人工湿地处理污染河水的持续性运行研究

Sustainable Operation of Subsurface Constructed Wetland Treating Polluted River Water

中国北方地区城市纳污河道内的污染河水具有水量、水质、水温季节性变化大的特点,这给人工湿地污染河水处理系统的持续性运行造成很大困难.通过1a多的连续性运行,对潜流人工湿地污染河水处理系统的可持续运行问题进行了系统研究,年平均水力负荷为15 cm/d.结果表明,季节变化对氨氮的去除效果影响很大,夏季氨氮去除效果良好,去除率达70%以上,而冬季水温降低到15℃以下时,氨氮去除率降低到30%以下,但季节变化对COD去除效果的影响较小.人工湿地在夏季雨季时期可以承受较大的短期洪水水力冲击负荷,在100 cm/d的负荷下,对氨氮和COD的去除率分别可以达到52%和36%.基质脱氢酶活性与温度和污染物去除效果的季节性变化存在一定的正相关关系.

Water quality, flux and temperature of polluted river in northern China fluctuate a lot in a year around, which is disadvantageous for sustainable operation of subsurface constructed wetland treating polluted river water. A pilot system of subsurface constructed wetland treating polluted river water was operated for one year to study the sustainable operation of the process. The results show that ammonia removal performance fluctuated a lot according to different seasons. At the hydraulic loading of 15 cm/d, ammonia nitrogen removal rates were above 70% in summer, however, below 30% in winter when water temperature was below 15℃. Changes of water temperature had little influence on COD removal performance. In the wet season of summer, the pilot wetland system could bear a short-period flood hydraulic loading, and ammonia nitrogen and COD removal rates were 52 % and 36% respectively at the hydraulic loading of 100 cm/d. The activity of soil dehydrogenase had a positive correlation with seasonal changes of temperature and pollution removal performance.