苏州市东山镇池塘养蟹面源污染现状及控制

Current status and control strategies of non-point source pollution from pond aquaculture in Dongshan town of Suzhou

结合全国污染源普查活动,以苏州市养殖老区东山镇养殖池塘为典型,调查其现行养殖模式、经济效益、养殖污染状况。调查结果显示,东山镇现有养殖面积为2 253.33 hm2,主养品种为河蟹。1个养殖周期中,养殖池塘通过沟渠排入外界的TN、TP含量分别平均为21.25 kg/hm2、2.34 kg/hm2;密度为9 000只/hm2的低密度养殖池外排的TN含量为16.79 kg/hm2,而无TP排出。分析苏州地区池塘养殖产生水环境污染的主要原因,从池塘管理体制改革、科学生态养殖技术及养殖尾水处理等方面探讨池塘养殖污水零排放技术,为苏州市养殖业面源污染的控制提供对策和措施。

Combining with national census of pollution sources and using large-scale pond aquaculture in Dongshan town in Suzhou as a case study, the current cultural modes, economic benefits, and aquaculture pollution were surveyed. The results showed that there were 2 253.33 hm2 of aquaculture in Dongshan town, and the Chinese mitten crab was the main specie. In a single aquaculture period, the discharged total nitrogen （TN） and total phosphorus （TP） from pounds to outside through canals and ditches were on average 21.25 kg/hm2 and 2.34 kg/hm2 respectively. However, in a lowdensity crab raising pond of 9000 ind/hm2, the discharged TN was 16.79 kg/hm2, and no TP was found to be discharged. Based on the case study, the main reasons for the water environment pollution by pond aquaculture were analyzed, and the zero discharge technologies for the waste water of pond aquaculture were discussed from aspects of the management system reform for pond, the scientific and ecological raising technique, and the aquaculture wastewater treatment. The possible strategies and countermeasures for controlling the aquacultural non-point source pollution in Suzhou were also provided.