title: Integrated photochemical and biological treatment of a commercial textile surfactant: process optimization, process kinetics and COD fractionation.
abstract: The biodegradability of surfactants is a frequent and complex issue arising both at domestic as well as industrial treatment facilities. In the present experimental study, the integrated photochemical (H(2)O(2)/UV-C) and biochemical (activated sludge) treatment of a commercial grade nonionic/anionic textile surfactant formulation was investigated. Photochemical baseline experiments have shown that once the initial pH and H(2)O(2) dose were optimized, practically complete COD removal (COD(o)=500+/-30mgL(-1)) could be achieved. Once the COD was elevated to values being typical for the textile fabric preparation stage, treatment efficiency was seriously retarded provided that the photochemical treatment conditions remained constant. Moreover, a definite relationship existed between H(2)O(2) consumption and COD removal for H(2)O(2)/UV-C advanced oxidation of the textile surfactant. In the second part of the study, COD abatement was modeled for the biodegradation of untreated and photochemically pretreated textile surfactant formulation according to their COD fractions. Results have indicated that the readily biodegradable and rapidly hydrolysable COD fractions of the textile surfactant solution could be appreciably increased upon exposure to an optimum H(2)O(2) concentration (60mM; i.e. 2.1g H(2)O(2) (g COD(o))(-1)) and extended UV-C irradiation times (i.e. 90 and 120min).
authors.affiliation: Istanbul Technical University, Faculty of Civil Engineering, Department of Environmental Engineering, 34469 Maslak, Istanbul, Turkey. arslanid@itu.edu.tr
authors.forename: Idil
authors.initials: I
authors.lastname: Arslan-Alaton
authors.forename: Emine Ubay
authors.initials: EU
authors.lastname: Cokgor
authors.forename: Baris
authors.initials: B
authors.lastname: Koban
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism; D012722:Sewage; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D013783:Textile Industry; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects
chemical_list: D012722:Sewage; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D010100:Oxygen