前期研究表明在人工潜流湿地(SFCWs)中设置好氧段和厌氧段可显著提高SFCWs对COD、NH4+-N的去除率.然而曝气产生的富氧环境不利于NO3--N和NO2--N的去除,一定程度上抑制了反硝化反应的进行.反硝化程度较低是实验中仍需进一步解决的问题.本研究在前期研究的基础上,对好氧/厌氧多级串联潜流人工湿地结构及工艺进行了改进优化,采用多点进水的措施来强化反硝化过程,并设计相应的区段去除该部分污染物.结果表明,水力负荷约为0.06m3.(m2.d)-1时,进一步优化结构和比例的好氧-缓冲-厌氧-缺氧-好氧曝气多点进水湿地对COD、NH4+-N和TN的去除率可达到91.6%、100%和87.7%.在补充进水之后的区段,COD/N迅速升高到10以上,做到了补充碳源的同时最大限度地利用湿地去除污染物.改良后的湿地达到了净化工艺优化的目的,为提高人工湿地总氮去除效率提供了理论依据及应用基础.
Previous studies showed that setting aerobic and anaerobic paragraph segments in the subsurface constructed wetlands(SFCWs) can improve the COD,NH+4-N,and TN removal rate,whereas the oxygen enrichment environment which produced by the artificial aeration could restrain the NO-3-N and NO-2-N removal process,and to a certain extent,inhibit the denitrification in SFCWs Therefore,in this research the structure and technology of SFCW with aerobic and anaerobic paragraph segments were optimized,by using the multi-point water inflow and setting the corresponding section for the extra pollutant removal.Results showed that with the hydraulic load of 0.06 m3·(m2·d)-1,the COD,NH+4-N and TN removal efficiencies in the optimized SFCW achieved 91.6%,100% and 87.7% respectively.COD/N increased to 10 speedily after the inflow supplement.The multi-point water inflow could add carbon sources,and simultaneously maximum utilization of wetland to remove pollutants.The optimized SFCW could achieve the purposes of purification process optimization,and provide theoretical basis and application foundation for improving the total nitrogen removal efficiency.