正渗透膜生物反应器与反渗透耦合系统的运行性能研究

Performance of a hybrid system of osmotic membrane bioreactor and reverse osmosis

针对目前正渗透膜生物反应器(OMBR)存在的汲取液回收和盐分积累的问题,借助反渗透(RO)膜的高效截留性能和微滤(MF)膜允许溶解性盐透过的特性,构建了新型的MFOMBR-RO组合系统.结果表明,由于MF的引入,OMBR中的盐度稳定在1.95~2.43mS/cm,盐分积累得到缓解.采用RO膜与FO膜进行耦合,可以将稀释后的汲取液电导率从33mS/cm浓缩至45mS/cm,同步实现汲取液的回收和水的回用.MF-OMBR-RO系统能够有效去除有机物、氮和磷等污染物,其中RO出水可以作为高品质水进行回用,而MF出水能够满足城市杂用水的要求.与三醋酸纤维素(CTA)和聚酰胺(TFC)材质的FO膜相比,水通道蛋白FO膜的运行通量略低,但是其生物污染较轻.

In order to overcome the problems including draw solute recovery and salt accumulation associated with the osmotic membrane bioreactors（OMBR）,a new OMBR system assisted with microfiltration（MF）membrane for discharging soluble salts and reverse osmosis（RO）membrane for recovering draw solute was proposed.The results indicated that the salinity in the bioreactor was controlled in the range of 1.95～2.43 mS/cm due to the introduction of MF membrane.RO membrane could effectively concentrate the draw solution from 33 mS/cm to 45 mS/cm,and thus achieving the simultaneous recovery of draw solute and water.The MF-OMBR-RO system effectively removed theorganic matters,ammonia nitrogen and phosphorus,i.e.,the RO permeate could be reused as a high quality water while MF effluent was suitable for urban miscellaneous water.Compared with the commercial forward osmosis（FO）membrane made of cellulose triacetate（CTA）and thin-film composite polyamide（TFC）,the aquaporin FO membrane used in this study had a lower initial water flux but a more stable operating flux due to a lower biofouling.