Measures taken against water pollution in the textile industries of Great Britain.

The majority of British textile finishing firms discharge their waste water to sewers for treatment by local authorities, and their problems are mainly those of pretreatment torender the wastes acceptable, by removal of alkali or acid, and other materials that are prohibited. Firms discharging to watercourses have to purify the waste water to a high standard before discharge and this usually involves the use of chemical or biological treatment. Research work at the Shirley Institute over the past 8 years has been concerned with the development of appropriate methods of meeting the demands of the receiving authorities and this has involved laboratory, pilot and full scale trials on a wide variety of effluents. Sampling procedures are important on the very variable discharges and a truly proportional sampler has been devised, which is now coming into commercial production. Water usage measurements on many textile processes have been made and the results indicate those processes where savings can be made or where comparatively clean wash waters can be recycled or used in other processes. Methods of treatment of waste water to give a high degree of purity have also been examined and these enable a substantial amount of water to be re-used. SURVEY OF EFFLUENT PRODUCTION AND DISPOSAL A survey made in 1963 of the textile industry in Great Britain showed that the majority of firms discharged their trade wastes to sewers for treatment by the local authority along with domestic wastes: the remainder, about 20 per cent of the firms, usually disposed of their wastes to rivers, or their strong wastes to sewers and the rest to a river. The volumes of effluent discharged covered a wide range. Out of more than 600 firms halfwerein the range 50 to 500 m 3 jday with a small number above 5000 m 3 /day. The waste Iiquors come from the wet processing of cotton, wool, linen, jute and man-made fibres in the form of fabrics and yarn, with the hosiery industry including garments and hosiery. This wet processing includes scouring, bleaching, milling, dyeing, printing and finishing in a variety of ways. REQUIREMENTS FOR DISCHARGE The requirements for the two principal methods of disposal are very different. F or discharge to watercourses the River Authorities in England and Wales impose fairly strict limits, particularly where the rivers are used for supplies of drinking water or where they support fish. Usually the Iimits