Adsorption of arsenate on soils. Part 1: Laboratory batch experiments using 16 Chinese soils with different physiochemical properties

Abstract

The Langmuir two-surface equation fits arsenate adsorption onto soils. AbstractLaboratory batch experiments were carried out to study the adsorption of arsenate on 16 Chinese soils with different physicochemical properties. Wide differences in arsenate adsorption were observed, and the Jiangxi and Hubei soils were more effective sorbents for arsenate than other soils. The Langmuir one-surface and two-surface equations were used to model the arsenate adsorption data. Except for the Jiangxi and Hubei soils, the Langmuir one-surface equation gave reasonably good fits to the arsenate adsorption data. However, the Langmuir two-surface equation generally provided a better fit than the Langmuir onesurface equation. For soils with relative high organic matter (OM), dissolved organic carbon (DOC) or extractable phosphate, the Langmuir one-surface and two-surface equations described the adsorption isotherms similarly. In contrast, for soils with relatively low contents of OM, DOC or extractable phosphate, the Langmuir two-surface equation gave the better fit to the arsenate adsorption data.

Removal of arsenate from water by using an Fe–Ce oxide adsorbent: Effects of coexistent fluoride and phosphate

“…Langmuir one-site and Langmuir two-site equations [20] were used to describe the adsorption of arsenate, As/F, and As/P on the Fe-Ce adsorbent. The Langmuir one-site equation is:…”

“…The Langmuir one-site and two-site equations [16,20,23] were used to fit the adsorption isotherms of arsenate at a given concentration range ( Figure S1, Supplementary material). As shown in Table 1, the predicted adsorption capacities (Q 0 and Q) were 1.33 mmol g −1 and 1.85 mmol g −1 for the Langmuir one-site and two-site equations, respectively.…”

“…doi:10.1016/j.jhazmat.2010.02.081 the adsorption of P and arsenate on soils [16][17][18][19][20]. Recently, the Langmuir two-site sorption isotherm has also been used to reveal the presence of two kinds of adsorption sites for orthophosphate adsorption in cationized solid wood residues and F adsorption on Fe-Al-Ce trimetal oxide [21,22], and for the study of competitive mechanisms of Pb, Cu, and Cd on peat [23].…”

“…Although the above approaches such as SCM or Langmuir twosite equation have been widely applied in describing the adsorption processes [11,14,15,[17][18][19]20,23], some researchers considered that the surface species and parameters selected may not be unique or physically meaningful. Very little information is available on the adsorption sites involved in the competitive adsorption of anions and no direct evidence has been provided for the competitive adsorption of anions.…”

Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

“…The effects of common environmental conditions on the adsorption of arsenicals onto TiO 2 surface have been studied a lot (Jiang et al, 2005;Xu et al, 2008) but studies on the influence of soil properties on the generation of ROS by TiO 2 are very rare. Ng et al (2013) once reported the production of OH by TiO 2 was influenced by its stability in solution, and the stability of TiO 2 in soil slurries appeared to be correlated with soil properties (Fang et al, 2009).…”