Removal and recovery of nickel(II) from aqueous solution by loofa sponge-immobilized biomass of Chlorella sorokiniana: characterization studies

The biosorption process for the removal of nickel(II) by loofa sponge-immobilized biomass of Chlorella sorokiniana (LIBCS), a newly developed immobilized biosorbent, was characterized. Effects of environmental factors on metal uptake capacity of LIBCS were studied and compared with free biomass of C. sorokiniana (FBCS). Nickel(II) removal by LIBCS was found to be influenced by pH of the solution, initial metal concentration, and biomass concentration. The biosorption of nickel(II) ions by both LIBCS and FBCS increased as the initial concentration of nickel(II) ions increased in the medium. No loss to biosorption capacity of LIBCS for nickel(II) was found due to the presence of loofa sponge, indeed as compared to FBCS an increase of 25.3% was noted in the biosorption capacity of LIBCS. Maximum biosorption capacities for FBCS and LIBCS were found as 48.08 and 60.38 mg nickel(II)/g, respectively, whereas the amount of nickel(II) ions adsorbed on the plain loofa sponge was 6.1mg/g. During these biosorption studies, LIBCS exhibited excellent physical and chemical stability without any significant release/loss of microalgal biomass from loofa sponge matrix. The kinetics of nickel(II) removal was extremely fast reaching at equilibrium in about 15 min for LIBCS and 20 min for FBCS. The biosorption equilibrium was well described by the Langmuir and Freundlich adsorption isotherms. The biosorption capacities were found to be solution pH dependent and the maximum adsorption was found at a solution pH 4-5. The LIBCS could be regenerated using 75 mM HCl, with up to 98% recovery. The LIBCS were shown to be robust and stable with little decrease in the nickel(II) uptake capacity when used in consecutive seven biosorption-desorption cycles. Continuous removal of nickel(II) from electroplating effluent by LIBCS packed in fixed bed column bioreactor confirm the possibility of developing a biological treatment process for the removal of toxic metals from authentic wastewater.     

Investigation of nickel(II) biosorption on Enteromorpha prolifera: optimization using response surface analysis

In this study, the biosorption of nickel(II) ions on Enteromorpha prolifera, a green algae, was investigated in a batch system. The single and combined effects of operating parameters such as initial pH, temperature, initial metal ion concentration and biosorbent concentration on the biosorption of nickel(II) ions on E. prolifera were analyzed using response surface methodology (RSM). The optimum biosorption conditions were determined as initial pH 4.3, temperature 27 degrees C, biosorbent concentration 1.2 g/L and initial nickel(II) ion concentration 100 mg/L. At optimum biosorption conditions, the biosorption capacity of E. prolifera for nickel(II) ions was found to be 36.8 mg/g after 120 min biosorption. The Langmuir and Freundlich isotherm models were applied to the equilibrium data and defined very well both isotherm models. The monolayer coverage capacity of E. prolifera for nickel(II) ions was found as 65.7 mg/g. In order to examine the rate limiting step of nickel(II) biosorption, such as the mass transfer and chemical reaction kinetics, the intraparticle diffusion model, external diffusion model and the pseudo second order kinetic model were tested with the experimental data. It was found that for both contributes to the actual biosorption process. The pseudo second order kinetic model described the nickel(II) biosorption process with a good fitting.     

Kinetic and equilibrium studies of biosorption of Pb(II) and Cd(II) from aqueous solution by macrofungus (Amanita rubescens) biomass

The biosorption characteristics of Pb(II) and Cd(II) ions from aqueous solution using the macrofungus (Amanita rubescens) biomass were investigated as a function of pH, biomass dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the metal ions by A. rubescens biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The maximum biosorption capacity of A. rubescens for Pb(II) and Cd(II) was found to be 38.4 and 27.3mg/g, respectively, at optimum conditions of pH 5.0, contact time of 30min, biomass dosage of 4 g/L, and temperature of 20 degrees C. The metal ions were desorbed from A. rubescens using both 1M HCl and 1M HNO(3). The recovery for both metal ions was found to be higher than 90%. The high stability of A. rubescens permitted ten times of adsorption-elution process along the studies without a decrease about 10% in recovery of both metal ions. The mean free energy values evaluated from the D-R model indicated that the biosorption of Pb(II) and Cd(II) onto A. rubescens biomass was taken place by chemical ion-exchange. The calculated thermodynamic parameters, DeltaG degrees , DeltaH degrees and DeltaS degrees showed that the biosorption of Pb(II) and Cd(II) ions onto A. rubescens biomass was feasible, spontaneous and exothermic under examined conditions. Experimental data were also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of both Pb(II) and Cd(II) followed well pseudo-second-order kinetics. Based on all results, It can be also concluded that it can be evaluated as an alternative biosorbent to treatment wastewater containing Pb(II) and Cd(II) ions, since A. rubescens is low-cost biomass and has a considerable high biosorption capacity.     

Copper(II) and zinc(II) biosorption on Pinus sylvestris L

The biosorption properties of copper(II) and zinc(II) onto a cone biomass of Pinus sylvestris L. was investigated by using batch techniques. The biosorption studies carried out with single metal solutions. The removal of copper(II) and zinc(II) from aqueous solution increased with pH and sharply decreased when pH of the solution was decreased. The maximum biosorption efficiency of P. sylvestris was 67% and 30% for Cu(II) and Zn(II), respectively. Batch kinetic and isotherm of biosorption metal ions were investigated. The second-order kinetic model was used to correlate the experimental data. The Freundlich and Langmuir model can describe the adsorption equilibrium of metal(II) on cone biomass. The biosorption constants were found from the Freundlich and Langmuir isotherms at 25 degrees C. It is found that the biosorption data of metals on cone biomass fitted both the Freundlich and Langmuir adsorption models.     

Zn(II) biosorption properties of Botrytis cinerea biomass

The study was aimed of determining the Zn(II) sorption performance of Botrytis cinerea (B. cinerea) biomass as a new biosorbent. Heat inactivated biomass was used in the determination of optimum conditions. The rate and extent of accumulation were effected by pH, contact time and initial zinc ion concentrations. The uptake capacity of B. cinerea was increased by chemical and physical pretreatment of the cells when compared with the native biomass. The maximum removal of Zn(II) at pH 5.0-6.0 was found to be 12.98+/-0.9623 mg g-1 at initial Zn(II) ion concentration of 100 mg l-1 by heat inactivated biomass. Freundlich and Langmuir isotherm models were used to evaluate the data and regression constants were derived. The biosorbent was regenerated using 10 mM HCl solution, with up to 98% recovery and reused five times in biosorption-desorption cycles successively. Competitive biosorption experiments were performed with zinc in the presence of copper, cadmium and nickel ions simultaneously. The nature of the possible cell-metal ions interactions was also evaluated by chemical and instrumental analysis including infrared spectroscopy, scanning electron microscopy and X-ray energy dispersion analysis.     

Kinetic studies for Ni(II) biosorption from industrial wastewater by Cassia fistula (Golden Shower) biomass

The present study explores the ability of Cassia fistula waste biomass to remove Ni(II) from industrial effluents. C. fistula biomass was found very effective for Ni(II) removal from wastewater of Ghee Industry (GI), Nickel Chrome Plating Industry (Ni-Cr PI), Battery Manufacturing Industry (BMI), Tanner Industry: Lower Heat Unit (TILHU), Tannery Industry: Higher Heat Unit (TIHHU), Textile Industry: Dying Unit (TIDU) and Textile Industry: Finishing Unit (TIFU). The initial Ni(II) concentration in industrial effluents was found to be 34.89+/-0.01, 183.56+/-0.08, 21.19+/-0.01, 43.29+/-0.03, 47.26+/-0.02, 31.38+/-0.01 and 31.09+/-0.01mg/L in GI, Ni-Cr PI, BMI, TILHU, TIHHU, TIDU and TIFU, respectively. After biosorption the final Ni(II) concentration in industrial effluents was found to be 0.05+/-0.01, 17.26+/-0.08, 0.03+/-0.01, 0.05+/-0.01, 0.1+/-0.01, 0.07+/-0.01 and 0.06+/-0.01mg/L in GI, Ni-Cr PI, BMI, TILHU, TIHHU, TIDU and TIFU, respectively. The % sorption Ni(II) ability of C. fistula from seven industries included in present study tend to be in following order: TILHU (99.88)>GI (99.85) approximately BMI (99.85)>TIFU (99.80)>TIHHU (99.78)>TIDU (99.77)>Ni-Cr PI (90.59). Sorption kinetic experiments were performed in order to investigate proper sorption time for Ni(II) removal from wastewater. Batch metal ion uptake capacity experiments indicated that sorption equilibrium reached much faster in case of industrial wastewater samples (480min) in comparison to synthetic wastewater (1440min) using same biosorbent. The kinetic data were analyzed in term of pseudo-first-order and pseudo-second-order expressions. Pseudo-second-order model described well the sorption kinetics of Ni(II) onto C. fistula biomass from industrial effluents in comparison to pseudo-first-order kinetic model. Due to unique high Ni(II) sorption capacity of C. fistula waste biomass it can be concluded that it is an excellent biosorbent for Ni(II) uptake from industrial effluents.     

Pb(II) biosorption from hazardous aqueous streams using Gossypium hirsutum (Cotton) waste biomass

Studies on the biosorptive ability of Gossypium hirsutum (Cotton) waste biomass outlined that smaller size of biosorbent (0.355mm), higher biomass dose (0.20g), 5 pH and 100mg/L initial Pb(II) concentration were more suitable for enhanced Pb(II) biosorption from aqueous medium. The Langmuir isotherm model and pseudo second order kinetic model fitted well to the data of Pb(II) biosorption. Highly negative magnitude of Gibbs free energy (DeltaG degrees ) indicated that the process was spontaneous in nature. In addition to this surface coverage and distribution coefficient values of Pb(II) biosorption process were also determined. At optimized conditions Pb(II) uptake was more rapid in case of industrial effluents in comparison to synthetic solutions. FTIR spectroscopic analysis revealed that the main functional groups involved in the uptake of Pb(II) on the surface of G. hirsutum biomass were carboxyl, carbonyl, amino and alcoholic.     

Biosorption characteristics of Bacillus sp. ATS-2 immobilized in silica gel for removal of Pb(II)

The bacterial strain Bacillus sp. ATS-2 isolated from Pb(II) polluted soil was immobilized with a silica matrix and Pb(II) biosorption properties of immobilized biosorbent were examined. Optimum biosorption conditions were investigated in the fixed bed column with the variation in the parameters of pH, bed length, flow rate and influent concentration. The Pb(II) biosorption equilibrium was attained within 60 min and the maximum biosorption yield for silica gel immobilized Bacillus sp. ATS-2 was determined as 91.73% at pH 4.0. The higher biosorption yields were observed at flow rates of 60 and 180 ml h(-1). The optimum bed length for the column was found as 10 cm. Data obtained from batch studies were evaluated by Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models. The maximum monolayer capacity of Bacillus sp. ATS-2 for Pb(II) was 2.36 x 10(-5) mol g(-1). The involvement of the functional groups on the surface of immobilized cells in biosorption process was also evaluated by FTIR spectral analysis.     

Batch kinetics and isotherms for biosorption of copper(II) ions onto pre-treated powdered waste sludge (PWS)

Waste sludge samples from different plants were tested for Cu(II) ion biosorption capacities with and without pre-treatment. Waste sludge from a paint industry wastewater treatment plant was found to perform better than the others after pre-treatment with 1% H(2)O(2). Powdered waste sludge (PWS) from the paint industry wastewater treatment plant was used for recovery of Cu(II) ions from aqueous solution by biosorption after pre-treatment with 1% H(2)O(2). Batch kinetics and isotherms of biosorption of Cu(II) ions were investigated at variable initial Cu(II) concentrations between 50 and 400 mg l(-1) with a PWS particle size of 64 microm. The pseudo-first and -second order kinetic models were used to correlate the experimental data. The kinetic constants were determined for both models and the second order kinetic model was found to be more suitable. The Langmuir, Freundlich and the generalized isotherm models were used to correlate the equilibrium biosorption data and the isotherm constants were determined. The Langmuir isotherm was found to fit the experimental data better than the other isotherms tested. The maximum biosorption capacity (116 mg g(-1)) of the pre-treated powdered waste sludge for Cu(II) ions was found to be superior as compared to the other biosorbents reported in literature.     

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

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

Kinetic and equilibrium studies of methylene blue biosorption by Posidonia oceanica (L.) fibres

Batch biosorption experiments were carried out for the removal of methylene blue, a basic dye, from aqueous solution using raw Posidonia oceanica (L.) fibres, a marine lignocellulosic biomass. A series of assays were undertaken to assess the effect of the system variables, i.e. contact time, solution pH, biosorbent dosage and initial dye concentration. The results had showed that biosorption capacity was optimal using 6-9 solution pH range and by increasing the biosorbent concentration up to 1 g/L. The biosorption kinetics were analyzed using irreversible-first-order, reversible-first-order and pseudo-second-order and the sorption data were very well described by the pseudo-second-order model for the entire adsorption time with squared correlation coefficients equal to unity for all experimented initial dye concentrations. Besides, equilibrium data were very well represented by both Langmuir and Redlich-Peterson isotherm models followed by Freundlich, which confirm the monolayer coverage of methylene blue molecules onto P. oceanica fibres.     

Evaluation of peanut husk as a novel,low cost biosorbent for the removal of Indosol Orange RSN dye from aqueous solutions: batch and fixed bed studies

The feasibility of using peanut husk biomass for the removal of Indosol Orange RSN dye was explored during this study. Batch experiments were conducted with native, polyethyleneimine (PEI) treated and Na-alginate immobilized biomass. Different important process parameters like pH, contact time, biosorbent dose, initial dye concentration, and temperature were optimized during batch study. Low pH and low biosorbent dose were found to be the feasible conditions for the maximum biosorption of dye. PEI-treated biomass exhibited maximum biosorption capacity (79.5 mg g^?1) for Indosol Orange RSN dye. Pseudo-second-order equation generated the best agreement with experimental data. Different equilibrium isotherm models were applied to the experimental data. Langmuir adsorption isotherm model showed better fitness to the experimental results. Biosorption process was found to be exothermic in nature and thermodynamic study was carried out to check out the feasibility of process. Continuous mode study was performed with native peanut husk biomass to optimize the bed height, flow rate, and initial dye concentration for maximum dye removal. The results indicate that maximum dye removal (8.8 mg L^?1) was obtained with 3 cm bed height and 1.8 mL min^?1 flow rate by using 70 mg L^?1 initial dye concentration. Characterization of biosorbent was carried out by determination of point of zero charge, scanning electron microscopy, and Fourier transform infrared spectroscopy. The findings revealed that peanut husk biomass has a high biosorption potential, and it can be exploited for the treatment of dye containing waste water.     

Hybrid biosorbent: An innovative matrix to enhance the biosorption of Cd(II) from aqueous solution

To enhance the metal removing capacity of a fungus biosorbent, a new idea of producing a hybrid biosorbent (HB) matrix by combining two different biosorbents using a simple and low-cost immobilization technique was tested for the sorption of Cd(II). The two biosorbents, used as the building block for the production of HB matrix, were the fungal biomass of Phanerochaete chrysosporium (B1) and fibrous network of papaya wood (B2). Maximum independent biosorption capacity of B1 and B2 was noted, respectively, to be 71.36 and 17.62 mgCd(II)g(-1) biosorbent. However, when two biosorbents were hybridized to form HB matrix, the combined biosorption capacity (141.63 mgCd(II)g(-1) biosorbent) was increased by 98.47, 703.80%, respectively, as compared to the ability of B1 and B2 when used alone, and by 59.17% than the sum of separate individual abilities of biosorbents B1 and B2. The kinetics of equilibrium was fast, approximately 88% of Cd(II) biosorption taking place within 30 min. Biosorption kinetics and equilibria followed the pseudo-second order kinetics and Langmuir adsorption isotherms model. HB matrix was also shown to be highly effective in removing Cd(II) from aqueous solution in a continuous flow fixed-bed column bioreactor, both in batch and repeated cycles.     

Biosorption of zinc from aqueous solution using Azadirachta indica bark: equilibrium and kinetic studies

The removal of zinc ions from aqueous solutions on the biomass of Azadirachta indica bark has been studied by using batch adsorption technique. The biosorption studies were determined as a function of contact time, pH, initial metal ion concentration, average biosorbent size and biosorbent dosage. The equilibrium metal uptake was increased and percentage biosorption was decreased with an increase in the initial concentration and particle size of biosorbent. The maximum zinc biosorption occurred at pH 6 and percentage biosorption increases with increase in the biosorbent dosage. Experimental data obtained were tested with the adsorption models like Langmuir, Freundlich and Redlich-Peterson isotherms. Biosorption isothermal data were well interpreted by Langmuir model with maximum biosorption capacity of 33.49mg/g of zinc ions on A. indica bark biomass and kinetic data were properly fitted with the pseudo-second-order kinetic model.     

The half saturation removal approach and mechanism of Lead (II) removal using eco-friendly industrial fish bone meal waste biosorbent

Lead (II)-laden wastewater from lead acid battery and printed wire board industries are hazardous to human health and environment due to their toxicity and persistent characteristics. This study focuses on eco-friendly industrial Lutjanus erythropterus fish bone meal waste as biosorbent for Lead (II) removal. In this study, the effects of optimization of biosorption, isotherm, kinetic, thermodynamic, characterization of biosorbent were investigated, and the characteristics of biosorbent were compared with those of commercial resins. The half saturation removal of biosorbent amount was determined at 0.09 g in order to represent the excessive metal in real industrial wastewater condition compared to biosorbent and to minimize the consumption of chemicals and biosorption operation time. Such approach is supported by optimization results and Langmuir isotherm. Results obtained were better with Freundlich than with Langmuir isotherm, confirming the presence of heterogeneous monolayer with reversible binding sites. The biosorption mean energy inferred that chemisorption occurred in Lead (II) biosorption, and pseudo-second-order kinetics implied that chemisorption mechanism is the rate-limiting factor. Thermodynamic described an endothermic non-spontaneous reaction with reversible bonding between Lead (II) ions and binding sites. Characterization analysis further confirmed a macroporous surface morphology with multi-binding sites of hydroxyl, carboxyl, and amide groups which contributed to reversible bonding in chemisorption mechanism. The 85 % of recovery supported reversible binding in chemisorption. The biosorbent is at least 70 times cheaper than resins. Hence, this developed biosorbent is a potential candidate to replace resins and can be used in the pretreatment of industrial wastewater application due to cost effectiveness and low environmental impacts. This study successfully gains an insight into green technology by converting waste to a useable product and zero waste concept by minimizing environmental solid management and pollution control.     

Biosorption of heavy metal ions from aqueous solution by red macroalgae

Biosorption is an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine algae has been reported to have high biosorption capacities for a number of heavy metal ions. In this study, four species of red seaweeds Corallina mediterranea, Galaxaura oblongata, Jania rubens and Pterocladia capillacea were examined to remove Co(II), Cd(II), Cr(III) and Pb(II) ions from aqueous solution. The experimental parameters that affect the biosorption process such as pH, contact time and biomass dosage were studied. The maximum biosorption capacity of metal ions was 105.2mg/g at biomass dosage 10 g/L, pH 5 and contact time 60 min. The biosorption efficiency of algal biomass for the removal of heavy metal ions from industrial wastewater was evaluated for two successive cycles. Galaxaura oblongata biomass was relatively more efficient to remove metal ions with mean biosorption efficiency of 84%. This study demonstrated that these seaweeds constitute a promising, efficient, cheap and biodegradable sorbent biomaterial for lowering the heavy metal pollution in the environment.     

Application of response surface methodology for optimization of lead biosorption in an aqueous solution by Aspergillus niger

Response surface methodology was applied to optimize the removal of lead ion by Aspergillus niger in an aqueous solution. Experiments were conducted based on a rotatable central composite design (CCD) and analyzed using response surface methodology (RSM). The biosorption process was investigated as a function of three independent factors viz. initial solution pH (2.8-7.2), initial lead concentration (8-30 mg/l) and biomass dosage (1.6-6 g/l). The optimum conditions for the lead biosorption were found to be 3.44, 19.28 mg/l and 3.74 g/l, respectively, for initial solution pH, initial lead ion concentration and biomass dosage. Lead biosorption capacity on dead A. niger fungal biomass was enhanced by pretreatment using NaOH. Under these conditions, maximum biosorption capacity of the biomass for removal of lead ions was obtained to 96.21%. The desirability function was used to evaluate all the factors and response in the biosorption experiments in order to find an optimum point where the desired conditions could be obtained. The A. niger particles with clean surface and high porosity may have application as biosorbent for heavy metal removal from wastewater effluents.     

Competitive adsorption of Cu (II), Co (II) and Ni (II) from their binary and tertiary aqueous solutions using chitosan-coated perlite beads as biosorbent

A new composite chitosan-coated biosorbent was prepared and was used for the removal and recovery of heavy metals from aqueous solution. In the present investigation, equilibrium adsorption characteristics of Cu (II), Ni (II), and Co (II) from their binary and tertiary solution on newly developed biosorbent chitosan-coated perlite beads were evaluated through batch and column studies. These beads were characterized by using FTIR, EDXRF and surface area analysis techniques. The effect of various biosorption parameters like effect of pH, agitation time, concentration of adsorbate and amount of adsorbent on extent of adsorption was investigated. The adsorption follows Lagergren first order kinetic model. The equilibrium adsorption data were fitted to Freundlich and Langmuir adsorption isotherm models and the model parameters were evaluated. Both the models represent the experimental data satisfactorily. The sorbent loaded with metal was regenerated with 0.1N NaOH solution. Furthermore the column dynamic studies indicate the re-usage of the biosorbent.     

Potential of Sargassum wightii biomass for copper(II) removal from aqueous solutions: application of different mathematical models to batch and continuous biosorption data

This paper reports biosorption of copper(II) ions onto Sargassum wightii biomass in batch and continuous mode of operation. Batch experiments were fundamentally aimed to determine the favorable pH for copper(II) biosorption. Langmuir model was used to describe the copper(II) biosorption isotherm and maximum uptake of 115 mg/g was obtained at pH 4.5. Continuous experiments in a packed column (2 cm i.d. and 35 cm height) were performed to study the influence of bed height, flow rate and inlet solute concentration on copper(II) biosorption. The highest bed height (25 cm), lowest flow rate (5 ml/min) and highest inlet Cu(II) concentration (100 mg/l) resulted in highest copper(II) uptake of 52.6 mg/g, compared to other conditions examined. Column data obtained at different conditions were described using the Thomas, Yoon-Nelson and modified dose-response models. All three models were able to predict breakthrough curves; in particular, the breakthrough curve prediction by the Thomas and Yoon-Nelson models were found to be very satisfactory. Also, the well-established design model, the Bed depth-service time (BDST) model was used to analyze the experimental data. The BDST model plot at 5 ml/min (flow rate) and 100 mg/l (inlet solute concentration) was used to predict bed depth-service time data at different conditions. The BDST model predicted values always coincide with experimental values with high correlation coefficients.