MBR工艺中膜系统污染与堵塞的研究

为节约水资源，城市中水正逐步用作电厂补充水。为防止可能带来的污染，启用膜生物反应器（MBR）成为目前首选。通过对某电厂长期运行的MBR系统膜组件进行污染物成分分析及电镜分析，研究了浸没式MBR膜系统主要污染物及运行周期对膜污染程度的影响。研究结果表明，浸没式MBR膜系统主要为有机物污染，随运行时间增加，污染物形成密实且不可逆堵塞层，导致膜孔隙窄化、膜系统化学清洗效率降低。建议缩短膜系统化学清洗周期、优化清洗工艺，并应在膜系统跨膜压差明显增高初期对膜组件进行化学清洗，以达到良好的清洗效果。

The Study of Membrane Fouling in MBR

Urban recycled water has been used as water supplement in coal-fired power plants for water conservation. The membrane bio-reactor (MBR) might be a prime choice to avoid the potential pollution. The predominant fouling substances in submerged MBR system and the effect of the operation cycle on membrane fouling degree are studied through the analysis on the fouling constituent and SEMs of the membrane module taken out from a long term operating MBR system. The results show that the pollutants in the submerged MBR membrane system are mainly organics. With the performance life prolonging, the pollutants are gradually developed into irreversible fouling layer, which leads to membrane pore getting narrower and cleaning efficiency getting lower. Therefore, this paper suggests that the cleaning cycle should be shortened and the cleaning process should be optimized. In addition, the cleaning should be conducted when the pressure difference between the membranes increases substantially in its early stage so as to achieve good cleaning effect.