title: Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology.
abstract: The integrated chemical-biological degradation combining advanced oxidation by UV/H(2)O(2) followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mgH(2)O(2)/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required.
authors.affiliation: Advanced Wastewater Management Centre, The University of Queensland, Qld 4072, Australia.
authors.forename: Gatut
authors.initials: G
authors.lastname: Sudarjanto
authors.forename: Beatrice
authors.initials: B
authors.lastname: Keller-Lehmann
authors.forename: Jurg
authors.initials: J
authors.lastname: Keller
mesh_terms: D001391:Azo Compounds / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000302:isolation & purification / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007220:Industrial Waste; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D013783:Textile Industry; D013997:Time Factors; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D010100:Oxygen