太阳能曝气人工垂直潜流湿地去除生活污水氮磷的试验研究

利用芦苇和砾石构建太阳能曝气人工垂直潜流湿地处理生活污水。设定水力负荷400 mm/d,气水比10∶1,当进水氨氮(NH₄-N)、总氮(TN)、溶解性反应磷(SRP)和总磷(TP)平均浓度为5.14,7.56,0.40,0.53 mg/L时,引入太阳能曝气后,各自的平均去除率分别提高24.8%,9.4%,15.7%和11.5%。随着气温下降和进水浓度降低,湿地微生物脱氮除磷能力下降,曝气对改善生活污水氮磷去除作用不显著。对试验系统而言,太阳能曝气湿地基本建设费用是无曝气湿地的2.85倍;但以20 a运行为基础折算出的污水处理费比无曝气湿地仅高0.02元/m³。综上,从污染去除性能和污水长期处理费用来看,太阳能曝气湿地在生活污水处理方面具有较好的技术经济优势。

Removal of Nitrogen and Phosphorus in Domestic Wastewater by Solar Aerated Vertical Subsurface Flow Constructed Wetlands

Reeds (Phragmites)and gravel were used to develop pilot scale solar aerated vertical subsurface flow constructed wetlands to treat domestic wastewater.The hydraulic loading rate was set 400 mm/d and air to water ra-tio was 10∶1.Experimental results indicated that solar aeration resulted in 24.8%,9.4%,15.7% and 11.5%increment in total mean removal respectively for ammonia-nitrogen(NH4-N),total nitrogen (TN),soluble reactive phosphorus (SRP)and total phosphorus(TP)with corresponding influent concentrations of 5.14 mg/L,7.56 mg/L,0.40 mg/L and 0.53 mg/L.Low atmospheric temperature and influent concentration,however,caused a negligible role of solar aeration in nitrogen and phosphorus removal.For the present experiment apparatus,the ex-penditure of solar aerated wetland is 2.85 times the non-aerated wetlands.Considering a total investment over a pe-riod of 20 years,the cost to treat domestic wastewater for solar aerated wetland is only 0.02 RMB/m3 higher than that of non-aerated wetland.In conclusion,solar aerated constructed wetland is a promising solution of treating do-mestic wastewater with competitive technical and economical advantages.