The Research On Prevention, Control And Planning Of Water Pollution In Shuanglui County, Chengdu

The water pollution is one of the great environmental problems in China. It not only influences the ecological environment, but also restricts the development of social economy in sorne degrees. So it will have an important social, economic and environmental meaning to control water pollution. The prevention and control plan of water pollution is the guide of the water pollution prevention and control, and it's also the basis to implement environmental construction and objective management. This research regards prevention and control of water pollution in Shuangliu County, Chengdu as the research object, uses the method combined the mathematics model with determining the nature, make a systematic research on pvevention, control and planning of water pollution in Shuangliu County, Chengdu.Through investigation on the water environmental quality current situation of Shuangliu County,It has been found that point sources in Shuangliu County distribute comparatively centralized. The discharge of sanitary sewage from north stretches of district, account for 83% of total amount of the whole county urban life sewage discharge; those from enterprises ranked the top 15 account for 74.1% of industrial sewage of emission. The handling rate of urban sanitary sewage is extremely low, whose handling rate was only 30% in 2003; CODcr from countryside and emission of ammonia and nitrogen account for more than 60% of total amount. Water environment in Shuangliu County is inferior in quality. Water quality of main river worsens. Fu River, White River, Jiangan River, Yangliu River all are seriously polluted, the pollution composite index is 6.01, 7.13, 4. 48 and 4.6 respectively; the surface water pollution presents in the form of ammonia nitrogen pollution combined with organic pollution. The water environmental function zone of Shuangliu County is divided into five kinds.Surface water environment is divided into 9 function areas, the whole county is divided into 3 water pollution control zones and 4 pollution control units. The analysis on water environmental capacity of Shuangliu County indicates that the environmental capacity of ideal water is abundant , The minimum (dry season) water environmental capacity is CODcr4033 ton per year, ammonia and nitrogen 181 tons per year. The biggest (wet season ) water environmental capacity is CODcr 11672 ton per year, ammonia and nitrogen 437 tons per year. According to analysis, the overall control scheme in Shuangliu County was proposed: The sewage which discharges into the river must be controlled in 3056.8 tons per year, the load of ammonia and nitrogen in 163.1 ton per year. The pollution load of CODcr in Fur River pollution control zone must be controlled in 2544.8 tons per year, the pollution load of ammonia and nitrogen is controlled in 320.8 tons per year, and those of CODcr, ammonia and nitrogen in Yanglui River pollution control zone are controlled in 512 ton per year and 27.3tons per year respectively.The planning of the pollutant to be cut down and project of renovating the industrial sewage, waste water from city and countryside, and the investment ways were also proposed. It has offered the policy basis for water pollution control of Shuangliu County,and reference for the regional prevention and control of water pollution in medium and small size in west of China.