title: Enhanced Phosphorus Locking by Novel Lanthanum/Aluminum-Hydroxide Composite: Implications for Eutrophication Control.
abstract: Lanthanum (La) bearing materials have been widely used to remove phosphorus (P) in water treatment. However, it remains a challenge to enhance phosphate (PO4) adsorption capacity and La usage efficiency. In this study, La was coprecipitated with aluminum (Al) to obtain a La/Al-hydroxide composite (LAH) for P adsorption. The maximum PO4adsorption capacities of LAH (5.3% La) were 76.3 and 45.3 mg P g-1at pH 4.0 and 8.5, which were 8.5 and 5.3 times higher than those of commercially available La-modified bentonite (Phoslock, 5.6% La), respectively. P K-edge X-ray absorption near edge structure analysis showed that PO4was preferentially bonded with Al under weakly acid conditions (pH 4.0), while tended to associate with La under alkaline conditions (pH 8.5). La LIII-edge extended X-ray absorption fine structure analysis indicated that PO4was bonded on La sites by forming inner sphere bidentate-binuclear complexes and oxygen defects exhibited on LAH surfaces, which could be active adsorption sites for PO4. The electrostatic interaction, ligand exchange, and oxygen defects on LAH surfaces jointly facilitated PO4adsorption but with varied contribution under different pH conditions. The combined contribution of two-component of La and Al may be an important direction for the next generation of commercial products for eutrophication mitigation.
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xu
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors.forename: Meiyi
authors.initials: M
authors.lastname: Zhang
authors.affiliation: School of Animal, Rural and Environmental Sciences, Nottingham Trent University , Brackenhurst Campus, Nottinghamshire NG25 0QF, United Kingdom.
authors.forename: Robert J G
authors.initials: RJ
authors.lastname: Mortimer
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.|School of Animal, Rural and Environmental Sciences, Nottingham Trent University , Brackenhurst Campus, Nottinghamshire NG25 0QF, United Kingdom.
authors.forename: Gang
authors.identifier: 0000-0003-0920-3018
authors.initials: G
authors.lastname: Pan
mesh_terms: D000327:Adsorption; D000535:Aluminum; D000536:Aluminum Hydroxide; D005068:Eutrophication; D007811:Lanthanum / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*
chemical_list: D010758:Phosphorus; D000536:Aluminum Hydroxide; D007811:Lanthanum; D000535:Aluminum