title: Enhanced phosphate selectivity from wastewater using copper-loaded chelating resin functionalized with polyethylenimine.
abstract: In water and wastewater, phosphate is considered a critical contaminant due to cause algae blooms and eutrophication. To meet the stringent regulation of phosphate in water, a new commercial chelating resin functionalized with polyethylenimine was tested for phosphate removal by loading Cu(2+) and Fe(2+)/Fe(3+) to enhance selectivity for phosphate. Batch and column experiments showed that CR20-Cu exhibited high selectivity for phosphate over other strong anions such as sulfate. The average binary phosphate/nitrate and phosphate/sulfate factors for CR20-Cu were calculated to be 7.3 and 4.8, respectively, which were more than 0.97 and 0.22 for a commercial anion exchanger (AMP16). The optimal pH for the phosphate removal efficiency was determined to be 7. According to the fixed-bed column test, the breakthrough sequence for multiple ions was HPO4(2-)>SO4(2-)>NO3(-)>Cl(-). Saturated CR20-Cu can be regenerated using 4% NaCl at pH 7. More than 95% of the phosphate from CR20-Cu was recovered, and the phosphate uptake capacity for CR20-Cu was not reduced after 7 regeneration cycles.
authors.affiliation: Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Byungryul
authors.initials: B
authors.lastname: An
authors.forename: Juhee
authors.initials: J
authors.lastname: Nam
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Choi
authors.forename: Seok-Won
authors.initials: SW
authors.lastname: Hong
authors.forename: Sang-Hyup
authors.initials: SH
authors.lastname: Lee
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010710:Phosphates / Q000302:isolation & purification*; D011094:Polyethyleneimine / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D010710:Phosphates; D012117:Resins, Synthetic; D014874:Water Pollutants, Chemical; D003300:Copper; D011094:Polyethyleneimine
keywords: Ion exchanger; Phosphate; Regeneration; Selectivity