不同深度人工复合生态床处理农村生活污水的比较

采用了2种填充深度(60cm和40cm)的人工复合生态床对滇池地区低浓度农村生活污水进行了处理试验研究结果表明,在30cm/d高水力负荷的条件下,对COD、总氮、氨氮和总磷的去除率,深度为60cm的床体分别为66.4%、57.7%、78.7%和63.2%,40cm深的床体分别为63.8%、59.1%、82.1%和61.3%.深度为60cm床体对COD和总磷的去除率高于深度为40cm的床体,但后者对氮的去除效果略优于前者.对氮、磷去除途径的分析表明:微生物的硝化/反硝化作用以及填料对磷的吸附沉淀作用是人工复合生态床去除氮、磷的主要途径;水生植物对氮、磷的吸收量分别占投加总量的10%和9%以上,也是一个重要途径.

Rural Sewage Treatment Performance of Constructed Wetlands with Different Depths

The treatment performance, for low concentration rural sewage, through constructed wetlands of different depths(60cm and 40cm), was comparatively investigated by using pilot-scale apparatus in Lake Dian-chi area, Yunnan province, China. The experiment results showed, under a high hydraulic loading rate of 30cm/d, that the removal efficiencies of COD, total nitrogen, ammonia-nitrogen and total phosphorus in the constructed wetland of 60cm depth were 66.4%, 57.7%, 78.7% and 63.2%, respectively, and were 63.8%, 59.1%, 82.1% and 61.3% in the 40cm depth, respectively. The removal efficiencies of COD and total phosphorus in the constructed wetland of 60cm depths were higher than those in the 40cm depth, but the nitrogen removal efficiency in the latter was higher than that in the former. Nitrogen and phosphorus removal mechanisms were studied. The results showed that nitrogen removal through nitrification/denitrification and the phosphorus revmoal through absorb and sedimentation were their main removal mechanisms. The nitrogen and phosphorus removed by plant harvesting were amounting to 10% and 9% of input TN and TP, respectively, which was also an important removal pathway for nitrogen and phosphorus.