title: Selective removal of phosphate from wastewater using hydrated metal oxides dispersed within anionic exchange media.
abstract: Hydrated ferric oxide (HFeO), hydrated zirconium oxide (HZrO) and hydrated copper oxide (HCuO) were immobilized within a microporous anion exchange resin (IRA-400), forming hybrid media for enhanced phosphate removal from aqueous systems. Empirical data from batch kinetic trials fitted the pseudo second order mechanism for chemical adsorption and each media was rate limited by intraparticle diffusion overall. These models were also used to predict the adsorption rate constants and the equilibrium adsorption capacities, which ranged from 26.51 to 30.44 mgP g(-1), and from 24.15 to 27.90 mgP g(-1) of media for the calculated and experimental capacities, respectively. The phosphate adsorption behavior by the hybrid materials fit both the Langmuir and Freundlich adsorption isotherms (R(2)>0.94), and the maximum adsorption capacities were 111.1 mgP g(-1) for HFeO, 91.74 mgP g(-1) for HZrO and 74.07 mgP g(-1) for HCuO. The effect of competing ions such as sulfate reduced these capacities to 18.52 mgP g(-1) for HFeO and 18.97 mgP g(-1) for HZrO. Despite this decrease, HFeO was capable of reducing the phosphate in a real wastewater matrix by 83%, and the HZrO media was able to reduce it by 86%, suggesting that such hybrid media have the potential for application at full scale.
authors.affiliation: Química de Recursos Energéticos y Medio Ambiente, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, UdeA - Colombia, Calle 70 No. 52-21, Medellín, Colombia.
authors.forename: Nancy Y
authors.initials: NY
authors.lastname: Acelas
authors.affiliation: Cranfield Water Science Institute, Cranfield University, Cranfield MK43 0AL, UK.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Martin
authors.affiliation: Química de Recursos Energéticos y Medio Ambiente, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, UdeA - Colombia, Calle 70 No. 52-21, Medellín, Colombia.
authors.forename: Diana
authors.initials: D
authors.lastname: López
authors.affiliation: Cranfield Water Science Institute, Cranfield University, Cranfield MK43 0AL, UK. Electronic address: B.Jefferson@cranfield.ac.uk.
authors.forename: Bruce
authors.initials: B
authors.lastname: Jefferson
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry; D004058:Diffusion; D005290:Ferric Compounds / Q000737:chemistry; D007700:Kinetics; D010710:Phosphates / Q000032:analysis / Q000302:isolation & purification*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D003300:Copper; D005290:Ferric Compounds; D010710:Phosphates; D062065:Wastewater; D014874:Water Pollutants, Chemical; C000499:ferric oxide; C000520:cuprous oxide
keywords: Freundlich isotherm; Hydrated metal oxides; Intraparticle diffusion mechanism; Langmuir isotherm; Pseudo-second order kinetics