Productive Experimental Study Of A/O+BIOFOR Treating Mixing Pharmaceutical Wastewater

The medical group in Jiangxi province mainly researches and develops、 products kinds of medical and health products、topical disinfection supplies. In the process of production, there are a certain amount of mixing pharmaceutical wastewater and domestic sewage. If the waste water is directly discharged without treatment, it could pollute environment of irreversible damage.The wastewater mainly come from the steps of extracting, washing drugs, washing bottles, washing equipments, washing workshop grounds and domestic sewage.The wastewater is organic wastewater with medium-low concentration, but the water quality changes greatly, COD of the influent is500to1500mg/L. In order to make the effluent to stably reach standard, we choose "A/O+BIOFOR bio-filter" to process the wastewater. A/O with pre-denitrification can remove organic compounds and ammonia nitrogen simultaneously. The effluent of A/O system enters into BIOFOR bio-filter in order to further remove COD and NH3-N.Finally.all kind of the effluent’s indexes could completely meet the discharge standard of discharge standard of water pollutants for pharmaceutical industry mixing/compounding and formulation category (GB21908-2008) table2. After three months" debugging and running, combined with literature data, we got the following conclusion:1、The influent was intermittent when A/O system started. In the first week, the influent’s flow rate is design flow’s50%. As the seed sludge adapt gradually the water quality.we comprehensively improve hydraulic loading.After1.5months. SV could reach20%-27%stably. the sludge biofloccus shows filemot and a good precipitation performance.The removal rate of COD can basically reach70%, the removal rate of NH3-N could increase into60%, A/O system are started successfully.2、When A/O system run stably, it is efficient in COD and NH3-N removal. COD of the influent change500～1500mg/L, COD of the effluent could stably reach200-250mg/L, the average removal rate could reach75%; and NH3-N of the influent change30～70mg/L, NH3-N of the effluent could stably reach18-25mg/L, the average removal rate could reach55%. 3、The optimum operating condition of A/O system:the operating temperature is25-35℃, SV30is20%～30%, MLSS is2500-4000mg/L, internal recycle ratio is200%. Anoxic pond influent’s pH maintain6.5-8.5, and DO is less than0.8mg/L; because oxic pond influent could be consumed alkalinity, pH maintain7.0-8.5. and DO of oxic pond’front end is4-5mg/L. DO of oxic pond’ distal end is2-3mg/L.4、BIOFOR reactor hangs biological membrane up with the mode of combination of natural hanging and vaccinational hanging that the biological membrane can have a fast formation. We’d better aerate in the water for three days without any air in the beginning, and the ratio of air to water must be set as1:1,the load about inlet water would be changed to low,then rises it up one week later. After hanging for20days, there is a layer of yellow filamentous biofloccus attaches to the surface of filter material which could be seen by our eyes, at this moment, the removal rate of COD rises to48%from25%.After hanging for45days, the biological membrane which attaches to the surface of the middle lower part filter material has formed in the BIOFOR reactor. it has a deep color.and the removal rate of COD is75%.the removal rate of NH3-N is50%. it means that the step of hanging biological membrane has finished.5、When BIOFOR bio-filter run stably. COD of the influent changes126～258mg/L. COD of the effluent could basically be less than60mg/L, the average COD of the effluent is44.2mg/L.the average removal rate could reach72.45%;and NH3-N of the influent changes11-27.2mg/L, NH3-N of the effluent could stably basically be less than10mg/L, the average NH3-N of the effluent is7.6mg/L,the average removal rate could reach56.8%.6、The optimum operating condition of BIOFOR bio-filter:gas-water ratio is5:1.Combined air-water backwash mode was taken in BIOFOR backwash:firstly single air backwash0.8-1.0m3/(m2·min) with the backwash time4-6min, then combined air-water backwash, the time is within6min, air backwash0.8-1.0m3(m2·min) and water backwash0.4-0.5m3/(m2·min); finally single water backwash0.6-0.8m3/(m2·min) with the backwash time5-7min.7、when "A/O+BIOFOR bio-filter" run stably, the average removal rate of COD can reach94%, the average removal rate of NH3-N could reach83%, the average removal rate of SS can reach63.7%, COD、 NH3-N and SS could completely meet the discharge standard of 《discharge standard of water pollutants for pharmaceutical industry mixing/compounding and formulation category》(GB21908-2008) table2.