WATER POLLUTION CONTROL SCHEMES FOR UPSTREAM OF HANJIANG RIVER

The upstream of the Hanjiang River is one of the major areas in waterenvironment program of the national tenth five-year plan. The Danjiangkou dam of strategic significance is a key protected water source. The present water source both in the main stream of the Hanjiang River and in the Danjiangkon dam has reached national gradeⅡ water-quality standard. However, this water source is being threatened by the seriously-polluted branch streams whose major pollutant COD may have exceeded the standard in the tenth five-year plan. The COD pollutants are mainly composed of daily life excreta 77.2%.Of the industrial pollu- tion sources, the pulp and papermaking industry is the largest pollution source whose COD excreta reaches 38. 29%. In this paper, is listed the pollution control scheme mainly based on the town wastewater treatment plants and composed of A, B and C types of engineer projects. The implementation of type A projects needs 275 000 000 yuan in investment, reducing the COD in the upstream of the Hangjiang River to 32 682.25 t in 2005, lower than the discharge level in the base yearof 1998 and within the range of the total discharges spec- ified by the Hubei provincial government. In this way, the water quality both in the main stream of the Han- jiang River and in the Danjiangkou dam is guaranteed to reach gradeⅡ national water-quality standard. Then the furtherimplementation of types B and C projects may guarantee the stable high water-quality standard and the conspicuous improvement of the water quality in the branch streams.