title: Relative performance of biofilm configuration over suspended growth operation on azo dye based wastewater treatment in periodic discontinuous batch mode operation.
abstract: Functional role of biofilm and suspended growth bioreactor configurations in response to the treatment of azo-dye (C.I. Acid Black 10B) bearing wastewater was evaluated in periodic discontinuous batch mode operation at varying dye concentrations. The biofilm system depicted higher dye removal efficiency (93.14%) compared to suspended mode (84.29%) at 350 mg dye/l operation. Both the reactor configurations did not show much process inhibition at higher dye loads studied. Azo reductase and dehydrogenase enzyme activities showed significant variation indicating the different metabolic capabilities of the native-microflora, stable proton shuttling between metabolic intermediates and differences in the delivery of reducing powers from the substrate metabolism towards dye removal. Voltammograms visualized marked variations in electron discharge properties with the function of reactor configuration, time intervals and dye load. Higher redox catalytic currents, lower Tafel slopes and polarization resistance showed good correlation with enzyme activities and dye removal.
authors.affiliation: Academy of Scientific and Innovative Research, India; Bioengineering and Environmental Centre (BEEC), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India. Electronic address: vmohan_s@yahoo.com.
authors.forename: S
authors.initials: S
authors.lastname: Venkata Mohan
authors.affiliation: Academy of Scientific and Innovative Research, India; Bioengineering and Environmental Centre (BEEC), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.
authors.forename: C
authors.initials: C
authors.lastname: Nagendranatha Reddy
authors.affiliation: Bioengineering and Environmental Centre (BEEC), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.
authors.forename: A
authors.initials: A
authors.lastname: Naresh Kumar
authors.affiliation: Bioengineering and Environmental Centre (BEEC), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.
authors.forename: J
authors.initials: J
authors.lastname: Annie Modestra
mesh_terms: D001391:Azo Compounds / Q000302:isolation & purification* / Q000378:metabolism; D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002384:Catalysis; D004396:Coloring Agents / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D010084:Oxidation-Reduction; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Azo reductase; Cyclic voltammetry (CV); Periodic discontinuous batch reactors (PDBR); Sequencing batch reactor (SBR); Toxicity