Removal of Perchlorate Using Reverse Osmosis and
Nanofiltration Membranes |
Jonghun Han1, Choongsik Kong2, Jiyong Heo3, Yeomin Yoon3, Heebum Lee1, and Namguk Her1† |
1Department of Chemistry and Environmental Sciences, Korea Army Academy at Youngcheon, Youngcheon 770-849, Korea 2Beautiful Environment Construction Co., Ltd., Seongnam 462-721, Korea 3Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC 29208, USA |
Corresponding Author:
Namguk Her ,Tel: +82-54-330-4760, Fax: +82-54-335-5790, Email: namguk@daum.net |
Received: June 28, 2012; Accepted: November 6, 2012. |
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ABSTRACT |
Rejection characteristics of perchlorate (ClO4
-) were examined for commercially available reverse osmosis (RO) and nanofiltration
(NF) membranes. A bench-scale dead-end stirred-cell filtration system was employed to determine the toxic ion rejection and the membrane
flux. Model water solutions were used to prepare ClO4
- solutions (approximately, 1,000 μg/L) in the presence of background salts
(NaCl, Na2SO4, and CaCl2) at various pH values (3.5, 7, and 9.5) and solution ionic strengths (0.001, 0.01, and 0.01 M NaCl) in the presence
of natural organic matter (NOM). Rejection by the membranes increased with increasing solution pH owing to increasingly negative
membrane charge. In addition, the rejection of the target ion by the membranes increased with increasing solution ionic strength. The
rejection of ClO4
- was consistently higher for the RO membrane than for the NF membrane and ClO4
- rejection followed the order CaCl2
< NaCl < Na2SO4 at conditions of constant pH and ionic strength for both the RO and NF membranes. The possible influence of NOM on
ClO4
- rejection by the membranes was also explored. |
Keywords:
Nanofiltration | Natural organic matter | Perchlorate | Reverse osmosis | Water treatment |
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