Zhang Wanzhu, Wang Lin, Dong Bingzhi
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China and Key Laboratory of Yangtze Water Environment of Ministry of Education, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China and Key Laboratory of Yangtze Water Environment of Ministry of Education, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, China E-mail:
Water Sci Technol. 2017 Dec;76(11-12):3160-3170. doi: 10.2166/wst.2017.392.
The fouling behavior during forward osmosis (FO) was investigated. Tannic acid was used as a model organic foulant for natural organic matter analysis since the main characteristics are similar, and calcium ions were added at different concentrations to explore the anti-pollution capability of FO membranes. The initial permeate flux and calcium ions strength were varied in different operating conditions to describe membrane fouling with membrane cleaning methods. The observed flux decline in FO changed dramatically with the type of foulant and the type of draw solution used to provide the osmotic driving force. Calcium ions aggravated membrane fouling and decreased transmembrane flux. Membrane cleaning methods included physical and physicochemical approaches, and there was no obvious difference among the typical cleaning methods (i.e., membrane flushing with different types of cleaning fluids at various crossflow velocities and backwashing with varying osmotic driving forces) with respect to flux recovery. Ultrasonic cleaning damaged the membrane structure and decreased permeate flux, and reverse diffusion of salt from the draw solution to the feed side accelerated after cleaning.
对正向渗透（FO）过程中的污染行为进行了研究。由于主要特性相似，使用单宁酸作为天然有机物分析的模型有机污染物，并添加不同浓度的钙离子以探究FO膜的抗污染能力。在不同操作条件下改变初始渗透通量和钙离子强度，以描述采用膜清洗方法时的膜污染情况。观察到的FO通量下降随污染物类型和用于提供渗透驱动力的汲取液类型而显著变化。钙离子加剧了膜污染并降低了跨膜通量。膜清洗方法包括物理和物理化学方法，典型清洗方法（即使用不同类型清洗液在不同错流速度下冲洗膜以及在不同渗透驱动力下进行反冲洗）在通量恢复方面没有明显差异。超声清洗会破坏膜结构并降低渗透通量，清洗后盐从汲取液向进料侧的反向扩散加速。
