Treatment Of High Salinity Pharmaceutical Wastewater Using Combined Processes Of Anaerobic Hydrolysis-A/O-MBR

Pharmaceutical wastewater has the characteristics of complex composition,high salinity and resistant degradation.According to the practical wastewater conditions of influent and effluent,selecting a reasonable treatment process combination and making parameters optimize can effectively remove pollutants and save economic costs.In this study,based on the actual wastewater quality and treatment requirement from a fine chemical pharmaceutical enterprise in the northeast of China,water quality analysis,design of treatment process and lab-scale research were carried out.Then,process was improved and parameters were optimized ombining with the experimental results,followed by the research of the stable operation with optimal parameters.Finally,the intact combined treatment process was designed n the basis of experimental results.The study results are as followed.(1)A/O process could remove COD effectively,and removal rate of COD was above 90%.However,it had poor denitrogenation effect.When the NH4+-N and TN of inflow was 110 mg/L and 124 mg/L,the removal rate was below 54% and 42%,respectively.Meanwhile,the sludge bulking in sedimentation basin resulted in turbidity of effluent.(2)On the basis of treatment effect of the progress of A/O,the combined process of anaerobic hydrolysis-A/O-MBR was designed.The laboratory research results showed that the combined process of anaerobic hydrolysis-A/O-MBR could denitrify more effectively compared with the progress of A/O.The removal rate was97%,92% and 76% respectively when the COD,NH4+-N and TN of inflow was 3233mg/L,121 mg/L and 136 mg/L.(3)The impacts of influent salinity,HRT and nitrification liquid reflux ratio on the treatment effects for the combined process of anaerobic hydrolysis-A/O-MBR were studied.The salinity should be lower than 4000 mg/L.The HRT of hydrolysis,A/O and MBR was 16 h,64 h(HRTA:HRTO=1:3)and 4.8 h,respectively.And nitrification liquid reflux ratio was 200%.(4)During the steady running period of the combined process of anaerobic hydrolysis-A/O-MBR,the average COD,NH4+-N,TKN and TN of effluent was 178mg/L,12 mg/L,15 mg/L and 48 mg/L,respectively.The total removal rates were95.8%,93.7%,93.2% and 78.9%.The water quality of effluent could meet the requirements of the sewage discharged into the pipe network of municipal wastewater treatment plant,in the standard DB 21/1627-2008.(5)Taking the results of laboratory research,the post denitrification unit,which could use existing waste liquid of methanol as organic carbon source,was designed on the rear of A/O process to ensure the TN of the effluent could meet standards when the TN of the inflow was too high.As a result,the combined process turned to be anaerobic hydrolysis-A/O/A-MBR process.The technological process,plane and section were designed.The investment estimation was also carried out.