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1.
BACKGROUND: An immobilized new biosorbent was prepared from macro fungi Lactarius salmonicolor for the effective removal of nickel ions from aqueous media. Operating conditions were optimized as functions of initial pH, agitation time, sorbent amount and dynamic flow rate. Immobilization and biosorption mechanism were examined and the developed biosorbent was tested for the removal of nickel ions from real wastewater. RESULTS: Biosorption performance of the biomass continuously increased in the pH range 2.0–8.0. The coverage of the biosorbent surface by silica gel resulted in a significant increase in biosorption yield of nickel ions. The highest nickel loading capacity was obtained as 114.44 mg g?1 using a relatively small amount of immobilized biosorbent. Biosorption equilibrium time was recorded as 5 min. Experimental data were analyzed by different isotherm and kinetic models. Infrared spectroscopy, scanning electron microscopy and X‐ray energy dispersive analysis confirmed the process. The sorbent exhibited relatively good recovery potential in dynamic flow mode studies. Biosorption capacity of immobilized biosorbent was noted as 14.90 mg g?1 in real wastewater. CONCLUSION: Silica gel immobilized biomass of L. salmonicolor is to be a low cost and potential biosorbent with high biosorption capacity for the removal of contaminating nickel from aqueous media. © 2012 Society of Chemical Industry  相似文献   

2.
Palladised biomass of Desulfovibrio desulfuricans ATCC 29577 (bio‐Pd(0)) effected reduction of Cr(VI) to Cr(III) under conditions where biomass alone or chemically‐prepared Pd(0) were ineffective. Reduction of 500 µmol dm?3 Cr(VI) by 0.4 mg cm?3 bio‐Pd(0) (Pd : biomass ratio of 1:1) was achieved from 1 mol dm?3 formate/acetate buffer at pH 1–7 at room temperature; the optimum pH was 3.0. The ratio of mass of Pd : dry mass of biomass, and the need for finely ground bio‐Pd(0) were important parameters for optimal Cr(VI) reduction, with a ratio of 1:1 giving 100% reduction of 500 µmol dm?3 Cr(VI) within 6 h at room temperature, decreasing to 30 min following heat treatment of the Pd(0)‐loaded biomass. The reduced Cr was recovered quantitatively as soluble Cr(III) at pH 3.0 with no poisoning of the bioinorganic catalyst with respect to continued reduction of Cr(VI). © 2002 Society of Chemical Industry  相似文献   

3.
BACKGROUND: The metal respiring bacterium Shewanella oneidensis has previously been used for reduction of Pd(II) into Pd(0) nanoparticles. This study investigated whether Shewanella oneidensis could also perform the reduction of Au(III) to Au(0). The kinetics of both the biosorption and reduction of Au(III) were studied. RESULTS: Biosorption of Au(III) was a fast and efficient process, and depended on the presence of an electron donor, the pH and the medium used. The reduction process, however, appeared to be a slow process, requiring the presence of an electron donor. As reduction also occurred in heat‐killed cells, it is suggested that the reduction is non‐enzymatic. At a concentration of 100 mg L?1 Au(III), the nanoparticles were mainly smaller than 10 nm and precipitated intracellularly. With H2 as the electron donor, it was shown that the location of the particles and the size could be steered by changing the concentration of Au(III). CONCLUSIONS: After a fast biosorption and slow reduction process, Au(0)‐nanoparticles were formed inside the cells or on the cell wall of Shewanella oneidensis. In most cases, these particles had interesting properties, such as small size and a narrow size distribution, which can make them suitable for applications in, for example, catalysis. Copyright © 2010 Society of Chemical Industry  相似文献   

4.
The biosorption capacities of palladium and platinum were studied in three different species of Desulfovibrio: Desulfovibrio desulfuricans, Desulfovibrio fructosivorans and Desulfovibrio vulgaris. The influence of several parameters such as pH, acidic background and competitor anions on biosorption equilibria and biosorption kinetics were evaluated. Differences were observed between the three strains of Desulfovibrio with respect to the optimum biosorption parameters of both metals, suggesting differences in the metal speciation–dependent sorption mechanisms involved. The most promising Pd and Pt biosorption results were obtained using D desulfuricans with rapid achievement of equilibrium (90% of total sorption was achieved in 5–15 min) and a maximum value of 190 mg g?1 dry biomass and 90 mg g?1 dry biomass for Pd and Pt accumulation respectively, at pH 3. Copyright © 2003 Society of Chemical Industry  相似文献   

5.
Biosorption of Acid Red 57 (AR57) on to Neurospora crassa was studied with variation of pH, contact time, biosorbent and dye concentrations and temperature to determine equilibrium and kinetic models. The AR57 biosorption was fast and equilibrium was attained within 40 min. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models were applied to experimental equilibrium data for AR57 biosorption at various temperatures. The equilibrium data fitted very well to all the equilibrium models in the studied concentration range of AR57. Maximum biosorption capacity (qmax) of AR57 on to N. crassa was 2.16 × 10?4 mol g?1 at 20 °C. The kinetics of biosorption of AR57 were analyzed and rate constants were derived. The overall biosorption process was best described by a pseudo‐second‐order kinetic model. The changes in Gibbs free energy, enthalpy and entropy of biosorption were also evaluated for the biosorption of AR57 on to N. crassa. The results indicate that the biosorption was spontaneous and exothermic in nature. Copyright © 2006 Society of Chemical Industry  相似文献   

6.
《分离科学与技术》2012,47(3):625-638
Abstract

Biosorption of chromium from effluent generated in chrome‐electroplating unit using waste yeast biomass Saccharomyces cerevisiae was carried out. Chromium concentration in the effluent was 204 mg/L. Chromium biosorption equilibration time was found to be 2 hours, with uptake of 6.607 mg/g. Biosorption increased with rise in pH and chromium concentration. Equilibrium biomass concentration and agitation speed were 2% and 150 rpm, respectively. The biosorption equilibrium data fit with Freundlich and Langmuir isotherm models revealed Kf and Qmax values of 0.3727 and 384.61 mg/g, respectively.  相似文献   

7.
BACKGROUND: Biosorption of heavy metals from aqueous solution by modified activated carbon with Phanerochaete chrysosporium immobilised in Ca‐alginate beads was investigated using a batch system and comparison of linear and nonlinear methods. RESULTS: The amount of Cu(II), Zn(II) and Pb(II) ion sorption by the beads was as follows: activated carbon with P. chrysosporium immobilised in Ca‐alginate beads (ACFCA) (193.4, 181.8, 136.6 mg g?1) > activated carbon immobilised in Ca‐alginate beads (ACCA) (174.8, 162.0, 130.7 mg g?1) > P. chrysosporium (F) (148.8, 125.6, 120.4 mg g?1) > activated carbon (AC) (138.8, 112.3, 109.3 mg g?1) > plain Ca‐alginate beads (PCA) (125.4, 105.2, 98.2 mg g?1). The widely used Langmuir and Freundlich isotherm models were utilised to describe the biosorption equilibrium process. CONCLUSION: The results of this study suggest that the immobilisation of modified activated carbon with P. chrysosporium in Ca‐alginate beads is suitable for a batch system. The isotherm parameters were estimated using linear and nonlinear regression analyses. The surface charge density of the biosorbents varied with the pH of the medium; the maximum biosorption of heavy metal ions on the biosorbents was obtained when the pH was between 5.6 and 7.4. Copyright © 2008 Society of Chemical Industry  相似文献   

8.
Biosorption potential of dried Neurospora crassa for Burazol Blue ED was studied with respect to pH, equilibrium time, biomass concentration and temperature to determine equilibrium and kinetic model parameters. The most suitable pH, equilibrium time and biomass concentration were determined as 1 ± 0.2, 60 min and 1.6 g L− 1, respectively, at 20 °C ± 1.0. The equilibrium data was best described by the Langmuir isotherm model. The maximum biosorption capacity (qm) of biomass obtained from the Langmuir fit was 110.1 mg g− 1 biomass at 30 °C. The overall biosorption process was best described by the pseudo-second-order kinetic model. The biosorption process was found to be favored at higher temperatures.  相似文献   

9.
10.
BACKGROUND: This work fulfils the need to develop an eco‐friendly biosorbent, elucidating the mechanism of biosorption. Removal of Cr(VI) by Rhizopus arrhizus was investigated in batch mode. Enhancement in the performance of the biosorbent was attempted by pre‐treating the biomass with inorganic and organic acids, chelating agent, cross‐linker and an organic solvent followed by autoclaving. The surface characterization of the biomass was carried out by potentiometric titration, surface area analysis, infrared spectroscopy, chemical modification of the biomass and scanning electron microscopy. RESULTS: All the physico‐chemical treatments of the biosorbent improved Cr(VI) uptake compared with the native biomass (21.72 mg g?1). The highest biosorption capacity (31.52 mg g?1) was achieved after pre‐treating the biomass with 0.5 mol L?1 HNO3 followed by autoclaving. Surface characterization of the biomass using pHzpc, potentiometry and Fourier transform infrared (FTIR) analysis revealed the role of amino and carboxyl groups in Cr(VI) removal by electrostatic attraction. Chemical modification of amino and carboxyl groups significantly decreased Cr(VI) uptake capacity confirming their role in biosorption. SEM analysis showed adsorption of Cr(VI) on the biosorbent surface. CONCLUSION: Rhizopus arrhizus biomass proved to be an effective and low cost alternative biosorbent for removal of Cr(VI) from aqueous solutions. Copyright © 2011 Society of Chemical Industry  相似文献   

11.
《分离科学与技术》2012,47(1):192-211
Abstract

In this study, the biosorption of Basic Blue 9 (BB9) dye from aqueous solutions onto a biomass of Euphorbia rigida was examined by means of the initial biosorbate concentration, biosorbent amount, particle size, and pH. Biosorption of BB9 onto E. rigida increases with both the initial biosorbate concentration and biosorbent amount, whereas decreases with the increasing particle size. The experimental data indicated that the biosorption isotherms are well‐described by the Langmuir equilibrium isotherm equation at 20, 30, and 40°C. Maximum biosorption capacity was 3.28×10?4 mol g?1 at 40°C. The biosorption kinetics of BB9 obeys the pseudo‐second‐order kinetic model. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated to estimate the nature of biosorption. These experimental results have indicated that E. rigida has the potential to act as a biosorbent for the removal of Basic Blue 9 from aqueous solutions.  相似文献   

12.
The feasibility of employing Tamarindus indica (tamarind) fruit shell (TFS) as low-cost biosorbent for removal of Cu(II) from aqueous solutions was investigated. Batch experiments were carried out as function of initial solution pH (2–7), contact time (10–240 min), initial Cu(II) concentration (20–100 mg L?1), biosorbent dose (0.5–5 g) and temperature (293–313 K). Biosorption equilibrium data were well described by the Langmuir isotherm model with maximum biosorption capacity of 80.01 mg g?1 at 313 K. Biosorption of Cu(II) followed pseudo-second-order kinetics. Gibbs free energy (ΔG0) was spontaneous for all interactions, and the biosorption process exhibited endothermic enthalpy values. To ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the Bed Depth Service Time (BDST) model was fitted to the dynamic flow experimental data to determine the column kinetic parameters useful for designing large-scale column studies. The Thomas model showed good agreement with the experimental results at all the process parameters studied. It could be concluded that TFS may be used as an inexpensive and effective biosorbent without any treatment or any other modification for the removal of Cu(II) ions from aqueous solutions.  相似文献   

13.
BACKGROUND: The removal of toxic metals from wastewaters by biosorption, based on the metal‐binding capacities of various biological materials, has attracted much interest. However, the success of this approach depends on economic feasibility, which can be obtained by optimisation of the environmental conditions. In this study, Ni(II) biosorption experiments were carried out using a preformed biomass of Rhizopus arrhizus. A pure culture of previously isolated R. arrhizus Env 3 was used for maximum biosorption of nickel metal from nickel‐electroplating industrial effluent. RESULTS: Various environmental factors such as nickel concentration, pH, temperature, mycelial pellet weight, pretreatment of fungal biomass, dead and living fungal biomass and time course of biosorption by R. arrhizus Env 3 were optimised for maximum removal of nickel from the effluent. The maximum nickel removal rate of 618.5 mg g?1 was observed with living biomass at pH 8, temperature 35 °C, nickel concentration 500 mg L?1, pellet size 3 g wet weight and shaker velocity 150 rpm. Maximum nickel biosorption was obtained after 72 h. CONCLUSION: Statistical analysis of different factors such as temperature, pH, mycelial pellet size, concentration of nickel in effluent and residual nickel level showed that all these factors had significant effects on the biosorption of nickel metal by R. arrhizus Env 3 from nickel‐electroplating industrial effluent. Copyright © 2008 Society of Chemical Industry  相似文献   

14.
Using submerged aquatic plants is a cheap and clean technique to remediate heavy metal water pollution at low concentrations. Biosorption of Cu(II) ions by fresh tissues of Myriophyllum spicatum, a submerged aquatic plant, was characterized in an artificial solution system under different values of contact time, temperature and pH in this paper. Cu(II) biosorption was fast and equilibrium was attained within 20 min. The equilibrium biosorption data were analyzed using three widely applied isotherm models: Langmuir, Freundlich and Redlich-Peterson isotherm. Langmuir isotherm parameters obtained from the three Langmuir linear equations by using linear method were dissimilar, except when the non-linear method was used. Best fits were yielded with Langmuir and Redlich-Peterson isotherms (R2=0.961–0.992 and 0.990–0.998, respectively). The saturated monolayer biosorption capacity of M. spicatum for Cu(II) at 298 K was calculated to be 0.19 mmol/g. The biosorption capacity of M. spicatum for Cu(II) increased with increasing pH, and the resulting isotherms were well described by Langmuir and extended Langmuir models (R2=0.931–0.993 and 0.961, respectively). The comparison of calculated q e and experimental q e values showed that the extended Langmuir model had a better simulation for Cu(II) biosorption by M. spicatum than the Langmuir isotherm model. FT-IR was used to characterize the interaction between M. spicatum and Cu(II), with the results indicating that carboxyl groups played an important role in Cu(II) binding.  相似文献   

15.
《分离科学与技术》2012,47(6):1045-1051
Brewer's yeast (bottom yeast, Saccharomyces cerevisiae subsp. uvarum) cells were magnetically modified using water-based magnetic fluid stabilized perchloric acid. The magnetically modified yeast cells were characterized by scanning electron microscopy (SEM). Cu2+ biosorption properties of magnetically modified yeast cells from synthetic solutions were utilized in a continuous magnetic system. The Cu2+ ion-binding capacity decreased drastically with the increase of the flow rate. The maximum Cu2+ biosorption capacity was obtained to be 1.2 mmol/g at 25°C. Biosorption of Cu2+ increased with increasing pH and then reached almost a plateau value around pH 4.0. The yeast biomass can be easily regenerated by 0.1 M HNO3 with higher effectiveness. Biosorption of heavy metal ions from artificial wastewater was also studied. The biosorption capacities are 0.92 mmol/g for Cu2+, 0.52 mmol/g for Hg2+, and 0.28 mmol/g for Ni2+. Magnetically-modified yeast cells exhibits the following metal ion-affinity sequence: Cu2+ > Hg2+ > Ni2+.  相似文献   

16.
Palladized biomass of Desulfovibrio vulgaris (Bio‐Pd(0)) reduced Cr(VI) to Cr(III) at an initial rate four‐fold higher than chemically‐prepared Pd(0) metal. Optimal Cr(VI) reduction by suspended Bio‐Pd(0) occurred at pH 3, whereas pH did not affect the rate of Cr(VI) reduction by Bio‐Pd(0) immobilized in agar beads. The rate of Cr(VI) reduction was concentration‐dependent below 300 µmol dm?3, and application of enzyme kinetics, considering Bio‐Pd(0) as an ‘artificial enzyme’, gave an apparent Km (Kmapp) of approx. 650 µmol dm?3 and Vmax of 1667 nmol h?1 mg Pd(0) for suspended Bio‐Pd(0). The potential of Bio‐Pd(0) as a method for the treatment of Cr(VI)‐wastes is discussed. Copyright © 2005 Society of Chemical Industry  相似文献   

17.
The hypothesis that the dried, ground biomass of the red marine alga Gracilaria tenuistipitata could be used for the efficient removal of lac dye from aqueous solution was assessed in this work. The effects of parameters such as initial pH, biosorbent dosage, contact time, initial dye concentration, and temperature on the biosorption capacity of the dye were investigated. Equilibrium data were analysed using Langmuir, Freundlich, and Temkin isotherm models, and the Freundlich model provided the highest coefficient of determination values. Biosorption kinetic data were successfully described with a pseudo‐second‐order model at initial dye concentrations of 50, 80, 100, and 120 mg l?1. The thermodynamic parameters of biosorption – enthalpy change (?H° = ?30.64 kJ mol?1), free energy change (?G° = 4.32 kJ mol?1 at 303 K to 7.78 kJ mol?1 at 333 K), and entropy change (?S° = ?115.38 J mol?1 K?1) – were determined. The negative value of the enthalpy change and positive values of the free energy change indicate that the biosorption process is exothermic and non‐spontaneous. The negative value of the entropy change is consistent with decreased randomness at the solid–liquid interface with dye biosorption. Attenuated total reflectance–Fourier transform infrared spectroscopic analysis confirmed the presence of lac dye on the G. tenuistipitata material. The efficiency of lac dye removal by this biomass material at 20 g l?1 and with an initial dye concentration of 50 mg l?1 in acidic solution was 71%, which indicated its potential usefulness as a new dye biosorbent.  相似文献   

18.
《分离科学与技术》2012,47(8):1167-1176
The present research is to investigate the possibility of macrofungus Lycoperdon perlatum biomass, which is an easily available, renewable plant, low-cost, as a new biomass for the removal of mercury (Hg(II)) ions from aqueous solutions. The effects of various parameters like pH of solution, biomass concentration, contact time, and temperature were studied by the using the batch method. The Langmuir model adequately described the equilibrium data. The biosorption capacity of the biomass was found to be 107.4 mg · g?1 at pH 6. The mean free energy value (10.9 kJ · mol?1) obtained from the D–R model indicated that the biosorption of Hg(II) onto fungal biomass was taken place via chemical ion-exchange. Thermodynamic parameters showed that the biosorption of Hg(II) onto L. perlatum biomass was feasible, spontaneous, and exothermic in nature. The kinetic results showed that the biosorption of Hg(II) onto fungal biomass followed second-order kinetics. This work also shows that L. perlatum biomass can be an alternative to the expensive materials like ion exchange resins and activated carbon for the treatment of water and wastewater containing mercury ions due to its ability of selectivity and higher biosorption capacity and also being low cost material.  相似文献   

19.
Use of biologically‐produced hydrogen (bio‐H2) as an electron donor for Cr(VI) reduction by native and palladized cells of Desulfovibrio vulgaris NCIMB 8303 was demonstrated. The bio‐H2 was produced fermentatively by Escherichia coli HD701 (a strain upregulated with respect to formate hydrogenlyase expression) using glucose solution or two industrial confectionery wastes as fermentable substrates. Maximum Cr(VI) reduction occurred at the expense of bio‐H2 using palladized biomass (bio‐Pd(0)), with negligible residual Cr(VI) remaining from a 0.5 mmol dm?3 solution after 2.5 h. Use of bio‐H2 as the electron donor for Cr(VI) reduction by agar‐immobilized bio‐Pd(0) in a continuous‐flow system gave 90% reduction efficiency at a flow residence time of 0.7 h, which was maintained for the duration of bio‐H2 evolution by E. coli HD701. This study shows the potential to remediate toxic metal waste at the expense of food processing waste, as a sustainable alternative to landfilling. Copyright © 2007 Society of Chemical Industry  相似文献   

20.
Multidye biosorption of Sunset yellow (SY), Eosin yellow (EY) and Indigo carmine (IC) dyes onto chemically modified biomass of brown alga Sargassum glaucescens was studied. Principal component-wavelet neural network (PC-WNN) was applied for the simultaneous determination of anionic dye concentrations in ternary solutions. Experimental parameters were optimized using response surface methodology (RSM) with a Doehlert design. The optimal biosorption conditions were identified as biosorbent dosage 0.2 g L?1, pH 3, and time 25 min. The maximum total biosorption capacity was 0.102 mmol g?1. The Hill isotherm was the most suitable adsorption models in single and ternary systems. Scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) analysis confirmed possible interactions between biosorbent surface and dye molecules.  相似文献   

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