The effluents from tanning industries in and around Palar river basin are the major cause of Cr (III) pollution. Forty-five chromium (III) tolerant bacterial strains were isolated from the Palar river basin. Bacillus subtilis VITSCCr01 showed tolerance up to 1500. mg/l and its Cr (III) bioremoval capacity was 64%. Increasing the concentration of Cr (III) increased exopolysaccharide (EPS) production by the bacteria. FT-IR spectral studies confirmed the presence of polysaccharides in the Cr (III) treated bacteria. Adaptation of Bacillus subtilis VITSCCr01 with higher Cr (III) concentration improved the bioremoval capacity to 85%. SEM-EDX showed that the adapted bacteria accumulated high concentration of chromium. Bacillus subtilis VITSCCr01 could be used as a tool for in situ removal of Cr (III) especially in the tannery polluted environment. © 2011 Elsevier B.V.

Sundar S

Department of Embedded Technology

School of Electronics Engineering

Vellore Campus

Chandra Sekaran N

Centre for Nanobiotechnology

Amitava Mukherjee

Sadiq M

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Journal of Hazardous Materials

Cadmium is one of the toxic heavy metals which tend to accumulate in the biome posing threat to the living system. The present study investigated the cadmium removal efficiency by effective cadmium-resistant isolate in a novel dual-chambered horizontal continuous-flow bioreactor. Cadmium-resistant bacterial isolates were obtained from sewage effluent samples and were tested for their maximum tolerable concentration. The isolate VITKKAJ1 was found to be highly resistant to cadmium and exhibited high degree of biofilm formation. The capability of VITKKAJ1 in producing short-chain quorum-sensing molecules (acyl-homoserine lactone) was significantly correlated with the increased production of exopolysaccharides. Substrates such as gravels and alginate beads were packed in the perforated compartments of the bioreactor with a bed height of 15 cm for the adsorption of cadmium. The percentage removal of cadmium with and without biofilm (substrates) was 90.56 and 70.7%, respectively. The phylogenetic analysis based on 16S rRNA sequencing indicated the isolate to be a representative of Aeromonas diversa (Acc. No. KU560509). © 2017, Islamic Azad University (IAU).

International Journal of Environmental Science and Technology

Bioremoval of cadmium using a dual-chambered fluidized bed bioreactor: a biofilm-based approach

The removal of Cr(VI) by the biomass of Acinetobacter junii immobilized on coconut fiber in batch and continuous systems were investigated. For batch system under optimized conditions (pH 2; contact time, 480 min; 30 °C; initial Cr(VI) concentration of 50 mg/L), an adsorption capacity of 17.4 mg/g was recorded. In continuous packed bed column reactors, a capacity of 39.4 mg/g was noted with a bed height of 18 cm, a flow rate of 5 mL/min, an initial Cr(VI) concentration of 50 mg/L was employed. The batch sorption data followed the Langmuir isotherm and pseudo first order kinetics. Adsorption studies using Cr(VI) spiked freshwater, ground water and domestic wastewater in a continuous packed bed column reactors demonstrated Cr(VI) removals of 29.3, 43.6, 37.3, 25 %, respectively.

Fulltext

Asian Journal of Chemistry

Adsorptive Removal of Cr(VI) by Acinetobacter junii VITSUKMW3 Immobilized on Coconut Fiber in Batch and Continuous Flow Reactor

The adsorptive removal of Cr(VI) by alginate beads containing Cr(VI)-adapted Acinetobacter junii, Escherichia coli and Bacillus subtilis in batch and continuous packed bed column reactors was investigated. Under optimized conditions (pH 3.0; contact time, 180. min; 30°C; initial Cr(VI) concentration of 100. mg/L), 65.86. mg/g adsorption capacity was recorded in the batch study. When an adsorbent dosage of 1. g/L, a flow rate of 5. mL/min, a bed height of 20. cm, an initial Cr(VI) concentration of 300. mg/L was employed, a capacity of 657. mg/g was noted for the continuous column assay. The batch sorption data followed the Langmuir isotherm and pseudo second order kinetics. Five sorption/desorption cycles yielded 100%, 99.63%, 95.31%, 80.7% and 74.22% regeneration, respectively. Cr(VI) adsorption studies using spiked ground water, freshwater and domestic wastewater in a packed bed reactor demonstrated Cr(VI) removals of 64.8%, 55.08%, 56.86% respectively. Cr(VI) sorption on immobilized bacteria was confirmed with Fourier-transform infrared and Energy dispersive X-ray spectroscopy.

Bioresource Technology

Batch and continuous flow studies of adsorptive removal of Cr(VI) by adapted bacterial consortia immobilized in alginate beads

Chrome mining activity has contributed intensively towards pollution of hexavalent chromium around Sukinda Valley, Orissa, India. In an attempt to study the specific contribution of exopolysaccharides (EPS) extracted from indigenous isolates towards Cr(VI) reduction, three chromium (VI) tolerant strains were isolated from the effluent mining sludge. Based on the tolerance towards Cr(VI) and EPS production capacity, one of them was selected for further work. The taxonomic identity of the selected strain was confirmed to be Enterobactercloacae (showing 98% similarity in BLAST search to E. cloacae) through 16S rRNA analysis. The EPS production was observed to increase with increasing Cr(VI) concentration in the growth medium, highest being 0. 078 at 100 mg/l Cr(VI). The extracted EPS from Enterobactercloacae SUKCr1D was able to reduce 31. 7% of Cr(VI) at 10 mg/l concentration, which was relevant to the prevailing natural concentrations at Sukinda mine effluent sludge. The FT-IR spectral studies confirmed the surface chemical interactions of hexavalent chromium with EPS. © 2011 Springer Science+Business Media B.V.

Biodegradation

Bio-reduction of Cr(VI) by exopolysaccharides (EPS) from indigenous bacterial species of Sukinda chromite mine, India

The current study focuses on the quantification and mechanistics of Cr(VI) biosorption with Acinetobacter junii, indigenous bacteria isolated from chromite mine sites of Sukinda valley, Orissa, India. The equilibrium sorption capacity 22.22, 13.88, 6.94mg of Cr(VI)g -1 of biomass was obtained for logarithmic phase, stationary phase and heat killed biomass respectively at optimum sorption conditions (pH: 2.0, contact time: 120min, temperature: 27°C, initial Cr(VI) concentration: 100mgL -1, biosorbent dosage: 2gL -1). The Langmuir isotherm model and pseudo first order (Lagergren kinetic model) were observed to hold good for the bio-sorbents. Three subsequent sorption/desorption cycles yielded 54.9, 38.4 and 34.5% regeneration of the biosorbent indicating an irreversible chromium(VI) binding property of the sorbent system. The mechanistic aspects of sorption by heat killed and log phase biomass were compared using FTIR and SEM techniques. The number of binding sites on biomass surface measured by acid/base titration (215μmolg -1 and 99μmolg -1 for logarithmic phase and heat killed biomass respectively) corroborated with the observations made by batch sorption studies. Detailed surface characterization studied through FT-IR, SEM, EDX and zeta potential measurement provided evidence for sorption through oxyanionic binding to the cell surface. The EPR spectroscopy revealed the reduction of Cr(VI) to Cr(V) on the biomass surface upon Cr(VI) sorption. © 2012 Elsevier B.V.

Chemical Engineering Journal

Comparative kinetics, equilibrium, thermodynamic and mechanistic studies on biosorption of hexavalent chromium by live and heat killed biomass of Acinetobacter junii VITSUKMW2, an indigenous chromite mine isolate

Evaluation of chromium(VI) removal behaviour by two isolates of Synechocystis sp. in terms of exopolysaccharide (EPS) production and monomer composition

Effects of some organic pollutants on the exopolysaccharides (EPSs) produced by some Pseudomonas spp. strains

Microporous and Mesoporous Materials

Zeolites as supports for the biorecovery of hexavalent and trivalent chromium

Biosorption of simulated dyed effluents by inactivated fungal biomasses

Biosorption of Pb(II) and Cr(III) from aqueous solution by lichen (Parmelina tiliaceae) biomass

Cr (III) bioremoval capacities of indigenous and adapted bacterial strains from Palar river basin

Journal	Data powered by TypesetJournal of Hazardous Materials
Publisher	Data powered by TypesetElsevier BV
ISSN	0304-3894
Open Access	0