Accepted Manuscript Modification of Ultrafiltration Membrane with Nanoscale Zerovalent Iron Layers for Humic Acid Fouling Reduction Baiwen Ma, Wenzheng Yu, William A. Jefferson, Huijuan Liu, Jiuhui Qu PII:
S0043-1354(14)00866-5
DOI:
10.1016/j.watres.2014.12.034
Reference:
WR 11070
To appear in:
Water Research
Received Date: 21 October 2014 Revised Date:
18 December 2014
Accepted Date: 21 December 2014
Please cite this article as: Ma, B., Yu, W., Jefferson, W.A., Liu, H., Qu, J., Modification of Ultrafiltration Membrane with Nanoscale Zerovalent Iron Layers for Humic Acid Fouling Reduction, Water Research (2015), doi: 10.1016/j.watres.2014.12.034. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT 20 mg/L HA 1 mM NZVI + 20 mg/L HA 1 mM NZVI (75% ethanol) + 20 mg/L HA
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Modification of Ultrafiltration Membrane with Nanoscale
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Zerovalent Iron Layers for Humic Acid Fouling Reduction
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Baiwen Maa,b, Wenzheng Yua, William A. Jeffersona,b, Huijuan Liua, Jiuhui Qua,*
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Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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University of Chinese Academy of Sciences, Beijing 100049, China
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Key Laboratory of Drinking Water Science and Technology, Research Center for
* Corresponding author. Tel.: +86 10 62849160; fax: +86 10 62923558.
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E-mail address:
[email protected] (J. Qu).
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ACCEPTED MANUSCRIPT Abstract: Nanoscale zerovalent iron (NZVI) was layered onto ultrafiltration (UF)
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membrane surface and tested for antifouling properties using humic acid (HA).
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Scanning electron microscopy showed that a relatively homogeneous layer was
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formed across the membrane surface by NZVI particles. Strong adhesion was
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observed between NZVI and UF membrane used. HA was significantly removed and
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membrane flux was increased in the presence of NZVI layer. Increased loadings of
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NZVI onto the membrane surface increased resistance to fouling while slightly
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reducing the clean water permeability of the membrane. However, the pore size of the
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layer formed by pristine NZVI was large, resulting in more chances of HA molecules
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getting to the membrane surface even blocking the membrane pores at the beginning.
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Membrane loaded with NZVI layer performed much better under acidic conditions.
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During NZVI synthesis, specific surface area of NZVI particle increased with
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increasing the ratio of ethanol (Vethanol/Vsolution), which also gradually decreased the
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average pore size of NZVI layer. As a result, the corresponding membrane flux
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steadily increased. Additionally, the results for permeate samples under different
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conditions showed that large molecular weight (MW, >30 kDa) and medium MW HA
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molecules (3-30 kDa) were removed much faster than those of small MW HA
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molecules (30 kDa) and medium
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MW HA molecules (3-30 kDa). In comparison with the pristine PVDF membrane, the
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proportions of large MW and medium MW HA molecules were reduced from 22.9%
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± 2.6% and 44.3% ± 3.5% to 14.1% ± 3.1% and 27.7% ± 1.5% in the presence of 1
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mM NZVI, while the proportion of small MW HA molecules (30 kDa)
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and medium MW (3-30 kDa) HA molecules were more easily rejected compared
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to the small MW (