title: Use of pH-sensitive polymer hydrogels in lead removal from aqueous solution.
abstract: Three gamma crosslinked polymeric hydrogels were synthesized and evaluated as lead ion sorbents. A crosslinked poly(acrylic acid) hydrogel was compared with two 4-vinylpiridine-grafted poly(acrylic acid) hydrogels (26.74 and 48.1% 4-vinylpiridine). The retention properties for Pb(II) from aqueous solutions of these three polymers were investigated by batch equilibrium procedure. The effects of pH, contact time and Pb(II) concentration were evaluated. The optimal pH range for all polymers was 4-6. The lightly grafted polymer (PAAc-g-4VP at 26.74%) exhibited a Pb(II) removal close to 80% at 5h and above 90% at 24h. The maximum Pb(II) removal was 117.9mg g(-1) of polymer and followed the Freundlich adsorption model. XPS characterization indicates that the carboxyl groups are involved in the Pb(II) removal.
authors.affiliation: Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco, km 14.5, Unidad El Rosedal, C.P. 50200, Toluca, Edo. de México, Méx, México.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ramírez
authors.forename: S Guillermina
authors.initials: SG
authors.lastname: Burillo
authors.forename: C
authors.initials: C
authors.lastname: Barrera-Díaz
authors.forename: Gabriela
authors.initials: G
authors.lastname: Roa
authors.forename: Bryan
authors.initials: B
authors.lastname: Bilyeu
mesh_terms: D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000302:isolation & purification*; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D020100:Hydrogels; D011108:Polymers; D012996:Solutions; D014867:Water; D007854:Lead