Design And Operation Control Of Wastewater Treatment For Hepatitis B Vaccine Production

The hepatitis B vaccine production wastewater contains high concentration of NH3-N, TP and COD, which makes it difficult to be treated. In this research, this kind of wastewater was chosen as a target, and its treatment process design, the start-up and operational control of the main treatment units were investigated. The results obtained are as follows:The treatment process of “MAP- contact oxidation” was utilized to treat the wastewater, considering its characteristics. The batch operation was applied in the reactor used for the chemical precipitation, and one operation period included mixing, reaction, precipitation and separation in turn. A kind of soft combination packing was filled in the contact oxidation pool with HRT of 48 h. The wastewater qualities after treatment were: pH 6~9, COD≤300mg/L, NH3-N≤30mg/L and TP≤3mg/L.The optimal MAP reaction conditions were determined as pH of 9 and the reagent proportion of n(Mg2+)/n(PO43-)/n(NH4+) of 1.44/1.2/1. After MAP reaction, PAC was added for coagulation processing. When average COD,NH3-N and TP values in the influent were 3818mg/L,2074mg/L and69.7 mg/L, respectively, the average COD, NH3-N and TP values in the effluent after MAP reaction were 2516mg/L, 57mg/L and 2.3mg/L, respectively. The corresponding removal rates of COD,NH3-N and TP were 34.5%,97.2% and 96.7%, respectively.The contact oxidation pool was used to treat the effluent of MAP reaction further. After initial start-up and load increasing period, the system operation became stable and efficient. When DO was controlled as 3~4mg/L and HRT was 48 h, average COD and NH3-N values in the influent were 2801mg/L and 53mg/L, respectively, the average COD and NH3-N values in the effluent after contact oxidation treatment were 158mg/L and 27mg/L, respectively. The corresponding removal rates of COD and NH3-N were 94.4% and 47.7%, respectively.When treatment process of “MAP- biological contact oxidation” was used to treat hepatitis b vaccine production wastewater, the average removal rates of COD, NH3-N, TP were achieved as 96.3%, 98.9% and 97.5%, respectively. The effluent quality could meet the standard requirement of the downstream wastewater treatment plant. The environmental benefit was significant. The total investment of the treatment system was 650,000 yuan, and the treatment cost was 88 yuan/m3. The floor area was relatively small and the treatment efficiency was high, which were the actual needs of the enterprise.