Biosorption Of Chromium Research Articles

Efficient removal of hexavalent chromium from aqueous solutions using autohydrolyzed Scots Pine (Pinus Sylvestris) sawdust as adsorbent

In this work, a low-cost lignocellulosic adsorbent with high biosorption capacity is proposed, suitable for the efficient removal of hexavalent chromium from water and wastewater media. The adsorbent was produced by autohydrolyzing Scots Pine (Pinus Sylvestris) sawdust. The effect of the autohydrolysis conditions, i.e., pretreatment time and temperature, on hexavalent chromium biosorption was investigated using energy-dispersive X-ray spectroscopy (EDS) and UV–visible spectrophotometry. The Freundlich, Langmuir, Sips, Radke-Prausnitz, Modified Radke-Prausnitz, Toth, UNILAN, Temkin and Dubinin-Radushkevich adsorption capacities and the rate constant values for pseudo-first- and pseudo-second-order kinetics indicated that the autohydrolyzed material exhibits significantly enhanced hexavalent chromium adsorption properties comparing with the untreated sawdust. The Freundlich’s adsorption capacity K F increased from 2.276 to 8.928 (mg g−1)(L mg−1)1/n , and the amount of hexavalent chromium adsorbed at saturation (Langmuir constant q m) increased from 87.4 to 345.9 mg g−1, indicating that autohydrolysis treatment at 240 °C for 50 min optimizes the adsorption behavior of the lignocellulosic material.

Chromium (VI) biosorption properties of multiple resistant bacteria isolated from industrial sewerage

Chromium (VI) [Cr (VI)] biosorption by four resistant autochthonous bacterial strains was investigated to determine their potential for use in sustainable marine water-pollution control. Maximum exchange between Cr (VI) ions and protons on the cells surfaces were at 30-35°C, pH 2.0 and 350-450mg/L. The bacterial strains effectively removed 79.0-90.5% Cr (VI) ions from solution. Furthermore, 85.3-93.0% of Cr (VI) ions were regenerated from the biomasses, and 83.4-91.7% of the metal was adsorbed when the biomasses was reused. Langmuir isotherm performed better than Freundlich isotherm, depicting that Cr (VI) affinity was in the sequence Rhodococcus sp. AL03Ni > Burkholderia cepacia AL96Co > Corynebacterium kutscheri FL108Hg > Pseudomonas aeruginosa CA207Ni. Biosorption isotherms confirmed that Rhodococcus sp. AL03Ni was a better biosorbent with a maximum uptake of 107.46mg of Cr (VI) per g (dry weight) of biomass. The results highlight the high potential of the organisms for bacteria-based detoxification of Cr (VI) via biosorption.

Biosorption and removal of chromium from water by using moringa seed cake (Moringa oleifera Lam.)

This study evaluated the adsorption capacity of chromium from contaminated aqueous solutions by using Moringa oleifera Lam. seeds. Parameters such as solution pH, adsorbent mass, contact time between solution and adsorbent, isotherms, thermodynamic, kinetics, and desorption were evaluated. The maximum adsorption capacity (Qm) calculated to be 3.191 mg g-1 for the biosorbent. Activated carbon was used for comparison purposes in addition to the biosorbent. The best fit was obtained by the Langmuir model for both adsorbents. The average desorption value indicated that both the biosorbent and activated carbon have a strong interaction with the metal. The results showed that the biosorbent has advantages owing to its low cost and efficiency in Cr3+ removal from contaminated waters.

Biosorptional studies on heavy metals in an up-flow packed bed reactor using biomaterials

Biosorption of copper, chromium, lead and cadmium in an up-flow packed-bed bioreactor with biosorbents [sanitary sewage sludge (SS), powdered coconut shell (PCS)] was conducted in a search for solutions to the environmental problem caused by heavy metals. Analysis of the results, demonstrated that the adsorbent had an extraordinary capacity for biosorption of the heavy metals, with a removal percentage of over 90% almost for all metals. The mechanism of the process was evaluated by FT-IR analysis and the functional groups employed in the process were determined. The presence of RNO2 peak at 1,421 cm–1 for unloaded sanitary SS and the presence of C-H group of aromatic ring for unloaded PCS play a major role in adsorption process. In regeneration experiments, increase in sorption performance was observed during cycles of sorption-desorption indicates a maximum adsorption during the onset of the process. Kinetic models (Adams-Bohart model, Yoon and Nelson equation and Thomas model) analysed for the continuous packed-bed biosorption systems are used to determine the biosorption capacity, breakthrough curve of biosorbent and to design of treatment processes.

Biosorption of hexavalent chromium from aqueous solution by six brown macroalgae

The biosorption potential of six brown macroalgae viz. Nizamuddina zanardinii, Stoechospermum marginatum, Cystoseira indica, Dictyota cervicornis, Padina australis, and Sargassum glaucescens, for the removal of hexavalent chromium (Cr(VI)) was investigated in the present study. Optimum conditions were determined by studying the effect of initial solution pH, biomass dosage, initial Cr(VI) concentration, and contact time on Cr(VI) removal by the macroalgae. Cr(VI) sorption was found to be highly pH dependent and maximum sorption was obtained at pH 1.0. Freundlich isotherm model showed the best fit with the equilibrium data. The removal rate of Cr(VI) was relatively rapid during the first 30 min, although the rate decreased gradually and the sorption reached equilibrium in about 70 min for S. marginatum, 90 min for N. zanardinii, and 150 min for D. cervicornis, P. australis, S. glaucescens, and C. indica. Different kinetic models such as pseudo-first-order, pseudo-second-order, and intra-particle diffusion model were tested, and the experimental data was in agreement with the pseudo-second-order model. The results of the present study suggest that brown macroalgae could be used as effective biosorbents for Cr(VI) removal from aqueous solution.

Hexavalent Chromium (Cr (VI)) Removal by Live Mycelium of a <i>Trichoderma harzianum</i> Strain

Response of Trichoderma harzianum strain to different chromium concentrations was investigated by poison food technique. It was noticed that, the mycelial growth was inhibited up to 94 % at 40 mg/L concentration followed by 30 mg/L (91%).The chromium (VI) biosorption ability of Trichoderma harzianum was tested in vitro . The organism was inoculated on Czapek Dox broth medium containing 30 mg/L of Cr (VI) salt. The metal residues were analyzed at different day's interval (4, 5, 6 and 7 days). The effect of different pH and temperature on metal removal was also investigated. Results indicated that, at 7 th day the metal removal reached the maximum level (90.2%). Further incubation did not increase the metal uptake. A pH range of 4~5 and temperature of 30℃ was optimum for Cr (VI) removal by T. harzianum in the present study.

Biossorção passiva de cromo (VI) através da microalga Spirulina platensis

Effluents containing toxic metals are dangerous and more economical, efficient and environmentally friendly treatments must be studied, with the biosorption process with microbial biomass constituting an efficient solution. Thus, the ability of Spirulina platensis biomass for removing chromium (VI) using passive and active biosorption was evaluated. Inactive microalgae biomass and synthetic solution containing chromium (VI) were used to evaluate important factors in the process and biomass biosorption ability. Results of the experiments showed that microalgae have potential for biosorption of chromium (VI), attaining removal of 100.39 mg g-1, and that pH was the variable with the greatest influence on the process.

Comparative Study of Chromium Biosorption by Mesorhizobium amorphae Strain CCNWGS0123 in Single and Binary Mixtures

The appearance of chromium in the aqueous effluent is a major concern for the modern industry. In this work, Mesorhizobium amorphae strain CCNWGS0123 was investigated as a biosorbent to remove chromium from aqueous solutions. The optimum pH for Cr(III) and Cr(VI) biosorption were 4 and 2, respectively. This isolate showed an experimental maximum Cr(III) adsorption capacity of 53.52 mg L(-1), while the result was 47.67 mg L(-1) for Cr(VI), with an initial 100 mg L(-1) Cr ions and 1.0 g L(-1) biomass. In terms of time equilibrium, Cr(III) ion was more readily adsorbed than Cr(VI) by this isolate. The biosorption data of both ions fit the Langmuir isotherm better than that of Freundlich model. Meanwhile, this organism exhibited a good capability to release Cr ions, with desorption efficiency of 70 % for Cr(III) and 76 % for Cr(VI). Fourier transform infrared spectroscopy analysis showed that -OH, -COO, -NH, amide I, and C=O were involved in Cr(III) and Cr(VI) binding. The biosorbent was further characterized by scanning electron microscopy and energy-dispersive X-ray spectrometry, which indicated an accumulation of chromium on the cellular level. In the binary mixtures, the removal ratio of total Cr and Cr(III) increased from pH 2 to 4. The highest removal ratio of the total Cr was observed in the 25/25 mg L(-1) mixture at pH 4. In addition, the removal efficiency of Cr(VI) was closely influenced by Cr(III) in the mixture, decreasing to 23.57 mg g(-1) in the 100/100 mg L(-1) mixture system, due to the competition of Cr(III). The potential usage of the chromium-resistant rhizobium for the remediation of chromium-contaminated effluents has been demonstrated based on the above results.

Entrapment of marine microalga, Isochrysis galbana, for biosorption of Cr(III) from aqueous solution: isotherms and spectroscopic characterization

Microalga, Isochrysis galbana, biomass was entrapped into alginate gel by liquid curing method in the presence of Ca(II) ions. The biosorption of chromium(III) by the entrapped live algal biomass was studied in a batch system. The effect of initial cadmium concentration, pH, temperature and liquid and solid ratio on Cr(III) removal was investigated. The maximum experimental biosorption capacities for entrapped live algal biomass were found to be 335.27 mg Cr(III) g−1 of dry algal biomass. The kinetics of chromium biosorption was slow; approximately 75 % of biosorption took place in 2 h. The percent adsorption increased with increase in pH; pH 5 of the solution was found to favor adsorption very strongly. The equilibrium biosorption data were evaluated by Langmuir and Freundlich isotherm models, and was best described by Langmuir and Freundlich isotherms. The biosorbent was characterized and evaluated, the functional groups –OH, –COOH and C=O were involved in the biosorption process. Since binding capacity was relatively high for immobilized live algal biomass, those algal forms are to be considered as suitable biosorbent for the removal of chromium in wastewater treatment.

Improved biosorption for Cr(VI) reduction and removal by Arthrobacter viscosus using zeolite

The aim of the present work was to optimize the reduction and removal of chromium from aqueous solutions by a biosorption system consisting of a bacteria supported on a zeolite. The system proposed combines the biosorption properties of Arthrobacter viscosus, with the ion exchange capacity of NaY zeolite. Experiments were also performed without the zeolite for comparison purposes. Experimental parameters such as solution pH, biomass concentration and initial Cr(VI) concentration were investigated in order to assess their influence on the biosorption system. The results revealed that chromium biosorption was highly pH dependent. The lower pH values favored Cr(VI) reduction, while higher solution pH enhanced total chromium removal. After the optimization of the parameters in study, the highest content of chromium in the zeolite (0.9%) and best uptake (13.0 mgCr/gzeolite) were obtained for the experiment at pH 4, biomass concentration of 5 g L−1 and initial Cr(VI) concentration of 100 mg L−1. After the biosorption process, the samples were characterized by chemical analyses (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The XPS spectra of bacteria revealed that the chromium loaded on the biomass surface was in the trivalent form.

Chromium (VI) biosorption and removal of chemical oxygen demand by Spirulina platensis from wastewater-supplemented culture medium

The inappropriate discharge of wastewater containing high concentrations of toxic metals is a serious threat to the environment. Given that the microalga Spirulina platensis has demonstrated a capacity for chromium VI (Cr (VI) biosorption, we assessed the ideal concentration of chromium-containing wastewater required for maximum removal of Cr (VI) and chemical oxygen demand (COD) from the environment by using this microalga. The Paracas and Leb-52 strains of S. platensis, with initial wastewater concentrations of 0%, 12.5%, 25%, and 50%, were cultured in Zarrouk medium diluted to 50% under controlled air, temperature, and lighting conditions. The cultures were maintained for 28 days, and pH, biomass growth, COD, and Cr (VI) were assessed. The wastewater concentration influenced microalgal growth, especially at high concentrations. Removal of 82.19% COD and 60.92% Cr (VI) was obtained, but the COD removal was greater than the Cr (VI) removal in both strains of S. platensis.

Biosorption of Co(II), Cr(III), Cd(II), and Pb(II) Ions from Aqueous Solution Using Nonliving Neochloris Pseudoalveolaris Deason & Bold: Equilibrium, Thermodynamic, and Kinetic Study

In this study, biosorption of cobalt(II), chromium(III), cadmium(II), and lead(II) ions from aqueous solution was studied using the algae nonliving biomass (Neochloris pseudoalveolaris, Np) as natural and biological sorbents. The effect of pH, contact time, temperature, and metal concentration on the adsorption capacity of metal ions was investigated. The maximum adsorption capacities for Co(II), Cr(II), Cd(II), and Pb(II) were found to be 20.1, 9.73, 51.4 and 96.2 mg/g at the optimum conditions, respectively. The experiments showed that when pH increased, an increase in the adsorption capacity of the biomass was observed too. The kinetic results of adsorption obeyed a pseudo second-order model. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data of metal ions adsorption and the value of R L for Pb(II), Cb,(II), Co(II), and Cr(III) was found to be 0.376, 0271, 0872, and 096, respectively. The thermodynamic parameters related to the adsorption process such as E a , ΔG 0, ΔH 0, and ΔS 0 were calculated. ΔH 0 values (positive) showed that the adsorption mechanism was endothermic. Weber-Morris and Urano-Tachikawa diffusion models were also applied to experimental equilibrium data. The algae biomass was effectively used as a sorbent for the removal of metal ions from aqueous solutions.

Use of ground crawfish shells for the removal of chromium in solution

Crawfish shells are an abundant waste product that has the potential to remediate contaminated bodies of water. This study demonstrates that ground crawfish shell could be used as an effective biosorbent material for the treatment of chromium in contaminated aqueous solutions. Phase I experiments determined that the adsorption was completed within 2h. For the time periods examined it could be concluded that the maximum chromium adsorption occurs within the first 2h. Phase II experiments demonstrated that chromium adsorption increased with sample volume and concentration, however the efficiency decreased with increasing sample volume for the relative high concentrations of chromium. Phase III experiments showed that chitin is a major constituent for biosorption of chromium and likely other metals in crustacean species including crawfish. Salinity experiments showed that salt (sodium chloride) at the 30ppt (parts per thousand) concentrations does not affect the crawfish shell ability to adsorb chromium. The pH was the most important factor for chromium adsorption by the crawfish powder. Chromium adsorption increased with increasing pH. The presence of lead ions did not significantly interfere with the adsorption of chromium ions onto the crawfish shell powder for the relatively high concentrations examined. However, for relatively low concentrations the chromium adsorption was somewhat suppressed by the lead ions.

Insights into trivalent chromium biosorption onto protonated brown algae Pelvetia canaliculata: Distribution of chromium ionic species on the binding sites

In the present study, biosorption of trivalent chromium by protonated brown algae, Pelvetia canaliculata, was studied in batch system. FTIR analyses provided information about the possible binding groups present in the algae, as carboxylic, hydroxyl and sulfonate groups. Potentiometric acid–base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl ones, following the Quasi-Gaussian affinity constant distribution suggested by Sips, which allowed to estimate the maximum amount of acidic functional groups (2.26±0.02mmolg−1) and proton binding parameters (pKH′=3.18±0.01;mH=0.78±0.03) for an ionic strength of 0.2M. The trivalent chromium removal was found to increase with pH and the maximum chromium uptake was observed at pH 4.0 (∼0.6mmol/g), corresponding to 1.34meq/g, since at that pH, 25.8% of total chromium is in the Cr3+ form and 72.7% as CrOH2+. An equilibrium model incorporating the hydrolysis reactions that chromium undergoes in the aqueous phase was able to predict the chromium biosorption at different pH values and chromium concentrations, enabling the prediction of the distribution of chromium ionic species on the binding sites. A mass transfer model provided a good representation of the chromium biosorption kinetics, resulting in intraparticle homogeneous diffusion coefficients of 4.6×10−7cm2/s for Cr3+ and 1.8×10−8cm2/s for CrOH2+. The distribution of chromium ionic species in the solution and on the binding sites was also predicted by the kinetic model.

REMOVAL OF HEXAVALENT CHROMIUM FROM AQUEOUS MEDIA USING MEDITERRANEAN POSIDONIA OCEANICA BIOMASS: ADSORPTION STUDIES AND SALT COMPETITION INVESTIGATION

The biosorption of hexavelent chromium from saline solutions by Posidonia oceanica, a marinebiomass, was studied as a function of pH, initial chromium (VI) and salt (NaCl) concentrations in batchsystem. The sorbent exhibited the maximal chromium (VI) uptake at pH 2 regardless of the presence ofincreasing salt concentration. Equilibrium uptake increased with chromium (VI) concentration up to 250 mg/l and decreased slightly in the presence of increasing salt concentrations of salt up to 50 g/l. The biomassadsorbed 14.48 mg of metal per gram of biomass at 100 mg/l initial chromium concentration in the absence ofsalt. When 50 g/l salt concentration was added to the solution, the value diminished to 11.49 mg/g under thesame conditions (i.e. a 20.6% decrease in the biosorption capacity). The equilibrium sorption data wereanalyzed using Freundlich, Langmuir and Redlich-Peterson models. The Langmuir equation was the mostsuitable adsorption model for describing the biosorption equilibrium data of chromium (VI) both in salt freeand loaded media. The pseudo-second-order type kinetic model depicted the biosorption kinetics accuratelyat all chromium concentrations in absence and presence of increasing concentrations of salt.

Improvement of chromium biosorption through protoplast electrofusion between Candida tropicalis and Candida lipolytica

Protoplasts from Candida tropicalis and Candida lipolytica were fused under an optimized electrofusion (electrical pulse strength 6 kV/cm, pulse duration time 40 μs and pulse times 5) and then regenerated on YEPD media for achieving new genotypes with higher chromium loading capacity. A target fusant RHJ-004 was screened out by its chromium resistance and chromium-sorbing capacity tests for further research. The comparative study of applicability shows that the fusant has better performance than its parent strains in respect of solution pH, biomass concentration and chromium loading capacity. Especially for treating low concentration Cr(VI) (≤20 mg/L), above 80% chromium is sequestered from the aqueous phase at pH 1–9. Atomic force microscopy (AFM) visualizes the distribution of chromium on the binding sites of the cells, suggesting that the altered surface structure and intracellular constitutes of the fusant associate with its increased biosorption capacity. The rapid biosorption processes of chromium follow the Langmuir model well.

Dynamic of soil microbial-community: Terminal restriction fragment length polymorphism analysis on natural secondary succession of Pinus tabulaeformis Carr. in the forest region of Loess Plateau, China

Optimization of a chromium biosorption process was performed by varying three independent variables pH (0.5 to 3.5), initial chromium ion concentration (10 to 30 mg/L), and Yarrowia lipolytica dosage (2 to 4 g/L) using a Doehlert experimental design (DD) involving response surface methodology (RSM). For the maximum biosorption of chromium ion in an aqueous solution by Y. lipolytica , a total of fifteen experimental runs were set and the experimental data fitted to the empirical second-order polynomial model of a suitable degree. The analysis of variance of the quadratic model demonstrates that the model was highly significant. The model showed that chromium uptake in aqueous solution was affected by all the three variables studied. The optimum values of the variables were found to be 2.07, 18.76 mg/L and 3.39 g/L for pH, initial chromium ion concentration and biomass dosage, respectively at contact time of 30 min. At these optimal conditions, the maximum percentage biosorption of chromium was predicted to be 41.59. The experimental values were in good agreement with predicted values and the correlation coefficient was found to be 0.9891. Therefore, it is apparent that the DD involving RSM not only gives valuable information on interactions between the variables but also leads to identification of feasible optimum values of the studied variables. Keywords: Biosorption, Doehlert experimental design, response surface methodology, Yarrowia lipolytica African Journal of Biotechnology , Vol 13(12), 1413-1422

Hexavalent chromium removal from aqueous solutions by using low-cost biological wastes: equilibrium and kinetic studies

The batch removal of hexavalent chromium from aqueous solutions using almond shell, activated sawdust, and activated carbon, which are low-cost biological wastes under different experimental conditions, was investigated in this study. The influences of initial concentration, adsorbent dose, adsorbent particle size, agitation speed, temperature, contact time, and pH of solution were investigated. The adsorption was solution pH dependent and the maximum adsorption was observed at a solution pH of 2.0. The capacity of chromium adsorption under equilibrium conditions increased with the decrease in particle sizes. The equilibrium was achieved for chromium ion after 30 min. Experimental results showed that low-cost biosorbents are effective for the removal of pollutants from aqueous solution. The pseudo-second-order kinetic model gave a better fit of the experimental data as compared to the pseudo-first-order kinetic model. Experimental data showed a good fit with the Freundlich isotherm model. Changes in the thermodynamic parameters, including Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo), indicated that the biosorption of hexavalent chromium onto almond shell, activated sawdust, and activated carbon was feasible, spontaneous, and endothermic in the temperature range 28–50 °C.

Biosorption and Recovery of Chromium from Industrial Wastewaters By Using Saccharomyces cerevisiae in a Flow-Through System

This study investigated the possibility to adsorb and recycle Cr(VI) from the wastewater of a Cr-electroplating process using Saccharomyces cerevisiae in a flow-through system at a pilot scale. In a first set of experiments, it was demonstrated that an HCl pretreatment of the biomass induced a 2-fold increase in the amount of Cr(VI) removed. In the following experiments, 30 L of wastewater was treated with HCl-pretreated yeast biomass confined in a filter press, obtaining an average specific metal removal of 13 mg per g of dry biomass. At the end of the bioremoval process, the biomass was incinerated and the ashes thus obtained were composed of >90% (w/w) chromium. The results obtained at pilot scale with chromium-containing wastewaters demonstrated the good metal sorption capability of the acid-pretreated S. cerevisiae biomass and the possibility to recover, at a high purity, the metal from the biomass at the end of the treatment process.

Biosorption of chromium(VI), nickel(II) and Remazol Blue by Rhodotorula muciloginosa biomass

The passive removal of commonly used reactive dye and two heavy metals, from aqueous solutions by inexpensive biomaterial, yeast Rhodotorula muciloginosa biomass, termed biosorption, was studied with respect to pH, initial dye concentration and initial metal ion concentration. The biomass exhibited maximum dye and chromium(VI) uptake at pH 5 and pH 6 for nickel(II) in media containing 50 mg/L heavy metal and 50 mg/L remazol blue. It was found that the highest chromium(VI) removal yields measured were 31.3% for 49.0 mg/l initial chromium(VI) concentrations. The nickel(II) removal yield was 32.5% for 22.3 mg/L. Higher R. Blue removal yields were obtained, such as 77.1% for 117.5 mg/L. The maximum dye biosorption yield was investigated in medium with a constant dye (approximately 50 mg/L) and increasing heavy metal concentration. In the medium with 48.8, 103.8 and 151.8 mg/L chromium(VI) and constant dye concentration, the maximum chromium(VI) biosorption was 7.4, 9.3 and 17.1%, whereas the maximum dye biosorption was 61.6, 56.6 and 55.9%. The maximum nickel(II) biosorptions in the medium with dye were 38.1, 22.1 and 8.8% at 23.7, 37.7 and 60.1 mg/L nickel(II) concentrations. In these media, dye biosorptions were 93.9, 86.4 and 93.3%, respectively.