewards. Since Tempol was found to be effective in reducing OS and expression of CPP following withdrawal, it may be a potential treatment for cocaine addiction.

  14. Diminished brain resilience syndrome: A modern day neurological pathology of increased susceptibility to mild brain trauma, concussion, and downstream neurodegeneration

    Science.gov (United States)

    Morley, Wendy A.; Seneff, Stephanie

    2014-01-01

    The number of sports-related concussions has been steadily rising in recent years. Diminished brain resilience syndrome is a term coined by the lead author to describe a particular physiological state of nutrient functional deficiency and disrupted homeostatic mechanisms leading to increased susceptibility to previously considered innocuous concussion. We discuss how modern day environmental toxicant exposure, along with major changes in our food supply and lifestyle practices, profoundly reduce the bioavailability of neuro-critical nutrients such that the normal processes of homeostatic balance and resilience are no longer functional. Their diminished capacity triggers physiological and biochemical ‘work around’ processes that result in undesirable downstream consequences. Exposure to certain environmental chemicals, particularly glyphosate, the active ingredient in the herbicide, Roundup®, may disrupt the body's innate switching mechanism, which normally turns off the immune response to brain injury once danger has been removed. Deficiencies in serotonin, due to disruption of the shikimate pathway, may lead to impaired melatonin supply, which reduces the resiliency of the brain through reduced antioxidant capacity and alterations in the cerebrospinal fluid, reducing critical protective buffering mechanisms in impact trauma. Depletion of certain rare minerals, overuse of sunscreen and/or overprotection from sun exposure, as well as overindulgence in heavily processed, nutrient deficient foods, further compromise the brain's resilience. Modifications to lifestyle practices, if widely implemented, could significantly reduce this trend of neurological damage. PMID:25024897

  15. Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function.

    Science.gov (United States)

    George, S J; Sherbone, J; Hinz, C; Tibbett, M

    2011-10-01

    Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Diminished motor timing control in children referred for diagnosis of learning problems.

    Science.gov (United States)

    Waber, D P; Weiler, M D; Bellinger, D C; Marcus, D J; Forbes, P W; Wypij, D; Wolff, P H

    2000-01-01

    Disabled readers exhibit motor timing control (MTC) deficits in bimanual coordination relative to average readers. This article evaluates to what extent poor MTC is specific to reading or if it is related to learning problems in general. Children (7 to 11 years of age) referred for learning impairment (LI; n = 100) and same-age children nonlearning impaired (NLI; n = 243) performed a paced finger-tapping task. Greater variability of interresponse intervals was associated with poorer reading, spelling, and arithmetic achievement. The LI group performed more poorly than the NLI group, a difference that persisted even after adjusting for reading skill. Poor MTC is associated with poor reading but may also be a characteristic of children referred for learning problems, possibly signaling increased vulnerability of underlying neural integrative processes relevant to the child's adaptation to academic demands, including reading.

  17. The Future of the Mississippi Delta: Shifting Baselines, Diminishing Resilience, and Growing Non-Sustainability

    Science.gov (United States)

    Day, J.

    2017-12-01

    Ecosystems and human communities of the Mississippi delta developed with predictable basin inputs, stable sea level, and as an open system with a high degree of interaction among drainage basin inputs, deltaic plain, and the coastal sea. Human activity changed altered the coast and lowered predictability. Management has become very energy intensive and dependent on cheap resources with more hard engineering and less ecological engineering. Pervasive alteration of the basin and delta and global change have altered the baseline and change is accelerating. Climate change projections include not only sea-level rise, but also more stronger hurricanes, increased large river floods, and more intense rainfall events and droughts. A sustainable Mississippi is outside of the boundaries of the current CMP.

  18. Genetic deficiency of Wnt5a diminishes disease severity in a murine model of rheumatoid arthritis.

    Science.gov (United States)

    MacLauchlan, Susan; Zuriaga, Maria A; Fuster, José J; Cuda, Carla M; Jonason, Jennifer; Behzadi, Fernanda; Duffen, Jennifer Parker; Haines, G Kenneth; Aprahamian, Tamar; Perlman, Harris; Walsh, Kenneth

    2017-07-19

    Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic inflammation of the joints, leading to bone erosion and joint dysfunction. Despite the recent successes of disease-modifying anti-rheumatic drugs (DMARDs), there is still clinical need for understanding the development and molecular etiology of RA. Wnts are developmental morphogens whose roles in adult pathology are poorly characterized. Wnt5a is a member of the non-canonical family of Wnts that modulates a wide range of cell processes, including differentiation, migration, and inflammation. Wnt5a has been implicated as a possible contributor to arthritis and it is upregulated in synovial fibroblasts from RA patients. We investigated the role of endogenous Wnt5a in RA. Tamoxifen-inducible, Wnt5a knockout (Wnt5a cKO) mice and littermate controls were monitored for arthritis development and joint pathology using the K/BxN serum transfer-induced arthritis (STIA) model. To explore a role of Wnt5a in osteoclast fusion, bone marrow-derived monocytes (BMDMs) were differentiated in vitro. Wnt5a cKO mice were resistant to arthritis development compared to control littermates as assessed by ankle thickness and histologic measurements. Some parameters of inflammation were reduced in the Wnt5a cKO mice, including the extent of polymononuclear cell infiltration and extra-articular inflammation. Wnt5a cKO mice also exhibited less cartilage destruction and a reduction in osteoclast activity with concomitant reduction in tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK), macrophage colony-stimulating factor (MCSF), matrix metalloproteinase (MMP)2 and MMP9 in the arthritic joints. Treatment of BMDMs with Wnt5a enhanced osteoclast fusion and increased the expression of dendrocyte-expressed seven transmembrane protein (DCSTAMP) and MMP9, that are necessary for osteoclast formation and activity. These data suggest that Wnt5a modulates the development of arthritis by promoting

  19. Determination of the cost of worker reproduction via diminished life span in the ant Diacamma sp.

    Science.gov (United States)

    Tsuji, Kazuki; Kikuta, Noritsugu; Kikuchi, Tomonori

    2012-05-01

    Workers of social Hymenoptera can usually produce male offspring, but rarely do so in the presence of a queen despite the potential individual fitness benefit. Various mechanisms have been hypothesized to regulate worker reproduction, including avoiding the colony-level cost of worker reproduction. However, firm quantitative evidence is lacking to support that hypothesis. Here, we accurately quantified this cost by studying an ant species (Diacamma sp.) in which worker reproduction is rare in the presence of the gamergate (the functional queen). A series of experiments to manipulate worker-gamergate contact revealed that short-term brood-production efficiency is not changed by the presence of worker reproduction. However, when workers reproduce, their average life span is reduced to between 74% and 88% of that in the absence of reproduction, indicating a long-term cost to the colony. In theory, this cost can explain the policing of worker reproduction under a queen-single mating system, but the cost does not appear to be high enough to stop worker reproduction. When contact with the gamergate is lost, it is only the nonreproductive workers whose life span was reduced; the reproductive workers lived as long as nonorphaned workers. We suggest that an increased workload can account for the reduction in life span better than a trade-off between reproduction and longevity. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  20. Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function

    International Nuclear Information System (INIS)

    George, S.J.; Sherbone, J.; Hinz, C.; Tibbett, M.

    2011-01-01

    Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons. - Highlights: → Effects of flowline additives on soil structure and microbial function highlighted. → Phosphonate salts (in scale inhibitor) were found to disrupt soil physical structure. → Glutaraldehyde (in biocides) caused significant reduction of hydrocarbon degradation in soil. → Flowline additive chemicals synergistically affects soil structure and remediative microbial function. - Scale inhibitor and biocide oilfield flowline additives interactively affect soil physical and microbial properties