高效藻类塘处理农村生活污水研究

Treatment of Domestic Wastewater with High-rate Algal Pond in Rural Areas

对高效藻类塘处理太湖地区农村生活污水的效果进行了研究。结果表明，太湖地区农村生活污水的水质受季节影响变化较大，秋、冬季的有机物浓度较夏季高3～4倍；高效藻类塘内存在的菌藻共生体系使塘内溶解氧浓度较高（保持好氧状态），而pH值则存在周期性变化；对COD的平均去除率可达70％，氨氮主要通过硝化作用去除，去除率〉90％，磷酸盐主要通过沉淀作用去除，去除率为50％。系统运行效果受季节性光照和温度变化影响很大，夏季停留时间需4d，冬季需8d。较高流速可强化系统的传质效果，提高了对污染物的去除能力。塘深较浅时，塘深对处理效果影响不大。高效藻类塘系统能较好地净化太湖地区的农村生活污水。

The treatment of domestic wastewater was studied with high-rate algal pond in rural area of Taihu. The study shows that the characteristics of domestic wastewater in the rural area vary remarkably in different seasons. In autumn and winter, the organic strength is observed to be 3 to 4 times of the strength in summer. Due to the mutualism relationship between algae and bacteria in the pond, dissolved oxygen concentration always remains at a high level and a periodic change each day is shown in pH level. In such a pond system, COD removal is about 70%. Ammonia nitrogen is mainly removed via nitrification and the removal efficiency is up to 90%. Owing to the precipitation at high pH, phosphorus removal reaches 50%. The treatment performance of the system depends greatly on the availability of sunshine and variation of temperature. Therefore, the HRT needs to be increased from 4 days in summer to 8 days in winter. The high velocity can promote mass transfer and thus improve the treatment performance. The water depth is found to have little effect on the treatment performance. High-rate algal pond is able to treat the domestic wastewater generated in rural area.