Environmental profile of textile wet processing in Finland

Abstract

This study was carried out in major Finnish textile companies in order to create an environmental impact profile for wet processing in Finland as a part of drafting the Best Available Technique (BAT) Reference documents for the European IPPC Bureau. System boundaries were defined for alternative process technologies to be used in BAT definitions. The use of resources and process emissions is, however, monitored for the whole wet processing only in the companies under study. No remarkable differences in energy and water consumption between continuous and batch wet processing could be measured; the lowest dyeing liquor ratios were reported on jet machines and the highest on winch dyeing machines. Dyestuff consumption depends on the colour shade required; some dyes have, however, low fixation rates, such as reactive and sulphur dyes, only 60% on average. About 20% of the process liquor containing unfixed dyestuffs and auxiliaries end up in sewage treatment plants. These chemicals are not recovered and reused in the companies under study. All industrial plants in Finland discharge their wastewater to municipal sewage treatment plants, which carry out wastewater analysis and control. All textile plants, which use more than 50 tonnes of organic solvents per year, are under official off-gas control in Finland.