水生植物法再生景观回用水水质稳定技术研究

建立了污水处理和景观回用中试试验系统，景观回用试验水量为11 m3，研究了城市污水经二级生物处理再生后用作景观环境用水的水质稳定性；构建了不同结构的水生植物系统，研究了该系统对再生景观环境用水水质的影响. 结果表明:在晴朗天气，白天水温为(28±2)　℃，夜间水温为(20±2)℃的条件下，二级生物处理的再生水在瓷砖水池中最多可以稳定3 d；结构完善的“挺水-浮叶-沉水-浮水”水生植物系统能够有效抑制再生景观回用水中藻类的滋生，并可降低其有机物和氮、磷的含量，在9 d内使ρ(COD_Cr)，ρ(TP)和ρ(NH₃-N)分别降低76.9%，95.8%和95.2%，从而使水质保持稳定并得以改善，使回用水水质完全符合再生景观回用水国家标准. 因此，构建结构完善的水生植物系统可实现污水再生景观回用. 

Study on Water Quality Stabilization Technology for Reclaimed Wastewater as Landscape-Environmental Water by Using Aquatic Plant System

Pilot systems for wastewater reclamation and landscape-environmental reuse at a scale of 11 m3 were constructed, and the stability of the reclaimed wastewater as landscape-environmental water was observed.The aquatic plant systems with different components were constructed in the landscape-environmental ponds, and the influence of the systems on the reclaimed water quality was studied. It shows that the longest stable time of the reclaimed wastewater in the ceramicpond is 3 d under the conditions of sunny days with water temperature of (28±2) ℃ in the day time and (20±2) ℃ at night; well-constructed “emergent-leaf-floating submergent-floating" aquatic plant system can inhibit the algaebreeding in the landscape-environmental water body, and the concentrations of organic matter, nitrogen and phosphorus are lowered in the process of reclaimed wastewater reuse; within 9 days the concentrations of COD_Cr, TP, NH₃-N decrease by 76.9%,95.8% and 95.2%, respectively, so the water quality keeps stable and is furtherimproved, thus making the reused water quality thoroughly meet the national standard for the reclaimed wastewater in landscape-environmental reuse. Therefore,it is a practical technology to construct aquatic plant system with complete components in the landscape-environmental ponds for the reclaimed wastewater reuse.