Pollution Research Paper

ABATEMENT OF ENVIRONMENTAL POLLUTION BY EFFLUENTS OF TEXTILE INDUSTRY

EVGENY VALEREVICH ALEKSEEV

Abstract

Widespread textile factories consume and emit into environment up to 400 m3 of water per each ton of final product. This article discusses the aspects of abatement of effluents containing stable organic compounds such as organic dyeing agents and surfactants which are major water pollutants of textile factories. The main purpose of the performed studies is to improve the efficiency of effluent treatment by flotation in combination with electrochemical destruction of organic constituent of flotation sludge in liquid phase and recycling of coagulant solution to treatment of effluents. The studies were performed with effluents of textile factory. It was established that the applied procedure, comprised of two-stage flotation, coagulation and filtration, resulted in the following efficiency of effluent treatment: in terms of color intensity – at least 85%, in terms of suspended substances – up to 99%, in terms of surfactants surfactants – at least 90%. In the course of studies of treatment of flotation sludge, it had been established that the oxidation rate of organic dyeing agents actually did not depend on pH. Upon oxidation of surfactants, the maximum effect was observed at pH £ 4. The extent of electrochemical destruction of the dyeing agents exceeded 90%. Herewith, power consumption was 10…12 Wh per 1 g of oxidized matters. The efficiency of electrochemical destruction of surfactants was not higher than 55…65% at specific power consumption of 12…15 Wh/g. Subsequent studies were aimed at intensification of electrochemical oxidation of surfactants with addition of chlorides and homogeneous catalysts. It was established that the oxidation rate of organic substances depended significantly on the amount of catalyst. Effective amount of catalyst, Fe3+ ion, was related with amount of chlorides in treated flotation sludge, it was in the range of 60…100 mg/L. The extent of electrochemical destruction of surfactants in flotation sludge in the presence of trivalent iron reached 96%. Herewith, the specific power consumption for destruction of stable organic substances in terms of chemical oxygen demand was in the range of 5...12 Wh/g. Electrochemical destruction makes it possible to recover coagulant, to decrease the weight of wastes disposed outside of factories, to reduce significantly atmospheric emissions of organic compounds.