The effects of food to microorganism （FIM） ratio and alcohol ethoxylate （AE） dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane b...The effects of food to microorganism （FIM） ratio and alcohol ethoxylate （AE） dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor （SAnMBR）. The fate of AE and its acute and/or chronic impact on the anaerobic microbes were also analyzed. The results indicated that AE had an inhibitory effect to methane production potential （lag-time depends on the AE dosage） and the negative effect attenuated subsequently and methane production could recover at FIM ratio of 0.088-0.357. VFA measurement proved that AE was degraded into small molecular organic acids and then converted into methane at lower FIM ratio （FIM 〈 0.158）. After long-term acclimation, anaerobic microbe could cope with the stress of AE by producing more EPS （extracellular polymeric substances） and SMP （soluble microbial products） due to its self-protection behavior and then enhance its tolerance ability. However, the methane production potential was considerably decreased when AE was present in wastewater at a higher FIM ratio of 1.054. Higher AE amount and FIM ratio may destroy the cell structure of microbe, which lead to the decrease of methane production activity of sludge and methane production potential.展开更多
文摘The effects of food to microorganism （FIM） ratio and alcohol ethoxylate （AE） dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor （SAnMBR）. The fate of AE and its acute and/or chronic impact on the anaerobic microbes were also analyzed. The results indicated that AE had an inhibitory effect to methane production potential （lag-time depends on the AE dosage） and the negative effect attenuated subsequently and methane production could recover at FIM ratio of 0.088-0.357. VFA measurement proved that AE was degraded into small molecular organic acids and then converted into methane at lower FIM ratio （FIM 〈 0.158）. After long-term acclimation, anaerobic microbe could cope with the stress of AE by producing more EPS （extracellular polymeric substances） and SMP （soluble microbial products） due to its self-protection behavior and then enhance its tolerance ability. However, the methane production potential was considerably decreased when AE was present in wastewater at a higher FIM ratio of 1.054. Higher AE amount and FIM ratio may destroy the cell structure of microbe, which lead to the decrease of methane production activity of sludge and methane production potential.
