Abstract:The treatment efficiency of the modified anaerobic baffled reactor (mABR) is greatly affected by the hydraulic characteristics, which is specifically influenced by upflow velocity of the riser chamber. In this study, two-dimensional multiphase-flow with CFD-fluent software was used to perform the numerically simulation for two-dimensional multi-phase flow. Under conditions of hydrolytic acidification (solid-liquid two-phase flow) of refractory wastewater and fermentation-gas yield (gas-liquid-solid three-phase flow) of high-concentration organic wastewater, when the variations of flow velocity and solid content occurred, the effects of upflow velocity on the flow field characteristics in mABR were investigated.. The results showed that the increase of upflow velocity and anaerobic biogas production was beneficial to the sludge-water interface lifting, sludge-water mixing enhancement and mass-transfer efficiency improvement. However, exorbitant upflow velocity could result in sludge loss and reduce the hold capacity of biomass. As a result analysis, the hydraulic agitation and solid content are preferable for sludge-water mixing at an upflow velocity of 2.0~2.5 m·h?1 for two-phase flow or an upflow velocity of 1.5~2.0 m·h?1 for three-phase flow, achieving the best pollutants removal performance. Key words:modified anaerobic baffled reactor(mABR)/ multiphase flow/ upflow velocity/ solid holdup.
图7两相流第2反应室X=0.165 m固含率分布及溢出口点(0.2,0.17)污泥浓度 Figure7.X=0.165 m solid content distribution in the second reaction chamber with two-phase flow and sludge concentration at overflow points (0.2, 0.17)
图11三相流第2反应室X=0.165 m固含率分布及溢出口点(0.2,0.17)污泥浓度 Figure11.X=0.165 m solid content distribution in the second reaction chamber with three-phase flow and sludge concentration at overflow points (0.2, 0.17)
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College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China Received Date: 2019-04-03 Accepted Date: 2019-06-20 Available Online: 2020-03-02 Keywords:modified anaerobic baffled reactor(mABR)/ multiphase flow/ upflow velocity/ solid holdup Abstract:The treatment efficiency of the modified anaerobic baffled reactor (mABR) is greatly affected by the hydraulic characteristics, which is specifically influenced by upflow velocity of the riser chamber. In this study, two-dimensional multiphase-flow with CFD-fluent software was used to perform the numerically simulation for two-dimensional multi-phase flow. Under conditions of hydrolytic acidification (solid-liquid two-phase flow) of refractory wastewater and fermentation-gas yield (gas-liquid-solid three-phase flow) of high-concentration organic wastewater, when the variations of flow velocity and solid content occurred, the effects of upflow velocity on the flow field characteristics in mABR were investigated.. The results showed that the increase of upflow velocity and anaerobic biogas production was beneficial to the sludge-water interface lifting, sludge-water mixing enhancement and mass-transfer efficiency improvement. However, exorbitant upflow velocity could result in sludge loss and reduce the hold capacity of biomass. As a result analysis, the hydraulic agitation and solid content are preferable for sludge-water mixing at an upflow velocity of 2.0~2.5 m·h?1 for two-phase flow or an upflow velocity of 1.5~2.0 m·h?1 for three-phase flow, achieving the best pollutants removal performance.