The Reuse Engineering Design Of Two-stage Pretreatment-A~2/O-BEMBR For Pharmaceutical Wastewater Treatment

Waste from the pharmaceutical industry can pose a serious risk to the environment and public health if discharged directly without disposal.Pharmaceutical industry wastewater is a product of the drug and formulation development process,its composition is complex,its biochemical properties are low and it is difficult to treat,so its safe disposal is vital for environmental health.There is a pharmaceutical plant in Linjiang City,Jilin Province,with a daily production wastewater of 810 m~3,of which 710 m~3/d is pharmaceutical wastewater,with the following water quality indicators:COD:1100 mg/L;BOD₅:100 mg/L;SS:120 mg/L;NH₃-N:25 mg/L;TP（in P）:6 mg/L;TN（in N）:50 mg/L;pH:7.2-8.0.The plant’s domestic wastewater is discharged at a rate of 100 m~3 per day.The better treated domestic wastewater is treated separately from the pharmaceutical wastewater.After fully studying the current situation of pharmaceutical wastewater treatment at home and abroad and some engineering examples,for the poor biochemical properties of the pharmaceutical plant wastewater,the characteristics of high nitrogen content,determine the pharmaceutical wastewater reuse treatment process as follows:pharmaceutical industrial wastewater---grating---conditioning tank---Fenton oxidation tank---coagulation and sedimentation tank---hydrolysis acidification tank---A~2/O tank---BEMBR reactor---disinfection Pool---Reuse storage tank.The domestic wastewater from the plant area is treated by the lifting pump room and cyclone sedimentation tank and then directly fed into the above A~2/O tank.The treatment process can produce a good effect on the domestic sewage and pharmaceutical wastewater discharged from the pharmaceutical plant,and the removal rate of BOD₅,COD,SS and NH₃-N in the wastewater is above 90%after treatment by this process,and the drainage can meet the current"urban wastewater recycling urban miscellaneous water quality"GB/T 18920-2020 and"pharmaceutical industry pollutant emission standards".The water can meet the standards for new enterprises in the mixed preparation category.The reused water is used for road spraying and toilet flushing.It not only reduces pollutants and realises the virtuous cycle of water resources in the plant,but also creates better economic benefits.