上海海域水污染源的变化趋势

Water Pollution Trend in Shanghai Seacoast

上海海域污染物主要来源于沿岸废水的排放和长江、黄浦江的携带。依据环保、水文、海洋部门发布的区域水环境质量公报，提取1981-2006年间上海水环境资料。分析城市废水排放、长江口和黄浦江污染物的排放。探讨上海海域水污染源的变化趋势。可得：过去25年。上海市年废水排放量在17．75-24．20亿t之间。其中。工业废水排放量持续减少，2000年以来工业废水排放的氰化物、重金属和砷的含量稳定在低值附近；生活废水排放量持续增长．其主要污染物为有机物。生活废水排放量与人口的增长呈正相关。过去25年上海市人均年生活废水的排放量增加了2．7倍。年增长量最大时达25％。近年来长江入海污染物的月通量在25．9～209．6万t之间；月通量在冬末最小．夏季最大；冬、夏季的差别达2．3～8．1倍。不同季节长江携带入海污染物的总量与长江径流量呈正相关：但多年比较。长江年排放入海污染物总量与其年径流量关系不显。黄浦江携带入海的污染物总量约占同期长江的1．2％～4％。近年来。上海排放到海域的有机污染物约相当于长江排放量的8％-25％，排放的重金属含量小于长江排放量的万分之三。

The pollutants in Shanghai sea area come mainly from the Yangtze river, Huangpu river and city wastewater discharging in coast. To research water pollution trend in Shanghai sea coast, the data of Shanghai water qualities are extracted from authorized communiqufs and reports on ocean, environment and water in 1981 - 2006, which include pollutant discharge of city wastewater, Yangtze fiver and Huangpu fiver. It can be found that the city wastewater, which includes industry wastewater and living wastewater, was around 1775 - 2420 million tons per year in past 25 years. The industry wastewater was decreasing by years. The concentrations of cyanide, heavy metal and arsenic in the industry wastewater has been controlled to a low level from 2000. The living wastewater has been increasing by years for past 25 years. The main pollutant in living wastewater was organic compound. There was relationsbip between discharge of living wastewater and population. The averaging living wastewater per person-year was increase 2.7 times in past 25 years, the largest increasing ratio in one year on living wastewater per year was 25%. The discharge pollutant flux in month from the Yangtze river was around 0.259 - 2.096 million tons in recent years, with the minimal at the end of winter and maximal in the summer. The difference between winter and summer was 2.3 - 8.1 times. There was relationship between discharge pollutant flux and nmoff in the Yangtze river for seasons, but no relationship for years. The discharge pollutant flux from Huangpu river is about 1.2% - 4% from the Yangtze river contemporarily. In the pollutants discharged to Shanghai sea-area in recent years, the organic compound from city wastewater was about 8% - 25% from the Yangtze fiver, the heavy metal from city wastewater was less than 0.03% from the Yangtze fiver. The pollutants in Shanghai sea-area were mainly nitrogen compound, phosphate and oil. The pollution in Shanghai sea-area was the most seriously around China coast. The pollution would be increasing at Shanghai sea-area with increasing population in Shanghai city and around areas.