水力停留时间对改良型AAO-MBR工艺处理夏季农村生活污水的影响

Effect of HRT on Performance of Modified AAO-MBR Process for Rural Domestic Wastewater Treatment in Summer

水力停留时间(HRT)是影响AAO工艺脱氮除磷效率的重要因素。采用改良型AAO-MBR工艺处理某农村生活污水,考察了夏季时HRT对处理装置出水效果的影响。试验结果表明,该工艺对低浓度农村生活污水中COD_(Cr)、氨氮的去除效果较稳定,平均去除率分别为69.50%、98.90%。TN去除率为26.50%~56.60%,随厌氧段和缺氧段HRT增加而显著提高。TP去除率随好氧段HRT增大而增大,随缺氧段HRT增大呈现先增大后减小的趋势。厌氧段、缺氧段、好氧段适宜HRT分别为2.0、4.0、10.0 h,此条件下装置出水COD_(Cr)、氨氮、TN、TP质量浓度分别为38、0.104、8.73、0.42 mg/L,稳定达到江苏省《农村生活污水处理设施水污染物排放标准》(DB 32/3462—2020)一级A标准。

Hydraulic retention time(HRT)is an important factor for the efficiency of nitrogen and phosphorus removal in AAO process.The modified AAO-MBR was adopted to treat rural domestic wastewater,and the effect of HRT on effluent performance in summer was investigated.Results showed that COD_(Cr) and ammonia nitrogen were stably removed by this process,average removal rates of COD_(Cr) and ammonia nitrogen were 69.50%and 98.90%,respectively.The removal rate of TN was 26.50%~56.60%,which increased significantly with the increase of HRT in anaerobic and anoxic sections.Meanwhile,the removal rate of TP increased with the increase of HRT in the aerobic section,and showed an initially increasing and then decreasing trend as the HRT of anoxic section increased.Under optimum HRT of 2.0,4.0,10.0 h in anaerobic,anoxic,and aerobic sections,the effluent concentrations of COD_(Cr),ammonia nitrogen,TN and TP were 38,0.104,8.73,0.42 mg/L,respectively,which satisfied first grade A criteria of Discharge Standard of Water Pollutants for Rural Domestic Sewage Treatment Facilities(DB 32/3462—2020)in Jiangsu Province.