title: Biocalalyst effects of immobilized anthraquinone on the anaerobic reduction of azo dyes by the salt-tolerant bacteria.
abstract: The accelerating effect of dissolved redox mediators has been studied in details in the bio-decolorization processes, but there are little literatures about the non-dissolved redox mediators. Here we describe the accelerating effect of anthraquinone as a redox mediator in the bio-decolorization. Decolorization of azo dyes was carried out experimentally using the salt-tolerant bacteria under immobilized anthraquinone and high salt conditions. Anthraquinone as a redox mediator was able to increase the decolorization rate of azo dyes, and was immobilized by entrapment in calcium alginate (CA), Polyvinyl alcohol (PVA)-H(3)BO(3) and agar, respectively. The effects of various operating conditions such as anthraquinone bead number, dissolved oxygen, temperature and pH on microbial decolorization were investigated experimentally. The reusability of the anthraquinone immobilization beads was evaluated with repeated-batch decolorization experiments. After four repeated experiments, the decolorization rate of CA immobilized anthraquinone retained over 90% of their original value. The experiments explored a great improvement of the redox mediator application and the new bio-treatment concept.
authors.affiliation: School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116023, PR China. jianbguo@yahoo.com.cn
authors.forename: Jianbo
authors.initials: J
authors.lastname: Guo
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Cunping
authors.initials: C
authors.lastname: Tian
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Salah Uddin
authors.forename: Hui
authors.initials: H
authors.lastname: Yu
mesh_terms: D000464:Alginates; D000880:Anthraquinones / Q000737:chemistry*; D001391:Azo Compounds / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002384:Catalysis; D004396:Coloring Agents / Q000378:metabolism*; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006863:Hydrogen-Ion Concentration; D008863:Microspheres; D010084:Oxidation-Reduction; D012965:Sodium Chloride / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D000464:Alginates; D000880:Anthraquinones; D001391:Azo Compounds; D004396:Coloring Agents; D006603:Hexuronic Acids; D012965:Sodium Chloride; D020723:Glucuronic Acid