The Treatment Of Pharmaceutical Wastewater By Hydrolysis And Acidification-A/O Process With Biological Carbon Fiber

The pharmaceutical industry is one of the leading industries in China. Containing complex chemicals and high concentration of organic pollutants, the pharmaceutical wastewater is considered difficult to be treated. Based on this fact and regarding the potential risk on environment caused by pharmaceutical wastwater, to explore a treatment technology which has high efficiency, low operation cost, stable operation and convenient maintenance has become an essential task.In this study, a technology of hydrolytic acidification-A/O coupling with the biological carbon fiber is employed for treatment of pharmaceutical wastewater. To investigate efficiency of the chosen technique, three issues including the improvement of hydrolysis acidification process, the optimum operating conditions of combined process and the stable operation of the combined process are studied.Below are the major results and conclusions.(1) The use of biological carbon fiber filler and aerating stirring are effective for the enhancement of the treatment efficiency of hydrolysis acidification and the biodegradability of wastewater; through hydrolysis acidification, the organic loading shock can be effectively buffered:when the volume load swells to5.984kgCOD·m-3d-1, the removal rate of can be maintained at more than22%and the removal rate can rise rapidly when the volume load reducing.(2) The optimal HRT for hydrolysis acidification process and A/O process are12h and16h (HRTA=4h, HRTO=12h), respectively; the optimal DO of the O pool is ranged from3.6to4.5mg/L; the optimal reflux ratio R is ranged from200%to300%. Under this optimal condition, the best removal efficiencies of CODCr, NH4+-N and TN of the combined process are94.2%,86.2%and72.2%, respectively.(3) The application and operating efficiency of the technology is stable, and the average concentration of CODcr, NH4+-N, TN, NO3-and NO2-are239.4mg/L,31.7mg/L,76.0mg/L,31.3mg/L and0.63mg/L, respectively. The effluent can achieve Ⅱ grade of Integrated Wastewater Discharge Standard (GB8978-1996).