Toxicity evaluation of reactive dyestus, auxiliaries and selected euents in textile ®nishing industry to luminescent bacteria Vibrio ®scheri Chunxia Wang a , Ayfer Yediler b, * , Doris Lienert c , Zijian Wang a , Antonius Kettrup b,c a Research Center for Eco-Environmental Sciences, State Key Laboratory of Environmental Aquatic Chemistry, Chinese Academy of Sciences, Beijing 100085, People's Republic of China b GSF ± National Research Center for Environment and Health, Institute of Ecological Chemistry, Postfach 1129, 85758 Neuherberg, Germany c Technical University of Munich, Chair of Ecological Chemistry, 85350 Freising, Germany Received 17 April 2000; accepted 18 December 2000 Abstract The toxicity of 17 selected process euents, 11 reactive dyestus and 8 auxiliaries from a textile dyeing and ®nishing mill in Ayazaga, Istanbul, Turkey was evaluated by bioluminescence test using bacteria Vibrio ®scheri in LUMIStox 300. The EC 20 and EC 50 for auxiliaries, the EC 20 for dyestus were determined. For selected process euents GL- values, the dilution level at which a wastewater sample causes less than 20% inhibition, were examined. Our results demonstrate that the toxicity assessment with luminescent bacteria is eective and of practical use for chemicals applied in textile ®nishing industry with the limitation of the deep dark-colored dye bath samples and for the related euents. Inhibition eects of numerous dyestus as well as auxiliaries to luminescent bacteria diered considerably with a range 5±600 mg l 1 for EC 20 and 9±6930 mg l 1 for EC 50 , respectively. Among 17 euents, 1 sample exhibited high toxicity GL  100), 7 showed moderate toxicity GL  12±32), and 9 had a GL-value <10 indicating a low or no toxic- ity. Ó 2002 Elsevier Science Ltd. All rights reserved. Keywords: Bioassay; Bioluminescence test; Textile ®nishing industry euents; Dyestus; Auxiliaries 1. Introduction The textile ®nishing industry is an important con- tributor to many national economies, encompassing both small- and large-scale operations worldwide. Due to the rapid change in customers' demands textile ®n- ishing industry is challenged to use high quantities of dyestus and auxiliaries. The total amount of dyestus used e.g., in one textile mill in Istanbul, Turkey in 1997 was 143,000 kg. Additionally 677,000 kg of auxiliaries wasconsumedinthesamemillPaker,1999).Thetextile industry utilizes about 10,000 dierent dyes and pig- ments in the world Spadaro et al., 1994). Over 50% of all the dyes used in the industry are azo dyes. They contain at least one and up to four azo groups usually attachedtotworadicalsofwhichatleastonebutusually both are aromatic groups. The increased use of cotton hasadditionallyledtosubstantialgrowthintheusageof reactive dyes. Consequently, the most pressing envi- ronmental problem facing the textile industry is related Chemosphere 46 2002) 339±344 www.elsevier.com/locate/chemosphere * Corresponding author. Tel.: +49-089-3187; fax: +49-089- 3187-3371. E-mail address: yediler@gsf.de A. Yediler). 0045-6535/02/$ - see front matter Ó 2002 Elsevier Science Ltd. All rights reserved. PII:S0045-653501)00086-8