Biosorption Of Chromium Research Articles

Calcium alginate as an eco-friendly supporting material for Baker’s yeast strain in chromium bioremediation

In this study, Baker’s yeast strain (Saccharomyces cerevisiae) biomass was immobilized in alginate extract 3% forming Biomass/Polymer Matrices Beads (BPMB). These beads were investigated for chromium biosorption from aqueous solution. Factors such as solution pH, contact times, temperature values, stirring rates, BPMB dosages and initial chromium ions concentrations were experimentally tested using repeated-batch process to determine the sorption capacity for chromium (VI) ions. Batch experiments were conducted at pH range from 1.5 to 7.5. The optimum pH value was 3.5 for direct chromium removal. The effect of chromium concentration was studied using different concentrations from 200 to 1000ppm. Freundlich’s isothermal model showed better representation of data than Langmuir’s isothermal model with correlation coefficient 0.922. The maximum biosorption capacity of chromium was found to be 154mgg−1 at initial concentration 200ppm under optimum conditions. At the end of the experiments, BPMB were investigated for chromium biosorption from tannery effluent sample. Results showed decrease in chromium concentration up to 85%. The availability of recycling of the BPMB was also studied for three subsequent cycles. The surface sequestration of metal ions by BPMB was characterized before and after metal binding using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray analysis (EDXA) and FTIR spectroscopy in order to determine the mechanisms of chromium biosorption.

Dry Trichoderma biomass: biosorption behavior for the treatment of toxic heavy metal ions

The dried biomass of Trichoderma sp. was investigated to remove toxic heavy metal ions using the batch method in the concentration range of 0.5 to 2.0 mg/L at different pH. The biosorption capacity of Trichoderma biomass was found to be pH dependent. Biosorption of nickel at pH 10 was observed 20% higher than at pH 2. The maximum sorption (91%) for Cd(II) was achieved (0.45 mg cadmium/g biomass) at pH 10 within 72 h equilibrium time. The maximum sorption capacity of Cr(VI) was achieved (0.053 mg chromium/g biomass) upon equilibration after 72 h. In comparison with nickel and cadmium, the biosorption of chromium was found to be pH independent, while nickel and cadmium showed a higher absorption capacity at higher pH. In addition, Freundlich and Langmuir adsorption isotherms were used to verify the biosorption performance of Trichoderma biomass. Langmuir adsorption isotherm was found to be fit better than Freundlich adsorption isotherm. The dried biomass of Trichoderma has been fruitfully applied for the removal and recovery of Ni(II), Cd(II), and Cr(VI) ions. Thus, it can be successfully used for the treatment of toxic heavy metal ions from the industrial effluents as well as natural waters.

Chromium and cobalt sequestration using exopolysaccharides produced by freshwater cyanobacterium Nostoc linckia

This study investigated biosorption of chromium(VI) and cobalt(II) by exopolysaccharides (EPS) of a freshwater cyanobacterium, Nostoc linckia HA-46 from aqueous solution. Experiments were performed in batch mode to determine the adsorption dynamics of the cyanobacterial EPS. The adsorption capacity for Cr(VI) and Co(II) ions by EPS is found to be dependent on pH, contact time and initial metal ion concentration. The uptake kinetics of the metal ions follow pseudo-second order model. The maximum adsorption coefficient of determination (0.993Cr and 0.997Co) for Langmuir model indicates best fitness of this model in explaining the sorption as a multilayer process. The maximum adsorption capacities of the EPS were 14.3mg Crg−1 (at pH 2.0) and 17.9mg Cog−1 (at pH 4.0) at an initial concentration of 20 mgL−1. The EPS of Nostoc linckia shows better biosorption capacity for Co(II) than Cr(IV) metal ion.

Equilibrium and kinetics studies of hexavalent chromium biosorption on a novel green macroalgae Enteromorpha sp.

This study focuses on the use of novel Enteromorpha sp. macroalgal biomass (EMAB), for the biosorption of hexavalent chromium from aqueous solutions. The biosorbent was characterized by Fourier transformer infrared spectroscopy, energy dispersive spectroscopy, and scanning electron microscopy techniques. The effect of experimental parameters such as pH, initial concentration of Cr(VI) ions, biosorbent dosage, and temperature were evaluated. The maximum biosorption capacity for Cr(VI) was observed at pH 2.0. The modeling of the experimental data at equilibrium was performed using two parameter isotherm models. Both Langmuir and Freundlich isotherm equations better fitted the equilibrium data. A contact time of different initial Cr(VI) concentrations was about 160 min to attain biosorption equilibrium. The kinetic data were fitted by models including pseudo-first-order, pseudo-second-order, and intraparticle diffusion. The pseudo-second-order and intraparticle diffusion kinetic models adequately described the kinetic data. Moreover, the thermodynamic parameters indicated that the biosorption process was spontaneous, endothermic, and increased randomness in nature. The results showed that EMAB could be used as an effective biosorbent for the removal of Cr(VI) from aqueous solution.

Kinetic and equilibrium studies of chromium (VI) biosorption by spent macroalgae Polysiphonia urceolata and Chondrus ocellatus

The removal of chromium (VI) from aqueous solutions by spent Polysiphonia urceolata and Chondrus ocellatus was investigated with respect to initial pH, amount of biosorbent, initial heavy metal concentrations and temperature. The Cr(VI) removal process was influenced significantly by variations in pH, and the optimum pH was determined to be about 2.0. The optimum algal dosage was 4 g/L and maximum biosorption was achieved at 45 °C in the experiment. The rate of Cr(VI) removal was relatively high in the first 40 min, and biosorption equilibriums were rapidly established in about 60 min for P. urceolata and 40 min for C. ocellatus. The biosorption kinetics followed well a pseudo-second-order model. Adsorption equilibriums were well described by Langmuir and Freundlich isotherm models. The maximum adsorption capacities were 170.6 mg/g for P. urceolata and 113.4 mg/g for C. ocellatus at 298 K and pH 2.0. Fourier transform infrared spectroscopy suggested that amino, hydroxy, C˭O and C–O groups could be involved in the biosorption of Cr(VI) onto P. urceolata and C. ocellatus.

Biosorption of Chromium by Bacillus subtilis and Pseudomonas aeruginosa Isolated from Waste Dump Site

Biosorption of Chromium by Bacillus subtilis and Pseudomonas aeruginosa Isolated from Waste Dump Site This study focused on biosorption of Chromium using Pseudomonas aeruginosa and Bacillus subtilis. The study was performed by varying the parameters that determine the efficiency of biosorption, i.e. pH, biomass concentration, metal concentration, temperature and contact time. The results obtained shows that higher percentage of Chromium biosorption was recorded with Bacillus subtilis. The optimum value for each of the parameters was obtained in the following order; for pH, optimum value was 4.0, with highest biosorption percentage of 80.6 and 86.7% for Pseudomonas aeruginosa and Bacillus subtilis respectively. Highest biosorption percentage of 83.0 and 86.7% were recorded at concentration of 2ml for Pseudomonas aeruginosa and Bacillus subtilis respectively for biomass concentration. Chromium concentration produced 73.6 and 86.7% highest biosorption at 5ppm for Pseudomonas aeruginosa and Bacillus subtilis respectively..

Heavy Metal Detoxification by Different Bacillus Species Isolated from Solar Salterns.

The biosorption mechanism is an alternative for chemical precipitation and ultrafiltration which have been employed to treat heavy metal contamination with a limited success. In the present study, three species of Bacillus which were isolated from solar salterns were screened for their detoxification potential of the heavy metals, lead, chromium, and copper, by biosorption. Biosorption potential of each isolate was determined by Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), and Energy Dispersive Spectroscopy (EDS) as the amount of metal present in the medium after the treatment with the isolates. Bacterial isolates, Bacillus licheniformis NSPA5, Bacillus cereus NSPA8, and Bacillus subtilis NSPA13, showed significant level of lead biosorption with maximum of 87–90% by Bacillus cereus NSPA8. The biosorption of copper and chromium was relatively low in comparison with lead. With the obtained results, we have concluded that the bacterial isolates are potential agents to treat metal contamination in more efficient and ecofriendly manner.

Potential of Live Spirulina platensis on Biosorption of Hexavalent Chromium and Its Conversion to Trivalent Chromium

Microalga biomass has been described worldwide according their capacity to realize biosorption of toxic metals. Chromium is one of the most toxic metals that could contaminate superficial and underground water. Considering the importance of Spirulina biomass in production of supplements for humans and for animal feed we assessed the biosorption of hexavalent chromium by living Spirulina platensis and its capacity to convert hexavalent chromium to trivalent chromium, less toxic, through its metabolism during growth. The active biomass was grown in Zarrouk medium diluted to 50% with distilled water, keeping the experiments under controlled conditions of aeration, temperature of 30°C and lighting of 1,800 lux. Hexavalent chromium was added using a potassium dichromate solution in fed-batch mode with the aim of evaluate the effect of several additions contaminant in the kinetic parameters of the culture. Cell growth was affected by the presence of chromium added at the beginning of cultures, and the best growth rates were obtained at lower metal concentrations in the medium. The biomass removed until 65.2% of hexavalent chromium added to the media, being 90.4% converted into trivalent chromium in the media and 9.6% retained in the biomass as trivalent chromium (0.931 mg.g−1).

Surfactant Assisted Enhancement of Bioremediation Rate for Hexavalent Chromium by Water Extract of Siris (Albizia lebbeck) Sawdust

Abstract Cr(VI) is introduced into environment as a byproduct of industries. It is highly toxic. Biosorption of hexavalent chromium by various types of sawdust appears as a very cost-effective alternative for decontamination of Cr(VI) bearing effluents. In this work water extract of siris sawdust is used for the bioremediation of hexavalent chromium. Cr(VI) ions were reduced to Cr(III) ions as a result of oxidation of organic components present in the water extract of siris sawdust. Formation of Cr(III) is proved by UV-VIS spectroscopy. Functional groups involved in the reduction of Cr(VI) are characterized by FTIR spectroscopy. Bioremediation rate is increased by the use of anionic surfactant sodium dodecylsulphate (SDS) and neutral surfactant Triton-X-100 (TX-100). Here they act as micellar catalyst. Formation of micelles which is responsible for the catalysis of the process is proved by SEM and optical images of the solution. In absence of surfactants 39 % of the total chromium(VI) is reduced within 531 h whereas removal percentage increases upto 54 % in presence of TX-100. Again in presence of SDS the reduction process is almost 99 % complete within 531 h.

Removal of copper(II) and chromium(VI) from aqueous solution using sorghum roots (S. bicolor): a kinetic and thermodynamic study

Biosorption of toxic metal ions from industrial effluents using different plant parts is an important branch of environmental chemistry. Biosorption of copper(II) and chromium(VI) ions from aqueous solution onto sorghum root (SR) powder have been investigated under batch mode. The optimum pH and temperature for biosorption of both the metals was found to be 2 and 20 °C, respectively. The maximum biosorption capacity q e for Cu(II) and Cr(VI) is 18.6 and 18.39 mg/g, respectively. The Langmuir model gave a better fit than other two models. The kinetic studies indicated that the biosorption process of the metal ions followed well pseudo-second-order model. The thermodynamic parameters were also calculated and the values indicated that the biosorption process was exothermic, spontaneous, and feasible in nature. Desorption experiments with 1 M HCl and 1 M HNO3 inferred the reusability of biomass. The results showed that SRs have excellent adsorption properties and thus can be used as an effective and low cost biosorbent for the removal of Cu(II) and Cr(VI) ions from aqueous solution.

Biosorption of Trivalent Chromium from Wastewater: An Approach towards Green Chemistry

AbstractChromium is one of the metals used in industry that create environmental toxicity and pollution problems. In the present study, chromium in wastewater was removed by a biosorption method using a bacterial culture of Bacillus pumilus. A mathematical model representing the biosorption kinetics was formulated, supporting the Langmuir isotherm for the adsorption of chromium. Fourier transform infrared and scanning electron microscopy studies were used to characterize the adsorption of chromium by the bacterial biomass. The analysis of pollution parameters (chemical oxygen demand, total organic content, total dissolved solid, total suspended solid) suggest a significant reduction of the pollution load. The results show that the method developed here is very effective for the removal of chromium from an aqueous environment.

Determination of Adsorption Isotherm Models for the Biosorption of Chromium Using Cherry Leaves (<i>Muntingia calabura</i> L.)

Contaminations of industrial metals into the river possess major threat to environment. Chromium is a heavy metal which has the wide applications in tannery and electroplating industries. Above the permitted level of Chromium(VI) into surface water leads to severe health hazards. Therefore, biosorption is a technology used for the sorption of heavy metal. In this present study adsorption isotherm models was studied for the biosorption of chromium by cherry leaves. From the adsorption isotherms it was found that the experimental data fits well with the Langmuir isotherm than the Freundlich isotherm. The monolayer capacity Qm was fond to be 11.98 mg/l and the adsorption affinity was found to be positive which indicates the efficient biosorption of chromium

Evaluation of Thermodynamic Properties for the Biosorption of Chromium by Using Cherry Leaves (<i>Muntingia calabura</i> L.)

Chromium is a heavy metal which has widely used in tannery and electroplating industries. Contaminations of these industrial metals into the river possess major threat to an environment. Therefore, biosorption is a technique which is applied for the sorption of heavy metal by a biomaterial. In the present study reveals that cherry leaves was used as a biomaterial and for that the thermodynamic properties was evaluated for the biosorption of chromium. From the thermodynamic studies it was found that the reaction was feasible, spontaneous and exothermic because the values of ∆G = negative, ∆S = negative and ∆H = positive. So, it was concluded that the experiment was thermodynamically feasible.

Determination of Adsorption Isotherm Models for the Biosorption of Chromium Using Cherry Leaves (<i>Muntingia calabura</i> L.)

Contaminations of industrial metals into the river possess major threat to environment. Chromium is a heavy metal which has the wide applications in tannery and electroplating industries. Above the permitted level of Chromium(VI) into surface water leads to severe health hazards. Therefore, biosorption is a technology used for the sorption of heavy metal. In this present study adsorption isotherm models was studied for the biosorption of chromium by cherry leaves. From the adsorption isotherms it was found that the experimental data fits well with the Langmuir isotherm than the Freundlich isotherm. The monolayer capacity Qm was fond to be 11.98 mg/l and the adsorption affinity was found to be positive which indicates the efficient biosorption of chromium

Evaluation of Thermodynamic Properties for the Biosorption of Chromium by Using Cherry Leaves (<i>Muntingia calabura</i> L.)

Chromium is a heavy metal which has widely used in tannery and electroplating industries. Contaminations of these industrial metals into the river possess major threat to an environment. Therefore, biosorption is a technique which is applied for the sorption of heavy metal by a biomaterial. In the present study reveals that cherry leaves was used as a biomaterial and for that the thermodynamic properties was evaluated for the biosorption of chromium. From the thermodynamic studies it was found that the reaction was feasible, spontaneous and exothermic because the values of ∆G = negative, ∆S = negative and ∆H = positive. So, it was concluded that the experiment was thermodynamically feasible.

Effect of pH on chromium and nickel biosorption by Litchi chinensis seeds in single and binary metal systems

Effect of pH on chromium and nickel biosorption by Litchi chinensis seeds in single and binary metal systems

Two metal biosorption of chromium and copper by Ca-loaded Laminaria japonica biomass

Cu and Cr sorption capacities of Ca-loaded Laminaria japonica biomass were studied using an equilibrium methodology and evaluation of the sorption performance, and modeling in a two-metal system was carried out with a modified multi-component Langmuir isotherm. The maximum Cu and Cr uptakes calculated from the Langmuir isotherm were 1.59 mmol/g (10.1 wt.%) and 1.81 mmol/g (9.4 wt.%) at pH 4.5, respectively. The desorption efficiency of the Cr-sorbed L. japonica was approximately 5% for 8 h in the 0.1 N HNO3 solution, while that of Cu-sorbed L. japonica was more than 99% in the 0.1 N HNO3 solution. The modified Langmuir model gave the following affinity correlated coefficients: 1.12 for Cu and 7.31 for Cr at pH 4.5. The interference of Cr with Cu biosorptive uptake was assessed by ‘cutting’ the three dimensional uptake isotherm surfaces at constant second-metal final concentrations. Equimolar final equilibrium concentrations of Cu and Cr of 1 mM at pH 4.5 reduced Cu and Cr uptakes by 75.5 and 11.0%, respectively.

Biosorption of chromium by alginate extraction products from Sargassum filipendula: investigation of adsorption mechanisms using X-ray photoelectron spectroscopy analysis.

The alginate extraction products from Brazilian brown seaweed Sargassum filipendula were studied for chromium biosorption. Batch experiments were conducted at pH 2 and 3 and 20°C to determine the sorption capacity of this biosorbents for chromium (VI) and (III). The biomass was characterized before and after metal binding by X-ray photoelectron spectroscopy (XPS) in order to determine the mechanisms of chromium biosorption. The residue has a high adsorption capacity, close the value obtained with seaweed and higher than that of alginate for both Cr(III) and Cr(VI). XPS analysis of the biosorbents revealed that carboxyl, amino and sulfonate groups are responsible for the binding of the metal ions. The analysis also indicated that the Cr(VI) bound to the biomass was reduced to Cr(III).

Biosorption of Chromium(VI) Ions by Deposits Produced from Chicken Feathers after Soluble Keratin Extraction

Keratin biosorbents were prepared by reprocessing the deposits produced from chicken feathers after soluble keratin extraction. Biosorption of Cr(VI) ions onto the obtained biosorbents from aqueous solution was studied. Experimental factors affecting biosorption process such as pH and initial concentration of Cr(VI) ions were investigated. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models were used to describe the biosorption process for Cr(VI) ions. The results showed that Langmuir model better fit the experimental data than the Freundlich and D–R models, and the maximum monolayer biosorption capacity for Cr(VI) ions was found to be 21.35 mg/g at pH 6, 200 mg/L initial concentration of Cr(VI) ions and 30°C. The free energy was calculated as 11.35 kJ/mol from the D–R model, indicating that the biosorption of Cr(VI) occurred chemically. This result was also confirmed by scanning electron microscopy and Fourier transform infrared regarding the changes in morphology and surface structure of the biosorbents before and after Cr(VI) biosorption. Overall, the deposits generated from chicken feathers after soluble keratin extraction, which currently treated as wastes, should be regarded as a favorable alternative for the removal of Cr(VI) ions from aqueous solution.

Chromium(VI) Biosorption and Bioaccumulation by Live and Acid-Modified Biomass of a Novel Morganella morganii Isolate

Conventional methods of chromium removal are often insufficient for the remediation of chromium-contaminated natural environments, necessitating the development of alternative strategies. In this paper, we report the isolation of a novel Morganella morganii strain capable of reducing hexavalent chromium to its less-toxic and less-soluble trivalent form. Cr(VI) reduction by this strain was evaluated in both acidic environments and conditions reflecting natural freshwater sources. The isolate achieved equilibrium within 3 h and displayed a specific uptake rate of 24.30 ± 1.67 mg Cr(VI)/g biomass following HCl treatment. Without acid treatment, a reduction of over 90% was recorded within 72 h for an initial Cr(VI) concentration 20 mg/L, corresponding to a Cr(VI) removal capacity of 19.36 ± 1.89 mg/g. Absorption data of acid-treated STB5 biomass most closely followed the Toth and Langmuir models. FTIR results indicate that hydroxyl groups and extracellular or cell membrane polysaccharides may be potential adsorption sites for hexavalent chromium. Our results suggest that the isolate may be used in situ for treatment of polluted freshwater environments.