Effect of chemical treatment on the acute toxicity of two commercial textile dye carriers


Arslan-Alaton I. , Iskender G., OZERKAN B., Babuna F. F. , Okay O. S.

WATER SCIENCE AND TECHNOLOGY, vol.55, no.10, pp.253-260, 2007 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 55 Issue: 10
  • Publication Date: 2007
  • Doi Number: 10.2166/wst.2007.329
  • Title of Journal : WATER SCIENCE AND TECHNOLOGY
  • Page Numbers: pp.253-260

Abstract

In the present experimental study, the effect of chemical treatment (coagulation-flocculation) on the acute toxicity exerted by two commercial dye carriers (called Carrier A and B herein) often used in the textile industry was investigated. Two different test organisms were selected to elucidate the situations in activated sludge treatment systems (activated sludge microorganisms) as well as in receiving water bodies (ultimate marine discharge). According to the results of a comprehensive analysis covering COD removal efficiencies, sludge settling characteristics and operating costs involved in coagulation-flocculation, the optimum treatment conditions were defined as follows; application of 750 mg/L ferrous sulphate at a pH of 9.0 for Carrier A; and application of 550 mg/L ferrous sulphate at a pH of 9.0 for Carrier B. The acute toxicities of both dye carriers towards marine microalgea Phaeodactylum tricornutum could be reduced significantly after being subjected to coagulation -flocculation. Fair toxicity removals (towards heterotrophic mixed bacterial culture accommodated in activated sludge treatment) were obtained with coagulation-flocculation for both of the carriers under investigation.