芦苇人工湿地对农村生活污水磷素的去除及途径

Phosphorus removal from rural domestic wastewater and removal pathways analysis using reed wetlands

构建了芦苇(Phragmites australis)水平潜流人工湿地处理农村生活污水中的磷素,考察了湿地除磷效果以及地上植物吸磷量。结果表明,人工湿地对磷素的去除随水力停留时间的延长而增加,停留时间大于5.3 d时,芦苇湿地除磷效率可以高于88%。湿地进水TP负荷与磷去除速率之间有较好的线性关系(R2>0.91)。湿地植物在11月份收割时,地上生物量为1.65 kg.m-2,芦苇地上部分吸收磷量为3.68 g.m-2.a-1。分析了湿地除磷途径,在试验条件下,湿地填料的吸附和沉淀等作用是水平潜流人工湿地除磷的主要途径,植物吸收仅占湿地总磷去除量的9.1%,但是湿地水生植物是人工湿地重要组成部分,可以通过影响湿地的其他条件间接影响湿地除磷效果。试验证明,人工湿地是适用于农村地区的优良的污水处理技术。

Subsurface horizontal-flow wetlands planted Phragmites australis was constructed to treat rural domestic wastewater. Phosphorus removal and plant uptake in constructed wetland from wastewater were interviewed. The results showedthat phosphorus removal efficiency increased with hydraulic retention time （HRT） increase. Phosphorus removal rate was greater than 88% when HRT was more than 7 days. The wetland exhibited a strong linear relationship of TP loading in influent and removal in effluent （ R2 〉 0.91 ） . Wetland plant was harvested in later November with an aboveground biomass of 1.65 kg·m^2. Plant uptake of TP was 3.68 g·m^-2·a^-1. Pathways of TP removal in constructed wetland were analyzed. Adsorption of substrate was main mechanism of TP removal in subsurface horizontal-flow wetland. Amount of plants uptake accounted for 9.1% of TP removed by wetland. However, the existence of macrophyte in constructed wetland plays important role on TP removal in wetland through influencing indirectly other TP removal mechanisms. The experiment shows that constructed wetland is a prospective strategy for treating rural domestic wastewater.