WorldWideScience

Sample records for bioadsorbents

  1. Recycling agriculture wastes of ramie stalk as bioadsorbents for Cd(2+) removal: a kinetic and thermodynamic study.

    Science.gov (United States)

    Xu, S; Gong, X F; Zou, H L; Liu, C Y; Chen, C L; Zeng, X X

    2016-01-01

    In this study, we exhibit the recycling of agriculture wastes of ramie stalk as bioadsorbents for Cd(2+) removal. Based on our experimental results, it is realized that Cd(2+) adsorption to ramie stalk is highly pH sensitive, indicating the adsorption is driven by surface complexation reaction. The high adsorption capacity of ramie stalk toward Cd(2+) (qm = 10.33 mg g(-1), 0.09 mol-Cd g(-1)), which corresponds to around 21.95% of active adsorption sites available of ramie stalk, is believed to be closely related to its high cellulose and lignin content. The inhomogeneous surface of ramie stalk due to the high cellulose and lignin content also accounts for the observation that the adsorption kinetic is described well by the pseudo second order kinetic model. Results from thermodynamic studies suggest that the adsorption process is endothermic and spontaneous. All these properties demonstrate the potential of ramie stalk as a low cost bioadsorbent for the application of heavy metal removal.

  2. Quince seed mucilage magnetic nanocomposites as novel bioadsorbents for efficient removal of cationic dyes from aqueous solutions.

    Science.gov (United States)

    Hosseinzadeh, Hossein; Mohammadi, Sina

    2015-12-10

    This study investigated the potential use of quince seed mucilage (QSM) as alternative bioadsorbents for methylene blue (MB) dye from aqueous solutions. This novel magnetic nanocomposite adsorbent (MNCA) based on QSM was synthesized by in situ formation of magnetic iron oxide nanoparticles into QSM solution. The MNCAs were characterized using FTIR, SEM, TEM, XRD, and VSM. Removal of MB was investigated by batch adsorption technique. The thermodynamic parameters suggest that the dye adsorption process is spontaneous and exothermic in nature. Moreover, the adsorbents showed high selectivity for the adsorption of cationic dyes with regenerated properties. The pseudo-second-order kinetics and Langmuir adsorption isotherm models also provide the best correlation of the experimental data for MB adsorption. The results indicate that the MNCAs can be employed as efficient low cost adsorbents with excellent dye adsorption performance in wastewater treatment process. PMID:26428118

  3. Metal-Induced Production of a Novel Bioadsorbent Exopolysaccharide in a Native Rhodotorula mucilaginosa from the Mexican Northeastern Region.

    Science.gov (United States)

    Garza-Gonzalez, Maria Teresa; Gonzalez Garza, Maria Teresa; Barboza Perez, Daniel; Vazquez Rodriguez, Augusto; Garcia-Gutierrez, Domingo Ixcoatl; Zarate, Xristo; Cantú Cardenas, Maria Elena; Urraca-Botello, Ludwing Ilytch; Lopez-Chuken, Ulrico Javier; Trevino-Torres, Alberto Ludovico; Cerino-Córdoba, Felipe de Jesus; Medina-Ruiz, Pavel; Villarreal-Chiu, Juan Francisco; Morones-Ramirez, Jose Ruben

    2016-01-01

    There is a current need to develop low-cost strategies to degrade and eliminate industrially used colorants discharged into the environment. Colorants discharged into natural water streams pose various threats, including: toxicity, degradation of aesthetics and inhibiting sunlight penetration into aquatic ecosystems. Dyes and colorants usually have complex aromatic molecular structures, which make them very stable and difficult to degrade and eliminate by conventional water treatment systems. The results in this work demonstrated that heavy metal-resistant Rhodotorula mucilaginosa strain UANL-001L isolated from the northeast region of Mexico produce an exopolysaccharide (EPS), during growth, which has colorant adsorption potential. The EPS produced was purified by precipitation and dialysis and was then physically and chemically characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and chemical elemental analysis. Here, the ability of the purified EPS produced to adsorb methylene blue (MB), which served as a model colorant, is studied. MB adsorption by the EPS is found to follow Langmuir Adsorption Isotherm kinetics at 25°C. Further, by calculating the Langmuir constant the adsorption capabilities of the EPS produced by the Rhodotorula mucilaginosa strain UANL-001L is compared to that of other adsorbents, both, microbially produced and from agroindustrial waste. The total adsorption capacity of the EPS, from the Rhodotorula mucilaginosa strain UANL-001L, was found to be two-fold greater than the best bioadsorbents reported in the literature. Finally, apart from determining which heavy metals stimulated EPS production in the strain, the optimal conditions of pH, heavy metal concentration, and rate of agitation of the growing culture for EPS production, was determined. The EPS reported here has the potential of aiding in the efficient removal of colorants both in water treatment plants and in situ in natural water streams. PMID

  4. Metal-Induced Production of a Novel Bioadsorbent Exopolysaccharide in a Native Rhodotorula mucilaginosa from the Mexican Northeastern Region.

    Directory of Open Access Journals (Sweden)

    Maria Teresa Garza-Gonzalez

    Full Text Available There is a current need to develop low-cost strategies to degrade and eliminate industrially used colorants discharged into the environment. Colorants discharged into natural water streams pose various threats, including: toxicity, degradation of aesthetics and inhibiting sunlight penetration into aquatic ecosystems. Dyes and colorants usually have complex aromatic molecular structures, which make them very stable and difficult to degrade and eliminate by conventional water treatment systems. The results in this work demonstrated that heavy metal-resistant Rhodotorula mucilaginosa strain UANL-001L isolated from the northeast region of Mexico produce an exopolysaccharide (EPS, during growth, which has colorant adsorption potential. The EPS produced was purified by precipitation and dialysis and was then physically and chemically characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and chemical elemental analysis. Here, the ability of the purified EPS produced to adsorb methylene blue (MB, which served as a model colorant, is studied. MB adsorption by the EPS is found to follow Langmuir Adsorption Isotherm kinetics at 25°C. Further, by calculating the Langmuir constant the adsorption capabilities of the EPS produced by the Rhodotorula mucilaginosa strain UANL-001L is compared to that of other adsorbents, both, microbially produced and from agroindustrial waste. The total adsorption capacity of the EPS, from the Rhodotorula mucilaginosa strain UANL-001L, was found to be two-fold greater than the best bioadsorbents reported in the literature. Finally, apart from determining which heavy metals stimulated EPS production in the strain, the optimal conditions of pH, heavy metal concentration, and rate of agitation of the growing culture for EPS production, was determined. The EPS reported here has the potential of aiding in the efficient removal of colorants both in water treatment plants and in situ in natural water

  5. Metal-Induced Production of a Novel Bioadsorbent Exopolysaccharide in a Native Rhodotorula mucilaginosa from the Mexican Northeastern Region.

    Science.gov (United States)

    Garza-Gonzalez, Maria Teresa; Gonzalez Garza, Maria Teresa; Barboza Perez, Daniel; Vazquez Rodriguez, Augusto; Garcia-Gutierrez, Domingo Ixcoatl; Zarate, Xristo; Cantú Cardenas, Maria Elena; Urraca-Botello, Ludwing Ilytch; Lopez-Chuken, Ulrico Javier; Trevino-Torres, Alberto Ludovico; Cerino-Córdoba, Felipe de Jesus; Medina-Ruiz, Pavel; Villarreal-Chiu, Juan Francisco; Morones-Ramirez, Jose Ruben

    2016-01-01

    There is a current need to develop low-cost strategies to degrade and eliminate industrially used colorants discharged into the environment. Colorants discharged into natural water streams pose various threats, including: toxicity, degradation of aesthetics and inhibiting sunlight penetration into aquatic ecosystems. Dyes and colorants usually have complex aromatic molecular structures, which make them very stable and difficult to degrade and eliminate by conventional water treatment systems. The results in this work demonstrated that heavy metal-resistant Rhodotorula mucilaginosa strain UANL-001L isolated from the northeast region of Mexico produce an exopolysaccharide (EPS), during growth, which has colorant adsorption potential. The EPS produced was purified by precipitation and dialysis and was then physically and chemically characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and chemical elemental analysis. Here, the ability of the purified EPS produced to adsorb methylene blue (MB), which served as a model colorant, is studied. MB adsorption by the EPS is found to follow Langmuir Adsorption Isotherm kinetics at 25°C. Further, by calculating the Langmuir constant the adsorption capabilities of the EPS produced by the Rhodotorula mucilaginosa strain UANL-001L is compared to that of other adsorbents, both, microbially produced and from agroindustrial waste. The total adsorption capacity of the EPS, from the Rhodotorula mucilaginosa strain UANL-001L, was found to be two-fold greater than the best bioadsorbents reported in the literature. Finally, apart from determining which heavy metals stimulated EPS production in the strain, the optimal conditions of pH, heavy metal concentration, and rate of agitation of the growing culture for EPS production, was determined. The EPS reported here has the potential of aiding in the efficient removal of colorants both in water treatment plants and in situ in natural water streams.

  6. Adsorption performance of Camellia cakes as bioadsorbent for removal of Ni2+%油茶饼粕生物吸附剂对Ni2+的吸附性能

    Institute of Scientific and Technical Information of China (English)

    袁红江; 全学军; 冉秀芝; 项锦欣; 蒋丽

    2011-01-01

    Camellia cakes are the waste product from processing industry of Camellia fruits, which are formed in the extraction process of its oil by a squeezer. The cakes contain a lot of valuable bioactive components such as tea saponin. In order to utilize Camellia cake resources, five kinds of bioadsorbents were prepared after the extraction of tea saponin by using alcohol extraction, ultrasound-assisted alcohol extraction, water extraction and ultrasound-assisted water extraction methods. The potential and mechanism of the five bioadsorbents for the removal of heavy metals from wastewater were investigated using Ni2+ ions. The bioadsorbent prepared by alcohol extraction process is superior to that by water extraction process. Ultrasound-assisted alcohol extraction improves the adsorptive performance of the sample obviously, with the maximum Langmuir adsorption ability of 17.57 mg · g-1, and increases the extraction efficiency of tea saponin to 19. 63%, probably due to the cavitation and mechanistic effects of ultrasound waves. The FTIR analysis of the bioadsorbents indicated that the -OH, -NH, C=O ,C-OH and -CN groups on the surface of the bioadsorbents may be the adsorptive sites to Ni2+ ions. The alcohol extraction process of tea saponin can retain these functional groups, while the water extraction process may cause the dissolution of the water soluble components from the biomaterials, reducing the amount of the functional groups and the adsorptive ability of the water extracted bioadsorbents.%为充分利用油茶资源,采用醇提、超声辅助醇提、水提和超声辅助水提方法,提取油茶饼粕中的茶皂素,考察了提取剩余物作为油茶饼粕生物吸附剂的可行性和机理.研究表明,超声辅助醇提茶皂素提取率最高,达到19.63%,5种牛物吸附剂吸附Ni2+均可在25 min之内达到吸附平衡,各吸附剂对Ni2+的等温吸附线更符合Langmuir等温吸附模型(R2>0.90).醇提茶皂素获得的生物吸附剂与原料

  7. Polyacrylamido-2-methyl-1-propane sulfonic acid-grafted-natural rubber as bio-adsorbent for heavy metal removal from aqueous standard solution and industrial wastewater.

    Science.gov (United States)

    Phetphaisit, Chor Wayakron; Yuanyang, Siriwan; Chaiyasith, Wipharat Chuachuad

    2016-01-15

    Bio-adsorbent modified natural rubber (modified NR) was prepared, by placing the sulfonic acid functional group on the isoprene chain. This modification was carried out with the aim to prepare material capable to remove heavy metals from aqueous solution. The structures of modified NR materials were characterized by FT-IR and NMR spectroscopies. Thermal gravimetric analysis of modified NR showed that the initial degradation temperature of rubber decreases with increasing amount of polyacrylamido-2-methyl-1-propane sulfonic acid (PAMPS) in the structure. In addition, water uptake of the rubber based materials was studied as a function of time and content of PAMPS. The influence of the amount of PAMPS grafted onto NR, time, pH, concentration of metal ions, temperature, and regeneration were studied in terms of their influence on the adsorption of heavy metals (Pb(2+), Cd(2+) and Cu(2+)). The adsorption isotherms of Pb(2+) and Cd(2+) were fitted to the Freundlich isotherm model, while Cu(2+) was fitted to the Langmuir isotherm. However, the results from these two isotherms resulted in a similar behavior. The adsorption capacity of the modified NR for the various heavy metals was in the following order: Pb(2+)∼Cd(2+)>Cu(2+). The maximum adsorption capacities of Pb(2+), Cd(2+), and Cu(2+) were 272.7, 267.2, and 89.7 mg/g of modified rubber, respectively. Moreover, the modified natural rubber was used for the removal of metal ions in real samples of industrial effluents where the efficiency and regeneration were also investigated.

  8. Dye removal from textile wastewater using bioadsorbent

    International Nuclear Information System (INIS)

    Textile industries throughout the world produce huge quantities of dyes and pigments annually. Effluents from textile industries are dye wastewater, and disposal of these wastes to freshwater bodies causes damage to the environment. Among the treatment technologies, adsorption is an attractive and viable option, provided that the sorbent is inexpensive and readily available for use. In this study, a typical basic dye, methylene blue, in wastewater was treated using Melia azedarach sawdust. The effects of contact time, adsorbent amount and particle size were investigated on the removal efficiency of adsorbent for methylene blue. Complete removal of the dye were attained at higher adsorbent dose of 3 g/L with 50 mg/L initial dye concentration. The maximum adsorption was at 240 minutes, whereas more than 90% removal with 105 meu m particle size of 1 g/L adsorbent for same initial dye concentration. The experimental data best fits with 2 Langmuir adsorption isotherm (R= 0.991). (author)

  9. EXTRACTION OF METHYLENE BLUE DYE FROM POLLUTED WATERS USING SOME BIOADSORBENTS

    Directory of Open Access Journals (Sweden)

    B. Srinivasa Reddy

    2012-12-01

    Full Text Available Sorbents derived from roots of Tephrosia purpurea, leaves and stems of Terminalia Arjuna and Bivalve snail shells have been explored for their sorption abilities towards Methylene Blue using synthetically prepared simulated waste waters. It is found that at high pHs, these bio-materials have shown strong affinity towards Methylene Blue. The physicochemical properties such as pH, sorbent concentration and time of equilibration have been optimized for the maximum removal of Methylene Blue from waste waters. Methodologies have been developed to extract good quantities of the dye. The roots powder of Tephrosia Purpurea has been proved to very effective even at 1.0 gm/500 ml of the sorption concentration at pH :8 or 10. More than 95.0% of extraction of Methylene Blue has been found with the bark powders of Terminalia Arjuna at all pH of study viz., 2-10. Interference of Fivefold excess of common anions and cations present in natural waters, have been studied. Anions have not interfered while Cation like Ca2+, Mg2+ and Cu2+ have shown some interference but Fe2+ and Zn2+ have synergistically maintained the maximum extraction of the dye. The procedures developed have been successfully applied to some industrial effluent.

  10. EXTRACTION OF METHYLENE BLUE DYE FROM POLLUTED WATERS USING SOME BIOADSORBENTS

    OpenAIRE

    B. Srinivasa Reddy; K. Venkata Ramana; K. Ravindhranath

    2012-01-01

    Sorbents derived from roots of Tephrosia purpurea, leaves and stems of Terminalia Arjuna and Bivalve snail shells have been explored for their sorption abilities towards Methylene Blue using synthetically prepared simulated waste waters. It is found that at high pHs, these bio-materials have shown strong affinity towards Methylene Blue. The physicochemical properties such as pH, sorbent concentration and time of equilibration have been optimized for the maximum removal of Methylene Blue from ...

  11. Pine bark as bio-adsorbent for Cd, Cu, Ni, Pb and Zn

    DEFF Research Database (Denmark)

    Cutillas-Barreiro, L.; Ansias-Manso, L.; Fernandez Calviño, David;

    2014-01-01

    The objective of this work was to determine the retention of five metals on pine bark using stirred flow and batch-type experiments. Resulting from batch-type kinetic experiments, adsorption was rapid, with no significant differences for the various contact times. Adsorption was between 98 and 99...... to the added concentrations, with Pb always showing the lowest levels. Stirred flow chamber experiments showed strong hysteresis for Pb and Cu, sorption being mostly irreversible. The differences affecting the studied heavy metals are mainly due to different affinity for the adsorption sites. Pine bark can...

  12. Kinetics of adsorption of organic pollutants by bioadsorbents; Cinetica de adsorcao de poluentes organicos por bioadsorventes

    Energy Technology Data Exchange (ETDEWEB)

    Santos, E.G. [Universidade Federal de Campina Grande, PB (Brazil). Programa de Recursos Humanos da ANP, PRH-25]. E-mail: elbagomes@uol.com.br; Alsina, O.L.S.; Silva, F.L.H. [Universidade Federal de Campina Grande, PB (Brazil). Centro de Ciencias e Tecnologia. Dept. de Engenharia Quimica]. E-mail: odelsia@deq.ufpb.br; flhs@deq.ufpb.br

    2003-07-01

    During the petroleum exploration and production processes, a great amount of water is produced together with the oil and the natural gas. This water needs an appropriate treatment before been discarded or reuse, due to a their great amount of organic pollutants content. Several separation processes are used in order to improve the effluent quality. In this way, the research of new adsorbent materials that present a low industrial cost has great importance. In this paper, adsorption experiments of organic pollutants using as adsorbent, the corn-cob, the powder wood and the coconut mesocarp, were accomplished. The organic effluent used in this work was simulated by a dispersion of gas in water and the experimental data were obtained through experiments in an agitated reactor. The kinetic curve was been adjusted for Michaelis-Menten equation and equilibrium isotherm modeling with Langmuir isotherm. Both model fitted well the experimental data. The obtained results show the viability of the use of the biomass as adsorbents for organic pollutants, once, with appropriate amounts of the gas/biomass, it was possible to eliminate, practically, the whole pollutant. (author)

  13. New Strategies for Designing Inexpensive but Selective Bioadsorbants for Environmental Pollutants: Selection of specific Ligands and Their Cell Surface Expression

    Energy Technology Data Exchange (ETDEWEB)

    Brent L. Iverson; George Georgiou; Mohammad M. Ataai; Richard R. Koepsel

    2001-02-22

    The Broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in our laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules we will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal.

  14. New Strategies for Designing Inexpensive but Selective Bioadsorbants for Environmental Pollutants: Selection of specific Ligands and Their Cell Surface Expression; FINAL

    International Nuclear Information System (INIS)

    The Broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in our laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules we will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal

  15. New strategies for designing inexpensive but selective bioadsorbants for environmental pollutants: Selection of specific ligands and their cell surface expression. 1998 annual progress report

    International Nuclear Information System (INIS)

    'The broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in the laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules the authors will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal. The authors are currently in year two of a three year program. Work has been focused on preparing the molecular biology constructs needed to carry out the optimization of a metal complex binding antibody, and on the isolation of a metal binding peptide.'

  16. New strategies for designing inexpensive but selective bioadsorbants for environmental pollutants: Selection of specific ligands and their cell surface expression. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Iverson, B.L.; Georgiou, G. [Univ. of Texas, Austin, TX (US); Ataai, M.M.; Koepsel, R.R. [Univ. of Pittsburgh, PA (US)

    1998-06-01

    'The broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in the laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules the authors will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal. The authors are currently in year two of a three year program. Work has been focused on preparing the molecular biology constructs needed to carry out the optimization of a metal complex binding antibody, and on the isolation of a metal binding peptide.'

  17. Evaluation of vermicompost as bioadsorbent substrate of Pb, Ni, V and Cr for waste waters remediation using Total Reflection X-ray Fluorescence

    International Nuclear Information System (INIS)

    The use of vermicompost as adsorbent substrate for removing Pb, Ni, V and Cr from waste waters is proposed. In this work, after a preliminary physical and chemical characterization of the vermicompost, the optimal parameters for the heavy metal adsorption were obtained. A synthetic multielemental solution of Pb, Cr and Ni and a solution of NH4VO3 for vanadium were evaluated. The optimized parameters were pH, vermicompost mass to volume ratio, agitation time and particle size of the adsorbent. A batch system was employed for the assays. The elements were determined in the supernatant solution after filtration of the substrate. An optimal pH of 4.5 was found for ion removal. The agitation time slightly influences the adsorption of Pb and Cr, but it has a high influence on the Ni and V adsorption. The highest adsorption and removal of the metals was observed for a vermicompost mass of 2 g per 500 mL using a particle size between 75 to 841 μm for Pb, Cr and Ni, and 841 till 1192 μm for V. The mean removal percentage for each element is around 95% for Pb. Ni and Cr in the multielemental synthetic sample, demonstrating a high removal capacity of the substrate. For V it was found a removal efficiency of 50%

  18. Evaluation of vermicompost as bioadsorbent substrate of Pb, Ni, V and Cr for waste waters remediation using Total Reflection X-ray Fluorescence

    Science.gov (United States)

    Urdaneta, Cynthia; Parra, Lué-Merú Marcó; Matute, Saida; Garaboto, Mayantino Angel; Barros, Hayden; Vázquez, Cristina

    2008-12-01

    The use of vermicompost as adsorbent substrate for removing Pb, Ni, V and Cr from waste waters is proposed. In this work, after a preliminary physical and chemical characterization of the vermicompost, the optimal parameters for the heavy metal adsorption were obtained. A synthetic multielemental solution of Pb, Cr and Ni and a solution of NH 4VO 3 for vanadium were evaluated. The optimized parameters were pH, vermicompost mass to volume ratio, agitation time and particle size of the adsorbent. A batch system was employed for the assays. The elements were determined in the supernatant solution after filtration of the substrate. An optimal pH of 4.5 was found for ion removal. The agitation time slightly influences the adsorption of Pb and Cr, but it has a high influence on the Ni and V adsorption. The highest adsorption and removal of the metals was observed for a vermicompost mass of 2 g per 500 mL using a particle size between 75 to 841 µm for Pb, Cr and Ni, and 841 till 1192 µm for V. The mean removal percentage for each element is around 95% for Pb. Ni and Cr in the multielemental synthetic sample, demonstrating a high removal capacity of the substrate. For V it was found a removal efficiency of 50%.

  19. Evaluation of vermicompost as bioadsorbent substrate of Pb, Ni, V and Cr for waste waters remediation using Total Reflection X-ray Fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Urdaneta, Cynthia [Universidad Experimental Politecnica, Dpto. Ingenieria Quimica, Barquisimeto (Venezuela, Bolivarian Republic of); Parra, Lue-Meru Marco [Universidad Centro Occidental Lisandro Alvarado, Decanato de Agronomia, Dpto. Quimica y Suelos, Modulo I, Tarabana, Cabudare, Edo. Lara. Venezuela (Venezuela, Bolivarian Republic of)], E-mail: luemerumarco@yahoo.es; Matute, Saida [Universidad Centro Occidental Lisandro Alvarado, Decanato de Agronomia, Dpto. Quimica y Suelos, Modulo I, Tarabana, Cabudare, Edo. Lara. Venezuela (Venezuela, Bolivarian Republic of); Garaboto, Mayantino Angel [Universidad Experimental Politecnica, Dpto. Ingenieria Quimica, Barquisimeto (Venezuela, Bolivarian Republic of); Barros, Hayden [Universidad Simon Bolivar, Dpto. Fisica, Lab-Fisica Nuclear, Edificio Fisica y Electronica I, Sartenejas, Baruta (Venezuela, Bolivarian Republic of); Vazquez, Cristina [Comision Nacional de Energia Atomica, Gerencia Quimica, Av. Gral. Paz 1499-1650-Buenos Aires (Argentina); Universidad de Buenos Aires, Facultad de Ingenieria, Laboratorio de Sistemas Heterogeneos, Av. Paseo Colon 950, Buenos Aires (Argentina)

    2008-12-15

    The use of vermicompost as adsorbent substrate for removing Pb, Ni, V and Cr from waste waters is proposed. In this work, after a preliminary physical and chemical characterization of the vermicompost, the optimal parameters for the heavy metal adsorption were obtained. A synthetic multielemental solution of Pb, Cr and Ni and a solution of NH{sub 4}VO{sub 3} for vanadium were evaluated. The optimized parameters were pH, vermicompost mass to volume ratio, agitation time and particle size of the adsorbent. A batch system was employed for the assays. The elements were determined in the supernatant solution after filtration of the substrate. An optimal pH of 4.5 was found for ion removal. The agitation time slightly influences the adsorption of Pb and Cr, but it has a high influence on the Ni and V adsorption. The highest adsorption and removal of the metals was observed for a vermicompost mass of 2 g per 500 mL using a particle size between 75 to 841 {mu}m for Pb, Cr and Ni, and 841 till 1192 {mu}m for V. The mean removal percentage for each element is around 95% for Pb. Ni and Cr in the multielemental synthetic sample, demonstrating a high removal capacity of the substrate. For V it was found a removal efficiency of 50%.

  20. New strategies for designing inexpensive but selective bioadsorbants for environmental pollutants: Selection of specific ligands and their cell surface expression. Technical progress report, September 15, 1996--September 14, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Iverson, B.

    1997-01-01

    'Progress for the last twelve months has revolved around setting up an antibody engineering and surface display system for use with a metal-complex binding antibody. (1) The author has isolated genes for the V regions of the heavy and light chains for the Ru(bpy)3 specific monoclonal AC1106 (Shreder, K S., Hariman, A., and Iverson, B.L., J. Am. Chem. Soc. 1996, 118, 3192-3201). This antibody binds Ru(bpy), derivatives with better than nanomolar affinity, and will serve as the generic metal-complex binding pocket. Cloning antibody genes from hybridomas is complicated by the fact that primers must be found that amplify the particular heavy and light chain genes in the hybridoma of interest. Antibody gene amplification primers are generally designed to amplify antibody repertoires from lymphocyte mRNA isolated from animals. While cloning repertoires from animals is routinely successful due to the diverse population of target m RNA, hybridomas have a single target sequence. Therefore, multiple primers and conditions must be tried before the correct primer combination is identified.'

  1. Extraction of alginate biopolymer present in marine alga sargassum filipendula and bioadsorption of metallic ions

    Directory of Open Access Journals (Sweden)

    Sirlei Jaiana Kleinübing

    2013-04-01

    Full Text Available This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, adsorption capacities greater than those found for the alga were observed, indicating that it is the main component responsible for the removal of metallic ions. For Zn2+ and Cd2+ ions, greater bioadsorption capacities were observed for the alga, indicating that other functional groups of the alga, such as sulfates and amino, are also important in the bioadsorption of these ions.

  2. Application of biomass in oil and fat reduction content in aqueous effluent; Aplicacao de biomassa na reducao do teor de oleos e graxas presentes em efluentes aquosos

    Energy Technology Data Exchange (ETDEWEB)

    Boni, Hevelin Tabata; Souza, Antonio Augusto Ulson de; Souza, Selene Maria de Arruda Guelli Ulson de [Universidade Federal de Santa Catarina (UFSC), SC (Brazil)

    2012-07-01

    In this work, we have studied the bagasse from sugarcane as an alternative bioadsorbent in the treatment to oils and greases contaminated waters. The synthetic effluent was simulated by a distilled water and decahydronaphthalene dispersion, with initial concentration of 8900 mg . L {sup -1}. Gas chromatography was the analytical operation chosen to quantify the oil residual after the adsorption. The biomass was characterized by moisture analysis, CHNS and SEM. The experiments were carried out in batch process with agitation of 120 rpm, evaluating the equilibrium time of adsorptive process and the influence of pH of aqueous level. Results showed that the adsorption process achieved equilibrium quickly, in just 5 minutes of contact between the dispersion and biomass. No significant influence was noticed in the removal of hydrocarbon with the change in pH. The adsorption isotherm was developed changing by the mass of bioadsorbent, at 25 deg C, pH 6 and 120 rpm of agitation. The experimental results were fitted by Langmuir and Langmuir- Freundlich models. The best fit was obtained with Langmuir-Freundlich, providing a maximum adsorption capacity of 6,65 g hydrocarbon / g biomass. The experiments showed the great potential of the sugarcane bagasse to be used as bioadsorbent in reducing the oil and grease levels in industrial effluents. This alternative presents itself as a sustainable route due to the abundance of sugar cane bagasse in the sugar and alcohol industry, avoided the impact of aqueous sources contamination coming from oil and petrochemical industry. (author)

  3. Feasibility of anaerobic digested corn stover as biosorbent for heavy metal.

    Science.gov (United States)

    Wang, Jin; Peng, Shu-chuan; Wan, Zheng-qiang; Yue, Zheng-bo; Wu, Jian; Chen, Tian-hu

    2013-03-01

    Anaerobic digested (AD) corn stover collected from a lab-scale reactor was used as bioadsorbent to remove the heavy metal in aqueous solution. Effects of contact time and initial heavy metal concentrations on the removal process of Cu(2+) and Cd(2+) were investigated. The maximum adsorption capacities of AD corn stover obtained from Langmuir isotherm models were 83.3 and 50.0mg/g for Cu(2+) and Cd(2+), respectively. Fourier transform infrared spectroscopy (FTIR) was also used to investigate the surface characteristic of raw and heavy metal loaded AD corn stover.

  4. Effect of the gamma irradiation on the bio-sorption of Cr (Vi) by orange peel;Efecto de la irradiacion gamma en la biosorcion de Cr(VI) por cascara de naranja

    Energy Technology Data Exchange (ETDEWEB)

    Lugo L, V.; Barrera D, C. E.; Sanchez M, V. [Universidad Autonoma del Estado de Mexico, Centro de Investigacion en Quimica Sustentable, Paseo Tollocan esquina Paseo Colon s/n, 50180 Toluca, Estado de Mexico (Mexico); Urena N, F., E-mail: violelugol@yahoo.e [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    The orange peel (Citrus sp.) is a bioadsorbent that contains functional groups able to remove Cr (Vi). To study the effect of gamma irradiation in the sorption capacity, the Nn materials were irradiated with gamma rays using a Co{sup 60} source to dose from 10 to 3500 KGy (Nlgamma). The biomass irradiation with gamma rays was successful since it increased the hexavalent chromium removal obtaining a maximum removal percentage of 100%. Sorption isotherms were realized to determine the concentration effect of initial Cr (Vi), the ph effect of the solution and the relationship m/v. (Author)

  5. Immobilization of thorium over fibroin by polyacrylonitrile (PAN)

    Energy Technology Data Exchange (ETDEWEB)

    Aslani, M.A.A.; Akyil, S.; Eral, M. [Ege Univ. Inst. of Nuclear Sciences, Bornova-Izmir (Turkey)

    1997-12-31

    This report describes a process for immobilization of thorium over fibroin, which was used as a bio-adsorbant, by polyacrylonitrile. The amounts of thorium in aqueous solutions which may be leached in various aqueous ambients were detected by a spectrophotometer. The results show that polyacrylonitrile processes are feasible to immobilize spent fibroins. The leachability of the materials immobilized with polyacrylonitrile can meet the requirements of storage and final disposal. The leachability of thorium ions from immobilized spent fibroin was rather low for 8 months.

  6. Avaliação do processo adsortivo utilizando mesocarpo de coco verde para remoção do corante cinza reativo BF-2R

    OpenAIRE

    Otidene Rossiter Sá da Rocha; Graziele Elisandra do Nascimento; Natália Ferreira Campos; Valdinete Lins da Silva; Marta Maria Menezes Bezerra Duarte

    2012-01-01

    This work used green coconut mesocarp as a bioadsorbent to remove Reactive Gray BF-2R dye. A 2³ factorial design was used to evaluate the influence of the variables adsorbent mass, particle size and stirring speed on the adsorptive process. Kinetic and adsorption equilibrium studies were performed. Results showed that the kinetic equilibrium was reached after 150 min. Using the Langmuir model, a q max of 21.9 mg g-1 and k of 0.30 L g-1 was obtained. The mesocarp of coconut, a residue of agrib...

  7. Removal of BTEX by using a surfactant--Bio originated composite.

    Science.gov (United States)

    Shakeri, H; Arshadi, M; Salvacion, J W L

    2016-03-15

    The application of ostrich bone waste-loaded a cationic surfactant (OBW-OH-CTABr) bioadsorbent for benzene, toluene, ethylbenzene and p-xylene (BTEX) removal from the synthetic and real waters have been studied, and the prepared biomaterials were studied by Fourier transform infrared (FTIR), X-ray diffraction (XRD), surface area measurements (BET), scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and point of zero (pH(PZC)). The immobilization of CTABr molecules on the framework of modified OBW showed good tendency to adsorb BTEX from aqueous solution. The exposure time to obtain equilibrium for maximum removal of BTEX was observed to be 60 min. The removal kinetics of BTEX has been evaluated in terms of pseudo-first- and -second-order kinetics, and the Freundlich and Langmuir isotherm models have also been utilized to the equilibrium removal data. The removal process was spontaneous and endothermic in nature and followed pseudo-second-order kinetic model. The immobilized CTABr showed high reusability because of its high adsorption efficiency after 12th cycles. The proposed low-cost bioadsorbent could also be utilized to adsorb BTEX from the real water (Anzali lagoon water). The OBW-OH-CTABr composite is indeed an attractive biomaterial for drinking water-based pollutants and act as an adsorbent for BTEX and oil spills especially in third world due to its low-cost preparation and regeneration and clean processing of the biomaterial with no byproducts after utilize. PMID:26724701

  8. Artificial neural network modeling of fixed bed biosorption using radial basis approach

    Science.gov (United States)

    Saha, Dipendu; Bhowal, Avijit; Datta, Siddhartha

    2010-04-01

    In modern day scenario, biosorption is a cost effective separation technology for the removal of various pollutants from wastewater and waste streams from various process industries. The difficulties associated in rigorous mathematical modeling of a fixed bed bio-adsorbing systems due to the complexities of the process often makes the development of pure black-box artificial neural network (ANN) models particularly useful in this field. In this work, radial basis function network has been employed as ANN to model the breakthrough curves in fixed bed biosorption. The prediction has been compared to the experimental breakthrough curves of Cadmium, Lanthanum and a dye available in the literature. Results show that this network gives fairly accurate representation of the actual breakthrough curves. The results obtained from ANN modeling approach shows the better agreement between experimental and predicted breakthrough curves as the error for all these situations are within 6%.

  9. Dunaliella salina as marine microalga highly tolerant to but a poor remover of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Folgar, S. [Departamento de Biologia Celular y Molecular, Laboratorio de Microbiologia, Facultad de Ciencias, Universidade da Coruna, Alejandro de la Sota no 1, 15008 La Coruna (Spain); Torres, E., E-mail: torres@udc.es [Departamento de Biologia Celular y Molecular, Laboratorio de Microbiologia, Facultad de Ciencias, Universidade da Coruna, Alejandro de la Sota no 1, 15008 La Coruna (Spain); Perez-Rama, M.; Cid, A.; Herrero, C.; Abalde, J. [Departamento de Biologia Celular y Molecular, Laboratorio de Microbiologia, Facultad de Ciencias, Universidade da Coruna, Alejandro de la Sota no 1, 15008 La Coruna (Spain)

    2009-06-15

    Cadmium tolerance and removal in the marine microalga Dunaliella salina were studied in cultures exposed to different metal concentrations (5-120 mg Cd l{sup -1}) for 96 h. This microalga can be included in the group of microalgal species most tolerant to cadmium due to the high value of EC50 that it possesses (48.9 mg Cd l{sup -1} at 96 h of culture). The greater percentage of cadmium removed was obtained in cultures exposed to 5 mg Cd l{sup -1} at 96 h, but removing only 11.3% of the added cadmium. In all cultures, the quantity of cadmium removed intracellularly was much lower than the bioadsorbed quantity and it was proportional to the sulfhydryl group levels. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of cadmium by living cells of D. salina.

  10. Potential of Agave lechuguilla biomass for Cr(III) removal from aqueous solutions: thermodynamic studies.

    Science.gov (United States)

    Romero-González, J; Peralta-Videa, J R; Rodríguez, E; Delgado, M; Gardea-Torresdey, J L

    2006-01-01

    Thermodynamic studies on the bioadsorption of Cr(III) onto Agave lechuguilla biomass were conduced. The experimental results at different temperatures were modeled using the Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. Both the Freundlich and Langmuir models were found to represent the bioadsorption process. The average adsorption capacities calculated from Freundlich (4.7 mg/g) and Langmuir (14.2 mg/g) isotherms showed A. lechuguilla to be an effective biomass in the removal of Cr(III) from an aqueous solution. Thermodynamic parameters (deltaG0, deltaH0 and deltaS0) determined in the temperature range from 10 to 40 degrees C along with the parameters of the Dubinin-Radushkevick equation support the idea that the binding of Cr(III) may be caused by interactions with functional groups such as carboxyl groups located on the outer surface of the cell tissue of the bioadsorbent. PMID:16154514

  11. Characterization and use of in natura and calcined rice husks for biosorption of heavy metals ions from aqueous effluents

    Directory of Open Access Journals (Sweden)

    M. G. A. Vieira

    2012-09-01

    Full Text Available Heavy metal removal by adsorption using rice husks as a bioadsorbent was evaluated as an alternative for wastewater treatment. Batch equilibrium experiments and kinetic sorption studies were performed using monocomponent solutions of Ni(II, Cd(II, Zn(II, Pb(II and Cu(II in surface samples of in natura(RH and calcined rice husks (RHA. RHA showed higher potential for removing lead and copper. Experimental data for adsorption isotherms of lead and copper were adjusted by Langmuir, Freundlich and Dubinin-Radushkevick (D-R models, being better represented by the Langmuir model. The calcination of RH increased its surface area, improving its adsorption properties. From a morphological analysis obtained by SEM and diffraction patterns (XRD, a longitudinal fibrous and amorphous structure was observed for RH. TGA resultsindicated a total mass loss of around 60% for RH and 24.5% for RHA.

  12. Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system

    Directory of Open Access Journals (Sweden)

    M. G. A. Vieira

    2014-06-01

    Full Text Available This study evaluated the kinetic adsorption of Pb and Cu ions using rice husk ash as adsorbent in a fixed bed. The maximum adsorption capacities obtained for lead and copper ions in the fixed bed were 0.0561 and 0.0682 mmol/g (at 20 ºC, respectively. The thermodynamic studies indicated that the lead adsorption process was exothermic and spontaneous, while the copper adsorption process was endothermic and spontaneous. Characterization results indicated the presence of several functional groups, amorphous silica and a fibrous and longitudinal structure of rice husks. Rice husk ash (RHA from northern Brazil can be used as a bioadsorbent for the individual removal of Pb(II and Cu(II ions from metal-containing effluents.

  13. Removal of {sup 99m}Tc and {sup 201}Tl by means of Lemna Gibba; Remocion de {sup 99m}Tc y {sup 201}Tl mediante Lemna Gibba

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E.; Carreno de L, M. C.; Cuevas S, J. C.; Hernadez T, U. O. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Fraccionamiento La Virgen, 52149 Metepec, Estado de Mexico (Mexico); Monroy G, F., E-mail: edelmiraf@yahoo.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    In this work the capacity of the water macrophyte Lemna gibba coming from San Pedro Tultepec in the Mexico State was studied to remove the radioisotopes {sup 99m}Tc and {sup 201}Tl, in order to show the capacity of this macrophyte for to treat some radioactive waste flowing that could contain this radioisotopes type. The removal capacity of {sup 99m}Tc and {sup 201}Tl of the macrophyte Lemna gibba was determined using the batch method. In accordance with the values of the obtained K{sub d}, the Lemna gibba with a size of particle diameter among 1mm - 300 {mu}m presents a better adsorption of {sup 99m}Tc. The {sup 201}Tl is adsorbed better in the bioadsorbent when it has a size of particle diameter <150{mu}m. (Author)

  14. Dunaliella salina as marine microalga highly tolerant to but a poor remover of cadmium

    International Nuclear Information System (INIS)

    Cadmium tolerance and removal in the marine microalga Dunaliella salina were studied in cultures exposed to different metal concentrations (5-120 mg Cd l-1) for 96 h. This microalga can be included in the group of microalgal species most tolerant to cadmium due to the high value of EC50 that it possesses (48.9 mg Cd l-1 at 96 h of culture). The greater percentage of cadmium removed was obtained in cultures exposed to 5 mg Cd l-1 at 96 h, but removing only 11.3% of the added cadmium. In all cultures, the quantity of cadmium removed intracellularly was much lower than the bioadsorbed quantity and it was proportional to the sulfhydryl group levels. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of cadmium by living cells of D. salina.

  15. Investigation on Adsorption of Lithospermum erythrorhizon onto Fungal Cell Wall Polysaccharides%真菌细胞壁多糖的紫草细胞吸附固定化研究

    Institute of Scientific and Technical Information of China (English)

    孟琴; 薛莲

    2003-01-01

    A culture of Lithospermum erythrorhizon adsorbed on fungal cell wall polysaccharides, a novel bio-adsorbent made from fnngal cell wall, has been established in this paper. Three steps were involved in this immo-bilization. The first step was preparation of suspended plant cells from tightly aggregated plant cell clumps. Thedisassembled ratio of 0.715g.g-1 (the disassembled cells over total cells) was obtained under optimum conditionfor the enzymatic reaction. Then, the adsorption of plant cells onto fungal cell wall polysaccharides was conductedand the saturated capacity of 12 g cell per gram of carrier was obtained in adsorption immobilization. Finally, theculture of cells adsorbed on fungal cell wall polysaccharides was compared with that of cells entrapped in alginateor suspension cell culture. While exposed to in situ liquid paraffin extraction coupled with cell culture, the shikoninproductivity of immobilized cells by adsorption was 10.67 g.L-1, which was 1.8 times of that in suspension cultureand 1.5 times of that entrapped in alginate.

  16. Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Chih-Huang, E-mail: chweng@isu.edu.tw [Department of Civil and Ecological Engineering, I-Shou University, Da-Hsu Township, Kaohsiung 84008, Taiwan (China); Lin, Yao-Tung; Tzeng, Tai-Wei [Department of Soil and Environmental Sciences, National Chung Hsing University, TaiChung 40227, Taiwan (China)

    2009-10-15

    The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68 x 10{sup -4} to 9.28 x 10{sup -4} mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution.

  17. Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder.

    Science.gov (United States)

    Weng, Chih-Huang; Lin, Yao-Tung; Tzeng, Tai-Wei

    2009-10-15

    The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68 x 10(-4) to 9.28 x 10(-4)mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution. PMID:19447547

  18. Kinetic and isotherm error optimization studies for adsorption of atrazine and imidacloprid on bark of Eucalyptus tereticornis L.

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera

    2016-01-01

    The aim of this study was to establish the bark of Eucalyptus tereticornis L. (EB) as a low cost bio-adsorbent for the removal of imidacloprid and atrazine from aqueous medium. The pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich and intra-particle diffusion (IPD) models were used to describe the kinetic data and rate constants were evaluated. Adsorption data was analysed using ten 2-, 3- and 4-parameter models viz. Freundlich, Jovanovic, Langmuir, Temkin, Koble-Corrigan, Redlich-Peterson, Sips, Toth, Radke-Prausnitz, and Fritz-Schluender isotherms. Six error functions were used to compute the best fit single component isotherm parameters by nonlinear regression analysis. The results showed that the sorption of atrazine was better explained by PSO model, whereas the sorption of imidacloprid followed the PFO kinetic model. Isotherm model optimization analysis suggested that the Freundlich along with Koble-Corrigan, Toth and Fritz-Schluender were the best models to predict atrazine and imidacloprid adsorption onto EB. Error analysis suggested that minimization of chi-square (χ(2)) error function provided the best determination of optimum parameter sets for all the isotherms.

  19. Investigation on Adsorption of Lithospermum erythrorhizon onto Fungal Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    孟琴; 薛莲

    2003-01-01

    A culture of Lithosperrnum erythrorhizon adsorbed on fungal cell wall polysaccharides, a novel bioadsorbent made from fungal cell wall, has been established in this paper. Three steps were involved in this immobilization. The first step was preparation of suspended plant cells from tightly aggregated plant cell clumps. The disassembled ratio of 0.715g·g-1 (the disassembled cells over total cells) was obtained under optimum condition for the enzymatic reaction. Then, the adsorption of plant cells onto fungal cell wall polysaccharides was conducted and the saturated capacity of 12g cell per gram of carrier was obtained in adsorption immobilization. Finally, the culture of cells adsorbed on fungal cell wall polysaccharides was compared with that of cells entrapped in alginate or suspension cell culture. While exposed to in situ liquid paraffin extraction coupled with cell culture, the shikonin productivity of immobilized cells by adsorption was 10.67g·L-1, which was 1.8 times of that in suspension culture and 1.5 times of that entrapped in alginate.

  20. Sorption of paracetamol onto biomaterials.

    Science.gov (United States)

    Ferchichi, Maroua; Dhaouadi, Hatem

    2016-01-01

    Pharmaceutical residues released into the environment are posing more and more public health problems. It is worthwhile to study the retention of pharmaceuticals residues by adsorption on solid supports. Batch sorption experiments are intended to identify the adsorption isotherms of the pharmaceutically active ingredient on the biomaterials. The results obtained in this study have shown that the retention possibilities of these compounds by bio-adsorbents (clay and sand) are not significant. The negligible sorption for these media is explained by the low hydrophobicity of paracetamol (Log K(ow) = 0.46). The retention of paracetamol on the dehydrated sewage sludge and on Posidonia oceanica showed a relatively significant adsorption with a maximal quantity of 0.956 mg g(-1) and 1.638 mg g(-1) for the dehydrate sludge and P. oceanica, respectively. On the other hand, the study of paracetamol retention on the powdered activated carbon showed a high adsorption capacity of about 515.27 mg g(-1). Isotherm data show a good fit with Langmuir's model. An infrared analysis is carried out. It shows identical bands before and after adsorption, with some modifications. PMID:27387007

  1. X-ray fluorescence in Member States: Venezuela

    International Nuclear Information System (INIS)

    The direct analysis of biological samples is the main research challenge of the scientific group at the Unidad de Analisis Instrumental of the Agronomy Faculty, Universidad Centro Occidental Lisandro Alvarado, (UCLA) Edo. Lara, Venezuela. The technique of total reflection X-ray fluorescence (TXRF) plays an important role in the scientific activities of the laboratory. In this field, the research is devoted to the design, development, evaluation and application of methods for the analysis of biological and related samples, such as biological tissues, fluids, biota, soil and water samples. The studies involve the evaluation of feasibility for direct determination of analytes, the in situ (in quartz sample holder) preparation techniques, the in situ pre-concentration and speciation among others studies. The methods are developed for the application in clinical studies, agronomy, environmental monitoring, bioremediation, statistical processing of data and neural network applications. The following projects are described: Direct analysis of biological samples by TXRF; Determination of calcium, potassium, manganese, iron, cooper and zinc levels in representative samples of two onion cultivars using TXRF and ultrasound extraction procedure; Evaluation of vermicompost as bioadsorbent substrate of Pb, Ni, V and Cr for waste waters remediation using total reflection X-ray fluorescence; Determination by TXRF of total As in onion plants growing in contaminated substrates

  2. Determination of Arsenic in Drinking Water Samples by Electrothermal Atomic Absorption Spectrometry after Preconcentration Using the Biomass of Aspergillus niger Loaded on Activated Charcoal

    Directory of Open Access Journals (Sweden)

    Mohsen Shahlaei

    2014-01-01

    Full Text Available A simple, fast, and sensitive method for determination of total arsenic in drinking water sample by ETAAS after solid phase preconcentration has been developed. The dead biomass of A. niger loaded on activated charcoal has been applied as bioadsorbent for preconcentration step. The effects of parameters such as pH, type and concentration of eluent, biosorption time, sample volume, and effect of interfering ions have also been studied. Under the optimum condition, the enrichment factor of 10 for the analyte has been obtained. The accuracy of the method has been investigated by the recovery of spiked standards and the recovery percents between 99 and 102% have been achieved. Total amount of arsenic was determined by reducing As (V to As (III with potassium iodide (KI and ascorbic acid in HCl solution. Under the optimum conditions, for 400 mL of drinking water samples, the detection limit (3σ and linear range were achieved 1 ng/mL and 5–100 ng/mL, respectively. The relative standard deviation for ten determinations of a spiked sample with concentration of 10 ng/mL As was 3.2%.

  3. Titanium(IV) hydrate based on chitosan template for defluoridation from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jie, E-mail: ljluck@126.com [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Li, Wan-Yi, E-mail: wanyili@whu.edu.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430079 (China); Department of Chemical Engineering, Columbia University, New York, NY 10027 (United States); Liu, Yunguo, E-mail: environmentalist13@126.com [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zeng, Qinghui, E-mail: xiaohui900108@yahoo.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430079 (China); Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Hong, Song, E-mail: songhongpku@126.com [School of Resource and Environmental Science, Wuhan University, Wuhan 430079 (China); Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079 (China)

    2014-02-28

    A cost effective bio-adsorbent, titanium(IV) hydrate based on chitosan template (Ti-CHI), was synthesized using Ti(SO{sub 4}){sub 2} and chitosan for defluoridation from aqueous solutions. The Ti-CHI material was characterized using FTIR, SEM with EDX, XRD, XPS and Zeta potential. The adsorption kinetics of fluoride onto Ti-CHI followed pseudo-second-order and intra-particle diffusion models. The Ti-CHI was effective for defluoridating systems with low fluoride concentrations (4.52 mg/L), exhibiting a 87.50% removal rate and permitting a residual fluoride concentration (0.55 mg/L). The most stable pH range for fluoride removal was from 4 to 9. After combining the results of pH effects, FTIR and Zeta potential, the -NH groups and Ti-OH groups were revealed as the fluoride adsorption sites on Ti-CHI. In addition, the carbonate ions present in the aqueous solutions adversely impact the fluoride adsorption. The Langmuir, Freundlich, and Langmuir–Freundlich models were used to illustrate the isotherms of the adsorption process. The adsorption of fluoride onto Ti-CHI fits the Langmuir and Langmuir–Freundlich isotherm models well. The maximum adsorption capacity for fluoride on the Ti-CHI was 16.12 mg/g. Thermodynamic studies revealed that the adsorption process was spontaneous.

  4. Rapid Purification of Glycerol by-product from Biodiesel Production through Combined Process of Microwave Assisted Acidification and Adsorption via Chitosan Immobilized with Yeast

    Directory of Open Access Journals (Sweden)

    N. Saifuddin

    2014-01-01

    Full Text Available Biodiesel is a proven alternative to the petroleum diesel fuel. During biodiesel production, glycerol is produced as a by-product. This by-product consist of impureties such as soap, salts, sodium catalyst and so on. Traditionally, two of the most conventional techniques that is applied to glycerol purification are distillation and ion-exchange. These techniques are, however, still expensive to generate pure glycerol. Recently, several alternative “combination” treatment procedures have been used. These treatment has several advantages over others methods such as producing large amounts of glycerol-rich layer that requires simple treatments and not causing any high operational cost. In this study, the combination treatment process have been used in order to reach high glycerol content. Basically, these stages starts with using microwave assisted acidification process and the next process utilizing a bioadsorbent synthesized from dead yeast cells immobilized on chitosan. The final yield of glycerol was about 93.1-94.2% (w/w.

  5. Synthesis of magnetic graphene nanocomposites decorated with ionic liquids for fast lead ion removal.

    Science.gov (United States)

    Sun, Weiyan; Li, Leilei; Luo, Chuannan; Fan, Lulu

    2016-04-01

    Seeking highly-efficient, low-cost and robust methods to remove metal ions from aqueous solutions is very much in demand. Here, we developed a novel magnetic composite bio-adsorbent, graphene oxide and magnetic chitosan-ionic liquids (GOMCS-ILs), for removing Pb(II) from water. This was the first time to combine ionic liquids and graphene oxide and magnetic chitosan, and apply to the adsorption of metal ions. The addition of ionic liquids can not only improve the dispersivity of the adsorbent, but also increase the adsorption sites. The characteristic result of FTIR, SEM, and XRD showed that GOMCS-ILs were prepared with large surface area and good magnetic responsiveness. The influence of various analytical parameters on the adsorption of Pb(II) such as pH, contact time, and initial ion concentration were studied in detail. The adsorption followed a pseudo second order kinetics. The equilibrium adsorption was well-described by the Langmuir isotherm model and the maximum adsorption capacity was to be 85mgg(-1). Moreover, the GOMCS-ILs could be repeatedly used by simple treatment without obvious structure and performance degradation. These results demonstrated the potential applications of GOMCS-ILs microspheres in efficient removal of Pb(II) from wastewater and deep-purification of polluted water.

  6. Synthesis of novel aminated cellulose microsphere adsorbent for efficient Cr(VI) removal

    Science.gov (United States)

    Yu, Tianlin; Liu, Siqi; Xu, Min; Peng, Jing; Li, Jiuqiang; Zhai, Maolin

    2016-08-01

    A novel aminated cellulose microsphere adsorbent (CVN) was successfully prepared by radiation-induced graft polymerization of vinylbenzyl chloride (VBC) onto cellulose microsphere (CMS), followed by amination. Micro-FTIR, XPS and SEM confirmed the structure of CVN. The adsorption behavior of Cr(VI) onto CVN from solution was well fitted by the pseudo-second order kinetic model. The isothermal adsorption of Cr(VI) was observed at pH 4.68 with adsorption capacity of 129 mg/g in accordance with Langmuir thermal model, and the removal of Cr(VI) from solution could be 91% at a low amount (20 mg) of adsorbent. The best pH for adsorption of Cr(VI) was nearly 3.08, and with the increasing of temperature, the adsorption capacity of Cr(VI) increased. XPS analysis confirmed the adsorption mechanism of Cr(VI) was ion-exchange mechanism, while common co-ions such as Na+, Mg2+, Cu2+, Ca2+, Zn2+, Ni2+, Cl-, NO3- has no significant effect on the adsorption capacity of Cr(VI), and the Cr(VI) removal of 80% still could be obtained compared with that of fresh CVN adsorbent. Finally, spent CVN could be regenerated under 2 mol/L NaCl. The work indicated that aminated cellulose adsorbent could be prepared successfully by radiation-induced grafting and amination and CVN is a promising bio-adsorbent in the removing Cr(VI) from waste water.

  7. Use of new sorption materials and technologies for nuclear power plant waste water treatment

    International Nuclear Information System (INIS)

    Waste water decontamination in the nuclear power plant was achieved using several methods, viz., condensed water treatment using the Ostsorb MV-6/5 activated bioadsorbent; waste water treatment using a two-stage filtration-sorption process with a combined sorption filter (activated Ostsorb MV and granulated activated charcoal in a ratio of 1:1) in the former stage and with a filter with an anion exchanger (Varion AT 660 or Wolfatit SBK) in the latter; waste water treatment using the above technique completed with an intermediate stage utilizing reverse osmosis. The results show that with respect to decontamination efficiency and operating sorption capacity the former process is suitable for the treatment of condensed waste water while the latter process is more suitable for the raw waste water treatment. The mean decontamination factor value is of the order of 103 in both cases. Reverse osmosis is a prospective and a suitable supplementary process for a reliable capture of multivalent ions and of nuclides bound in a chemically complex or colloidal form. (J.B.)

  8. Study of adsorption capacity of biomass for organic contaminants; Estudo da capacidade de adsorcao de biomassas para contaminantes organicos

    Energy Technology Data Exchange (ETDEWEB)

    Santos, E.G. [Universidade Federal de Campina Grande, PB (Brazil). Programa de Recursos Humanos da ANP, PRH-25]. E-mail: elbagomes@uol.com.br; Alsina, O.L.S.; Silva, F.L.H. [Universidade Federal de Campina Grande, PB (Brazil). Centro de Ciencias e Tecnologia. Dept. de Engenharia Quimica]. E-mail: odelsia@deq.ufpb.br; flhs@deq.ufpb.br

    2003-07-01

    Great amounts of water are found in the oil reservoirs associated to the oil generating many effluents. In the petroleum industry, the adsorption has been getting attention, because its efficiencies in the treatment of effluents. Adsorption had been proposed because their advantages when compared with other conventional purification process. Among the adsorbent materials, the biomass has a great importance due to the low cost presented. Experiments of organic pollutants adsorption were accomplished, using as biomass: corn-cob, wood powder and coconut mesocarp, in the natural forms and with acid treatment. In this paper, the behavior of the effluent with organic pollutant was simulated, by a dispersion of gas in water. By means of factorial experimental planning, it was possible to verify the influence of the input variables: gas initial concentration, amount of biomass and the system rotation, on the output variable; the adsorption capacity, as well as the effect of the acid treatment used. The results show that the most appropriate bioadsorbent for adsorption of organic pollutants was the coconut mesocarp. (author)

  9. Banana peel: an effective biosorbent for aflatoxins.

    Science.gov (United States)

    Shar, Zahid Hussain; Fletcher, Mary T; Sumbal, Gul Amer; Sherazi, Syed Tufail Hussain; Giles, Cindy; Bhanger, Muhammad Iqbal; Nizamani, Shafi Muhammad

    2016-05-01

    This work reports the application of banana peel as a novel bioadsorbent for in vitro removal of five mycotoxins (aflatoxins (AFB1, AFB2, AFG1, AFG2) and ochratoxin A). The effect of operational parameters including initial pH, adsorbent dose, contact time and temperature were studied in batch adsorption experiments. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and point of zero charge (pHpzc) analysis were used to characterise the adsorbent material. Aflatoxins' adsorption equilibrium was achieved in 15 min, with highest adsorption at alkaline pH (6-8), while ochratoxin has not shown any significant adsorption due to surface charge repulsion. The experimental equilibrium data were tested by Langmuir, Freundlich and Hill isotherms. The Langmuir isotherm was found to be the best fitted model for aflatoxins, and the maximum monolayer coverage (Q0) was determined to be 8.4, 9.5, 0.4 and 1.1 ng mg(-1) for AFB1, AFB2, AFG1 and AFG2 respectively. Thermodynamic parameters including changes in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were determined for the four aflatoxins. Free energy change and enthalpy change demonstrated that the adsorption process was exothermic and spontaneous. Adsorption and desorption study at different pH further demonstrated that the sorption of toxins was strong enough to sustain pH changes that would be experienced in the gastrointestinal tract. This study suggests that biosorption of aflatoxins by dried banana peel may be an effective low-cost decontamination method for incorporation in animal feed diets. PMID:27052947

  10. Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: An explanation of how mesophilic organisms can rapidly colonise extremely toxic environments

    International Nuclear Information System (INIS)

    Highlights: •Some microalgae species survive to extreme environments in ponds of residual waters from uranium mining. •Adaptation of microalgae to U arose very fast. •Spontaneous mutations that confer large adaptive value were able to produce the adaptation to residual waters of U mining. •Adaptation to more extreme waters of U mining is only possible after the recombination subsequent to sexual mating. •Resistant microalgae bio-adsorbs uranium to the cell wall and internalises uranium inside the cytoplasm. -- Abstract: Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These “lucky mutants” could allow for the evolutionary rescue of populations faced with rapid environmental change

  11. Enhanced adsorption of trivalent arsenic from water by functionalized diatom silica shells.

    Directory of Open Access Journals (Sweden)

    Jianying Zhang

    Full Text Available The potential of porous diatom silica shells as a naturally abundant low-cost sorbent for the removal of arsenic in aqueous solutions was investigated in a batch study. The objective of this work was to chemically modify the silica shells of a diatom Melosira sp. with bifunctional (thiol and amino groups to effectively remove arsenic in its toxic As(III form (arsenite predominant in the aquatic environment. Sorption experiments with this novel sorbent were conducted under varying conditions of pH, time, dosage, and As(III concentration. A maximum adsorption capacity of 10.99 mg g-1 was achieved within 26 h for a solution containing 12 mg L-1 As(III at pH 4 and sorbent dosage of 2 g L-1. The functionalized diatom silica shells had a surface morphological change which was accompanied by increased pore size at the expense of reduced specific surface area and total pore volume. As(III adsorption was best fitted with the Langmuir-Freundlich model, and the adsorption kinetic data using pore surface diffusion model showed that both the external (film and internal (intraparticle diffusion can be rate-determining for As(III adsorption. Fourier transform infrared spectroscopy (FTIR indicated that the thiol and amino groups potentially responsible for As(III adsorption were grafted on the surface of diatom silica shells. X-ray photoelectron spectroscopy (XPS further verified that this unique sorbent proceeded via a chemisorption mechanism through the exchange between oxygen-containing groups of neutral As(III and thiol groups, and through the surface complexation between As(III and protonated nitrogen and hydroxyl groups. Results indicate that this functionalized bioadsorbent with a high As(III adsorption capacity holds promise for the treatment of As(III containing wastewater.

  12. Banana peel: an effective biosorbent for aflatoxins.

    Science.gov (United States)

    Shar, Zahid Hussain; Fletcher, Mary T; Sumbal, Gul Amer; Sherazi, Syed Tufail Hussain; Giles, Cindy; Bhanger, Muhammad Iqbal; Nizamani, Shafi Muhammad

    2016-05-01

    This work reports the application of banana peel as a novel bioadsorbent for in vitro removal of five mycotoxins (aflatoxins (AFB1, AFB2, AFG1, AFG2) and ochratoxin A). The effect of operational parameters including initial pH, adsorbent dose, contact time and temperature were studied in batch adsorption experiments. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and point of zero charge (pHpzc) analysis were used to characterise the adsorbent material. Aflatoxins' adsorption equilibrium was achieved in 15 min, with highest adsorption at alkaline pH (6-8), while ochratoxin has not shown any significant adsorption due to surface charge repulsion. The experimental equilibrium data were tested by Langmuir, Freundlich and Hill isotherms. The Langmuir isotherm was found to be the best fitted model for aflatoxins, and the maximum monolayer coverage (Q0) was determined to be 8.4, 9.5, 0.4 and 1.1 ng mg(-1) for AFB1, AFB2, AFG1 and AFG2 respectively. Thermodynamic parameters including changes in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were determined for the four aflatoxins. Free energy change and enthalpy change demonstrated that the adsorption process was exothermic and spontaneous. Adsorption and desorption study at different pH further demonstrated that the sorption of toxins was strong enough to sustain pH changes that would be experienced in the gastrointestinal tract. This study suggests that biosorption of aflatoxins by dried banana peel may be an effective low-cost decontamination method for incorporation in animal feed diets.

  13. Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: An explanation of how mesophilic organisms can rapidly colonise extremely toxic environments

    Energy Technology Data Exchange (ETDEWEB)

    García-Balboa, C.; Baselga-Cervera, B. [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain); García-Sanchez, A.; Igual, J.M. [Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), PO Box 257, 37071 Salamanca (Spain); Lopez-Rodas, V. [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain); Costas, E., E-mail: ecostas@vet.ucm.es [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain)

    2013-11-15

    Highlights: •Some microalgae species survive to extreme environments in ponds of residual waters from uranium mining. •Adaptation of microalgae to U arose very fast. •Spontaneous mutations that confer large adaptive value were able to produce the adaptation to residual waters of U mining. •Adaptation to more extreme waters of U mining is only possible after the recombination subsequent to sexual mating. •Resistant microalgae bio-adsorbs uranium to the cell wall and internalises uranium inside the cytoplasm. -- Abstract: Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These “lucky mutants” could allow for the evolutionary rescue of populations faced with rapid environmental change.

  14. Evaluation of adsorption of uranium from aqueous solution using biochar materials

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Wagner Clayton; Guilhen, Sabine Neusatz; Ortiz, Nilce; Fungaro, Denise Alves, E-mail: wcorrea@ipen.br, E-mail: snguilhen@ipen.br, E-mail: notriz@ipen.br, E-mail: dfungaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Uranium is present in the environment as a result of leaching from natural deposits and activities associated with nuclear fuel, copper mining, uranium mining, milling industry, etc. For the purpose of protecting ecosystem stability and public health, it is crucial to eliminate uranium from aqueous solutions before they are discharged into the environment. Various technologies have been used for removing U(VI) ions from aqueous systems. Among these methods, adsorption has been applied in wastewater because of simple operation procedure and high removal efficiency. Brazil is the largest producer of charcoal in the world, with nearly half of the woody biomass harvested for energy in Brazil being transformed into charcoal. Biochar exhibits a great potential as an adsorbent because of favorable physical/chemical surface characteristics. The objective of this work was to evaluate the adsorption potential of biochar materials prepared from pyrolysis of Bamboo (CBM), Eucalyptus (CEM) and Macauba (CMA) nuts for the removal of uranium from solutions. Adsorption experiments were carried out by a batch technique. Equilibrium adsorption experiments were performed by shaking a known amount of biochar material with 100 mL of U(VI) solution in Erlenmeyer flasks in a shaker at 120 rpm and room temperature (25 deg C) for 24 h. The adsorbent was separated by centrifugation from the solution. The U(VI) concentration remaining in the supernatant solution was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). The influences of different experimental parameters such as solution pH and bioadsorbent dose on adsorption were investigated. The highest uranium adsorption capacity were obtained at pH 3.0 and 16 g/L biomass dosage for CMA, pH 3.0 and 12 g/L biomass dosage for CBM and pH 2.0 and 10 g/L biomass dosage for CEM. The results demonstrated that the biomass derived char can be used as a low-cost adsorbent for removal of uranium from wastewater. (author)

  15. 碱改性泡桐树叶粉末对水中Pb2+的吸附特性%The Adsorbability of Alkali-modified Paulownia Leaf Powder on Pb2+in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    王俊丽; 乔辛悦; 陈学斌; 刘文霞

    2015-01-01

    生物吸附剂的改性方法不同,影响吸附剂性能和其对重金属离子的去除效果.本研究采用泡桐树叶粉末经Ca(OH)2改性后,吸附废水中Pb2+,并探讨了反应时间、吸附剂浓度、pH这三个因素对吸附效果的影响.结果表明,吸附剂浓度0.8 g/L,溶液pH为5,吸附60 min即可达到平衡,此时吸附量为60.43 mg/g,去除率为95.61%,吸附过程可用准二级吸附动力学模型描述.通过扫描电镜(SEM)发现泡桐树叶粉末经改性,表面变得松散粗糙;能谱分析(XPS)发现,吸附过程中发生了阳离子交换,Pb2+被吸附到泡桐粉末表面,而Ca2+被释放到溶液中. Ca(OH)2改性泡桐树叶粉末对Pb2+具有良好的吸附性能,可以用于重金属污染废水的处理.%Different bio-adsorbent modification methods will exert different influences on its adsorbability and heavy metal ion removal efficiency. In this work,Paulownia leaves were modified by Ca(OH)2 to absorb Pb2+ in wastewater. Further,the effects of reaction terms,sorption agent concentration and pH value on the absorption were evaluated. The results showed that the sorption agent concentration of 0.8 g/L,pH of 5 and reaction time of 60 min were favor for the adsorption equilibrium. The maximal adsorption was 60.43 mg/g and the Pb2+ removal rate was 95.61%,and the process was agree with Quasi-two adsorption kinetics model. The scanning electron microscopy (SEM)showed that the surface of Paulownia leaf powder becomes rough and loose. Spectroscopy(XPS)showed that the cation exchange occured during adsorption,Pb2+is adsorbed onto the surface of Paulownia leaves powder, and Ca2 + is released into the solution. Paulownia leaves powder modified by Ca(OH)2 presented good Pb2 +adsorption properties,and could be used for treatment heavy metal contaminated wastewater.

  16. OBTENCIÓN, ELECTRODEPOSICIÓN Y CARACTERIZACIÓN DE UN RECUBRIMIENTO POLIMÉRICO BIOABSORBIBLE A PARTIR DE ÁCIDO L - LÁCTICO PARA APLICACIONES BIOMÉDICAS SYNTHESIS, ELECTRODEPOSITION AND CHARACTERIZATION OF A BIOABSORBABLE POLYMER COATING FROM L-LACTIC ACID FOR BIOMEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Diana Carolina Parada Quinayá

    2009-12-01

    Full Text Available El ácido poli (L-láctico (APL ha sido usado ampliamente en aplicaciones biomédicas como suturas e implantes bioabsorbibles debido a su capacidad para permitir el crecimiento controlado de tejido biológico durante su biodegradación controlada. En este trabajo se obtuvo APL a partir de la policondensación de ácido láctico en presencia de un catalizador de zinc metálico en condiciones de vacío y atmósfera inerte. Se variaron las concentraciones de Zn++ y el tiempo de polimerización con el fin de obtener varias muestras que fueron caracterizadas mediante espectroscopia infrarroja (IR, calorimetría diferencial de barrido (DSC, análisis termogravimétrico (TGA y microscopia electrónica de barrido (SEM. Se obtuvieron recubrimientos poliméricos por electrodeposición catódica sobre sustratos de Ti6Al4V, usando una celda electrolítica con capacidad de 200 ml y dos ánodos de grafito cuya área expuesta fue de 12,57 cm². El electrolito consistió en una disolución 30:70 v/v de APL y acetona. Las variables involucradas fueron: voltaje, tiempo, temperatura, velocidad de agitación y las condiciones de preparación del polímero. Los recubrimientos obtenidos se caracterizaron mediante microscopia óptica y ataque químico. Los resultados revelaron la obtención de APL y la influencia del iniciador de Zn++, el cual promovió la migración y formación de grupos catiónicos que lograron neutralizarse y condensarse sobre Ti6Al4V bajo cargas catódicas. El análisis térmico mostró que en el rango de temperatura, entre 25 °C - 50 °C, no hubo variaciones importantes en la degradación térmica, indicando que el material podría ser utilizado para recubrir implantes ortopédicos.Poli (L-lactic (PLA has been used broadly in biomedical applications, such as sutures and bioadsorbable implant due to its capacity to allow the controlled growth of the biological tissue during their controlled biodegradation. In this work, a material polymeric PLA

  17. Removal of Reactive Dyes (Green, Orange, and Yellow from Aqueous Solutions by Peanut Shell Powder as a Natural Adsorbent

    Directory of Open Access Journals (Sweden)

    Hosein Nadi

    2012-11-01

    textile wastewater by TiO 2 nanoparticles. Desalination 2009;239(1-3:309-16. 13. Maleki A, Mahvi A, Ebrahimi R, Zandsalimi Y. Study of photochemical and sonochemical processes efficiency for degradation of dyes in aqueous solution. Korean J Chem Eng. 2010;27(6:1805-10. 14. Mahvi AH, Heibati B, Yari AR, Vaezi N. Efficiency of Reactive Black 5 dye removals and determination of Isotherm Models in aqueous solution by use of activated carbon made of walnut wood. Res J Chem Environ 2012;16(3:26-30. 15. Pajooheshfar SP, Saeedi M. Adsorptive removal of phenol from contaminated water and wastewater by activated carbon, almond, and walnut shells charcoal. Water Environ Res 2009;81(6:641-8. 16. Rodrigues LA, da Silva MLCP, Alvarez-Mendes MO, Coutinho AR, Thim, GP. Phenol removal from aqueous solution by activated carbon produced from avocado kernel seeds. Chem Eng J 2011;174(1:49-57. 17. Rasoulifard MH, Taheri Qazvini N, Farhangnia E, Heidari A, Doust Mohamadi SMM. [Removal of direct yellow 9 and reactive orange 122 from contaminated water using Chitosan as a polymeric bioadsorbent by adsorption process]. J Color Sci Technol 2010;4(1:17-23. (Full Text in Persian 18. Asgari G, Sidmohammadi A, Ebrahimi A, Gholami Z, Hosseinzadeh E. [Study on phenol removing by using modified zolite (Clinoptilolite with FeCl3 from aqueous solutions]. J Health Syst Res 2010;89:848-57. (Full Text in Persian 19. Ahmadi Moghadam M, Amiri H. [Investigation of TOC removal from industrial wastewaters using electrocoagulation process]. Iran J Health Environ 2010;3(2:185-94. (Full Text in Persian 20. Daraei H, Manshouri M, Yazdanbakhsh AR. [Removal of Phenol from Aqueous Solution Using Ostrich Feathers Ash]. J Mazand Univ Med Sci 2010;20(79: 81-7 (Full Text in Persian. 21. Shokouhi R, Ebrahimzadeh L, Rahmani AR, Ebrahimi SJAD, Samarghandi MR. [Comparison of the advanced oxidation processes in phenol degradation in laboratory scale]. Water Wastewater 2010;20(4(72;30-5. (Full Text in Persian 22. Lin SH, Juang RS