海水盐度对潜流人工湿地系统净化效果的影响

Influence of Seawater Salinity on Purification Efficiency of Subsurface flow Constructed Wetland

在不同海水盐度下,研究了芦苇床、碱蓬床和混合植物床潜流人工湿地对污水中有机污染物的去除规律,以及海水比例和污染负荷对去除效果的影响。结果表明,当进水中的海水比例<40%时,各植物床对有机污染物均有良好的去除效果,种植植物的人工湿地对COD的去除率比无植物系统高20%～30%;海水比例的变化对芦苇床、碱蓬床和无植物系统去除COD的影响不大,当海水比例由30%提升至40%时,混合植物床的处理能力明显下降;芦苇床和碱蓬床在进水COD为160 mg/L时具有最高的去除率,分别为81.1%和71.8%,而混合植物床在进水COD为120mg/L时可达到最大的去除率(77%)。

Subsurface-flow constructed wetlands planted with Phragmites australis, Suaeda salsa and mixed plants were used to treat a mixture of seawater and domestic sewage. The influence of salinity and COD load on COD removal was investigated. The results demonstrate that when the seawater proportion in the influent is under 40%, the wetlands planted with the different plants can remove organic pollutants effectively. The COD removal rate in the planted wetlands is 20% to 30% higher than that in the unplanted wetland. The variation of seawater proportion does not affect COD removal rates in the wetlands planted with Phragmites australis and Suaeda salsa and the unplanted wetland. The pollutants removal capacity of the wetland planted with mixed plants is reduced when the seawater proportion is increased from 30% to 40%. The COD removal rate of the wetlands planted with Phragmites australis and Suaeda salsa reaches their maximum, 81.1% and 71.8%, when the influent COD is 160 mg/L. Furthermore, the wetland planted with mixed plants attains its maximal COD removal rate, 77%, when the influent COD is 120 mg/L.