Influence Of Technological Parameters In Removal Of Pharmaceutical Pollutants In Wastewater Treated By Inversed A~2/O Process

Due to improper use of human and animal medicines, a variety of pharmaceuticalpollutants are generally detected in municipal wastewater, which cause potential harmto the environment and human health. A2/O wastewater treatment process has goodremoval for nitrogen and phosphorus, and the process of simple structure, steadyrunning and therefore is a kind of biological treatment of sewage treatment plantwidely used methods. Through technology improvement, the reversed A2/O process isalso more and more used by urban wastewater treatment plant, but due to the differentwastewater treatment plant of the difference of geographical position and the externalenvironment, so as to make the reversed A2/O process operation parameters aredifferent, therefore, this experiment was carried out by the reversed A2/O processdifferent operation parameters on the law of pharmaceutical pollutant.This topic through simulation in the laboratory of xi’an fourth wastewatertreatment plant of reversed A2/O process to establish reaction device of continuousrunning, analysis of detected in xi’ an sewage phenacetin (PNT), gemfibrozil (GFZ),caffeine (CAF), diclofenac (DCF) and cholesterol (CH) five pharmaceutical pollutantsremoval performance, as campus wastewater water, control the six parameters of thereactor operation conditions (hydraulic retention time (HRT), inflow concentration,temperature, pH, dissolved oxygen (DO) sludge retention time (SRT)), by changing theoperation parameters, analysis the five kinds of selected pharmaceutical pollutantsremoval effect.Experimental analysis found that the biodegradability of PNT is best, in a longerHRT、higher temperature、pH neutral and aerobic reaction pool DO=2.5mg/L can be almost completely under the condition of the degradation, degradation efficiency canreach more than90%on average, while in the degradation effect of PNT short sludgeretention time is bad, the concentration of the detected in inflow water for300μg/L，Aerobic reaction pool water also detected100μg/L residual concentration; CAF inaerobic, high temperature and pH=7.5neutral condition, the removal efficiency of99%on average, but when the temperature falls, the concentration in the aerobicreaction pool is significantly higher than other conditions; the removal efficiency ofGFZ is95%, when the neutral condition and the water temperature of25℃, in thetemperature is20℃, aerobic reaction pool and the effluent, the water concentrationappear obvious fluctuations, almost no removal efficiency; Mud samples, it is foundthat there is higher content of DCF, so it may be the sludge adsorption removal, underacid condition, about77%of the DCF is sludge adsorption, explain DCF not easilybiodegradable and easy to be sludge adsorption; And CH in various process parameterschange on effect was not obvious difference, when anoxia and anaerobic, CH havebetter removal rate, can reach55.7%and39.4%respectively, and the removal rate ofaerobic condition is only4.9%, to detect a small amount of CH in the sludge, analystssay, it may be due to the effect of the order of reactor, make the CH under aerobicconditions removal ratio is less, the removal of part of the sludge adsorption effecttogether with the microbial degradation.Through this topic research found that the reversed A2/O process forpharmaceutical pollutants removal efficiency to a certain extent, but the effluent stillcontains pharmaceutical pollutants, in order to reduce the pharmaceutical pollutants tothe environment, should strengthen the source control, and then the wastewatertreatment.