Control of membrane fouling during hyperhaline municipal wastewater treatment using a pilot-scale anoxic/aerobic-membrane bioreactor system

• Published in: Journal of environmental sciences (China) 2011-01, Vol.23 (10), p.1619-1625
• Main Authors: Sun, Jingmei, Rong, Jiangxiu, Dai, Lifeng, Liu, Baoshan, Zhu, Wenting
• Format: Article
• Language: English
• Subjects: aeration; anoxic/oxic membrane bioreactor; bioreactors; Bioreactors - microbiology; China; environmental factors; fouling; hyperhaline municipal sewage; long term effects; membrane fouling control; Membranes, Artificial; microorganisms; municipal wastewater; Pilot Projects; pollution control; relationship of various factors; sewage; Sewage - chemistry; Sewage - microbiology; sludge; viscosity; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; wastewater treatment; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; 中试; 好氧; 暂停时间; 污水处理; 生物反应器系统; 缺氧; 膜污染控制; 膜生物反应器
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/S1001-0742(10)60632-8

Membrane fouling limits the effects of long-term stable operation of membrane bioreactor （MBR）. Control of membrane fouling can extend the membrane life and reduce water treatment cost effectively. A pilot scale anoxic/aerobic-membrane bioreactor （A/O- MBR, 40 L/hr） was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin, China. Impact factors including mixed liquid sludge suspension （MLSS）, sludge viscosity （Ix）, microorganisms, extracellular polymeric substances （EPS）, aeration intensity and suction/suspended time on membrane fouling and pollution control were studied. The relationships among various factors associated with membrane fouling were analyzed. Results showed that there was a positive correlation among MLSS, sludge viscosity and trans-membrane pressure （TMP）. Considering water treatment efficiency and stable operation of the membrane module, MLSS of 5 g/L was suggested for the process. There was a same trend among EPS, sludge viscosity and TMP. Numbers and species of microorganisms affected membrane fouling. Either too high or too low aeration intensity was not conducive to membrane fouling control. Aeration intensity of 1.0 m3/hr （gas/water ratio of 25：1） is suggested for the process. A long suction time caused a rapid increase in membrane resistance. However, long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface. The suction/suspended time of 12 min/3 rain was selected for the process. The interaction of various environmental factors and operation conditions must be considered synthetically.