Pollution prevention studies in the textile wet processing industry

The objective of this study was to investigate pollution prevention (PP) opportunities in the textile wet processing industry. This industry uses vast amounts of water, energy and chemicals. PP audits were conducted at four textile companies. The companies were located in Virginia and included: a denim and soft wash laundry- a fiberglass yam processing plant; a plant dyeing and printing cotton fabric; and a nylon yam dyeing and finishing plant.

Each company was visited several times. Information about the operations, consumption of water, energy and chemicals were obtained by interviewing personnel. Information about waste water characteristics, permit applications, water treatment and disposal records were obtained from the plant's records. Waste water samples from several operations were analyzed for COD, DOC, color, TSS, pH and temperature. Lead, copper, zinc and chromium concentrations were also determined.

The collected information was used to make recommendations to the management of each plant concerning possible implementations. Reusing non-contact cooling water at the fiberglass processing plant will reduce the water consumption by 76% and results in a savings of $ 99,400 per year, if an additional chilling unit is not needed. There were several possibilities to reduce the consumption of water and energy and chemicals at the cotton dyeing and printing mill. Implementing counter-current flow between bleach washers will save $ 154,000 per year due to reduced consumption of water and energy.

The savings will be $ 336,000 per year if the existing washers are replaced by more efficient washers. Improving the wash schedules and communication with clients at the laundry will reduce the consumption of water and chemicals. Dyebath reuse and countercurrent flow of rinse waters were recommended for the nylon yarn dyeing and finishing mill.