title: Superior removal of arsenic from water with zirconium metal-organic framework UiO-66.
abstract: In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5-280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds.
authors.affiliation: NUS Graduate School for Integrative Sciences &Engineering (NGS), National University of Singapore, Singapore, 117456, Singapore.|Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore.|Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Chenghong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Xinlei
authors.initials: X
authors.lastname: Liu
authors.affiliation: NUS Graduate School for Integrative Sciences &Engineering (NGS), National University of Singapore, Singapore, 117456, Singapore.|Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Kang
authors.initials: K
authors.lastname: Li
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D013696:Temperature; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D015040:Zirconium; D001151:Arsenic; C028541:zirconium oxide