Treatment Of Pharmaceutical Wastewater By Combined Process Of Coagulation Air Flotation, Hydrolytic Acidification, ABR/pre-anoxic, Two- Stage A/O, Coagulation Sedimentation

A pharmaceutical company in Chongqing mainly produces antibiotics such as vancomycin,lovastatin,medimycin,mycophenolic acid and tobramycin,which produce about 2000m³ of high-concentration antibiotic pharmaceutical wastewater every day,while washing tanks,equipment cleaning and The living use also produces 400m³ low-concentration wastewater with high concentration of CODcr,NH₄-N,TN and SS,poor biodegradability,bio-inhibition and large pH change.The company's wastewater treatment station originally handled pharmaceutical wastewater for two pharmaceutical companies.Since one of the pharmaceutical companies stopped production,the influent water quality and water volume of the wastewater treatment station changed significantly compared with the previous one,so the treatment of the original wastewater treatment station was carried out.After the investigation of the process and equipment facilities,on the basis of making full use of the existing equipment and facilities,the“three-stage”combination process using physical and chemical pretreatment-biochemical treatment-deep treatment was determined.Then through small trials to determine the best type of coagulant and coagulant dosage and reaction time,volume load and sludge load of anaerobic process and A/O process,the final treatment process is coagulation air flotation-Hydrolysis acidification-ABR-two-stage A/O-coagulation precipitation combined treatment process.During the project commissioning process,due to the obvious change of the influent water quality caused by the product rotation production,a variety of on-site pilot tests were supplemented at the project site,and the treatment process and operating parameters were continuously adjusted and optimized to cope with the water quality different from the initial start-up.In the case,the final treatment process is coagulation air flotation-hydrolysis acidification-ABR/pre-anoxic tank-two-stage A/O-coagulation sedimentation.Compared with the previous process,when the influent water quality changes greatly,the effluent water quality It is also able to achieve compliance and has a large advantage in operating costs.Through the small test,the research on the shortcomings of the treatment process and the actual engineering debugging are carried out,and the following conclusions are drawn:?1?The content of CODcr,NH₄-N and TN in pharmaceutical wastewater is high,but because the wastewater contains a large amount of organic matter that is difficult to be biodegraded,this part of the organic matter in the denitrification reaction cannot be utilized by microorganisms,and it is necessary to supplement glucose to meet denitrification.The carbon source required;the higher the concentration of ammonia nitrogen,often due to the lack of corresponding alkalinity in the nitrification reaction,should pay attention to the timely addition of alkalinity.?2?If the content of organic matter that is difficult to biodegrade is too high,the CODcr of the effluent will exceed the standard.The coagulation and precipitation will be used to treat the pharmaceutical wastewater.The coagulant FeCl₃ is better than the PAC for the biodegradable CODcr in the pharmaceutical wastewater.The optimal processing parameters for the pilot test were:when the FeCl₃ dosage was 300 mg/L,the removal rate of CODcr reached 33.93%.The Fenton oxidation reaction has a slightly better removal effect of refractory CODcr in pharmaceutical wastewater than coagulant,but it has a lower advantage than FeCl3 due to higher processing cost.?3?The ABR part of the anaerobic reactor is transformed into the front anoxic section.Under the premise that the effluent water quality meets the standard,the CODcr removal rate in the anaerobic stage is appropriately reduced,and the carbon source in the raw water is fully utilized to reduce the denitrification reaction.The dosage of the carbon source has a good effect on the rational use of the carbon source in the raw water and the reduction of the treatment cost.?4?For the high-concentration CODcr antibiotic pharmaceutical wastewater,the coagulation air flotation-hydrolysis acidification-ABR/pre-anoxic section-two-stage A/O-coagulation sedimentation combined process can achieve good treatment effect,and the combined process It can adapt to a wide range of water quality changes,especially in the case of large changes in pH,CODcr and ammonia nitrogen of the influent water,and the effluent water quality is stable.