title: Heavy metal removal from multicomponent system by sulfate reducing bacteria: Mechanism and cell surface characterization.
abstract: This study evaluated the combined effect of Cd(II), Cu(II), Ni(II), Fe(III), Pb(II) and Zn(II) on each other removal by anaerobic biomass under sulfate reducing condition. Statistically valid Plackett-Burman design of experiments was employed to carry out this mixture study. The results obtained showed a maximum removal of Cu(II) (98.9%), followed by Ni(II) (97%), Cd(II) (94.8%), Zn(II) (94.6%), Pb(II) (94.4%) and Fe(III) (93.9%). Analysis of variance (ANOVA) of the sulfate and chemical oxygen demand (COD) reduction revealed that the effect due to copper was highly significant (P value<0.05) on sulfate and COD removal. To establish the role of sulfate reducing bacteria (SRB) in the metal removal process, surface morphology and composition of the metal loaded biomass were analyzed by transmission electron microscopy (TEM) equipped with energy dispersive spectroscopy (EDS) and by field emission scanning electron microscopy (FESEM) integrated with energy dispersive X-ray spectroscopy (EDX). The results obtained revealed that the metal precipitates are associated with the outer and inner cell surface of the SRB as a result of the sulfide generated by SRB.
authors: Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
authors: M Gopi
authors: MG
authors: Kiran
authors: Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India. Electronic address: pakshi@iitg.ernet.in.
authors: Kannan
authors: K
authors: Pakshirajan
authors: Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
authors: Gopal
authors: G
authors: Das
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D003901:Desulfovibrio / Q000378:metabolism; D019216:Metals, Heavy / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D013431:Sulfates / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D013431:Sulfates
keywords: Anaerobic biomass; Heavy metals; Multicomponent system; Plackett–Burman design; Sulfate reducing bacteria