Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes
博士 === 臺灣大學 === 環境工程學研究所 === 95 === In this study, two types of commercial nanofiltration (NF) membranes (NF70 and NF270) were chosen to remove four model disinfection by-product (DBP) precursors (resorcinol, phloroglucinol, 3-hydroxybenzoic acid, and tannic acid) with different functional groups....
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ndltd-TW-095NTU055150462015-10-13T13:55:54Z http://ndltd.ncl.edu.tw/handle/09936835993841767189 Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes 奈米薄膜去除消毒副產物有機前質之機制研究 Yi-Li Lin 林怡利 博士 臺灣大學 環境工程學研究所 95 In this study, two types of commercial nanofiltration (NF) membranes (NF70 and NF270) were chosen to remove four model disinfection by-product (DBP) precursors (resorcinol, phloroglucinol, 3-hydroxybenzoic acid, and tannic acid) with different functional groups. The clean NF membranes were characterized by physico-chemical properties including molecular weight cutoff, membrane pore radius, hydrophobicity (contact angle measurement), membrane surface morphology (SEM and AFM), membrane surface charge (streaming potential measurement), membrane elemental composition (XPS and energy dispersive X-ray spectrometer, EDX) and surface roughness (AFM) to validate the NF rejection mechanisms of DBP precursors. The filtration experiments of the model compounds were assessed under various pH values (3-10) in which the removal efficiencies for both membranes were reasonably good at high pH values. Electrostatic repulsion is the prevailing mechanism for the model compounds with negatively ionizable functional groups rejected by the negatively charged NF membranes at high pH values, while steric hindrance exclusion and adsorption are controlling factors for the rejection of unionized small organic molecules. The presence of calcium does not significantly affect model compounds retentions. The calcium rejection rises with the presence of model compounds as well as an increase of pH due to its formation of complex ion between calcium and model compounds. For the examination of membrane surface roughness, it is essential to use the same scan area when comparing the surface roughness of different membranes. In general, membranes with rougher surface posses a higher fouling potential, which makes the flux decline more rapidly. Pen-Chi Chiang 蔣本基 2007 學位論文 ; thesis 158 en_US |
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博士 === 臺灣大學 === 環境工程學研究所 === 95 === In this study, two types of commercial nanofiltration (NF) membranes (NF70 and NF270) were chosen to remove four model disinfection by-product (DBP) precursors (resorcinol, phloroglucinol, 3-hydroxybenzoic acid, and tannic acid) with different functional groups. The clean NF membranes were characterized by physico-chemical properties including molecular weight cutoff, membrane pore radius, hydrophobicity (contact angle measurement), membrane surface morphology (SEM and AFM), membrane surface charge (streaming potential measurement), membrane elemental composition (XPS and energy dispersive X-ray spectrometer, EDX) and surface roughness (AFM) to validate the NF rejection mechanisms of DBP precursors.
The filtration experiments of the model compounds were assessed under various pH values (3-10) in which the removal efficiencies for both membranes were reasonably good at high pH values. Electrostatic repulsion is the prevailing mechanism for the model compounds with negatively ionizable functional groups rejected by the negatively charged NF membranes at high pH values, while steric hindrance exclusion and adsorption are controlling factors for the rejection of unionized small organic molecules. The presence of calcium does not significantly affect model compounds retentions. The calcium rejection rises with the presence of model compounds as well as an increase of pH due to its formation of complex ion between calcium and model compounds.
For the examination of membrane surface roughness, it is essential to use the same scan area when comparing the surface roughness of different membranes. In general, membranes with rougher surface posses a higher fouling potential, which makes the flux decline more rapidly.
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author2 |
Pen-Chi Chiang |
author_facet |
Pen-Chi Chiang Yi-Li Lin 林怡利 |
author |
Yi-Li Lin 林怡利 |
spellingShingle |
Yi-Li Lin 林怡利 Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes |
author_sort |
Yi-Li Lin |
title |
Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes |
title_short |
Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes |
title_full |
Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes |
title_fullStr |
Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes |
title_full_unstemmed |
Mechanisms Study of Organic DBP Precursors Removal by Nanofiltration Membranes |
title_sort |
mechanisms study of organic dbp precursors removal by nanofiltration membranes |
publishDate |
2007 |
url |
http://ndltd.ncl.edu.tw/handle/09936835993841767189 |
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