Study On The Performance Of Hybrid A-A/O Process Under Different Conditions

Wastewater recycling is an important way to deal with the problem of water shortage andhave economic advantages compared with exploiding water sources.With the DischargeStandards of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002) becomingmore strict for effluent of the wastewater treatment plant,new urban wastewater treatmentplant must take into account the nitrogen and phosphorus removal,and some of our existingsewage treatment plant is facing the problem of upgrading.In this study, suspension carriers were put into the aerobic tank of conventional A-A/Oprocess, and concentrated on the performance of hybrid A-A/O process and nitrification rateunder different operating conditions.In the dynamic test,DO and SRT was selected as avariable factor respectively,and the treatment effect was studied.In the static test,the conditionof aerobic tank in dynamic test was simulated,the nitrification rate between suspended sludgeand attached film was detected and the effect of temperature and SRT on nitrification rate wasdetected.The results show that temperature of20-27℃,the system maintained at SRT of12d,aerobic tank DO was maintained at2.5(±0.20) mg/L,effluent NH4+-N、TN、COD meet theDischarge Standards of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002stair A),and TP satisfied the discharge standard of GB18918-2002stair B,and anoxic andaerobic phosphorus uptaken capacity remained at70%and20%,and at the same time theobvious effect of SND could be found.Yobs increased with the reduction of SRT,sludgereduction was implemented by higher microbial predation.Comparing with conventionalA-A/O process,because of putting suspension carriers into the system,nitification rate wasimproved and was effeted by SRT,and lower temperature has little effect on attachednitrifying bacteria,while do has obvious effect on suspended nitrifying bacteria.