石臼漾水源生态湿地工程的水质改善效果

Water Quality Improvement of Shijiuyang Water Source Ecological Wetland

嘉兴市石臼漾水源生态湿地工程是我国目前最大的城市饮用水源处理系统,成为我国微污染水源水质改善的成功范例,已稳定运行4年。对该湿地近3年的水质改善效果研究表明,经过湿地净化,饮用水源水的DO、TP、NH3-N、粪大肠菌群等主要指标提高了一个等级,湿地的主体功能区即根孔生态净化区和深度净化区发挥着相辅相成的净化作用;湿地水质净化效果的季节性变化明显,通常夏、秋暖季的净化效果较好,而冬、春冷季的效果较差;湿地运行3年期间对氨氮的去除效果和DO浓度的增长呈逐年上升趋势,而对浊度、Fe、Mn和TN的去除效果则逐年下降。另外,分析了湿地目前存在的主要问题并提出了相应的对策建议。

Shijiuyang water source ecological wetland in Jiaxing City is presently the largest urban drinking water source treatment system in China. It has operated stably for four years and has become an example of successfully solving the micropollution problem of stream networks. Performance analysis of the wetland during its three years operation period showed that the Shijiuyang wetland could improve the drinking source water quality for DO, TP, NH3 - N and fecal coliform by one grade. The principal func- tioning zones including root channel purification zone and advanced purification zone played complemen- tary roles in guaranteeing drinking water safety. The purification effect of the wetland was better in the warmer summer and autumn seasons, and worse in the colder winter and spring seasons. During the three years operation period, the removal efficiency of NH3 - N and the increase rate of DO were gradually in- creased each year. However, the removal effieiencies of turbidity, Fe, Mn and TN were gradually de- creased. The existing problems and the corresponding countermeasures were put forward.