两级序批式MBR膜污染控制方法研究

STUDY ON MEMBRANE FOULING CONTROL METHOD OF TWO-STAGE SEQUENCING BATCH MBR

针对MBR在实际应用过程中存在的同步脱氮除磷效果不佳、膜污染严重等问题,提出两级序批式MBR工艺,对该工艺的膜污染影响因素及控制方法进行了试验研究。结果表明,在MBR中保持适宜的污泥质量浓度对于膜污染的控制有重要的作用,当污泥质量浓度稳定在6～7g·L-1时,膜比流量基本稳定,随着污泥质量浓度的增加,膜比流量逐步降低,当污泥质量浓度超过10g·L-1以后,膜比流量直线下降;投加PAC至1g·L-1可以增加污泥粒径、减少大分子有机物在膜表面沉积,从而有助于延缓膜污染;序批式间歇运行与空曝相结合的运行方式可以有效降低泥饼层污染及凝胶层污染,使系统在更高膜通量下运行,而膜污染速率却远低于连续流单级好氧MBR系统。

The two-stage sequencing batch membrane bioreactor （TSBMB） process was put forward to face with the problems in poor effect of simultaneous nitrogen and phosphorus removal and serious membrane fouling during practical applications of MBR. The factors of membrane fouling and operation mode of MSMBR have been investigated. The results indicated that keeping proper sludge concentration in MBR played an important role in membrane fouling control. When the sludge concentration was stabilized at 6-7 g ·L^-1, the membrane flux was stable. The membrane flux slowed gradually as the sludge concentration increases, and there was a steep decline in the membrane flux when the sludge concentration higher than 10 g·L^-1. The sludge size increased and the deposition of macromolecular organism on the membrane surface decreased when the addition of PAC increased to 1 g·L^-1. Sequencing batch operation mode and the combination of intermittent membrane suction and idle aeration could reduce the cake layer fouling and the colloidal layer fouling effectively. The system could run under higher membrane flux and the membrane fouling rate was far lower than one-stage aerobic MBR.