Research Institute, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands.
Water Sci Technol. 2011;63(8):1557-65. doi: 10.2166/wst.2011.206.
An innovative osmotic membrane bioreactor (OMBR) is currently under development for the reclamation of wastewater, which combines activated sludge treatment and forward osmosis (FO) membrane separation with a RO post-treatment. The research focus is FO membrane fouling and performance using different activated sludge investigated both at laboratory scale (membrane area of 112cm2) and at on-site bench scale (flat sheet membrane area of 0.1 m2). FO performance on laboratory-scale (i) increased with temperature due to a decrease in viscosity and (ii) was independent of the type of activated sludge. Draw solution leakage increased with temperature and varied for different activated sludge. FO performance on bench-scale (i) increased with osmotic driving force, (ii) depended on the membrane orientation due to internal concentration polarization and (iii) was invariant to feed flow decrease and air injection at the feed and draw side. Draw solution leakage could not be evaluated on bench-scale due to experimental limitation. Membrane fouling was not found on laboratory scale and bench-scale, however, partially reversible fouling was found on laboratory scale for FO membranes facing the draw solution. Economic assessment indicated a minimum flux of 15L.m-2 h-1 at 0.5M NaCl for OMBR-RO to be cost effective, depending on the FO membrane price.
一种创新的渗透膜生物反应器（OMBR）目前正在开发中，用于废水的回收，它将活性污泥处理和正向渗透（FO）膜分离与 RO 后处理相结合。研究重点是使用不同的活性污泥在实验室规模（膜面积为 112cm2）和现场台架规模（平板膜面积为 0.1 m2）上研究 FO 膜的污染和性能。实验室规模的 FO 性能（i）随温度升高而增加，因为粘度降低，（ii）与活性污泥的类型无关。渗滤液泄漏随温度增加而增加，且因不同的活性污泥而不同。台架规模的 FO 性能（i）随渗透压驱动力增加而增加，（ii）由于内部浓差极化，取决于膜的取向，（iii）不受进料流量减少和在进料和渗滤侧注气的影响。由于实验限制，无法在台架规模上评估渗滤液泄漏。在实验室规模和台架规模上均未发现膜污染，但在 FO 膜面向渗滤液的实验室规模上发现了部分可恢复的污染。经济评估表明，取决于 FO 膜的价格，OMBR-RO 的最低通量为 15L.m-2 h-1，在 0.5M NaCl 下具有成本效益。
