Removal of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranes

Handle URI:
http://hdl.handle.net/10754/561422
Title:
Removal of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranes
Authors:
Yoon, Jaekyung; Amy, Gary L.; Chung, Jinwook; Sohn, Jinsik; Yoon, Yeomin
Abstract:
Rejection characteristics of chromate, arsenate, and perchlorate were examined for one reverse osmosis (RO, LFC-1), two nanofiltration (NF, ESNA, and MX07), and one ultrafiltration (UF and GM) membranes that are commercially available. A bench-scale cross-flow flat-sheet filtration system was employed to determine the toxic ion rejection and the membrane flux. Both model and natural waters were used to prepare chromate, arsenate, and perchlorate solutions (approximately 100 μg L-1 for each anion) in mixtures in the presence of other salts (KCl, K2SO4, and CaCl2); and at varying pH conditions (4, 6, 8, and 10) and solution conductivities (30, 60, and 115 mS m-1). The rejection of target ions by the membranes increases with increasing solution pH due to the increasingly negative membrane charge with synthetic model waters. Cr(VI), As(V), and ClO4 - rejection follows the order LFC-1 (>90%) > MX07 (25-95%) ≅ ESNA (30-90%) > GM (3-47%) at all pH conditions. In contrast, the rejection of target ions by the membranes decreases with increasing solution conductivity due to the decreasingly negative membrane charge. Cr(VI), As(V), and ClO4 - rejection follows the order CaCl2 < KCl ≅ K2SO4 at constant pH and conductivity conditions for the NF and UF membranes tested. For natural waters the LFC-1 RO membrane with a small pore size (0.34 nm) had a significantly greater rejection for those target anions (>90%) excluding NO3 - (71-74%) than the ESNA NF membrane (11-56%) with a relatively large pore size (0.44 nm), indicating that size exclusion is at least partially responsible for the rejection. The ratio of solute radius (ri,s) to effective membrane pore radius (rp) was employed to compare ion rejection. For all of the ions, the rejection is higher than 70% when the ri,s/rp ratio is greater than 0.4 for the LFC-1 membrane, while for di-valent ions (CrO4 2 -, SO4 2 -, and HAsSO4 2 -) the rejection (38-56%) is fairly proportional to the ri,s/rp ratio (0.32-0.62) for the ESNA membrane. © 2009 Elsevier Ltd. All rights reserved.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division
Publisher:
Elsevier BV
Journal:
Chemosphere
Issue Date:
Sep-2009
DOI:
10.1016/j.chemosphere.2009.07.028
PubMed ID:
19679331
Type:
Article
ISSN:
00456535
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorYoon, Jaekyungen
dc.contributor.authorAmy, Gary L.en
dc.contributor.authorChung, Jinwooken
dc.contributor.authorSohn, Jinsiken
dc.contributor.authorYoon, Yeominen
dc.date.accessioned2015-08-02T09:10:51Zen
dc.date.available2015-08-02T09:10:51Zen
dc.date.issued2009-09en
dc.identifier.issn00456535en
dc.identifier.pmid19679331en
dc.identifier.doi10.1016/j.chemosphere.2009.07.028en
dc.identifier.urihttp://hdl.handle.net/10754/561422en
dc.description.abstractRejection characteristics of chromate, arsenate, and perchlorate were examined for one reverse osmosis (RO, LFC-1), two nanofiltration (NF, ESNA, and MX07), and one ultrafiltration (UF and GM) membranes that are commercially available. A bench-scale cross-flow flat-sheet filtration system was employed to determine the toxic ion rejection and the membrane flux. Both model and natural waters were used to prepare chromate, arsenate, and perchlorate solutions (approximately 100 μg L-1 for each anion) in mixtures in the presence of other salts (KCl, K2SO4, and CaCl2); and at varying pH conditions (4, 6, 8, and 10) and solution conductivities (30, 60, and 115 mS m-1). The rejection of target ions by the membranes increases with increasing solution pH due to the increasingly negative membrane charge with synthetic model waters. Cr(VI), As(V), and ClO4 - rejection follows the order LFC-1 (>90%) > MX07 (25-95%) ≅ ESNA (30-90%) > GM (3-47%) at all pH conditions. In contrast, the rejection of target ions by the membranes decreases with increasing solution conductivity due to the decreasingly negative membrane charge. Cr(VI), As(V), and ClO4 - rejection follows the order CaCl2 < KCl ≅ K2SO4 at constant pH and conductivity conditions for the NF and UF membranes tested. For natural waters the LFC-1 RO membrane with a small pore size (0.34 nm) had a significantly greater rejection for those target anions (>90%) excluding NO3 - (71-74%) than the ESNA NF membrane (11-56%) with a relatively large pore size (0.44 nm), indicating that size exclusion is at least partially responsible for the rejection. The ratio of solute radius (ri,s) to effective membrane pore radius (rp) was employed to compare ion rejection. For all of the ions, the rejection is higher than 70% when the ri,s/rp ratio is greater than 0.4 for the LFC-1 membrane, while for di-valent ions (CrO4 2 -, SO4 2 -, and HAsSO4 2 -) the rejection (38-56%) is fairly proportional to the ri,s/rp ratio (0.32-0.62) for the ESNA membrane. © 2009 Elsevier Ltd. All rights reserved.en
dc.publisherElsevier BVen
dc.subjectArsenateen
dc.subjectChromateen
dc.subjectMembrane rejectionen
dc.subjectPerchlorateen
dc.subjectWater treatmenten
dc.titleRemoval of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranesen
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalChemosphereen
dc.contributor.institutionKorea Institute of Energy Research, New and Renewable Energy Research Division, 71-2 Jang-Dong, Yuseong-Gu, Daejeon, 305-343, South Koreaen
dc.contributor.institutionSamsung Engineering Co., Ltd., R and D Center, 39-3, Sungbok-Dong, Yongin, Gyeonggi-Do 449-844, South Koreaen
dc.contributor.institutionKookmin University, Civil and Environmental Department, Seoul, 136-702, South Koreaen
dc.contributor.institutionDepartment of Civil and Environmental Engineering, University of South Carolina, Columbia, SC 29208, United Statesen
kaust.authorAmy, Gary L.en
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