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dc.contributor.authorGuo L; Hunt BJ; Santschi PHen_US
dc.contributor.editoren_US
dc.contributor.otherWater Researchen_US
dc.date.accessioned2010-02-15T17:12:53Z
dc.date.available2010-02-15T17:12:53Z
dc.date.issued2001en_US
dc.identifier.urihttp://hdl.handle.net/1969.3/22855
dc.description1500-1508en_US
dc.description.abstractAquatic colloids, including macromolecules and microparticles, with sizes ranging between 1 nm to 1 mum, play important roles in the mobility and bioavailability of heavy metals and other contaminants in natural waters. Cross-flow ultrafiltration has become one of the most commonly used techniques for isolating aquatic colloids. However, the ultrafiltration behavior of chemical species remains poorly understood. We report here the permeation behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters during ultrafiltration using an Amicon 1 kDa ultrafiltration membrane (S10N1). Water samples across a salinity gradient of 0-20permill were collected from the Trinity River and Galveston Bay. The permeation behavior of major ions was well predicted by a permeation model, resulting in a constant permeation coefficient for each ion. The value of the model-derived permeation coefficient (Pc) was 0.99 for Na, 0.97 for Cl, and 0.95 for F, respectively, in Trinity River waters. Values of Pc close to 1 indicate that retention of Na, Cl, and F by the 1 kDa membrane during ultrafiltration was indeed minimal (< 1-5%). In contrast, significant (14-36%) retention was observed for SO4, Ca, and Mg in Trinity River waters, with a Pc value of 0.64, 0.82, and 0.86 for SO4, Ca and Mg, respectively. However, these retained major ions can further permeate through the 1 kDa membrane during diafiltration with ultrapure water. The selective retention of major ions during ultrafiltration may have important implications for the measurement of chemical and physical speciation of trace elements when using cross-flow ultrafiltration membranes to separate colloidal species from natural waters. Our results also demonstrate that the percent retention of major ions during ultrafiltration decreases with increasing salinity or ionic strength. This retention is largely attributed to electrostatic repulsion by the negatively charged cartridge membraneen_US
dc.description.urihttp://gbic.tamug.edu/request.htmen_US
dc.publisheren_US
dc.relation.ispartofseries50260.00en_US
dc.relation.urien_US
dc.subjectcalcium: 7440-70-2,major ion; chloride: 16887-00-6,major ion; dissolved organic carbon: DOC; fluoride: 16984-48-8,major ion; magnesium: 7439-95-4,major ion; sodium: 7440-23-5,major ion; sulfate: 14808-79-8,major ion;Estuarine Ecology: Ecology,Environmental Sciences; Freshwater Ecology: Ecology,Environmental Sciences;natural waters; salinity;[07510] Ecology: environmental biology - Oceanography and limnology;[07514] Ecology: environmental biology - Limnology;[10060] Biochemistry studies - General;[10069] Biochemistry studies - Minerals;en_US
dc.titleUltrafiltration behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural watersen_US
dc.typeJournalen_US
dc.placeen_US
dc.seriesen_US
dc.vol-issue35(6)en_US
dc.geo-codeen_US
dc.locationen_US
dc.scaleen_US
dc.latitudeen_US
dc.longitudeen_US
dc.contract-noen_US
dc.notesDB - BIOSIS PreviewsAN - PREV200100221435IN - International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK, 99775-7335, USACY - USAPT - ArticleLG - Englishen_US
dc.degreeen_US
dc.acquisition-srcDownloaded from-BIOSISen_US
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