长江流域总磷污染:分布特征•来源解析•控制对策

摘要

The spatial and temporal characteristics of the total phosphorus ( TP ) pollution in the Yangtze River Basin were investigated. The most serious phosphorus sources were explored in the Minjiang River and Tuojiang River in the upper reaches of the Yangtze River Basin. The control strategy of TP in the Yangtze River basin was formed. Since 2016, TP has become the main pollution factor in the Yangtze River basin, concentrations order of TP were upstream>lower reaches>middle reaches. Overall, the TP concentration showed a downward trend. The TP pollution in the dry∕flat water period is sevever than that in the wet season of the Yangtze River, indicating that point source is the main source. Reasons for the high level of TP in the Yangtze River include: high load from phosphate mining and phosphorus chemical industry; large emission of urban living pollution caused by insufficient infrastructure construction; inadequate utilization of livestock waste resources; lack of ecological flow; missing of the water pollution control guide and pollution source supervision. In consideration of the characteristics of TP pollution in the Yangtze River Basin, according to two principles, control strategy of total phosphorus was formed as following:( 1) Screen out the key control areas of total phosphorus in the upper reaches of the Yangtze River basin. ( 2 ) Strengthen the control of the main pollution sources of phosphorus, phosphorus chemical industry, urban life and livestock and poultry breeding, and reduce the discharge load of phosphorus pollution. ( 3) Use environmental supervision effective means to perfect the water environment standards and regulatory system.%针对长江流域总磷污染,开展总磷污染时空特征分析,选择长江流域总磷污染最严重的上游地区岷江和沱江为典型区,分析总磷来源,提出总磷污染控制对策.研究表明:2016年开始总磷成为长江流域主要污染因子,其中上游污染最重,中游污染最轻,总体呈降低趋势;长江流域枯∕平水期总磷污染较重,丰水期污染较轻,说明流域主要污染负荷来自点源.总体来说,造成长江流域总磷较高的原因有:磷矿开采和磷化工的污染源高负荷排放,造成部分河段水质严重超标;基础设施建设滞后,城镇生活污染源排放影响河流水质;畜禽养殖废物资源化利用不足;生态流量不足,加剧水污染问题;水污染治理导向不全面和污染源监管措施不系统,影响总磷水质同步改善.针对长江流域总磷污染特征,按照"分区控制、分类治理""突出重点、精准施策"原则,提出长江流域总磷污染控制建议:①抓住长江流域上游重点片区,开展流域总磷污染整治.②抓住磷化工、城镇生活和畜禽养殖等三类涉磷重点污染源的治理,控制磷污染负荷排放.③抓住环境监管有效手段,进一步完善水环境标准和监管体系.