Removal of cadmium(II) ion from aqueous system by dry biomass, immobilized live and heat-inactivated Oscillatoria sp. H1 isolated from freshwater (Mogan Lake)

Oscillatoria sp. H1 (Cyanobacteria, microalgae) isolated from Mogan Lake was used for the removal of cadmium ions from aqueous solutions as its dry biomass, alive and heat-inactivated immobilized form on Ca-alginate. Particularly, the effect of physicochemical parameters like pH, initial concentration and contact time were investigated. The sorption of Cd(II) ions on the sorbent used was examined for the cadmium concentrations within the range of 25-250 mg/L. The biosorption of Cd(II) increased as the initial concentration of Cd(II) ions increased in the medium up to 100 mg/L. Maximum biosorption capacities for plain alginate beads, dry biomass, immobilized live Oscillatoria sp. H1 and immobilized heat-inactivated Oscillatoria sp. H1 were 21.2, 30.1, 32.2 and 27.5 mg/g, respectively. Biosorption equilibrium was established in about 1 h for the biosorption processes. The biosorption was well described by Langmuir and Freundlich adsorption isotherms. Maximum adsorption was observed at pH 6.0. The alginate-algae beads could be regenerated using 50 mL of 0.1 mol/L HCl solution with about 85% recovery.     

Entrapment of white-rot fungus Trametes versicolor in Ca-alginate beads: preparation and biosorption kinetic analysis for cadmium removal from an aqueous solution

The biosorption of cadmium ions onto entrapped Trametes versicolor mycelia has been studied in a batch system. The maximum experimental biosorption capacities for entrapped live and dead fungal mycelia of T. versicolor were found as 102.3 +/- 3.2 mg Cd(II) g(-1) and 120.6 +/- 3.8 mg Cd(II) g(-1), respectively. Biosorption equilibrium was established in about 1 h and biosorption was well described by the Langmuir and Freundlich biosorption isotherms. The change in the biosorption capacity with time was found to fit the pseudo-second-order equation. Since the biosorption capacities were relatively high for both entrapped live and dead forms, those fungal forms could be considered as suitable biosorbents for the removal of cadmium in wastewater-treatment systems. The biosorbents were reused in three consecutive adsorption/desorption cycles without a significant loss in the biosorption capacity.     

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

Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption–desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l⁻¹ of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of ≈13 and 3 mg g⁻¹, respectively, for algae Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1 M HNO₃ solution was 100% effective. After two consecutive sorption–desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.     

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

The biosorption of lead, copper and zinc ions on Rhizopus arrhizus has been studied for three single-component and two binary systems. The equilibrium data have been analysed using the Freundlich adsorption model. The characteristic parameters for the Freundlich adsorption model have been determined and the competition coefficients for the competitive biosorption of Pb(II)-Cu(II) at pH 4.0 and 5.0, and Pb(II)-Zn(II) at pH 5.0 have been calculated. For the individual single-component isotherms, lead has the highest biosorption capacity followed by copper, then zinc. The capacity of lead in the two binary systems is always significantly greater than those of the other metal ions, in agreement with the single-component data. Only a partial selectivity for copper ions has been obtained at pH 4.0. Received: 21 June 1999 / Accepted: 2 November 1999     

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

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

The removal of Cu(II) from aqueous solutions by Ulothrix zonata

In this work, adsorption of copper(II) ions on alga has been studied by using batch adsorption techniques. The equilibrium biosorption level was determined as a function of contact time at several initial metal ion concentrations. The effect of adsorbent concentration on the amount adsorbed was also investigated. The experimental adsorption data were fitted to the Langmuir adsorption model. The free energy change (deltaG0) for the adsorption process was found to be -12.60 kJ/mol. The results indicated that the biomass of Ulothrix zonata is a suitable biosorbent for both the removal and recovery of heavy metals from wastewater.     

Copper biosorption on Lyngbya putealis: Application of response surface methodology (RSM)

The potential use of biosorbent prepared from an indigenously isolated cyanobacterium, Lyngbya putealis, for the removal of copper from aqueous solution has been investigated under optimized conditions in this study. Batch mode experiments were performed to determine the adsorption equilibrium and kinetic behavior of copper in aqueous solution allowing the computation of kinetic parameters and maximum metal adsorption capacity. Influences of other parameters like initial metal ion concentration (10-100 mg l⁻¹), pH (2-8) and biosorbent dose (0.1-1.0 g/100 ml) on copper adsorption were also examined, using Box-Behnken design matrix. Very high regression coefficient between the variables and the response (R² = 0.9533) indicates excellent evaluation of experimental data by second order polynomial regression model. The response surface method indicated that 40-50 mg l⁻¹ initial copper concentration, 6.0-6.5 pH and biosorbent dose of 0.6-0.8 g/100 ml were optimal for biosorption of copper by biosorbent prepared from L. putealis. On the basis of experimental results and model parameters, it can be inferred that the biosorbent which has quite high biosorption capacity can be utilized for the removal of copper from aqueous solution.     

Biosorption of binary mixtures of copper and cobalt by Penicillium brevicompactum

This work reports on a study of the biosorption of copper and cobalt, both singly and in combination (in equimolar concentrations), by the resting cells of Penicillium brevicompactum. Equilibrium batch sorption studies were carried out at 30 degrees C and pH 5.0 for a contact time of 1 hour to guarantee that equilibrium was reached. The equilibrium data were analyzed using the Langmuir and Freundlich isotherms. The adsorption of binary mixtures of heavy metal solutions on the fungal biomass was found to be of competitive type where the adsorption capacity for any single metal decreased in the presence of the other. The cobalt ions showed a higher affinity for Penicillium brevicompactum than the copper ions.     

Biosorption of copper(II) ions onto powdered waste sludge in a completely mixed fed-batch reactor: estimation of design parameters

Biosorption of Cu(II) ions onto pre-treated powdered waste sludge (PWS) was investigated using a fed-batch operated completely mixed reactor. Fed-batch adsorption experiments were performed by varying the feed flow rate ( 0.075-0.325 l h(-1)), feed copper (II) ion concentrations (50-300 mg l(-1)) and the amount of adsorbent (1-6 g PWS) using fed-batch operation. Breakthrough curves describing the variations of effluent copper ion concentrations with time were determined for different operating conditions. Percent copper ion removals from the aqueous phase decreased, but the biosorbed (solid phase) copper ion concentrations increased with increasing the feed flow rate and Cu(II) concentration. A modified Bohart-Adams equation was used to determine the biosorption capacity of PWS and the rate constant for Cu(II) ion biosorption. Adsorption rate constant in fed-batch operation was an order of magnitude larger than those obtained in adsorption columns because of elimination of mass transfer limitations encountered in the column operations while the biosorption capacity of PWS was comparable with powdered activated (PAC) in column operations. Therefore, a completely mixed reactor operated in fed-batch mode was proven to be more advantageous as compared to adsorption columns due to better contact between the phases yielding faster adsorption rates.     

Ternary biosorption studies of Cd(II), Cr(III) and Ni(II) on shelled Moringa oleifera seeds

Competitive biosorption of Cd(II), Cr(III) and Ni(II) on unmodified shelled Moringa oleifera seeds (SMOS) present in ternary mixture were compared with the single metal solution. The extent of adsorption capacity of the ternary metal ions tested on unmodified SMOS was low (10-20%) as compared to single metal ions. SMOS removed the target metal ions in the selectivity order of Cd(II) > Cr(III) > Ni(II). Sorption equilibria, calculated from adsorption data, explained favorable performance of biosorption system. Regeneration of exhausted biomass was also attempted for several cycles with a view to restore the sorbent to its original state.     

A natural macroalgae consortium for biosorption of copper from aqueous solution: Optimization,modeling and design studies

In this study, the capacity of a natural macroalgae consortium consisting of Chaetomorpha sp., Polysiphonia sp., Ulva sp. and Cystoseira sp. species for the removal of copper ions from aqueous environment was investigated at different operating conditions, such as solution pH, copper ion concentration and contact time. These environmental parameters affecting the biosorption process were optimized on the basis of batch experiments. The experimentally obtained data for the biosorption of copper ions onto the macroalgae-based biosorbent were modeled using the isotherm models of Freundlich, Langmuir, Sips and Dubinin–Radushkevich and the kinetic models of pseudo-first-order, pseudo-second-order, Elovich and Weber and Morris. The pseudo-first-order and Sips equations were the most suitable models to describe the copper biosorption from aqueous solution. The thermodynamic data revealed the feasibility, spontaneity and physical nature of biosorption process. Based on the data of Sips isotherm model, the biosorption capacity of biosorbent for copper ions was calculated as 105.370 mg g^?1 under the optimum operating conditions. A single-stage batch biosorption system was developed to predict the real-scale-based copper removal performance of biosorbent. The results of this investigation showed the potential utility of macroalgae consortium for the biosorption of copper ions from aqueous medium.     

Immobilization of blue green microalgae on loofa sponge to biosorb cadmium in repeated shake flask batch and continuous flow fixed bed column reactor system

Summary An indigenous strain of blue green microalga, Synechococcus sp., isolated from wastewater, was immobilized onto loofa sponge discs and investigated as a potential biosorbent for the removal of cadmium from aqueous solutions. Immobilization has enhanced the sorption of cadmium and an increase of biosorption (21%) at equilibrium was noted as compared to free biomass. The kinetics of cadmium biosorption was extremely rapid, with (96%) of adsorption within the first 5 min and equilibrium reached at 15 min. Increasing initial pH or initial cadmium concentration resulted in an increase in cadmium uptake. The maximum biosorption capacity of free and loofa immobilized biomass of Synechococcus sp. was found to be 47.73 and 57.76 mg g⁻¹ biomass respectively. The biosorption equilibrium was well described by Langmuir adsorption isotherm model. The biosorbed cadmium was desorbed by washing the immobilized biomass with dilute HCl (0.1 M) and desorbed biomass was reused in five biosorption–desorption cycles without an apparent decrease in its metal biosorption capacity. The metal removing capacity of loofa immobilized biomass was also tested in a continuous flow fixed-bed column bioreactor and was found to be highly effective in removing cadmium from aqueous solution. The results suggested that the loofa sponge-immobilized biomass of Synechococcus sp. could be used as a biosorbent for an efficient removal of heavy metal ions from aqueous solution.     

An ecofriendly approach for bioremediation of contaminated water environment: Potential contribution of a coastal seaweed community to environmental improvement

High levels of heavy metals like copper ions in many industrial based effluents lead to serious environmental and health problems. Biosorption is a potential environmental biotechnology approach for biotreatment of aquatic sites polluted with heavy metal ions. Seaweeds have received great attention for their high bioremediation potential in recent years. However, the co-application of marine macroalgae for removal of heavy metals from wastewater is very limited. Thus, for the first time in literature, a coastal seaweed community composed of Chaetomorpha sp., Polysiphonia sp., Ulva sp. and Cystoseira sp. species was applied to remove copper ions from synthetic aqueous medium in this study. The biosorption experiments in batch mode were conducted to examine the effects of operating variables including pH, biosorbent amount, metal ion concentration and contact time on the biosorption process. The biosorption behavior of biosorbent was described by various equilibrium, kinetic and thermodynamic models. The biosorption of copper ions was strongly influenced by the operating parameters. The results indicated that the equilibrium data of biosorption were best modeled by Sips isotherm model. The values of mean free energy of biosorption computed from Dubinin-Radushkevich isotherm model and the standard Gibbs free energy change indicated a feasible, spontaneous and physical biotreatment system. The pseudo-second-order rate equation successfully defined the kinetic behavior of copper biosorption. The pore diffusion also played role in the control of biosorption process. The maximum copper uptake capacity of biosorbent was found to be greater than those of many other biosorbents. The obtained results revealed that this novel biosorbent could be a promising material for copper ion bioremediation implementations.     

Biosorption of Copper by Cyanobacterial Bloom-Derived Biomass Harvested from the Eutrophic Lake Dianchi in China

Biomass of cyanobacterial bloom from Lake Dianchi was used as a biosorbent for copper removal from aqueous solution. The maximum capacity was found at conditions of pH 4, initial concentration of copper was 10 mg/l and initial dose of biomass was 1.0 g/l. HNO₃ demonstrated the highest desorption efficiency compared with HCl, EDTA, and citric acid. Physical adsorption was assumed not to be the dominant mechanism of biosorption as revealed by scanning electron microscopy and surface area measurement of the biomass. Infrared ray spectra analysis of the biomass suggested that ion-exchange is the principal mechanism for biosorption. Considering the advantages—low cost, easy to collect, and huge in quantity—the Microcystis bloom biomass could be used as a sorbent for copper and other heavy metals removal.     

Biosorption of lead(II), cadmium(II), copper(II) and nickel(II) by anaerobic granular biomass

Biosorption is potentially an attractive technology for treatment of wastewater for retaining heavy metals from dilute solutions. This study investigated the feasibility of anaerobic granules as a novel type of biosorbent, for lead, copper, cadmium, and nickel removal from aqueous solutions. Anaerobic sludge supplied from a wastewater treatment plant in the province of Quebec was used. Anaerobic granules are microbial aggregates with a strong, compact and porous structure and excellent settling ability. After treatment of the biomass with Ca ions, the cation exchange capacity of the biomass was approximately 111 meq/100 g of biomass dry weight which is comparable to the metal binding capacities of commercial ion exchange resins. This work investigated the equilibrium, batch dynamics for the biosorption process. Binding capacity experiments using viable biomass revealed a higher value than those for nonviable biomass. Binding capacity experiments using non-viable biomass treated with Ca revealed a high value of metals uptake. The solution initial pH value affected metal sorption. Over the pH range of 4.0-5.5, pH-related effects were not significant. Meanwhile, at lower pH values the uptake capacity decreased. Time dependency experiments for the metal ions uptake showed that adsorption equilibrium was reached almost 30 min after metal addition. It was found that the q(max) for Pb2+, Cd2+, Cu2+, and Ni2+ ions, were 255, 60, 55, and 26 mg/g respectively (1.23, 0.53, 0.87, and 0.44 mmol/g respectively). The data pertaining to the sorption dependence upon metal ion concentration could be fitted to a Langmiur isotherm model. Based on the results, the anaerobic granules treated with Ca appear to be a promising biosorbent for removal of heavy metals from wastewater due to its optimal uptake of heavy metals, its particulate shape, compact porous structure, excellent settling ability, and its high mechanical strength.     

Enhancement of Lead(II) Biosorption by Microalgal Biomass Immobilized onto Loofa (Luffa cylindrica) Sponge

A unicellular green microalga, Chlorella sorokiniana, was immobilized on loofa (Luffa cylindrica) sponge and successfully used as a new biosorption system for the removal of lead(II) ions from aqueous solutions. The biosorption of lead(II) ions on both free and immobilized biomass of C. sorokiniana was investigated using aqueous solutions in the concentration range of 10–300 mg/L. The biosorption of lead(II) ions by C. sorokiniana biomass increased as the initial concentration of lead(II) ions increased in the medium. The maximum biosorption capacity for free and immobilized biomass of C. sorokiniana was found to be 108.04 and 123.67 mg lead(II)/g biomass, respectively. The biosorption kinetics were found to be fast, with 96 % of adsorption within the first 5 min and equilibrium reached at 15 min. The adsorption of lead(II) both by free and immobilized C. sorokiniana biomass followed the Langmuir isotherm. The biosorption capacities were detected to be dependent on the pH of the solution; and the maximum adsorption was obtained at a solution pH of about 5. The effect of light metal ions on lead(II) uptake was also studied and it was shown that the presence of light metal ions did not significantly affect lead(II) uptake. The loofa sponge‐immobilized C. sorokiniana biomass could be regenerated using 0.1 M HCl, with up to 99 % recovery. The desorbed biomass was used in five biosorption‐desorption cycles, and no noticeable loss in the biosorption capacity was observed. In addition, fixed bed breakthrough curves for lead(II) removal were presented. These studies demonstrated that loofa sponge‐immobilized biomass of C. sorokiniana could be used as an efficient biosorbent for the treatment of lead(II) containing wastewater.     

Adsorptive removal of copper and nickel ions from water using chitosan coated PVC beads

A new biosorbent was developed by coating chitosan, a naturally and abundantly available biopolymer, on to polyvinyl chloride (PVC) beads. The biosorbent was characterized by FTIR spectra, porosity and surface area analyses. Equilibrium and column flow adsorption characteristics of copper(II) and nickel(II) ions on the biosorbent were studied. The effect of pH, agitation time, concentration of adsorbate and amount of adsorbent on the extent of adsorption was investigated. The experimental data were fitted to Langmuir and Freundlich adsorption isotherms. The data were analyzed on the basis of Lagergren pseudo first order, pseudo-second order and Weber-Morris intraparticle diffusion models. The maximum monolayer adsorption capacity of chitosan coated PVC sorbent as obtained from Langmuir adsorption isotherm was found to be 87.9 mg g(-1) for Cu(II) and 120.5 mg g(-1) for Ni(II) ions, respectively. In addition, breakthrough curves were obtained from column flow experiments. The experimental results demonstrated that chitosan coated PVC beads could be used for the removal of Cu(II) and Ni(II) ions from aqueous medium through adsorption.     

Biosorption of Cr (VI) with Trichoderma viride immobilized fungal biomass and cell free Ca-alginate beads

Ability of Cr (VI) biosorption with immobilized Trichoderma viride biomass and cell free Ca-alginate beads was studied in the present study. Biosorption efficiency in the powdered fungal biomass entrapped in polymeric matric of calcium alginate compared with cell free calcium alginate beads. Effect of pH, initial metal ion concentration, time and biomass dose on the Cr (VI) removal by immobilized and cell free Ca-alginate beads were also determined. Biosorption of Cr (VI) was pH dependent and the maximum adsorption was observed at pH 2.0. The adsorption equilibrium was reached in 90 min. The maximum adsorption capacity of 16.075 mgg(-1) was observed at dose 0.2 mg in 100 ml of Cr (VI) solution. The high value of kinetics rate constant Kad (3.73 x 10(-2)) with immobilized fungal biomass and (3.75 x 10(-2)) with cell free Ca- alginate beads showed that the sorption of Cr (VI) ions on immobilized biomass and cell free Ca-alginate beads followed pseudo first order kinetics. The experimental results were fitted satisfactory to the Langmuir and Freundlich isotherm models. The hydroxyl (-OH) and amino (-NH) functional groups were responsible in biosorption of Cr (VI) with fungal biomass spp. Trichoderma viride analysed using Fourier Transform Infrared (FTIR) Spectrometer.     

花生壳粉生物吸附水溶液中阴离子染料的研究

An untried,low cost, locally available biosorbent for its anionic dye removal capacity from aqueous solution was investigated. Powder prepared from peanut hull had been used for hiosorption of three anionic dyes, amaranth (Am), sunset yellow (SY) and fast green FCF (FG). The effects of various experimental parameters (e.g.initial pH and dye concentration, sorbent dosage, particle size, ion strength, contact time etc.) were examined and optimal experimental conditions were decided. At initial pH 2.0, three dyes studied could be removed effectively.When the dye concentration was 50 mg" L-1 the percentages of dyes sorbed was 95.5 % in Am, 91.3 % in SY and 94.98 % in FG, respectively. The ratios of dyes sorbed had neared maximum values in all three dyes whensorbent dose of 5.0 g·L^-1 and the sorbent particle size in 80—100 mesh was used. The increasing the ion strength of solution caused the decrease in biosorption percentages of dyes. The equilibrium values arrived at about 36 hour for all three dyes. The isothermal data of biosorption followed the Langmuir and Freundlich models. The biosorption processes conformed the pseudo-first-order rate kinetics. The results indicated that powdered peanut hull was an attractive candidate for removing anionic dyes from dye wastewater.