title: Preferable removal of phosphate from water using hydrous zirconium oxide-based nanocomposite of high stability.
abstract: In this study, we employed a new nanocomposite adsorbent HZO-201, which featured high stability under varying solution chemistry, for preferable removal of phosphate from synthetic solution and a real effluent. An anion exchange resin (D-201) was employed as the host of HZO-201, where nano-hydrous zirconium oxide (HZO) was encapsulated as the active species. D-201 binds phosphate through nonspecific electrostatic affinity, whereas the loaded HZO nanoparticles capture phosphate through formation of the inner-sphere complexes. Quantitative contribution of both species to phosphate adsorption was predicted based on the double-Langmuir model. Preferable removal of phosphate by HZO-201 was observed in the presence of the competing anions at higher levels (Cl(-), NO3(-), SO4(2-), HCO3(-)). Fixed-bed adsorption indicated that the effective volume capacity of a synthetic water (2.0 mg P-PO4(3-)/L) by using HZO-201 was ∼1600 BV in the first run (<0.5mg P-PO4(3-)/L), comparable to Fe(III)-based nanocomposite HFO-201 (∼1500 BV) and much larger than D-201 (<250 BV). The exhausted HZO-201 can be in situ regenerated by using a binary NaOH-NaCl solution for cyclic runs, whether fed with the synthetic solution or real effluent. In general, HZO-201 is a promising alternative to Fe(III)-based adsorbents for trace phosphate removal from effluent particularly at acidic pH.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China. Electronic address: bcpan@nju.edu.cn.
authors.forename: Bingcai
authors.initials: B
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Weixian
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China. Electronic address: huaming@nju.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Hua
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
authors.forename: Weiming
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D000837:Anion Exchange Resins; D000838:Anions; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010710:Phosphates / Q000302:isolation & purification*; D055672:Static Electricity; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000837:Anion Exchange Resins; D000838:Anions; D008024:Ligands; D010710:Phosphates; D014874:Water Pollutants, Chemical; D014867:Water; D015040:Zirconium; C028541:zirconium oxide
keywords: Anion exchanger; Hydrous zirconium oxide; Nanocomposite adsorbent; Phosphate removal; Selective adsorption