| Summary: | 碩士 === 國立交通大學 === 環境工程系所 === 95 === Organic matters are major foulants during ultrafiltration and limit the development of membrane. The influence of humic acid on the organic fouling of ultrafiltration was studied as a function of calcium ions.
Molecular weight and microscopy were used to study the characterization of membrane and organic foulants. Flux decline of filtration in the presence calcium ions was very severe. The saturated bond was decreased by calcium ions bridging with humic acids, decreasing the contact angle. Thus, the membrane, after filtration with humic acid and calcium ions, was hydrophilic.
UF membrane flux declines seriously with the absence of calcium ions in a humic acid solution, attributing to membrane pore blocking. Humic acid and calcium ions, due to complex formation, reduce molecular weight distribution. Molecular weight determines a membranes pore size. The molecular weight of complex is similar to membrane pore size. The molecular weight of humic acid is smaller than 50kDa and causes serious membrane fouling for a UF membrane (30kDa).
In the results of SEM, the pore sizes were smaller after filtration. There were significant amounts of foulants on the membrane surface in the presence of calcium ions. This research focuses on the humic acid curled by calcium ions that lead to immediate flux decline soon.
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