Adsorptive removal of arsenic from water by an iron–zirconium binary oxide adsorbent

Abstract

a b s t r a c tArsenate and arsenite may exist simultaneously in groundwater and have led to a greater risk to human health. In this study, an iron-zirconium (Fe-Zr) binary oxide adsorbent for both arsenate and arsenite removal was prepared by a coprecipitation method. The adsorbent was amorphous with a specific surface area of 339 m 2 /g. It was effective for both As(V) and As(III) removal; the maximum adsorption capacities were 46.1 and 120.0 mg/g at pH 7.0, respectively, much higher than for many reported adsorbents. Both As(V) and As(III) adsorption occurred rapidly and achieved equilibrium within 25 h, which were well fitted by the pseudo-second-order equation. Competitive anions hindered the sorption according to the sequence PO 4 . The ionic strength effect experiment, measurement of zeta potential, and FTIR study indicate that As(V) forms inner-sphere surface complexes, while As(III) forms both inner-and outer-sphere surface complexes at the water/Fe-Zr binary oxide interface. The high uptake capability and good stability of the Fe-Zr binary oxide make it a potentially attractive adsorbent for the removal of both As(V) and As(III) from water.

Nanostructured iron(III)-copper(II) binary oxide: A novel adsorbent for enhanced arsenic removal from aqueous solutions

“…2a. It demonstrates two broad peaks at approximately 35.1 and 62.2 , respectively, which are similar to those of poorly ordered 2-line ferrihydrite (Schwertmann and Cornell, 2000;Ren et al, 2011). This indicates that the prepared FeeCu binary oxide is amorphous and 2-line ferrihydrite-like.…”

“…Li et al (2010) synthesized a CeeTi oxide sorbent with high efficiency at both As(V) and As(III) removal. Ren et al (2011) found that an FeeZr binary oxide prepared in their laboratory had high sorption capacity towards arsenic.…”

Adsorption of Phosphate from Aqueous Solution Using an Iron–Zirconium Binary Oxide Sorbent

“…The Fe-Zr binary oxide was prepared according to the following procedure, which has been described in our previous publication (Ren et al 2011): Ferric chloride hexahydrate (FeCl 3 ·6H 2 O, 0.05 mol) and zirconyl chloride octahydrate (ZrOCl 2 ·8H 2 O, 0.0125 mol) were dissolved in 400 ml deionized water. Under vigorous magnetic-stirring, sodium hydroxide solution (2 M) was added dropwise to raise the solution pH to around 7.5.…”

“…Thus, it is expected that an iron-zirconium composite material originated from the combination of iron oxide and zirconium oxide may take full use of the advantages of both parent materials and have the potential for phosphate removal. In our previous studies (Ren et al 2011), an iron-zirconium (Fe-Zr) binary oxide was synthesized and was found to have high adsorption capacities towards both arsenate and arsenite. Furthermore, phosphate was found to be the most competitive anion for arsenic adsorption by the binary oxide.…”

Simultaneous removal of arsenate and arsenite by a nanostructured zirconium–manganese binary hydrous oxide: Behavior and mechanism

“…Multi-component sorbents often exhibit different sorption behaviors compared to single-component sorbents [20,21]. It is believed that the differences in physical-chemical properties between multi-and single-component solids are the primary reason for the differences in sorption behaviors.…”