A Trial Run Of Biotreatment Of Norfloxacin Intermediate Pharmaceutical Wastewater By CASS Process Under Low Load

This experiment is to use the vacant CASS tank of a fine chemical sewage treatment station in Luoyang as the test equipment,and use the effluent from the hydrolysis station of the sewage station as the experimental influent.The operating conditions of the CASS process for the treatment of norfloxacin intermediate pharmaceutical wastewater are tested.By changing the operating conditions of the CASS tank,the effects of operating parameters such as influent duration,sludge reflux ratio,drainage ratio,aeration time,dissolved oxygen?DO?at aeration end and sludge concentration?MLVSS?on system operation were analyzed.The optimal operating parameters were obtained,and the kinetic analysis of sludge increase and substrate degradation during the influent and reaction phases of the CASS process was carried out.The main test results are as follows:When the CASS process was used to treat norfloxacin intermediate pharmaceutical wastewater,the influent effect was best at 4h;the sludge reflux ratio and drainage ratio had little effect on the removal of pollutants,and the sludge reflux ratio was the best at 133%.The optimal drainage ratio is 1/5;the aeration time has a great influence on the pollutant removal effect,and the effect is better when the aeration time is longer,but considering the cost-effectiveness of the removal effect and energy consumption,the aeration time is 6h.Good;the reasonable interval of dissolved oxygen at the end of aeration is 2.8⁴.0mg/L,which is higher than the traditional dissolved oxygen concentration.Considering the system should strengthen the removal effect of COD,so the dissolved oxygen at the end of aeration is controlled at 3.0³.5mg/L.When the suitable sludge concentration?MLVSS?of CASS process is 2300mg/L²500mg/L,the removal effect of pollutants is the best.Based on the reaction kinetics analysis of the CASS process,the kinetic equations of the influent and reaction phases were obtained,and the sludge kinetics constant of the CASS process was obtained:Y=0.3108mgVSS/mgCOD;K_d=0.0929d^-1;kinetic constant of degradation of organic matter:V_max=0.15,K_S=386.58.The results of the test were applied to the actual project,the treatment effect of the sewage station was significantly improved,and the water quality of the effluent was greatly improved.After adjustment,the COD removal rate was increased from76.14%to 86.57%,the average effluent concentration was 169.2mg/L;the NH₃-N removal rate was increased from 86.79%to 96.21%,and the average effluent concentration was 1.31mg/L.All indicators can meet the"Water Pollution Emission Standards for Chemical Synthetic Pharmaceutical Industry".