Organic fouling in forward osmosis: Governing factors and a direct comparison with membrane filtration driven by hydraulic pressure
Organic fouling in forward osmosis: Governing factors and a direct comparison with membrane filtration driven by hydraulic pressure
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DOI：
10.1016/j.memsci.2020.118759
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发表时间：
2021-02
影响因子：
9.5
通讯作者：
Francesco Ricceri;Mattia Giagnorio;K. Zodrow;A. Tiraferri
中科院分区：
文献类型：
--
作者：
Francesco Ricceri;Mattia Giagnorio;K. Zodrow;A. Tiraferri
基于文献中报道的大量实验，人们普遍认为，相对于液压驱动的膜应用，水力驱动的正向渗透（FO）的结垢行为是上级的。然而，经常存在实验混杂因素，妨碍不同工艺之间的公平比较，其中之一是部署不可比的膜。本研究系统地研究了影响FO中有机污染的条件，并在同等条件下比较了FO和液压驱动过程中的行为。在测试中使用相同的现有技术的聚酰胺FO膜，其用真实的进料溶液并在不同条件下运行以观察初始通量、汲取溶液和进料离子组成的影响。结果表明，初始通量和钙通量下降和恢复的程度有最强的影响。当流量相对较低时，FO中不同驱动溶液的影响变得明显。污染指数和有效驱动力的分析，以及膜污染后的直接观察，支持的结论是，与类似的液压驱动相比，FO过程的污染行为不一定更好，特别是在相关的操作条件下，当两个过程以类似的通量工作。
The fouling behavior of osmotically-driven forward osmosis (FO) is widely believed to be superior with respect to hydraulic pressure-driven membrane applications, based on a number of experiments reported in the literature. However, experimental confounders often exist, preventing fair comparison between the different processes, one being the deployment of non-comparable membranes. This study systematically investigates the conditions influencing organic fouling in FO and compares the behavior in FO and in a hydraulic pressure-driven process, under equivalent conditions. The same state-of-the-art polyamide FO membranes were used in the tests, which were run with real feed solutions and under varying conditions to observe the effect of initial flux, draw solution, and feed ionic composition. The results suggest that initial flux and calcium have the strongest influence on the extent of flux decline and recovery. The influence of different draw solutions in FO becomes apparent when the flux is relatively low. Analysis of the fouling indices and of the effective driving force, as well as direct observation of membranes following fouling, support the conclusion that the fouling behavior of the FO process is not necessarily better compared to an analogous hydraulic pressure-driven one, especially under relevant operational conditions and when the two processes work with similar fluxes.