不同污染负荷下垂直流人工湿地对农村灰水的净化效果及其影响分析

ANALYSIS ON PURIFICATION EFFECTS AND INFLUENCES OF VERTICAL FLOW CONSTRUCTED WETLAND FOR THE TREATMENT OF RURAL GREY WATER UNDER DIFFERENT POLLUTION LOADS

为进一步研究不同污染负荷下垂直流人工湿地对农村灰水的净化效果,利用室内构建的垂直流人工湿地模拟装置,在湿地床填充火山石、陶粒、沸石,设置3种不同的污染负荷,研究其对农村灰水中污染物去除率的影响。结果表明:1)不同污染负荷下,湿地系统对污染物的去除存在显著差异(P<0.05),在污染负荷1[ρ(NH^(+)_(4)-N)=7.13 mg/L、ρ(TN)=9.1 mg/L、ρ(PO_(4)^(3-)-P)=0.30 mg/L、ρ(TP)=0.61 mg/L、ρ(COD)=71.76 mg/L]情况下,显示较好的去除效果,其中PO_(4)^(3-)-P去除率高达87.15%,出水TP质量浓度满足GB 3838—2002《地表水环境质量标准》Ⅲ类水质要求;2)在3种污染负荷条件下,NH^(+)_(4)-N去除率分别达到77.75%、65.76%和54.78%,TN去除率分别达到66.04%、54.89%和58.13%;3)在污染负荷2[ρ(NH^(+)_(4)-N)=13.34 mg/L、ρ(TN)=14.29 mg/L、ρ(PO_(4)^(3-)-P)=0.74 mg/L、ρ(TP)=1.50 mg/L、ρ(COD)=192.57 mg/L]情况下,出水ρ(COD)可达到GB 5084—2021《农田灌溉水质标准》中水田作物及蔬菜标准。污染负荷不仅是造成系统微环境指标变化的关键因素,同时也会对系统净化效果产生重要影响。研究结果对农村灰水处理中垂直流人工湿地系统的稳定运行及后续优化具有重要的参考意义。

In order to further study the purification effect of sagging once through constructed wetland with different pollution loads on rural grey water,the vertical flow constructed wetland simulation device built indoors was used to fill the wetland bed with volcanic stone,ceramsite and zeolite,and set three different pollution loads to study its impact on the pollutant removal rate of rural grey water.The results showed that:1)under different pollution loads,the removal of pollutants in the wetland system was significantly different(P<0.05).Under the condition of pollution load 1[ρ(NH^(+)_(4)-N)=7.13 mg/L,ρ(TN)=9.1 mg/L,ρ(PO_(4)^(3-)-P)=0.30 mg/L,ρ(TP)=0.61 mg/L,ρ(COD)=71.76 mg/L],the system showed good removal effect,and the removal rate of PO_(4)^(3-)-P was as high as 87.15%.The effluent TP concentration standard theⅢclass water quality requirements of Surface Water Environmental Quality Standards(GB 3838-2002).2)The removal rates of NH^(+)_(4)-N in the system can reach 77.75%,65.76%and 54.78%under three different pollution loads,respectively.Their corresponding TN removal rates of the system can reach 66.04%,54.89%and 58.13%.3)Under pollution loads 2[ρ(NH^(+)_(4)-N)=13.34 mg/L,ρ(TN)=14.29 mg/L,ρ(PO_(4)^(3-)-P)=0.74 mg/L,ρ(TP)=1.50 mg/L,ρ(COD)=192.57 mg/L],the effluentρ(COD)can meet the standards for paddy crops and vegetables in the Standard for Water Quality of Farmland Irrigation(GB 5084-2021).Pollution load is not only the key factor causing the change of system microenvironment index,but also has an important impact on the purification effect of the system.The research results have important reference significance for the stable operation and subsequent optimization of vertical flow constructed wetland system in rural grey water treatment.