置入式生态滤床对低温季节重污染河水水质的改善效果

Effects of Inserted Ecological Filter Bed Improving Water Quality of Heavily Polluted River in Low-Temperature Seasons

在传统水平潜流人工湿地(SSFW)的基础上,设计了一种下部存在水层的置入式生态滤床系统(IEF),对比研究了IEF和SSFW在不同季度的污染物去除效果。结果表明:与SSFW相比,IEF对污染物的去除率较高,在整个实验期间对总氮(TN)、氨氮(NH_3-N)、总磷(TP)和高锰酸盐指数(COD_(Mn))的总平均去除率分别为63.6%、78.4%、64.7%和51.9%,比SSFW高出13.1%、6.9%、12.1%和7.3%。温度对SSFW的去除率影响较大,在温度较低的第4季度(10—12月),SSFW的去除率明显下降,但IEF的处理效率依然能保持较高水平,对TN、NH3-N、TP和COD_(Mn)的平均去除率达57.9%、63.0%、58.7%和51.8%,比SSFW高12.8%、11.1%、10.2%和7.2%,表明IEF能够部分解决低温季节湿地处理效率低的问题,对重污染河流水质净化具有重要的指导意义。

On the basis of the traditional system of horizontal subsurface flow constructed wetland( SSFW),a new system,namely,inserted ecological filter bed( IEF),was developed. Comparison was made between the two systems in pollutant removing effect in different seasons. Results show that IEF was higher than SSFW in pollutant removing rate and removed total nitrogen( TN),ammonia nitrogen( NH_3-N),total phosphorus( TP) and permanganate index( COD_(Mn)) by63.6%,78.4%,64.7% and 51.9%,respectively,on average,during the entire experiment period,which was 13.1%,6.9%,12.1% and 7.3%,respectively,higher than what the latter did. Temperature was an important factor affecting pollutant removing rate of SSFW. The rate dropped significantly during the fourth season( Oct. to Dec.) of a year when temperature is low,while IEF still maintained a relative high pollutant removing efficiency in winter,removing TN,NH3-N,TP and COD_(Mn) by 57. 9%,63.0%,58. 7% and 51. 8%,respectively,which was 12. 8%,11. 1%,10. 2% and 7. 2%,higher than what SSFW did,respectively. All the findings in this experiment indicate that IEF can solve the problem of SSFW being low in pollutant removing efficiency in the low-temperature season,and has certain important significance in guiding purification of heavily polluted rivers.