Enhanced Phosphorus Locking by Novel Lanthanum/Aluminum–Hydroxide Composite: Implications for Eutrophication Control

• DOI: 10.1021/acs.est.6b05623
• Publication Date: 2017-02-22T14:31:52Z
• Authors: Rui Xu; Meiyi Zhang; Robert J. G. Mort...; Gang Pan
• Keywords: Lanthanum; Bentonite; Aluminium hydroxide

Lanthanum (La) bearing materials have been widely used to remove phosphorus (P) in water treatment. However, it remains a challenge enhance phosphate (PO4) adsorption capacity and La usage efficiency. In this study, was coprecipitated with aluminum (Al) obtain La/Al–hydroxide composite (LAH) for P adsorption. The maximum PO4 capacities of LAH (5.3% La) were 76.3 45.3 mg g–1 at pH 4.0 8.5, which 8.5 5.3 times higher than those commercially available La-modified bentonite (Phoslock, 5.6% La), respectively. K-edge X-ray absorption near edge structure analysis showed that preferentially bonded Al under weakly acid conditions (pH 4.0), while tended associate alkaline 8.5). LIII-edge extended fine indicated on sites by forming inner sphere bidentate-binuclear complexes oxygen defects exhibited surfaces, could be active PO4. electrostatic interaction, ligand exchange, surfaces jointly facilitated but varied contribution different conditions. combined two-component may an important direction the next generation commercial products eutrophication mitigation.