Tran Duc-Trung, Mendret Julie, Méricq Jean-Pierre, Faur Catherine, Brosillon Stephan
IEM (Institut Européen des Membranes), UMR 5635 (CNRS-ENSCM-UM2), Université de Montpellier, 34095 Montpellier, France.
Membranes (Basel). 2022 Feb 21;12(2):245. doi: 10.3390/membranes12020245.
In this study, the anti-fouling performance of PVDF-TiO composite membranes, indicated by their permeate flux, was studied with different types of synthetic feed solutions. Photo-filtration (filtration under continuous UV irradiation) of solutions containing inorganic and organic components, which are ubiquitous in drinking/natural water, was performed to evaluate their influence on the photo-induced properties and performance of the membranes. The results indicated that inorganic fouling was unlikely to occur on PVDF-TiO membranes, and the presence of common inorganic ions in drinking water did not hinder their performance. However, in the particular case where a small amount of Cu coexisted alongside HCO in the feed solution, inorganic fouling occurred, causing severe flux decline and prohibiting the photo-induced properties of the membranes. On the other hand, when used to filter organic fouling solutions, the membranes showed strong resistance to sodium alginate fouling, and less so for humic acids. In terms of separation efficiency, the membranes showed no advantages when operated in photo-filtration mode, as the rejection rate of both foulants under photo-filtration was not higher than that under normal filtration. In the case of humic acids, the photodegradation of humic substances into smaller compounds that were able to enter the permeate stream led to a lower rejection rate. Nevertheless, photo-filtration of these organic foulants still offered a higher permeate flux than normal filtration, up to a certain concentration level (5 mg/L for humic acids and 50 mg/L for sodium alginate).
在本研究中，通过不同类型的合成进料溶液研究了以渗透通量表示的聚偏氟乙烯-二氧化钛（PVDF-TiO）复合膜的抗污染性能。对含有饮用水/天然水中普遍存在的无机和有机成分的溶液进行光过滤（在连续紫外光照射下过滤），以评估它们对膜的光诱导性能和性能的影响。结果表明，PVDF-TiO膜不太可能发生无机污染，饮用水中常见无机离子的存在不会阻碍其性能。然而，在进料溶液中少量铜与碳酸氢根共存的特殊情况下，发生了无机污染，导致通量严重下降并抑制了膜的光诱导性能。另一方面，当用于过滤有机污染溶液时，膜对海藻酸钠污染表现出较强的抗性，对腐殖酸的抗性则较弱。在分离效率方面，膜在光过滤模式下运行时没有优势，因为光过滤下两种污染物的截留率均不高于正常过滤下的截留率。对于腐殖酸，腐殖物质光降解为能够进入渗透物流的较小化合物导致截留率降低。尽管如此，这些有机污染物的光过滤仍比正常过滤提供更高的渗透通量，直至达到一定浓度水平（腐殖酸为5mg/L，海藻酸钠为50mg/L）。
