Fouling and natural organic matter removal in adsorbent/membrane systems for drinking water treatment.
Fouling and natural organic matter removal in adsorbent/membrane systems for drinking water treatment.
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DOI：
10.1021/es0260418
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发表时间：
2003-03
影响因子：
11.4
通讯作者：
Miaomiao Zhang;Chun Xing Li;M. Benjamin;Yujung Chang
中科院分区：
文献类型：
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作者：
Miaomiao Zhang;Chun Xing Li;M. Benjamin;Yujung Chang
添加到处理饮用水的超滤 (UF) 系统中的吸附颗粒可以去除水中的天然有机物 (NOM) 和一些其他污染物，但它们对膜污染的影响并不一致 - 在某些情况下，污染会减少，而在其他情况下，污染会加剧。本研究调查了添加了粉末活性炭 (PAC)、加热氧化铁颗粒 (HIOP) 或（非吸附性）SiO2 颗粒的超滤系统的行为。从质量角度来看，PAC 从溶液中去除了大部分 NOM，HIOP 去除较少，而 SiO2 基本上没有去除。然而，对于 PAC 和 SiO2，增加固体剂量会导致结垢稳步增加，而添加 HIOP 时则出现相反的趋势。在没有 NOM 的情况下，没有任何固体明显污染膜。因此，尽管 NOM 是结垢的原因，但将其从溶液中去除并不一定能减少结垢；如果去除发生在膜表面附近的滤饼层中，则去除的机制可能与去除的绝对量一样重要。三个系统中形成的滤饼层的扫描电子显微镜图像表明，NOM 将 PAC 或 SiO2 颗粒彼此结合并与膜表面结合，从而使这些颗粒成为系统中污垢的一部分。相比之下，NOM 似乎将 HIOP 彼此结合，但不与膜结合。该过程在滤饼层中留下了足够的孔隙空间，使水能够以最小的阻力到达膜，并且减少了 NOM 或 HIOP 污染膜表面的趋势。
Adsorbent particles added to ultrafiltration (UF) systems treating drinking water can remove natural organic matter (NOM) and some other contaminants from the water, but their effect on membrane fouling is inconsistent-in some cases, fouling is reduced, and in others, it is exacerbated. This research investigated the behavior of UF systems to which powdered activated carbon (PAC), heated iron oxide particles (HIOPs), or (nonadsorbent) SiO2 particles were added. On a mass basis, the PAC removed the most NOM from solution, the HIOPs removed less, and the SiO2 removed essentially none. However, in the case of both PAC and SiO2, increasing the dose of solids led to a steady increase in fouling, whereas the opposite trend applied when HIOPs were added. In the absence of NOM, none of the solids fouled the membrane significantly. Thus, even though NOM is a causative agent for fouling, removing it from solution does not necessarily reduce fouling; the mechanism of removal can be just as important as the absolute amount removed, if the removal occurs in a cake layer near the membrane surface. Scanning electron microscopy images of the cake layers formed in the three systems suggest that the NOM binds PAC or SiO2 particles to one another and to the membrane surface, so that the particles become part of the foulant in the system. By contrast, the NOM appears to bind HIOPs to one another but not to the membrane. This process leaves enough pore space in the cake layer for water to reach the membrane with minimal resistance, and it reduces the tendency for either the NOM or the HIOPs to foul the membrane surface.