湿地底质环境对不同浓度污水的净化效果

Purification effect of wetland sediment environment on different concentrations wastewater

实验以扎龙湿地底泥做为介质,模拟表面流湿地系统,研究了不同底质和进水浓度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高、中、低3种浓度梯度下,高、中浓度进水时,湿地底质的净化效果更好。粘土对TN、NO3--N去除效果最好,粉砂土对NH4+-N、COD去除效果较好。3种底质对磷的去除效果没有显著差异。此外,随着进水浓度的不同,底质因素的影响也发生相应的变化。即粘土和粉砂土的去除率受进水浓度影响大,亚砂土的去除效果相对稳定。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,为表面流人工湿地净化不同浓度的污水水质和选择最佳净化效果的湿地底质提供理论依据。

Abstract The experiment, simulating the surface flow wetland system with Zhalong wetland sediment as medium, studies the influence of various sediments and influent concentrations on purification efficieney and sta- bility of the surface flow wetland. By means of the comprehensive analysis of removal rate mean, coefficient of variation and variance, the experimental results showed that among three different concentration gradients, the higher the influent concentration, the better purification efficiency of the wetland sediment. On the other hand, clay for TN,NO3--N and the silt soil for NH4-N, COD are better on the removal efficiency. By contrast, three sediments have no significant difference on the removal of phosphorus. In addition, with the different influent concentrations, the effect of sediment factors also changes accordingly. The influence for the removal rate of Clay and silt soil by the influent concentration is larger, while the sandy loam is relatively stable. The results objec- tively reflect the water purification function of different sediments in Zhalong wetland and provide the theoretical basis for the surface flow constructed wetland purification of different concentrations wastewater and the selection of wetland sediment with the best purification effect.