复合型前置库系统去除面源主要污染物的研究

Eliminating non-point source pollution in a pre-dam complex system in the Tangma Reservoir,Jiangsu Province

以江苏省溧阳市塘马水库水源地水质安全保障工程为背景,针对水库型水源地面源污染存在的主要问题,构建以沉淀区、浅水区、深水区、潜流人工湿地及生物填料组成强化净化区的复合型前置库分区净化系统,研究面源主要污染物去除规律,为工程示范提供技术参数.结果表明,系统滞水时间为1 d时,去除氮、磷、CODCr均有良好效果,分别达到了67.2%、68.2%及89.3%,滞水时间为2～3 d时各污染物去除率增加较少并趋于稳定.引入潜流湿地及强化净化区明显提高了SS、氮、磷、有机物的去除效果,特别是提升了对小颗粒(粒径小于15μm)的去除效果,基于上述研究结果,建议工程示范中滞水时间为2～3 d,并适当优化系统分区结构,提高复合型前置库的净化效率及面积利用率.

In this study, the effieieneies of a pre-dam complex system for non-point source pollution control was investigated for the management of the Tangma Reservoir in Liyang City, Jiangsu Province. The pre-dam complex is composed of settling area （A） , shallow-water area （B） , deep-water area 1 （ C ） , deep-water area 2 （ D ） , surface flow wetland （ E ） , and biological membrane purification area （F）. The results showed that the pre-dam complex system under the study contributed to significant improvement in the quality of agricultural non-point source pollution flowing through the pre-dam. The removal of TN, TP, CODcr could he up to 67.2% , 68.2% and 89.3% , respectively, when the retention time was 1 d. The removal efficiency was increased with increasing of retention time, while the increment was small and stable. Moreover, increased areas （E and F） could significantly improve the removals of SS, TN, TP and CODc,, particularly the smaller SS which was consisted of size less than 15 μm. Furthermore, based on laboratory results, it was suggested that the retention time be 2 -3 d in the Tangma project, and the system be optimized to improve the purification efficiency and high utilization of the area.