title: Effect of phosphate on the particle size of ferric oxyhydroxides anchored onto activated carbon: As(V) removal from water.
abstract: The surface area of iron oxyhydroxides is a key factor when removing As from water. However, research related to this matter shows that this issue has not been explored in detail. The use of capping agents is a viable method to synthesize ferric oxyhydroxide nanoparticles; however, this method to our knowledge has not been applied for the anchorage of iron oxyhydroxide nanoparticles on activated carbon (AC). In the present work, the addition of PO(4) (as a capping agent) in forced hydrolysis of FeCl(3) in AC was investigated. Results revealed that the surface area of modified materials reached a maximum of about 900 m(2)/g with a molar ratio PO(4)/Fe of 0.1. Moreover, microscopy studies indicate a size range of iron nanoparticles from 2 to 300 nm, where the smallest particles are attained with the highest concentration of PO(4). The surface charge distribution of modified samples became less positive; however, the As removal increased, indicating that electrostatic interaction is not the controlling sorption mechanism. Modified samples showed a 40% increase on As(V) adsorption capacity when using a molar ratio PO(4)/Fe of 1.5. The proposed method allowed anchoring of iron oxyhydroxides nanoparticles on AC, which have a high As(V) adsorption capacity (5 mg/g).
authors.affiliation: División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), San Luis Potosí, SLP, México.
authors.forename: Javier A
authors.initials: JA
authors.lastname: Arcibar-Orozco
authors.forename: Miguel
authors.initials: M
authors.lastname: Avalos-Borja
authors.forename: J Rene
authors.initials: JR
authors.lastname: Rangel-Mendez
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000302:isolation & purification*; D002606:Charcoal / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry*; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D010710:Phosphates; D014874:Water Pollutants, Chemical; D002606:Charcoal; C021024:ferric hydroxide; D001151:Arsenic