Abstract: One combined wetland system was used in aquaculture wastewater purification of the lake pond, in order to achieve water recycling utilization and reduce the pollution of the surrounding water environment. The combined wetland system was composed of three lotus purification ponds with an area of 2.1 hm² each, one ecological ditch of 1.47 hm²and one constructed wetland of 0.52 hm². The lotus coverage rates of the three purification ponds were respectively 0%, 30%, and 60%. Water chemical indicators were determined by sampling along the way. The results showed that the combination system could effectively reduce the total nitrogen, total phosphorus, ammonia nitrogen, COD and other chemical indexes in the aquaculture wastewater. Total nitrogen and total phosphorus were decreased from 0.76mg/L, 1.3mg/L to 0.4 mg/L, 0.09 mg/L respectively, with the removal rates of 41.5% and 77.5%; ammonia nitrogen and COD were decreased from 0.27mg/L, 42mg/L to 0.06 mg/L, 27 mg/L respectively, with the removal rates being 77.7% and 35%. The research showed that this cycling mode was effective in purifying aquaculture wastewater, realized the goal of "internally circulating and externally sealing" and could effectively alleviate the pollution load of Nansi Lake.

Key words:  lotus purification pond, ecological ditch, constructed wetland, aquaculture wastewater, purification efficiency

摘要： 利用组合湿地系统对湖区池塘养殖尾水进行净化，以实现水体循环再利用，减少对周围水环境的污染。组合湿地系统由3个莲藕净化塘、1个生态沟渠和1个人工湿地组成，面积分别为2.1 hm²、1.47 hm²和0.52 hm²，其中净化塘莲藕的覆盖度分别为0%、30%、60%。沿程采样测定水化学指标。结果显示，组合系统能够有效降低养殖尾水中的总氮（TN）、总磷(TP)、氨氮(NH4+-N)和化学耗氧量(COD)等指标。TN、TP由初始值1.3 mg/L、0.76 mg/L降到0.4 mg/L、0.09 mg/L，去除率分别为41.5%、77.5%；NH4+-N、COD由初始值0.27 mg/L、42 mg/L降到0.06 mg/L、27 mg/L，去除率分别为77.7%、35%。研究表明，该循环模式能有效净化养殖尾水，实现水体循环再利用，可有效缓解南四湖的入湖污染负荷。

关键词: 莲藕净化塘, 生态沟渠, 人工湿地, 养殖尾水, 净化效果