Operation Characteristics Study On The Treatment Of Chinese Patent Medicines Wastewater With UASB-BCO-BAF Process

Upflow Anaerobic Sludge Bed Reactor(UASB) and Biological AeratedFilter(BAF) were used in the reconstruction and extension of a chinese traditionalpatent medicine wastewater treatment station. These two new reactors with theoriginal biological contact oxidation unit(BCO) reunited the UASB-BCO-BAFanaerobic-aerobic combined process to treat the medium-low concentration organicwastewater.The experimental result revealed that using WWTP anaerobic digestion sludgeas the inoculum, the UASB reactor start-up could be finished in one month. Underupflow velocity 0.55m/h, even volume organic load 1.5kgCOD/(m~3·d) condition,UASB cultivated anaerobic granular sludge. These granular sludges have minimum27m/h sedimentation velocity and maximum 1.5mm diameter. To treatingmedium-low concentration chinese patent medicines wastewater, while the eveninfluent COD concentration was 1000mg/L, the UASB could reach 70% CODremoval efficiency. Research proved a positive correlation between the UASBreactor COD removal efficiency and reactor influent COD concentration. WhileUASB reactor's influent COD concentration ranged form 500mg/L to 1600mg/L,lower inlet concentration led lower COD removal efficiency. Furthermore, to treatingmedium-low concentration wastewater, temperature had less impact on the reactor'sCOD removal efficiency.The new multi-stage aerobic procedures composed of reserved BCO units andthe newly-built BAF. Once the UASB malfunctioned, the multi-stage aerobicprocedures could enhance the system emergency treatment performance and keepthe effluent quality. The application of anaerobic sludge granulation technique andgranular ceramic support material microbial immobilization technology extended thedormancy period of microbial in famine condition, and the whole system could beshutdown completely in the manufacturer's off-season. After 28 days halt, theUASB-BCO-BAF system recovered rapidly. The reconstructed anaerobci-aerobic combined system has stronger resistanceto impact load resist and cheaper operation cost than pure aerobic process.Long-term-operating effluent metⅠ-class criteria of Integrated Wastewater DischargeStandard (GB8978-1996).