Sludge granulation and the effect of gas-liquid-solid separator （GLSS） design on the efficiency of upflow anaerobic sludge blanket （UASB） and upflow anaerobic sludge filter （UASF） reactors, operating at HRTs ran...Sludge granulation and the effect of gas-liquid-solid separator （GLSS） design on the efficiency of upflow anaerobic sludge blanket （UASB） and upflow anaerobic sludge filter （UASF） reactors, operating at HRTs ranging from 3 to 12 h was investigated. VSS/TS ratio gradually increased in both the reactors with increasing sludge age （from 0.5 to more than 0.7 for UASB reactor and 0.012 to 0.043 for UASF reactor）. X-Ray diffraction analysis of the UASF sludge showed the presence of expanding clays revealing its additional absorption capability. Fuoraphyllite and albite precipitation related to excellular polymers of the microbial shell structure, showed the extended growth of microorganisms during sludge granulation. A gradual decrease （82%-69%） in COD removal with decreasing HRT was apparent in UASF reactor. In case of UASB reactor, this decrease was marginal because addition of GLSS device significantly improved （14%-20%） the overall efficiency of the UASB reactor. GLSS enhanced the efficiency of the UASB reactor by increasing the settleability of suspended particles and accelerating the coagulation of colloidal particles due to the velocity gradient.展开更多
The solid holdup,in a 150 mm-ID×2460 mm-height gas-liquid-solid expanded bed with air,water and glass beads(the diameter of particles is 0.6-0.8 mm)was firstly investigated based on the immersion-type online mult...The solid holdup,in a 150 mm-ID×2460 mm-height gas-liquid-solid expanded bed with air,water and glass beads(the diameter of particles is 0.6-0.8 mm)was firstly investigated based on the immersion-type online multiphase measuring instrument,and bubble behavior was studied via the BVW-2 double electrical conductivity probe.The effect of the superficial gas velocity and liquid velocity on the expanded ratio,the transition ratio,the bubble rising velocity,the gas holdup and the solid holdup was studied.It is discovered that compared with the gas velocity,the liquid velocity has stronger impact on the expanded ratio,but it is opposite for the transition ratio.The average gas holdup and solid holdup increase linearly as the superficial gas velocity goes up.Among it,the gas holdup increases greater in the center,while the solid holdup increases greater near the wall.Compared with it,when the superficial liquid velocity rises,the average gas holdup hardly changes,but the average solid holdup keeps decreasing,especially the solid holdup distributes flatter with the increase of the superficial liquid velocity.展开更多
文摘Sludge granulation and the effect of gas-liquid-solid separator （GLSS） design on the efficiency of upflow anaerobic sludge blanket （UASB） and upflow anaerobic sludge filter （UASF） reactors, operating at HRTs ranging from 3 to 12 h was investigated. VSS/TS ratio gradually increased in both the reactors with increasing sludge age （from 0.5 to more than 0.7 for UASB reactor and 0.012 to 0.043 for UASF reactor）. X-Ray diffraction analysis of the UASF sludge showed the presence of expanding clays revealing its additional absorption capability. Fuoraphyllite and albite precipitation related to excellular polymers of the microbial shell structure, showed the extended growth of microorganisms during sludge granulation. A gradual decrease （82%-69%） in COD removal with decreasing HRT was apparent in UASF reactor. In case of UASB reactor, this decrease was marginal because addition of GLSS device significantly improved （14%-20%） the overall efficiency of the UASB reactor. GLSS enhanced the efficiency of the UASB reactor by increasing the settleability of suspended particles and accelerating the coagulation of colloidal particles due to the velocity gradient.
基金supported by the National Natural Science Foundation of China(Nos.91834303,22008169)the Open Research Fund of State Key Laboratory of Multiphase Complex Systems(No.MPCS-2019-D-11).
文摘The solid holdup,in a 150 mm-ID×2460 mm-height gas-liquid-solid expanded bed with air,water and glass beads(the diameter of particles is 0.6-0.8 mm)was firstly investigated based on the immersion-type online multiphase measuring instrument,and bubble behavior was studied via the BVW-2 double electrical conductivity probe.The effect of the superficial gas velocity and liquid velocity on the expanded ratio,the transition ratio,the bubble rising velocity,the gas holdup and the solid holdup was studied.It is discovered that compared with the gas velocity,the liquid velocity has stronger impact on the expanded ratio,but it is opposite for the transition ratio.The average gas holdup and solid holdup increase linearly as the superficial gas velocity goes up.Among it,the gas holdup increases greater in the center,while the solid holdup increases greater near the wall.Compared with it,when the superficial liquid velocity rises,the average gas holdup hardly changes,but the average solid holdup keeps decreasing,especially the solid holdup distributes flatter with the increase of the superficial liquid velocity.
