Effect of photochemical treatment on the biocompatibility of a commercial nonionic surfactant used in the textile industry


Arslan-Alaton I. , ERDINC E.

WATER RESEARCH, vol.40, no.18, pp.3409-3418, 2006 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 18
  • Publication Date: 2006
  • Doi Number: 10.1016/j.watres.2006.07.014
  • Title of Journal : WATER RESEARCH
  • Page Numbers: pp.3409-3418

Abstract

The degradability of surfactants is a frequent and complex issue arising both at domestic as well as industrial treatment facilities. The present paper describes a laboratory study conducted to elucidate the photochemical and biochemical treatability of a nonionic, alkyl polyethylene ether-based surfactant formulation commonly used in the textile preparation stage. The application of H2O2/UV-C advanced photochemical oxidation appeared to be a suitable treatment alternative and 90% COD removal (COD0 approximate to 500 mg/L) could be achieved under optimized process conditions. A significant COD removal efficiency (74%) could also be reached after biodegradation (final COD = 135 mg/L) of the surfactant; however, necessitated an acclimation period of at least 6 weeks for the achievement of steady-state conditions. H2O2/UV-C treatment efficiency was seriously retarded upon elevation of the initial COD to around 1000mg/L, resulting in 46% COD and 38% TOC removal after 120min photochemical oxidation (H2O2,0 = 1020mg/L; pH(0) = 9.1). The BOD5/COD ratio increased from 0.23 to 0.31 after the application of H2O2/UV-C revealing that photochemical pretreatment may have a positive effect on the ultimate biodegradation of the nonionic surfactant. Although the time required for activated sludge treatment to reach steady-state conditions could be reduced to 3 weeks for the photochemically pretreated surfactant formulation biochemical COD removal efficiency dramatically decreased from 74% to 39% for the nonionic surfactant being subjected to H2O2/LTV-C pretreatment (ultimate COD after activated sludge treatment = 265 mg/L). (c) 2006 Elsevier Ltd. All rights reserved.