潜流人工湿地中3种基质对氮磷净化的影响

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。

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

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.