Ultrafiltration behaviors of alginate blocks at various calcium concentrations
Alginate, a linear copolymer, is composed of 1,4-linked β-d-mannuronic acid (M) and α-l-guluronic acid (G), which are combined into homopolymeric blocks (MM-block and GG-block) and heteropolymeric block (MG-block). It has been widely used as a model foulant in various studies of membrane fouling, th...
Saved in:
Main Authors: | , , |
---|---|
Other Authors: | |
Format: | Article |
Language: | English |
Published: |
2015
|
Subjects: | |
Online Access: | https://hdl.handle.net/10356/102971 http://hdl.handle.net/10220/38689 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Institution: | Nanyang Technological University |
Language: | English |
id |
sg-ntu-dr.10356-102971 |
---|---|
record_format |
dspace |
spelling |
sg-ntu-dr.10356-1029712020-09-26T21:57:50Z Ultrafiltration behaviors of alginate blocks at various calcium concentrations Meng, Shujuan Winters, Harvey Liu, Yu School of Civil and Environmental Engineering Nanyang Environment and Water Research Institute DRNTU::Engineering::Environmental engineering::Water treatment Alginate, a linear copolymer, is composed of 1,4-linked β-d-mannuronic acid (M) and α-l-guluronic acid (G), which are combined into homopolymeric blocks (MM-block and GG-block) and heteropolymeric block (MG-block). It has been widely used as a model foulant in various studies of membrane fouling, thus this study investigated the impacts of calcium ion on MG-, MM- and GG-blocks of alginate and the filtration behaviors of the three types of alginate blocks at different concentrations of calcium ion. Results showed that calcium ion had the most serious effects on GG-blocks and significantly promotes the formation of transparent exopolymeric particles (TEP) from GG-blocks which in turn led to rapid formation of thick cake layer on membrane surface during the filtration of GG-blocks. As for MM-blocks, it was found that the formation of TEP was proportional to the Ca2+ concentration in MM-blocks solution, while the membrane fouling was enhanced by Ca2+ in the filtration of MM-blocks solution. Unlike MM- and GG-blocks, MG-blocks were nearly not affected by addition of calcium ion, as the result, there was no significant increase in TEP. The initial fouling rates and the mass of foulants deposed on the membrane surfaces further revealed a close correlation between the TEP concentration and the membrane fouling propensity. The observations by field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) further confirmed the formation process of the cake layer by TEP on the membrane surface. This study offers deep insights into the development of membrane fouling by different alginate blocks in the presence of calcium ion, and suggests that TEP formed from alginate blocks played a very significant role in the fouling development. Accepted version 2015-09-15T05:43:37Z 2019-12-06T21:03:02Z 2015-09-15T05:43:37Z 2019-12-06T21:03:02Z 2015 2015 Journal Article Meng, S., Winters, H., & Liu, Y. (2015). Ultrafiltration behaviors of alginate blocks at various calcium concentrations. Water Research, 83, 248-257. 0043-1354 https://hdl.handle.net/10356/102971 http://hdl.handle.net/10220/38689 10.1016/j.watres.2015.06.008 en Water Research © 2015 Elsevier Ltd. This is the author created version of a work that has been peer reviewed and accepted for publication by Water Research, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.watres.2015.06.008]. 21 p. application/pdf |
institution |
Nanyang Technological University |
building |
NTU Library |
country |
Singapore |
collection |
DR-NTU |
language |
English |
topic |
DRNTU::Engineering::Environmental engineering::Water treatment |
spellingShingle |
DRNTU::Engineering::Environmental engineering::Water treatment Meng, Shujuan Winters, Harvey Liu, Yu Ultrafiltration behaviors of alginate blocks at various calcium concentrations |
description |
Alginate, a linear copolymer, is composed of 1,4-linked β-d-mannuronic acid (M) and α-l-guluronic acid (G), which are combined into homopolymeric blocks (MM-block and GG-block) and heteropolymeric block (MG-block). It has been widely used as a model foulant in various studies of membrane fouling, thus this study investigated the impacts of calcium ion on MG-, MM- and GG-blocks of alginate and the filtration behaviors of the three types of alginate blocks at different concentrations of calcium ion. Results showed that calcium ion had the most serious effects on GG-blocks and significantly promotes the formation of transparent exopolymeric particles (TEP) from GG-blocks which in turn led to rapid formation of thick cake layer on membrane surface during the filtration of GG-blocks. As for MM-blocks, it was found that the formation of TEP was proportional to the Ca2+ concentration in MM-blocks solution, while the membrane fouling was enhanced by Ca2+ in the filtration of MM-blocks solution. Unlike MM- and GG-blocks, MG-blocks were nearly not affected by addition of calcium ion, as the result, there was no significant increase in TEP. The initial fouling rates and the mass of foulants deposed on the membrane surfaces further revealed a close correlation between the TEP concentration and the membrane fouling propensity. The observations by field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) further confirmed the formation process of the cake layer by TEP on the membrane surface. This study offers deep insights into the development of membrane fouling by different alginate blocks in the presence of calcium ion, and suggests that TEP formed from alginate blocks played a very significant role in the fouling development. |
author2 |
School of Civil and Environmental Engineering |
author_facet |
School of Civil and Environmental Engineering Meng, Shujuan Winters, Harvey Liu, Yu |
format |
Article |
author |
Meng, Shujuan Winters, Harvey Liu, Yu |
author_sort |
Meng, Shujuan |
title |
Ultrafiltration behaviors of alginate blocks at various calcium concentrations |
title_short |
Ultrafiltration behaviors of alginate blocks at various calcium concentrations |
title_full |
Ultrafiltration behaviors of alginate blocks at various calcium concentrations |
title_fullStr |
Ultrafiltration behaviors of alginate blocks at various calcium concentrations |
title_full_unstemmed |
Ultrafiltration behaviors of alginate blocks at various calcium concentrations |
title_sort |
ultrafiltration behaviors of alginate blocks at various calcium concentrations |
publishDate |
2015 |
url |
https://hdl.handle.net/10356/102971 http://hdl.handle.net/10220/38689 |
_version_ |
1681056306377523200 |