Engineering Design On Comprehensive Treatment Of Tea Polyphenol Pharmaceutical Wastewater(Biochemical Part)

With the rapid development of the pharmaceutical industry,Tea polyphenols(TP)is widely used for its functions of health care,anti-cancer,and prevention of cardiovascular diseases and so on.The production process of TP produces a large amount of pharmaceutical wastewater.This kind of wastewater has become one of the most difficult wastewater to deal with in China for its characteristics of high organic pollution concentration,difficult biodegradation,inhibition to mi Croorganisms,high chroma and so on.With the continuous improvement of wastewater discharge standards in the pharmaceutical industry,it has brought more difficulties to the discharge of such wastewater.Based on the Zhejiang Public Welfare Fund project,this paper aim to designs a reliable,economical,efficient and stable wastewater treatment process for the actual production of tea polyphenol extraction wastewater.This pharmaceutical factory located in Nanma Town,Zhejiang Province.The paper comprehensively considers the water quality characteristics,plant site restrictions and other factors,using pretreatment + ana erobic + hydrolysis acidification + biological contact oxidation + advanced treatment process.This thesis focuses on the engineering design and research of the biochemical treatment part.During the debugging process,the changes of COD,p H,BOD5,VFA,MLSS,SS and other parameters of the water in and out of each structure are recorded to study the antibacterial effect on microorganisms.Discussing the technical feasibility of the biochemical combination process,ensure the stable operation of the system and the discharge of water to meet the standard,and finally assist the enterprise to complete the project acceptance.The upflow anaerobic sludge blanket(UASB)adopts the dilution water inlet and low load start mode.After 85 days of commissioning operation,the design load reaches 5 kg COD/(m3·d)and the system runs stably.The p H of the reactor inlet water was controlled at 7.0-7.5.After more than 40 days of operation,a large amount of flocculent sludge was washed out of the pond,and it was found that finely divided granular sludge was formed,and the effluent VFA gradually de Creased.Continue to in Crease the volumetric load of the influent.We finally succeeded in cultivating granular sludge with a particle size of 0.5-2.0mm.but the degree of granulation is not high,and the VFA drops below 200 mg/L.Scanning electron mi Croscopy to observe the surface of the particles,It was found that a large number of filamentous bacteria in the gap were symbiotic with the methanogenic mexican,and some short bacteria and vibrio existed.After UASB is stable,the removal efficiency of TP and COD in wastewater can reach 75% and 83.6%.The whole startup operation is good and there is no system collapse.The hydrolysis acidification tank was started by continuous low-load water intake after 48 hours of suffocating exposure,and the system was stable after 40 days of operation.The hydraulic retention time(HRT)in the hydrolysis acidification tank is 16 h.When the sludge concentration in the control tank is 8000mg/L,the system’s removal efficiency of chromaticity can reach 64.3%.The removal of COD and TP by the hydrolysis acidification tank was not obvious,but the B/C in Creased from 0.43 to 0.56,which has a significant effect on the improvement of biodegradability.The biological contact oxidation tank adopts the "smoke exposure + continuous water inlet" startup mode.The system runs to 32 d and the film is successfully wound.The gas-water ratio in the reactor is controlled at 13-15:1,and the COD removal efficiency of the system can reach 87.7%.Since the TP which is not completely removed is oxidized into an anthraquinone in the contact oxidation pool,it appears red,and the effluent color slightly in Creases,but does not affect the effluent,and the effluent color is less than 30 times.After the anaerobic + hydrolysis acidification + multi-stage biological contact oxidation combined biochemical treatment process is completed.The positive system is officially put into operation,and after the stable operation,the removal efficiency of the main pollutants of the whole system is above 90%.The effluent indicators can meet the design requirements,thus reducing the burden of subsequent deep processing and reducing operating costs.The wastewater has recently implemented the relevant discharge standards for pharmaceutical wastewater.It is expected that after the regional sewage treatment plant is built,the local management standard will be implemented.At this time,the secondary sedimentation tank is far higher than the standard.