Determination of Wastewater LC of the Different Process Stages of the Textile Industry

• Published in: Ecotoxicology and environmental safety 2001-01, Vol.48 (1), p.56-61
• Main Authors: Villegas-Navarro, A, Ramirez-M, Y, Salvador, M S, Gallardo, J M
• Format: Article
• Language: English
• Subjects: Daphnia; textiles
• ISSN: 0147-6513
• DOI: 10.1006/eesa.2000.1986

Textile plants are very important sources of toxic discharges. The purpose of the research described in this paper was to use bioassays with daphnids to determine the LC sub(50) values of textile wastewater samples taken from different stages of the finishing textile industry. Toxicity due to dyeing, chlorination, and the absence of adequate physicochemical conditions for daphnid survival were considered. Wastewater samples corresponding to each process stage were collected at five finishing textile industries and assayed according to previously published procedures. The sensitivity of daphnids to chemicals was assayed using sodium dodecyl sulfate and was similar to other reports (14.6 plus or minus 6.8 vs 14.5 plus or minus 2.3 mg/L). All effluents from the five company samples were toxic in terms of LC sub(50) and exhibited very high toxicity with acute toxicity unit (ATU) levels between 2.2 and 960, indicating that the five textile industries produced toxic water. The sensory characteristics indicated that the dyes contributed to overall sample toxicity at all process stages. The most toxic contaminant seemed to be ClO super(-) at levels between 0.2 and 6.8 mg/L, suggesting that further research is needed on the economic costs of stage-by-stage and total effluent treatments. Copyright 2001 Academic Press.