Sulfur-doped Fe–Cu–La trimetallic oxides as a novel magnetic adsorbent for efficient removal of As(iii) and As(v) from aqueous solution. Issue 11 (1st September 2021)

• Record Type: Journal Article
• Authors: Liu, Baoxia; Liu, Haiyan; Li, Wei; Li, Yuxin; Lan, Yeqing; Li, Ying
• Is Part Of: Environmental science. Volume 7:Issue 11(2021)
• Page Start: 1985
• Page End: 1995
• Publication Date: 2021-09-01
• Subjects: Water-supply -- Periodicals; Water security -- Periodicals; Water resources development -- Periodicals; Water chemistry -- Periodicals; 553.705
• DOI: 10.1039/d1ew00330e
• Languages: English
• ISSNs: 2053-1400

Abstract

Abstract : The magnetic material S-FeCuLaO not only can effectively remove As(iii ) and As(v ) but also possesses good stability and high reusability. It has a potential application for arsenic removal from contaminated waters. Abstract : Sulfur-doped Fe–Cu–La trimetallic oxides (S-FeCuLaO) were synthesized by a coprecipitation method and applied as a novel magnetic adsorbent for the removal of As(iii ) and As(v ) in water. Batch experimental results demonstrated that the material exhibited excellent adsorption properties for both As(iii ) and As(v ) in a wide pH range and the maximum adsorption capacities of S-FeCuLaO at initial pH 6.0 were 181 mg g −1 for As(iii ) and 250 mg g −1 for As(v ), respectively. Both As(iii ) and As(v ) (10 mg L −1 ) were completely removed by the regenerated adsorbent after the third cycle. Furthermore, the residual As(iii ) concentration in well water containing 1 mg L −1 As(iii ) decreased to below 10 μg L −1 after adsorption for 8 h. The adsorption process complied with the Langmuir isothermal model and the pseudo-second-order kinetic model. Among the five coexisting ions investigated (Cl −, NO3 −, SO4 2−, CO3 2− and PO4 3− ), only PO4 3− could significantly inhibit the adsorption of As(iii ) and As(v ) by competing for active adsorption sites. The removal mechanism of arsenic was proposed as (1) the oxidization of As(iii ) to As(v ) by superoxide radicals (O2 ˙ − ) produced between Cu(i ) and the dissolved O2 and (2) the adsorption of As(v ) through electrostatic attraction and the further formation of inner-sphere complexes via ligand exchange. Thus, S-FeCuLaO could be used as an attractive material for arsenic removal from wastewater and groundwater.