Removal of acute toxicity with ozonation in textile plant waste water

Abstract

Textile industry is one of the most common and essential sector in the world. The textile industry consumes large quantities of water at its different steps of dyeing and finishing, among other processes. The non-biodegradable nature of dyes and their stability toward light and oxidizing agents complicate the selection of a suitable method for their removal. Moreover, toxicity bioassays have demonstrated that most of them are toxic. The acute toxicity of waste water of textile plant was investigated using Daphnia magna (water fleas) and ozonation. In this study, samples were taken from a cotton textile plant in Bursa at the first stage, the treatment was made by ozonation and then the toxicity tests were performed. In ozonation, the appropriate pH, dosage of ozone (O3) and ozonation time were determined. In toxicity tests, monitoring of toxicity were made at different dilution rates using Daphnia magna both in treated water with ozonation and in wastewater. The acute toxicity scale LD50 (Lethal Dose) values were determined as 50 % in waste water and 90 % in water treated with ozonation. As a result, it can be concluded that ozonation demonstrated a positive contribution to the removal of acute toxicity in textile wastewaters