太湖西沿岸区底泥污染及生态应急清淤研究

Study on Sediment Pollution and Ecological Emergency Silting in the Western Coastal Area of Tai Lake

太湖底泥生态疏浚作为生态修复的措施之一已经广泛应用于太湖流域水环境综合治理中。2017年5月,江苏省宜兴和无锡太湖近岸水域发生多起水质异常现象,因此实施了应急清淤工程。在对研究区域基本情况及底泥污染情况充分了解和分析基础上,确定生态清淤范围和工程量,本次疏浚面积为2.89 km^2,合计清淤工程量为79.29万m^3。从清淤要求、清淤深度、清淤设备选择、清淤工艺等关键技术点着手制订清淤方案。根据分析,该工程可将至少清除太湖底泥中蓄积的有机质1.16万t、TP 436.3t、TN 1347.8 t,清淤后清淤区氮、磷年释放量可分别下降24.0%和14.0%,环境和社会效益显著。

As one of the measures of ecological restoration,the ecological dredging of sediment in Tai lake has been widely used in the comprehensive treatment of water environment in the Tai lake River Basin. In view of the water quality anomalies in the near shore waters of Yixing and Wuxi in May 2017,the emergency silting project was carried out. On the basis of fully understanding and analyzing the basic situation of the study area and the pollution of the sediment,we determined the scope and quantity of the ecological dredging and the requirements for dredging,dredging equipment etal. The dredged area is 2. 89 km2,and the total quantity of dredging project is 79. 29 ×104 m3. According to the analysis,the project will eliminate at least 1. 16 × 104 t organic matter,436. 3 t TP and 1347. 8 t TN accumulated in the sediment of Taihu,and the annual release amount of nitrogen and phosphorus can be reduced by 24% and 14% respectively after dredging,and the environmental and social benefits are significant.