Im Sung-Ju, Choi Jungwon, Lee Jung-Gil, Jeong Sanghyun, Jang Am
Graduate School of Water Resources, Sungkyunkwan University (SKKU), 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Republic of Korea.
King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Biological and Environmental Science & Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
Chemosphere. 2018 Mar;194:76-84. doi: 10.1016/j.chemosphere.2017.11.067. Epub 2017 Nov 15.
A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.
本研究首次提出并评估了体积延迟渗透与低压膜（VRO-LPM）混合工艺的新概念。在VRO-LPM混合工艺中使用了市售的正向渗透（FO）膜和超滤（UF）膜，以克服FO工艺中汲取液（DS）再生和渗透液生产的能量限制。为了评估其作为水回收工艺的可行性并优化操作条件，分别对错流FO工艺和死端模式UF工艺进行了评估。对于FO工艺，确定0.15 g/mL的聚磺酸苯乙烯（PSS）的DS浓度为最佳，其通量高且反向盐通量低。选择截留分子量为1 kDa的UF膜是因为其在LPM工艺中对PSS的截留率高。作为单一工艺，UF（LPM）的通量高于FO，但这可以通过调整VRO-LPM系统中FO膜和UF膜的有效膜面积来控制。VRO-LPM混合工艺仅需要为FO工艺配备循环泵。这导致VRO-LPM工艺生产饮用水的比能耗降低，与单一FO工艺相似。因此，新开发的VRO-LPM混合工艺，通过适当选择DS，可以用作节能的水生产方法，并且性能优于传统的水回收工艺。
