BOMBAY-based Century Textiles and Industries Ltd of the Birla group created a ripple recently when it got a special mention from the United Nations Environment Programme in its survey, Cleaner Production Worldwide, and also received the India Merchant Chamber Award for outstanding contribution in textile research.

The company, which exports about 90 per cent of its goods, shot to fame when it dramatically reduced the sulphides used in dyeing. Traditionally, sulphur dyes were treated with highly-polluting sodium sulphide, which increased the sulphide content in the mills effluent.

Although the company had another option, that of using an alkaline solution of glucose, its cost was a deterrent. The company's manager, Mahesh Sharma, in charge of chemical technology, then identified, hydrol, a byproduct from the maize starch industry. The substitution has reduced sulphide concentration in the effluent from 30 parts per million to 2 ppm. The company then made further efforts at substituting chemicals with enzymes.

Century has used enzymes for desizing*** the fabric, for removing starch from the fabric after weaving, and for giving the fabric its final, polished look. Conventional chemicals and acids used for desizing, apart from adding to the pollution load, also act on the fabric itself. Enzymes are also being used for removing the fuzziness, or the microfibres, from the fabric to smooth its surface.