潜流人工湿地中3种基质对氮磷净化的影响

Effect of Substrates in Constructed Wetland on the Purification of Nitrogen and Phosphorus

通过潜流人工湿地装置,采用间歇运行方式考察不同停留时间下土壤、砾石、炉渣基质在以NO3--N、NH4+-N和PO4--P为主要氮组分的模拟污水对污水中氮的净化效能,并研究湿地系统基质与pH变化、NO3--N和NH4+-N净化效率的关系。结果表明,当水力停留时间为10d时,土壤-炉渣湿地的N,P净化效能高于以其他基质构建的湿地。在试验周期内,各基质的人工湿地系统NH4+-N的净化效率均高于NO3--N的净化效率,氮素的净化效能上层大于下层,湿地系统中pH值先降低后升高的拐点可作为NH4+-N氧化反应结束的指示参数。

Soil,gravel and slag were selected as wetland substrates in the horizontal subsurface flow constructed wetland,and purified simulated wastewater containing ammonia nitrogen（NH＋4-N）,nitrate nitrogen（NO-3-N） and phosphate phosphorus（PO-4-P） as the main component of nitrogen with different retention time.And the effect of substrates in constructed wetland on the variety of pH,the removal efficiency of NO-3-N and NH＋4-N were investigated.Results demonstrated that the removal efficiencies of nitrogen and phosphorus in soil-slag constructed wetland were best than these of other constructed wetlands when the hydraulic retention time was 10 days.The removal rates of NH＋4-N in each constructed wetland was higher than that of NO-3-N.The purification efficiency of nitrogen in top layer was higher than bottom layer.The break-point of pH curve indicated the termination of NH＋4-N oxidation reaction in constructed wetland.