首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
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.
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   

3.
This paper describes a feasibility study of a for lactic acid production integrated with are treatment of wastewater from an industrial starch plant. Rhizopus oryzae two strains, Rhizopus arrhizus and Rhizopus oligosporus were tested with respect to their capability to carry out simultaneous saccharification and fermentation to lactic acid using potato wastewater. Rhizopus arrhizus DAR 36017 was identified as a suitable strain that demonstrated a high capacity for starch saccharification and lactic acid synthesis. The optimal conditions, in terms of pH, temperature and starch concentration, for lactic acid production were determined. The selected fungal strain grew well in a pH range from 3.0 to 7.0. The addition of CaCO310 g dm?3 maintained the pH at 5.0–6.0 and significantly enhanced lactic acid production. Kinetic study revealed that almost complete starch saccharification and a lactic acid yield of 450g kg?1 could be achieved in 20 h and 28 h cultivation, respectively. The maximum lactic acid production 21 g dm?3 and mycelial biomass (1.7 g dm?3) were obtained at 30 °C. Besides the multiple bioproducts, total removal of suspended solids and 90% reduction of COD were achieved in a single no‐aseptic operation. Copyright © 2003 Society of Chemical Industry  相似文献   

4.
Factors affecting silver biosorption by Saccharomyces cerevisiae biomass, obtained as a waste product from industry, were examined. Maximum removal of silver from solution was achieved within 5 min. Increasing the concentration of biomass in experimental flasks from 1 to 8 mg cm−3 decreased both silver accumulation, from 224·7 to 89·5 μmol Ag g−1 dry wt, and associated H+ ion release, from 109·4 to 31·7 μmol H+ g−1 dry wt. The presence of 1·0 mol dm−3 cadmium or methionine decreased silver biosorption by 40% and 93% respectively. Boiling in 100 mmol dm−3 NaOH or 10 mmol dm−3 sodium dodecyl sulphate decreased silver biosorption by 54% and 25% respectively. A temperature increase from 4°C to 55°C decreased silver biosorption by 9%. The metabolic state of the yeast had no effect on silver biosorption. Decreasing the pH of the silver solution caused a reduction in metal removal by the biomass.  相似文献   

5.
Gold adsorption from cyanide solution by bacterial (Bacillus subtilis), fungal (Penicillium chrysogenum) and seaweed (Sargassum fluitans) biomass was examined. At pH 2.0, these biomass types were capable of sequestering up to 8.0 µmol g−1, 7.2 µmol g−1 and 3.2 µmol g−1, respectively. An adverse effect of increasing solution ionic strength (NaNO3) on gold biosorption was observed. Gold‐loaded biomass could be eluted with 0.1 mol dm−3 NaOH with efficiencies higher than 90% at pH 5.0 at the Solid‐to‐Liquid ratio, S/L, = 4 (g dm−3). Cyanide mass balances for the adsorption, desorption as well as for the AVR process indicated the stability of the gold‐cyanide which did not dissociate either upon acidification or upon binding by biomass functional groups. Gold biosorption mainly involved anionic AuCN2 species bound by ionizable biomass functional groups carrying a positive charge when protonated. FTIR analyses indicated that the main biomass functional groups involved in gold biosorption are most probably nitrogen‐containing weak base groups. The present results confirmed that waste microbial biomaterials have some potential for removing and concentrating gold from solutions where it occurs as a gold‐cyanide complex. © 1999 Society of Chemical Industry  相似文献   

6.
The biosorption of nickel(II) was studied by using crab shell particles of diameter (d p =0.012 mm) under different initial concentrations of nickel(II) in solution (0.01–5.0 g/l), temperature (20–40 °C), pH (2–6.5), and biosorbent dosages (0.5–10 g/l). The maximum removal of nickel(II) occurred at pH 6.5 and temperature 40 °C for a biosorbent dosage of 6 g/l. The results were modeled by response surface methodology (RSM), which determines the maximum biosorption of nickel(II) as a function of the above four independent variables, and the optimum values for the efficient biosorption of nickel(II) were obtained. The RSM studies were carried out using Box-Behnken design and the analysis of variance confirms the adequacy of the quadratic model with coefficient of correlation R2 to be 0.9999. The quadratic model fitted the data well with Prob>F to be <0.0001, indicating the applicability of the present proposed model.  相似文献   

7.
L ‐Cysteine increased gold‐cyanide biosorption by protonated Bacillus subtilis, Penicillium chrysogenum and Sargassum fluitans biomass. At pH 2, the maximum Au uptakes were 20.5 µmol g−1, 14.2 µmol g−1 and 4.7 µmol g−1 of Au, respectively, approximately 148–250% of the biosorption performance in the absence of cysteine. Au biosorption mainly involved anionic AuCN2 species adsorbed by ionizable functional groups on cysteine‐loaded biomass carrying a positive charge when protonated [(biomass–cysteine–H+)–(AuCN2)]. Deposited gold could be eluted from Au‐loaded biomass at pH 3–5. The elution efficiencies were higher than 92% at pH 5.0 with the Solid‐to‐Liquid ratio, S/L, = 4. Increasing solution ionic strength (NaNO)3 decreased Au uptake. FTIR analyses indicated that the main functional groups involved in gold biosorption in the presence of L ‐cysteine are probably N‐, S‐ and O‐containing groups. The present results confirm that certain waste microbial biomaterials are capable of effectively removing and concentrating gold from solutions containing residual cyanide if applied under appropriate conditions. © 2000 Society of Chemical Industry  相似文献   

8.
Four kinds of bioreactor were evaluated for thorium removal by fungal biomass. Static-bed or stirred-bed bioreactors did not give satisfactory thorium removal probably because of poor mixing. An air-lift bioreactor removed approximately 90–95% of the thorium supplied over extended time periods and exhibited a well-defined breakthrough point after biosorbent saturation. The air-lift bioreactor promoted efficient circulation and effective contact between the thorium solution and the mycelial pellets. Of several fungal species tested, Rhizopus arrhizus and Aspergillus niger were the most effective biosorbents with loading capacities of 0.5 and 0.6 mmol g?1 respectively (116 and 138 mg g?1) at an inflow thorium concentration of 3 mmol dm?3. The efficiency of thorium biosorption by A. niger was markedly reduced in the presence of other inorganic solutes while thorium biosorption by R. arrhizus was relatively unaffected. Air-lift bioreactors containing R. arrhizus biomass could effectively remove thorium from acidic solution (1 mol dm?3 HNO3) over a wide range of initial thorium concentrations (0.1–3 mmol dm?3). The biotechnological application and significance of these results are discussed in the wider context of fungal biosorption of radionuclides.  相似文献   

9.
《分离科学与技术》2012,47(5):1221-1238
Abstract

Mercury removal from wastewater is a recognized pollution control challenge today. In the present investigation, the biosorption of Hg(II) onto the dead biomass of four different species of marine Aspergillus, prepared by alkaline treatment, was studied. Among the cultures studied, A. niger was found to be the most efficient for Hg(II) removal. The effects of initial Hg(II) concentration, contact time, pH, temperature, and biosorbent dosage on biosorption were also investigated. It was observed that biosorption equilibriums were established in about 2 h. Under the optimum conditions (pH: 3.0, Hg(II) concentration: 250 mg/L, biomass dose: 0.8 g/L, temperature: 40°C and contact time: 2 h), 40.53 mg Hg(II) was biosorbed per gram of dead biomass of A. niger. Kinetic studies based on fractional power, zero order, first order, pseudo first order, Elovich, second order, and second order rate expressions have also been carried out where the pseudo second order model exhibited best fit to experimental data. The intra‐particle diffusion study revealed that film diffusion is the rate‐limiting sorption process for Hg(II) on A. niger. The nature of the possible cell–metal ion interactions was evaluated by FTIR, SEM, and EDAX analysis. These examinations indicated the involvement of ‐OH and ‐NH2 + groups in the biosorption process present on the surface of the dead fungal biomass. Here, Hg(II) ions were deposited on the surface of the biomass as a film like structure.  相似文献   

10.
《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   

11.
《分离科学与技术》2012,47(15):3149-3165
Abstract

Biosorption of nickel (II) and copper (II) ions from aqueous solution by dead sphaeroplea algae in natural and acid treated forms were studied as a function of concentration, pH, and adsorbent dose. The optimum pH for nickel (II) and copper (II) biosorption was found to be 6.0 and 4.0 respectively. The metal ion uptake increased with initial metal ion concentration studied up to 500 mg/L. Both the Freundlich and Langmuir adsorption models could fit the equilibrium data. The adsorption reasonably fitted the Lagergren kinetic model. Further the biomass was characterized by FTIR spectra. Surface area values are measured to be 0.9 and 2.1 m2/g for natural and acid treated forms respectively. The maximum adsorption capacity was found to be 3.40, 4.15 mmol/g for nickel (II) and 2.21, 3.41 mmol/g for copper (II) in natural and acid treated forms respectively.  相似文献   

12.
《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   

13.
《分离科学与技术》2012,47(6):997-1004
Equilibrium, thermodynamic, and kinetic studies on the biosorption of Cu(II) using biomass, Trichoderma viride were carried out. The biosorbent was characterized by Fourier transform infrared spectroscopy and Scanning Electron Microscopy. The Langmuir and Freundlich isotherm models were applied to describe the biosorption process. The influence of pH, the biomass dosage, the contact time, the initial metal ion concentration, and the temperature of the solution on the biosorption was studied. The maximum Cu(II) biosorption was attained at pH 5. The equilibrium data were better fit by the Langmuir isotherm model than by the Freundlich isotherm. The maximum biosorption capacity of T. viride biomass was found to be 19.6 mg/g for Cu(II). The kinetic studies indicated that the biosorption of Cu(II) followed the pseudo-second-order model. The calculated thermodynamic parameters, Gibbs-free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo) showed that the biosorption of Cu(II) onto T. viride biomass was spontaneous and endothermic. It can be concluded that the T. viride biomass has the potential as an effective and low-cost biosorbent for Cu(II) removal from aqueous solutions.  相似文献   

14.
This work reported the rate of nickel biosorption using acid‐washed barley straw (AWBS) at different initial nickel concentration, AWBS particle size, solution pH, and temperature. The biosorption process was rapid and the equilibrium was reached in about 100 min with initial nickel concentrations from 250 to 1000 mg/L. AWBS with particle size of <0.425 mm exhibited a greater adsorption rate and reached equilibrium faster than particle sizes of 0.425–1.18 mm. An increase in pH from 3.0 ± 0.1 to 7.0 ± 0.1 increased the rate of adsorption and resulted in a higher equilibrium nickel uptake. Nickel adsorption was more favourable at 23 ± 1°C compared to 5 ± 1°C and 40 ± 1°C. The external mass transfer model was able to fit the dynamic nickel biosorption data and provided acceptable overall volumetric mass transfer coefficients.  相似文献   

15.
Powdered waste sludge (PWS) obtained from a paint industry wastewater treatment plant and pretreated with 1% H2O2 was used for biosorption of Zn(II) ions from aqueous solution. The effects of operating conditions, pH, temperature, agitation speed, PWS particle size, Zn ion and PWS concentrations on the extent of Zn ion biosorption were investigated in batch experiments. The optimum pH resulting in maximum Zn ion biosorption was found to be pH = 5, since Zn ions precipitated in the form of Zn(OH)2 at pH levels above 5. The rate and extent of Zn ion biosorption increased with temperature between 25 and 50 °C, although biosorption was not strongly sensitive to temperature variations since the activation energy was low at 4.5 kcal mol?1. Biosorbent particle size had a significant effect on Zn ion biosorption, yielding high percentage Zn removals at small particle sizes (Dp < 100 µm) or large surface areas of PWS. Agitation speed also considerably affected the extent of Zn ion removal, and should be above 150 rpm in order to obtain a high rate. The extent of Zn ion biosorption was also affected by the initial Zn ion and PWS concentrations. At constant biosorbent (PWS) concentration, percentage Zn ion removal decreased, but the biosorbed Zn concentration increased with increasing initial Zn ion concentrations. However, at constant initial Zn concentrations, percentage Zn removal increased, but the biosorbed Zn ion concentration decreased with increasing adsorbent (PWS) concentration. With a maximum Zn ion biosorption capacity of 168 mg g?1 powdered waste sludge was proven to be an effective biosorbent compared to other biosorbents. Copyright © 2006 Society of Chemical Industry  相似文献   

16.
BACKGROUND: Bioaccumulation and biosorption by Pichia stipitis yeast has not yet been explored. This paper evaluates, for the first time, the use of both viable and nonviable P. stipitis yeast to eliminate Cu(II) and Cr(III) from aqueous solutions. The effect of Cu(II) and Cr(III) ions on the growth and bioaccumulation properties of adapted and nonadapted biomass is investigated as a function of initial metal concentration. Binding capacity experiments using nonviable biomass are also performed as a function of temperature. RESULTS: The addition of Cu(II) and Cr(III) had a significant negative effect on the growth of yeast. Nonadapted cells could tolerate Cu(II) and Cr(III) ions up to a concentration of 75 ppm. The growth rate of nonadapted and adapted cells decreased with the increase in Cu(II) and Cr(III) concentration. Adapted P. stipitis biomass was capable of removing Cu(II) and Cr(III) with a maximum specific uptake capacity of 15.85 and 9.10 mg g−1, respectively, at 100 ppm initial Cu(II) and Cr(III) concentration at pH 4.5. Adsorption data on nonviable cells were found to be well modeled by the Langmuir and Temkin isotherms. The maximum loading capacity of dry biomass predicted from Langmuir isotherm for Cu(II) and Cr(III) at 20 °C were 16.89 and 19.2 mg g−1, respectively, at pH 4.5. Biosorptive capacities were dependent on temperature for Cu(II) and Cr(III) solutions. CONCLUSION: Cu(II)‐ and Cr(III)‐adapted cells grow and accumulate these ions at high ratios. On the other hand, nonviable P. stipitis was found to be an effective biosorbent for Cu(II) and Cr(III) biosorption. Copyright © 2008 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.
The kinetics and equilibrium of cadmium biosorption from aqueous solutions were investigated using fresh tissues of Hydrilla verticillata. The biosorptive characteristics of cadmium ions were studied with respect to well‐established effective parameters, including pH, temperature and contact time. The biosorptive capacity of H. verticillata for cadmium increased with increasing pH. In addition, the resulting isotherms were well‐described by Langmuir and extended Langmuir models (R2 = 0.9794–0.9957 and 0.9880, respectively). The comparison between calculated and experimental qe values showed that the extended Langmuir model had a better simulation for the cadmium biosorption by H. verticillata than the Langmuir isotherm model. The equilibrium biosorption data at a constant temperature were well‐interpreted by the Langmuir model. The maximum biosorptive capacity increased from 33.54 to 37.46 mg/g when the solution temperature was increased from 278 to 298 K. Other various thermodynamic parameters were also estimated. Biosorptive equilibrium was established within approximately 20 min. Moreover, the pseudo‐second‐order equation was more appropriate in predicting biosorptive capacity than the pseudo‐first‐order equation. In practical viewpoints, the abundant and inexpensive plant biomass H. verticillata can be used as an effective and environmentally friendly biosorbent for the detoxification of cadmium from aqueous solutions. © 2012 Canadian Society for Chemical Engineering  相似文献   

19.
The removal of trivalent chromium from solutions using biosorption in cork powder is described. The adsorption isotherm was determined, along with the effect of different variables, such as biomass particle size, solid–liquid ratio, reaction time, metal concentration and pH, on the efficiency of chromium removal. It was concluded that the adsorption is slow and favoured by an increase in pH. Therefore, using a solid–liquid ratio of 4 g dm?3 it is possible to reduce the chromium concentration in the solution from 10 mg dm?3 to less than 1.5 mg dm?3 in 2 h at 22 °C. The kinetic studies verified that the sorption of chromium by cork was described by a second‐order model. The elution results showed that 50% of the chromium bound to the cork was eluted using 0.5 mol dm?3 H2SO4 and that cork maintains its binding capacity over four cycles of biosorption/elution. © 2002 Society of Chemical Industry  相似文献   

20.
The removal of cupric ions from aqueous solution by a biosorption column in which the Rhizopus arrhizus fungal biomass was immobilized in reticulated foam biomass support particles was studied. Solution pH was found to be crucial to copper uptake, with the optimum range being 6·7–7·0. The removal efficiency was usually higher at low influent copper concentration and long residence time. The presence of other cations and anions inhibited copper uptake in the following order: for the cations, Mn2+ ? Zn2+ > Cd2+ > Mg2+ > Ca2+; for the anions, EDTA ? SO ? Cl?. The biosorption process was fully reversible and regenerated columns showed undiminished performance.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号