水力负荷对垂直流人工湿地堵塞影响研究

THE STUDY FOR THE INFLUENCE OF HYDRAULIC LOAD ON CLOGGING OF THE VERTICAL-FLOW CONSTRUCTED WETLAND

采用基质孔隙率的变化和堵塞物的定量化分析方法研究了0.3、0.6、0.9、1.2 m.3m-.2d-1 4个水力负荷对垂直流人工湿地基质堵塞的影响,同时分析了人工湿地去除污染物的能力随运行时间的变化情况。结果表明,水力负荷对人工湿地基质堵塞有较大影响,在水力负荷小于0.3 m3.m-2.d-1时不易发生堵塞;基质中累积物的含量随着基质深度的增加而减小,其中无机物的积累比有机物的积累高出4.5倍以上;基质的堵塞对COD的去除效果影响不明显,但对氨氮的去除效果影响较大。随着基质堵塞程度的加剧,氨氮的去除率逐渐下降。应结合考虑基质堵塞和污染物去除效果2方面因素来选择垂直流人工湿地的水力负荷条件,以确保人工湿地持久稳定的运行。

In this study,the change of matrix porosity and the quantitative analysis of clogging substance were used to investigate the relationship between 4 hydraulic load and matrix clogging of vertical-flow constructed wetland.4 hydraulic load were 0.3,0.6,0.9 and 1.2 m3·m-2·d-1.Meanwhile,the removal efficiency of the pollutants in constructed wetland was analyzed during different reaction time.The results indicated that hydraulic load had a great impact on the clogging of constructed wetland and the clogging was not easy to happen when the hydraulic load was less than 0.3 m3·m-2·d-1.The contents of the cumulative substance in matrix were decreased when the depth of matrix increased.And the accumulation of inorganic was 4.5 times higher than that of organic.The clogging had little effect on the removal efficiency of COD while had greater impact on the removal efficiency of ammonia nitrogen.The removal rate of ammonia nitrogen decreased when the clogging condition aggravated.The conditions of hydraulic load should be chosen by considering matrix porosity and removal efficiency of pollutants generally,in order to ensure the stability operation of the constructed wetland.