湿地底质环境对污水水质净化的影响研究

以扎龙湿地底泥为介质,模拟表面流湿地系统,研究了不同底质及其环境要素Eh对表面流湿地净化效率及其稳定性的影响。通过对各个指标去除率均值,变异系数和方差的综合分析,表明在本实验设计的三种Eh梯度下,Eh=-200 mV有利于TN、NO3--N的去除,Eh=200 mV有利于NH4+-N、P和COD的去除;黏土对TN、NO3--N和P去除效果最好,粉砂土对NH4+-N、COD去除效果最好。此外,随着Eh的不同,底质因素的影响也发生相应的变化。即黏土的去除率受Eh变化影响小,亚砂土和粉砂土的去除效果受Eh变化影响大。实验结果客观反映了扎龙湿地不同底质地段的净化污水功能和底质氧化还原环境对污染物去除的影响,为表面流人工湿地净化功能影响因素(基质和Eh)的调控提供理论依据。

STUDY ON THE EFFECT OF WETLAND SEDIMENT ENVIRONMENT ON THE SEWAGE WATER PURIFICATION

The experiment is done with Zhalong Wetland sediment as medium,which simulates the surface flow wetland system and studies the effects of various sediments and environmental elements Eh on the surface flow wetland purification efficiency and stability.Through the comprehensive analysis of removal rate mean,coefficient of variation and variance,the experiment indicates that in three Eh gradients,Eh=-200 mV is beneficial to the removing of the TN and NO3——N,Eh=200 mV is beneficial to the removing of the NH4+-N,P and COD.The removal efficiency of clay for TN,NO3——N,P is the best.The removal efficiency of the silt soil for NH4+-N and COD is the best.In addition,with different Eh sediment factors also change accordingly,i.e.the change of clay removal rate along with Eh is small,the removal effect of silty sand and sandy loam along with Eh changes greatly.The results objectively reflect the water purification function of Zhalong Wetland different sediments and the effect of sediment redox environment on the removal of pollutants,which provides theoretical basis for regulating the influence factors(sediment and Eh) of the surface flow constructed wetland purification function.