Tetravalent Manganese Feroxyhyte: A Novel Nanoadsorbent Equally Selective for As(III) and As(V) Removal from Drinking Water

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• 作者：Sofia Tresintsi ; Konstantinos Simeonidis ; Sonia Estrad茅 ; Carlos Martinez-Boubeta ; George Vourlias ; Fani Pinakidou ; Maria Katsikini ; Eleni C. Paloura ; George Stavropoulos ; Manassis Mitrakas
• 刊名：Environmental Science & Technology
• 出版年：2013
• 出版时间：September 3, 2013
• 年：2013
• 卷：47
• 期：17
• 页码：9699-9705
• 全文大小：419K
• 年卷期：v.47,no.17(September 3, 2013)
• ISSN：1520-5851

文摘

The development of a single-phase Fe/Mn oxy-hydroxide (未-Fe_0.76Mn_0.24OOH), highly efficient at adsorbing both As(III) and As(V), is reported. Its synthesis involves the coprecipitation of FeSO₄ and KMnO₄ in a kilogram-scale continuous process, in acidic and strongly oxidizing environments. The produced material was identified as a manganese feroxyhyte in which tetravalent manganese is homogeneously distributed into the crystal unit, whereas a second-order hollow spherical morphology is favored. According to this structuration, the oxy-hydroxide maintains the high adsorption capacity for As(V) of a single Fe oxy-hydroxide combined with enhanced As(III) removal based on the oxidizing mediation of Mn(IV). Ion-exchange between arsenic species and sulfates as well as the strongly positive surface charge further facilitate arsenic adsorption. Batch adsorption tests performed in natural-like water indicate that Mn(IV)-feroxyhyte can remove 11.7 渭g As(V)/mg and 6.7 渭g As(III)/mg at equilibrium pH 7, before residual concentration overcomes the regulation limit of 10 渭g As/L for drinking water. The improved efficiency of this material, its low cost, and the possibility for scaling-up its production to industry indicate the high practical impact and environmental importance of this novel adsorbent.