Effect of calcium ions on fouling properties of alginate solution and its mechanisms
Effect of calcium ions on fouling properties of alginate solution and its mechanisms
复制标题
钙离子对海藻酸盐溶液污染特性的影响及其机制
DOI：
10.1016/j.memsci.2016.12.006
复制
发表时间：
2017-03-01
影响因子：
9.5
通讯作者：
Li, Renjie
中科院分区：
文献类型：
--
作者：
Zhang, Meijia;Lin, Hongjun;Li, Renjie
本文系统研究了钙离子对海藻酸钠溶液过滤行为的影响及其机理。结果表明，随着Ca ~（2+）浓度的增加，形成的凝胶层的过滤阻力和海藻酸钠溶液的比过滤阻力（SFR）均呈单峰曲线，最大SFR高达3.63 × 10 ~（15）m.kg（-1）。系列分析表明，Ca 2+浓度对所形成的凝胶的抗孔堵塞性、官能团组成和元素组成没有明显影响。相反，Ca 2+浓度的增加引起的胶体形成和海藻酸盐聚合物在溶液中的微形态的转变，以及对应的单峰模式的过滤行为。结果表明，Flory-Huggins机理控制了海藻酸钠凝胶极高的SFR。海藻酸钠与钙离子的初始结合发生在分子间而非分子内，这是海藻酸钠凝胶微形态和SFR随钙离子浓度增加而变化的主要机制。这些研究结果提供了深入了解海藻酸盐凝胶污染与钙离子，也给膜生物反应器中的膜污染控制的启示。
In this study, effect of calcium ions on the filtration behaviors of alginate solution and its underlying mechanisms were systematically investigated. It was found that, the filtration resistance of the formed gel layer and the specific filtration resistance (SFR) of alginate solution showed an unimodal pattern with increase in Ca2+ concentration, and the maximal SFR was as extremely high as 3.63x10(15) m.kg(-1). Series analyses showed that Ca2+ concentration exerted no apparent impact on pore clogging resistance, composition of functional groups and elements of the formed gel. In contrary, increase in Ca2+ concentration caused transitions of colloid formation and alginate polymer micromorphology in solution, well corresponding to the unimodal pattern of filtration behaviors. It was proposed that, Flory-Huggins mechanism governed the extremely high SFR of the alginate gel. Meanwhile, it was suggested that initial calcium binding by alginate occurred in intermolecular rather than intramolecular, which was the key mechanism governing the development of micromorphology and SFR of alginate gel with increase in Ca2+ concentration. These findings offered deep insights into alginate gel fouling associated with calcium ions, and also gave implications to membrane fouling control in membrane bioreactors.