潜流构造湿地去除农田排水中磷的效果

对潜流构造湿地处理农业面源污水的除磷效果进行了中试研究.结果表明,潜流湿地除磷效果在名义水力停留时间(即空床水力停留时间)小于5d时,除磷效果随水力停留时间的增加而增加,通过间歇式和连续流试验均证明过长的水力停留时间会引起pH值的明显下降,导致磷的析出或溶解,降低除磷效率.芦苇(Phragmitascommunis)和茭草(zizania caduciflora)吸收磷量约占去除磷量的15.8%和9.5%.温度对除磷效果影响较为明显,冬季除磷效率较夏季下降30%.

Phosphorus Removal of Agriculture Wastewater Through Subsurface Constructed Wetland

Phosphorus removal in subsurface constructed wetland treating agriculture non pointed wastewater was studied in pilot scale. The experimental results showed that the removal rates of TP increased with HRT increasing when the nominal hydraulic retention time was less than 5 days. The pH decreased distinctly when the retention time was too longer in the batch and sequence style, it may bring on a lower removel rate of TP. The amount of TP that can be removed by harvesting were about 15.8% and 9.5% compared to the total quantity of removing in Phragmitas communis and zizania caduciflora constructed system respectively. Temperature impacted on the romovel of TP, the removel rate of TP decreased 30% in the winter compared to summuer.