石灰石和黄铁矿-石灰石人工湿地净化河水的研究

Limestone and Pyrite-Limestone Constructed Wetlands for Treating River Water

利用石灰石和黄铁矿-石灰石水平潜流人工湿地处理受到污染的河水,了解它们对河水中污染物,尤其是对氮和磷的去除效果,并分析这些矿物的作用,考察了水力停留时间变化对2种人工湿地污染物净化效果的影响.结果表明,污染物去除效果的最佳停留时间出现在3 d左右,COD、TN和TP的平均去除率分别达到51%、70%和95%.在相同进水水质和水力负荷运行条件下,石灰石和黄铁矿-石灰石这2种人工湿地对COD的平均去除率分别为53.93%和51.66%,对NH4+-N的平均去除率分别为82.13%和77.43%,对TN的平均去除率分别为66%和72.06%,对TP的平均去除率分别为50.9%和97.35%.2种人工湿地对COD的去除效果差距不大,黄铁矿-石灰石人工湿地的脱氮除磷效果优于石灰石湿地,对磷有较好的去除效果,不受温度影响且净化效果稳定,适宜长期稳定运行.

Polluted river water was treated with limestone and pyrite-limestone subsurface horizontal constructed wetlands.The aims were to know the performance of two wetlands on removal of common pollutants,especially nitrogen and phosphorus,and analyze the actions of these minerals.The relationship between hydraulic retention time and purification performance of two constructed wetlands was studied.The optimal hydraulic retention time for pollutant removal was about 3 d,The average removal efficiency of COD,TN and TP were 51%,70% and 95%,respectively.With same influent and hydraulic loading,the average removal efficiency of COD,NH4＋ N,TN and TP were 53.93%,82.13%,66%,50.9%,and 51.66%,77.43%,72.06%,97.35% for limestone and pyritelimestone constructed wetlands,respectively.There were few differences between limestone and pyrite-limestone wetlands on COD removal,but the nitrogen and phosphorus removal of pyrite-limestone constructed wetland was higher than that of limestone constructed wetland.The phosphorus removal of pyrite-limestone wetland was more efficiency and stable,not affected by temperature.