潜流人工湿地污染河水处理系统中的填料堵塞问题研究

Substrate clogging of constructed wetland system for subsurface treatment of polluted river water

利用潜流人工湿地系统处理污染河水,水力负荷为0.15m3/(m2·d)。研究了该系统长期运行过程中的填料堵塞问题及其对污染物去除率的影响。构建了潜流人工湿地污染河水处理中试系统,在运行两年后,潜流人工湿地填料存在一定的堵塞现象,填料孔隙率最大减少了2.67%。填料孔隙堵塞现象主要发生在该中试系统的前段(沿水流方向距进水点0～5m),其填料堵塞物质主要为无机颗粒物。植物对填料堵塞问题的改善作用并不显著。填料的部分堵塞对该中试系统中污染物的去除率有一定的影响,运行第2年氨氮的去除率略有降低,而COD的去除率有增加的趋势。

Two pilot scale constructed wetland （SFCW） systems （15.0 m×1.5 m ×0.7 m each, with and without plants covering the first 5 m section from the inlet） were operated for subsurface treatment of a polluted river water at a hydraulic loading of 0.15 m^3/（m2 ·d）. Substrate clogging and treatment performance （removal of ammonia and COD） were monitored for 2 years after the start up period. Up to 2.67% reduction in the system＇s substrate po- rosity was observed after 2 year＇s operation, with more reduction found in the first 3 m of the front end due primarily to the deposits of inorganic particulate matters. The plant covering had no significant effects on the substrate porosity and/or the SFCW＇s treatment performance. The slight reduction in the substrate porosity resulted in a small decrease in ammonia removal and a more notable increase in organic removal which was likely caused by enhanced biodegradation due to bacterial growth on the substrate.