[Objective] The aim was to study the influence factors of membrane fouling in the A/O-MBR system so as to control membrane fouling belter,prolong the service life of membrane,further reduce the coal of water treatment and promote the popularization of membrane bio reactor (MBR) effectively. [Method] Based on small A/O-MBR device.an orthogonal teat with three factors (including aeration intensity, pump-slop ratio and mixed liquor suspended Solid) and three levels was designed to optimise three parameters,and the effects of factors on membrane fouling and their mechanisms were studied through single-factor analysis. [ Result ] The order of operation parameters affecting mem brane fouling in A/O-MBR was aeration intensity > pump-stop ratio > mixed liquor ftugpentfed solid1and the optimum operating parameters were composed of 1. 6 m3/h of aeration intensity ,4 500 mg/L of mixed liquor suspended solid and 9:2 of pump-slop ratio. With the increase of running lime,soluble microbial product (SMP) and extracellular polymeric substance (EPS) accumulated gradually in reactor,especially EPS, and membrane fouling was accelerated,so EPS is the priority factor for membrane fouling compared with SMP. In addition, membrane fouling was accelerated gradually with the increase of protein content in EPS,while the variation of polysaceharides content in EPS had no obvious effect on membrane fouling,so protein content in EPS is the priority factor for membrane fouling. [Conclusion] The sludy could provide theoret ical references for the choice of parameters,operation and running in practical engineering.%[目的]研究A/O-MBR试验系统中影响膜污染的因素,以便更好地控制膜污染、延长膜的使用寿命,从而有效降低水处理成本及促进MBR工艺的推广.[方法]以小型A/O-MBR装置为载体,选定曝气强度、混合液污泥浓度、抽停比设计三因素三水平的正交试验,对膜污染进行参教优化,通过单因素分析,研究各因素时膜污染的影响并探讨其机理.[结果] A/O-MBR工艺中各远行参教对膜污染的影响次序为:曝气强度＞抽停比＞污泥浓度,最优运行参数为曝气量1.6m3/h,污泥浓度4500 mg/L,抽停比9:2.随着运行时间的延长,胞外聚合物(EPS)和溶解性微生物产物(SMP)逐渐积累,且EPS的积累速度稍大于SMP;随着EPS和SMP浓度的增加,膜污染速率逐渐增大,EPS是导致膜污染的主要因素；随着EPS中蛋白质含量增加,膜污染速率逐渐增大,多聚糖含量的变化对于膜污染速率影响不大,EPS中蛋白质的含量是影响膜污染的主要因素.[结论]该研究为实际工程中参数选定和操作运行提供了理论参考.
展开▼
