Optimal Biosorption Conditions Research Articles

Competitive sequestration behavior and mechanism of Cd2+, Pb2+and Ni2+ ions from single, binary and ternary metal laden solution by Hevea brasiliensis wood sawdust (HBS)

HeveaBrasiliensis wood sawdust (HBS), a lignocellulosic material, was employed for the eradication of Cd(II), Pb(II), and Ni(II) from synthetic single and multi-metalsystem. In the realm of multimetal adsorption, HBS exhibited the most substantial adsorption capacities for heavy metals, in the order: Pb(II) > Cd(II) > Ni(II). Experiments involving batch process were carried out to explore the rolesofpH, contact duration, HBS quantity, and preliminary metal concentrations on the adsorption capacity. Optimal conditions for biosorption of metal ions were determined as pH 5.0, dosage of 7 gL−1, and an equilibrium time of 90 min. The pseudo-second-order kinetics andLangmuirisotherm had a favorable alignment with the biosorption of all individual metal ions. Adsorption capacity was 8.45, 13.01 and 6.04 mg g− 1 for Cd, Pb and Ni respectively in single metal system. In binary and ternary system the capacity and adsorption percentages decreases significantly due the presence of competitive metal ions. HBS demonstrated effectiveness in treating real wastewater containing Cd2+, Pb2+and Ni2+ ionsin both single and mixed metal solutions, highlighting the necessity of thoroughly considering the impact of competitive adsorption. SEM with EDS results indicated single metal fixing in a multi-ion solution followed complex mechanisms. The surface area and functional group studies were conducted utilizing BET and a FTIR Spectrometer. Electrostatic attraction and complexation mechanisms were identified as responsible factor for capturing metal ions to the active surfaces of the bio sorbent. Cost analysis reflected the adsorbent cost was $0.021 per liter of mixed contaminated ternary effluent (30 mg L−1).

Comparison of biosorption efficiency for hexavalent chromium remediation in synthetic wastewater using unmodified and chemically modified chicken feathers

The aim of the present study was to compare the effectiveness of raw chicken feathers (RCFs), NaOH and ethylenediamine-modified chicken feathers (MCFs), and xanthate-modified chicken feathers (XMCFs), treated with both NaOH, ethylenediamine, and carbon disulfide. The physicochemical characteristics of the biosorbents were analyzed using attenuated total reflection Fourier transform infrared spectrophotometry (ATR-FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), adsorption of N2 at −196°C and point of zero charge determination (pHpzc). The biosorption of Cr(VI) using MCFs and XMCFs was evaluated through various parameters, namely, pH, biosorbent amount, and contact time in batch experiments. The results showed a significant increase in the biosorption capacities of MCFs (90.90 mg/g) and XMCFs (100 mg/g) compared to RCFs (52.63 mg/g). The batch adsorption experiments indicated that the optimal conditions for biosorption were pH 2.0, with an equilibrium contact time of 90 min for RCFs, and 60 min for both MCFs and XMCFs. The optimal biosorbent concentrations were 16 g L−1 for RCFs and 12 g L−1 for both MCFs and XMCFs. The biosorption behavior was well described by the Langmuir isotherm and pseudo-second-order kinetic models. The thermodynamic parameters indicated that the biosorption of Cr(VI) onto the biosorbents was a spontaneous and endothermic process. Desorption analysis was carried out using a 0.1 M NaOH solution.

Biosorption performance of the multi-metal tolerant fungus Aspergillus sp. for removal of some metallic nanoparticles from aqueous solutions

The wide spread of nanotechnology applications currently carries with it the possibility of polluting the environment with the residues of these nanomaterials, especially those in the metallic form. Therefore, it is necessary to study the possibility of treating and removing various nanoscale metal pollutants in environmentally friendly ways. The present study focused on the isolation of multi-metal tolerant fungi to be applied in the bioremoval of Zn, Fe, Se, and Ag nanoparticles as potential nanoscale metal pollutants. Aspergillus sp. has been isolated as multi-metal tolerant fingus and investigated in the bioremoval of targeted nanometals from their aquoues solutions. The effect of biomass age, pH, and contact time was studied to determine the optimal biosorption conditions for fungal pellets towards metal NPs. The results showed a high percentage of fungal biosorption on the of two-day-old cells, which amounted to 39.3, 52.2, 91.7, and 76.8% of zinc, iron, selenium, and silver, respectively. The pH 7 was recorded the highest percentage of NPs removal for the four studied metals i.e. 38.8, 68.1, 80.4, and 82.0% of Zn-, Fe-, Se- and Ag-NPs, respectively. The contact time required between Aspergillus sp. and the metal nanoparticles to obtain the best adsorption was only 10 min in the case of Zn and Ag, but it was 40 min for both Fe and Se NPs. The efficiency of living fungal pellets in removing the four metallic NPs exceeded that of dead biomass by 1.8, 5.7, 2.5, and 2.5 folds for Zn, Fe, Se and Ag, respectively. However, utilization of dead fungal biomass for metallic NPs removal could be considered more applicable to the actual environmental applications.

Evaluation of the Adsorptive Performances of Rapeseed Waste in the Removal of Toxic Metal Ions in Aqueous Media

Rapeseed seeds are one of the most important categories of raw materials used to obtain biofuels. However, the biomass resulting after oil extraction is still considered waste, for which valorization solutions are sought. In this study, we propose the use of this type of residual biomass (rapeseed waste biomass (RWB)) as a biosorbent for the removal of toxic metal ions from aqueous media. Two toxic metal ions were selected for the experimental studies, namely: Pb(II) and Hg(II). The optimal biosorption conditions, for both metal ions, were selected based on response surface methodology and were verified experimentally in batch systems. More than 92% of the initial amount of Pb(II) and Hg(II) are retained under the following conditions: pH = 6.5 for Pb(II) and 4.0 for Hg(II); biosorbent dosage = 4.0 g/L; contact time = 3 h; temperature = 25 ± 1 °C. Isotherm (Langmuir, Freundlich and Temkin models) and kinetic (pseudo-first order, pseudo-second order and intra-particle diffusion models) modelling of the experimental data were used for the quantitative evaluation of both biosorption processes. Although the Langmuir maximum biosorption capacities are different (higher in the case of Pb(II) (61.97 mg/g) than in the case of Hg(II) (51.32 mg/g)), the pseudo-second order kinetic constants have the same order of magnitude. This shows that the retention of both metal ions involves similar elementary steps and that RWB behaves as a typical biosorbent. These characteristics, together with the very good desorption behavior, provide a complete picture of the possible applications of this waste in environmental decontamination processes.

Biosorción de Cd (II) y Pb (II) de soluciones acousas en residuos agrícolas de Phaseolus vulgaris L.: Optimización, cinética, isotermas y desorción

Industrial activities are the most common cause of water contamination by heavy metals, which endanger the quality of water resources and human health, due to their bioaccumulation capacity and consequent biomagnification. For this reason, the removal of metals from effluents before their discharge into the receiving water bodies is of crucial importance. This is why, in the present investigation, the biosorption processes of Cd (II) and Pb (II) in Phaseolus vulgaris L. (bean) agricultural residues (stems, leaves and leaf sheaths) were optimized. The influence of pH, biosorbent doses and initial concentration levels of metallic ions was evaluated using the response surface methodology (RSM). Quadratic models were developed for the percent removal of Cd (II) and Pb (II). Optimal biosorption conditions were attained at pH = 4.3, a 7.4 g/L biosorbent dose and an initial 9.14 mg/L concentration of each metal, achieving percent removals of 87.70 and 95.58% for Cd (II) and Pb (II), respectively. The FT-IR characterization showed that the functional groups involved in adsorption would be in the range of 2300 to 2400 cm-1. The biosorption kinetics were described by the pseudo first order model and the equilibrium data was adjusted to the Freundlich isotherm. An approximate desorption of 98% of Cd (II) and Pb (II) was achieved. The Phaseolus vulgaris L. residue showed a great biosorption capacity of Cd (II) and Pb (II) simultaneously.

Two plant growth promoting bacterial Bacillus strains possess different mechanisms in adsorption and resistance to cadmium

Microorganisms are promising biosorbents for decontaminating cadmium-polluted soil or water systems, but the underlying remediation mechanisms are still unclear. In this study, the cadmium biosorption mechanisms and capabilities of plant growth-promoting microorganisms (Bacillus megaterium NCT-2 and Bacillus paranthracis NT1) were investigated. Batch biosorption experiments showed that the optimal biosorption conditions for B. megaterium NCT-2 and B. paranthracis NT1 were pH 6.0, a biomass dosage of 1.0 g L−1, and an initial Cd2+ concentration of 10 mg L−1, and pH 8.0, a biomass dosage of 1.0 g L−1, and an initial Cd2+ concentration of 10 mg L−1, respectively. The biosorption processes of both biosorbents were well described by the pseudo-second order kinetic model, which indicated that the biosorption of Cd2+ was mainly chemisorption. The intracellular accumulation portion of adsorbed Cd2+ in B. megaterium NCT-2 was much higher than in B. paranthracis NT1 (43.11% and 3.25%, respectively), which resulted in the lower cadmium tolerance (14 mg L−1 and 280 mg L−1, respectively) and higher cadmium removal efficiency (46.79% and 20.45%, respectively) of B. megaterium NCT-2 compared to B. paranthracis NT1. SEM-EDS and FTIR analysis suggested the probable interactions of Cd2+ with the biosorbent surface ligands, such as -OH, -NH, -SO3, CO and -COOH during surface adsorption. Results of qRT-PCR illustrated that the difference in cadmium resistant mechanism and adsorption performance between B. megaterium NCT-2 and B. paranthracis NT1 may be regulated by the genes cadA, zitB, khtT, and bshA and cadA, trkA, czcD, and bshA, respectively. Our results revealed that these two biosorbents have the potential for further use in the development of cadmium remediation technologies and could provide insight into the mechanisms of cadmium biosorption.

Pb2+ biosorption from aqueous solutions by live and dead biosorbents of the hydrocarbon-degrading strain Rhodococcus sp. HX-2.

In this study, the Pb2+ biosorption potential of live and dead biosorbents of the hydrocarbon-degrading strain Rhodococcus sp. HX-2 was analyzed. Optimal biosorption conditions were determined via single factor optimization, which were as follows: temperature, 25°C; pH, 5.0, and biosorbent dose, 0.75 g L-1. A response surface software (Design Expert 10.0) was used to analyze optimal biosorption conditions. The biosorption data for live and dead biosorbents were suitable for the Freundlich model at a Pb2+ concentration of 200 mg L-1. At this same concentration, the maximum biosorption capacity was 88.74 mg g-1 (0.428 mmol g-1) for live biosorbents and 125.5 mg g-1 (0.606 mmol g-1) for dead biosorbents. Moreover, in comparison with the pseudo-first-order model, the pseudo-second-order model seemed better to depict the biosorption process. Dead biosorbents seemed to have lower binding strength than live biosorbents, showing a higher desorption capacity at pH 1.0. The order of influence of competitive metal ions on Pb2+ adsorption was Cu2+ > Cd2+ > Ni+. Fourier-transform infrared spectroscopy analyses revealed that several functional groups were involved in the biosorption process of dead biosorbents. Scanning electron microscopy showed that Pb2+ attached to the surface of dead biosorbents more readily than on the surface of live biosorbents, whereas transmission electron microscopy confirmed the transfer of biosorbed Pb2+ into the cells in the case of both live and dead biosorbents. It can thus be concluded that dead biosorbents are better than live biosorbents for Pb2+ biosorption, and they can accordingly be used for wastewater treatment.

ESTUDIO DE LA BIOADSORCIÓN DE COBRE Y ZINC CON BIOMASA SECA DE Escherichia coli PRETRATADA Y SIN TRATAR

Nowadays, new technologies are being developed for the removal of heavy metals, which are intended to have low operating costs and easy to implement. The copper and zinc bioadsorption in batch system was studies in pre-treated, with sodium hydroxide, and untreated Escherichia coli dried biomass . The E. coli was isolated and identified from water samples from the San Pedro river, Sonora, Mexico. The dry biomass of E. coli was pretreated with 0.1 N sodium hydroxide. The optimal biosorption conditions were at pH 5, 30 oC and 100 rpm. These studies demonstrated the effectiveness of the pre-treated biomass in determining the maximum bioadsorption capacity using the Langmuir model, and they were for copper of 204.49 mg/g and zinc of 151.97 mg/g, and for biomass untreated with copper and zinc were 107.52 mg/g and 125 mg/g, respectively. In addition, with the characterization by scanning electron microscopy and dispersive energy spectroscopy, the presence of copper and zinc were observed. The absorption bands by Fourier transform infrared spectrophotometry confirmed carboxyl, hydroxyl, amino and phosphate groups on the surface of E. coli . The use of dry biomass of pre-treated Escherichia coli in this study, showed to be effective in the bioadsorption process.

Application of Arthrospira (Spirulina) platensis biomass for silver removal from aqueous solutions

ABSTRACTThe cyanobacterium Arthrospira (Spirulina) platensis was used to study the process of silver biosorption. Effects of various parameters such as contact time, dosage of biosorbent, initial pH, temperature, and initial concentration of Ag(I) were investigated for a batch adsorption system. The optimal biosorption conditions were determined as pH 5.0, biosorbent dosage of 0.4 g, and initial silver concentration of 30 mg/L. Equilibrium adsorption data were analyzed by the Langmuir and Freundlich models – however, the Freundlich model provided a better fit to the experimental data. The kinetic data fit the pseudo-second-order model well, with a correlation coefficient of 0.99. The analysis of thermodynamic parameters (ΔG°, ΔH° and ΔS°) revealed that the adsorption process of silver ion by spirulina biomass was exothermic and spontaneous (ΔG° < 0), and exothermic (ΔH° < 0) process. The biosorption capacity of biomass A. platensis serves as a basis for the development of green technology for environmental remediation.

Simultaneous multidye biosorption by chemically modified Sargassum glaucescens: Doehlert optimization and kinetic, equilibrium, and thermodynamic study in ternary system

ABSTRACTMultidye 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.

Characteristics of uranium biosorption from aqueous solutions on fungus Pleurotus ostreatus.

Uranium(VI) biosorption from aqueous solutions was investigated in batch studies by using fungus Pleurotus ostreatus biomass. The optimal biosorption conditions were examined by investigating the reaction time, biomass dosage, pH, temperature, and uranium initial concentration. The interaction between fungus biomass and uranium was confirmed using Fourier transformed infrared (FT-IR), scanning electronic microscopy energy dispersive X-ray (SEM-EDX), and X-ray photoelectron spectroscopy (XPS) analysis. Results exhibited that the maximum biosorption capacity of uranium on P. ostreatus was 19.95±1.17mg/g at pH 4.0. Carboxylic, amine, as well as hydroxyl groups were involved in uranium biosorption according to FT-IR analysis. The pseudo-second-order model properly evaluated the U(VI) biosorption on fungus P. ostreatus biomass. The Langmuir equation provided better fitting in comparison with Freundlich isotherm models. The obtained thermodynamic parameters suggested that biosorption is feasible, endothermic, and spontaneous. SEM-EDX and XPS were additionally conducted to comprehend the biosorption process that could be described as a complex process involving several mechanisms of physical adsorption, chemisorptions, and ion exchange. Results obtained from this work indicated that fungus P. ostreatus biomass can be used as potential biosorbent to eliminate uranium or other radionuclides from aqueous solutions.

Biosorption of Cr(III) and Pb(II) by Schoenoplectus californicus and Insights into the Binding Mechanism

Biosorption and desorption of chromium and lead on shoots biomass of Schoenoplectus californicus were investigated by performing batch sorption tests in different conditions of pH, biosorbent dose, and initial concentration in simple and binary solutions. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models were employed to describe sorption equilibrium. Filters and biomass were characterized before and after treatments by environmental scanning electron microscopy and X-ray energy-dispersive spectrometry. The optimal conditions for biosorption were found to be pH 5 for both metals. The contact time to reach pseudoequilibrium changed as a function of pH and the metal studied. The highest optimisation of biosorbent dose was 5 g L−1 at pH 7 and 15 g L−1 at pH 5 for both metals. The most effective extracting agents for lead and chromium proved to be HNO3 and NaOH, respectively. The recovery of lead was greater than of chromium because the Cr(III) sorption mechanisms involve a stronger binding energy than the mechanisms for Pb(II), such as in intern sphere complexes. Both metals accounted for a high % removal (&gt;90%) under the best sorption conditions. The use of Schoenoplectus californicus proved to be an efficient and economical alternative for the treatment of effluents contaminated with lead and chromium.

Modelling and optimization of chromiumIII biosorption on soybean meal

Abstract Abstract In this investigation a waste biological material, soybean meal, was applied as a biosorbent for heavy metal ions (CrIII). The diffusive Webber-Morris model and the pseudo-II-order model suitably described the kinetics of CrIII ions binding on soybean meal. The Langmuir-Freundlich equation was valid for the description of the isotherm. Inductively coupled plasma optical emission spectroscopy (ICP-OES), FTIR and scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) were used in order to identify the mechanism of the metal ions binding. The analysis of the composition of the enriched soybean meal confirmed the contribution of ion exchange in the biosorption process. Three-variable-three-level Box-Behnken design was used to determine the optimal conditions for biosorption of CrIII on soybean meal. The optimal conditions for predicted maximum Cr3+ uptake (61.07 mg g−1) by soybean meal were estimated by Matlab and established as temperature of 38.04°C, initial metal concentration 500 mg L−1 and biosorbent dosage 1 g L−1. Graphical abstract

Biosorption of copper and zinc by immobilised and free algal biomass, and the effects of metal biosorption on the growth and cellular structure of Chlorella sp. and Chlamydomonas sp. isolated from rivers in Penang, Malaysia

In this study, the biosorption of copper and zinc ions by Chlorella sp. and Chlamydomonas sp. isolated from local environments in Malaysia was investigated in a batch system and by microscopic analyses. Under optimal biosorption conditions, the biosorption capacity of Chlorella sp. for copper and zinc ions was 33.4 and 28.5 mg/g, respectively, after 6 hr of biosorption in an immobilised system. Batch experiments showed that the biosorption capacity of algal biomass immobilised in the form of sodium alginate beads was higher than that of the free biomass. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed that copper and zinc were mainly sorbed at the cell surface during biosorption. Exposure to 5 mg/L of copper and zinc affected both the chlorophyll content and cell count of the algal cells after the first 12 hr of contact time.

Acidithiobacillus caldus, Leptospirillum spp., Ferroplasma spp. and Sulphobacillus spp. mixed strains for use in cobalt and copper removal from water

Bacteria from the genus Acidithiobacillus, Leptospirillum and Ferroplasma, Sulphobacillus are often associated with water remediation. In this study a consortium of Acidithiobacillus caldus, Leptospirillum spp., Ferroplasma spp. and Sulphobacillus spp. was cultured and used to remove Cu2+ and Co2+ from synthetic aqueous sulphate solutions. The influence of experimental conditions such as pH, temperature, time, volume and metal concentration on the efficiency of the biosorption process was investigated. Biosorption of 54 to 67% Cu (pH 2, 37°C, 24 h) and 23-70% Co (pH 2, 37°C, 24 h) was observed from solutions containing 3.86 g·l-1 Cu2+ ions and 3.36 g·l-1 Co2+ ions. Such findings suggest that if optimal conditions for biosorption of the metals by micro-organisms are achieved, this should afford a cost-effective method of removing metal species from water and aqueous solutions

Characteristic and Equilibrium Studies of Fungi &lt;i&gt;Penicillium&lt;/i&gt; sp. QQ Biosorption Bacteria &lt;i&gt;Exiguobacterium&lt;/i&gt; sp. TL

This study aimed at investigating the characteristics and equilibrium of Penicillium sp. QQ biosorption bacteria Exiguobacterium sp. TL. The optimal biosorption conditions were as follows: 50 mM Fe3+, 2.50 g of strain QQ, 480.80 mg/L of strain TL, 120 min of contact time, pH 5 and 40oC. The biosorption isotherms of strain TL by strain QQ could be well described by both Langmuir and Freundlich models. The maximal biosorption capacity of strain QQ for TL was 62.62 (mg/g) at 40oC, evaluated by Langmuir isotherm. It could be concluded from the results that the strain QQ was a promising biological carrier for the biosoption of strain TL, and the establishing of fungi-bacteria biosorption system was potential for pollutant removal and field application.

Preparation and characterization of baker's yeast modified by nano-Fe 3O 4: Application of biosorption of methyl violet in aqueous solution

The magnetic baker's yeast biomass (MB) was prepared by combining baker's yeast and nano-Fe 3O 4 using glutaraldehyde as a cross link agent. The MB was successfully used for the biosorption of methyl violet (MV) and was easily recycled by using an applied magnetic field. The mechanism of MV biosorption by MB was investigated by SEM, XRD, FTIR, zeta potential and potentiometric titration. The results revealed that nano-Fe 3O 4, with spherical and granular morphology, were distributed on the surface of baker's yeast biomass. The functional groups such as carboxyl, hydroxyl and amino groups found on the surface of MB may be responsible for MV biosorption. The optimal biosorption conditions were determined as pH 6.0, MV concentration 300 mg/L and contact time 30 min. The biosorption capacity in the optimal conditions was 60.84 mg/g. The biosorption process followed the pseudo-second-order kinetic model and the Langmuir isotherm equation. The thermodynamic parameters Δ G°, Δ H° and Δ S° showed that the biosorption was feasible, spontaneous and endothermic. The desorption and regeneration experiments were investigated and the biosorption/desorption cycles of MV were repeated three times. The MB regeneration efficiency and the MV recovery efficiency were 82.64% and 84.54% respectively in the third cycle by using HAc as an eluent solution.

The effect of silica concentration on the biosorption of Cu&lt;sup&gt;2+&lt;/sup&gt; and Co&lt;sup&gt;2+&lt;/sup&gt; from aqueous solutions mediated by strains of &lt;i&gt;Bacillus&lt;/i&gt;

Bacillus strains were isolated from a mine tailings dump in Nigel town, south-east of Johannesburg. These were then grown at 37(±0.5)°C in a trace element-agitated liquid media. The effects of pH, contact time, initial ion concentration and the presence of co-cations were studied to ascertain the optimal conditions for biosorption to take place. Test solutions contained 0.002 M, 0.07 M and 0.2 M of either copper or cobalt ions. The Bacillus strains removed the copper and cobalt more efficiently from solutions of low concentration (0.002 M and 0.07 M) than from solutions of high concentration (0.2 M) over a 48 h period. Maximum biosorption was obtained at pH 6.5 and 5.5 for copper and cobalt solutions, respectively. The presence of silica led to an initial increase in both copper and cobalt biosorption, though higher concentrations of silica resulted in a decrease in metal uptake by Bacillus strains.Keywords: biosorption, Bacillus, silica, copper, cobalt

Biosorption of Cd(II), Ni(II) and Pb(II) from Aqueous Solution by Dried Biomass of Aspergillus niger: Application of Response Surface Methodology to the Optimization of Process Parameters

AbstractIn this study, the biosorption of Cd(II), Ni(II) and Pb(II) on Aspergillus niger in a batch system was investigated, and optimal condition determined by means of central composite design (CCD) under response surface methodology (RSM). Biomass inactivated by heat and pretreated by alkali solution was used in the determination of optimal conditions. The effect of initial solution pH, biomass dose and initial ion concentration on the removal efficiency of metal ions by A. niger was optimized using a design of experiment (DOE) method. Experimental results indicated that the optimal conditions for biosorption were 5.22 g/L, 89.93 mg/L and 6.01 for biomass dose, initial ion concentration and solution pH, respectively. Enhancement of metal biosorption capacity of the dried biomass by pretreatment with sodium hydroxide was observed. Maximal removal efficiencies for Cd(II), Ni(III) and Pb(II) ions of 98, 80 and 99% were achieved, respectively. The biosorption capacity of A. niger biomass obtained for Cd(II), Ni(II) and Pb(II) ions was 2.2, 1.6 and 4.7 mg/g, respectively. According to these observations the fungal biomass of A. niger is a suitable biosorbent for the removal of heavy metals from aqueous solutions. Multiple response optimization was applied to the experimental data to discover the optimal conditions for a set of responses, simultaneously, by using a desirability function.