Surface water biopolymer fractionation for fouling mitigation in low-pressure membranes
Surface water biopolymer fractionation for fouling mitigation in low-pressure membranes
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DOI：
10.1016/j.memsci.2018.02.024
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发表时间：
2018-05-15
影响因子：
9.5
通讯作者：
Huber, Stefan A.
中科院分区：
文献类型：
--
作者：
Kimura, Katsuki;Shikato, Koki;Huber, Stefan A.
随着液相色谱-有机碳检测（LC-OCD）技术在微滤（MF）和超滤（UF）等低压膜污染研究中的广泛应用，大分子亲水性生物聚合物组分引起的膜污染已被认识。在这项研究中，饮用水源进行了为期16个月的深入调查。膜过滤使用中空纤维MF膜进行了定期反冲洗恒通量模式，和两个预处理（铝凝聚和阴离子交换）进行了检查方面的生物聚合物的去除和污染缓解。较高的生物聚合物去除率实现阴离子交换比混凝没有引起更好的控制膜污染MF。混凝和阴离子交换去除了不同类型的生物聚合物，这意味着生物聚合物部分的多样性。检查了LC-OCD分析的改进设置，其中两个不同的柱顺序连接。结果表明，生物聚合物组分检测为单峰，分子量> 10，000 Da，常规LC-OCD装置由分子量> 1，000，000 Da的各种分子组成。发现混凝去除具有较高结垢潜力的大尺寸生物聚合物;而阴离子交换优先去除具有较低结垢潜力的小尺寸生物聚合物。在不同日期收集的给水中的大尺寸生物聚合物的浓度与膜污染的程度相关。为了推广从使用特定饮用水源的实验中得出的结论，还进行了过滤从不同饮用水源分离的生物聚合物的分批MF测试。大尺寸的生物聚合物馏分在膜污染的演变的重要性也建议与不同的饮用水源。
With the widespread application of liquid chromatography with organic carbon detection (LC-OCD) to investigate membrane fouling in low-pressure membranes such as microfiltration (MF) and ultrafiltration (UF), membrane fouling by macromolecular hydrophilic biopolymer fraction has been recognized. In this study, a drinking water source was intensively investigated over 16 months. Membrane filtration using hollow-fiber MF membranes was carried out in constant flux mode with periodic backwashing, and two pretreatments (aluminum coagulation and anion exchange) were examined in terms of biopolymer removal and fouling mitigation. Higher biopolymer removal rates achieved by anion exchange than coagulation did not cause better control of membrane fouling in MF. Coagulation and anion exchange removed different types of biopolymers, which implied diversity in the biopolymer fraction. A modified set-up of LC-OCD analysis in which two different columns were sequentially connected was examined. It was demonstrated that the biopolymer fraction detected as a single peak with molecular weight of > 10,000 Da with the conventional LC-OCD set-up comprised of molecules with a variety of molecular weights including > 1,000,000 Da. It was found that coagulation removed large-size biopolymers with higher fouling potentials; while anion exchange preferentially removed small-size biopolymers with lower fouling potential. Concentration of large-size biopolymers in the feed water collected on different dates correlated with the degree of membrane fouling. In an attempt to generalize the conclusion drawn from the experiments using the specific drinking water source, batch MF tests filtering biopolymers isolated from different drinking water sources were also carried out. Importance of the large-size biopolymer fraction in the evolution of membrane fouling was also suggested with different drinking water sources.