Removal of Arsenic(V) from Aqueous Solutions Using Iron‐Oxide‐Coated Modified Activated Carbon

Abstract

Removal of arsenic(V) from aqueous solutions was evaluated with the following three different sorption materials: coal-based activated carbon 12 3 40 (activated carbon), iron(II) oxide (FeO)/activated carbon-H, and iron oxide. The apparent characteristics and physical chemistry performances of these adsorbents were investigated by X-ray diffraction, nitrogen adsorption, and scanning electronic microscope. Also, batch experiments for arsenic removal were performed, and the effects of pH value on arsenic(V) removal were studied. The results suggest that the main phases of the iron oxide surface are magnetite, maghemite, hematite, and goethite; fine and uniform iron oxide particles can cover activated carbon surfaces and affect the surface area or pore structures of activated carbon; adsorption kinetics obey a pseudo-first-order rate equation; and adsorption capacities of adsorbents are affected by the values of pH. The optimum value of pH for iron oxide lies in a narrow range between 4.0 and 5.5, and arsenic(V) removal by FeO/activated carbon-H is ideal and stable in the pH range 3 to 7, while activated carbon has the lowest adsorption capacity in the entire pH range. Also, the adsorption characteristics of FeO/activated carbon-H composites and virgin activated carbon match well the Langmuir adsorption model, while those of iron oxide fit well the Freundlich adsorption model. Water Environ. Res., 79, 931 (2007).

Enhanced adsorption of arsenate onto a natural polymer-based sorbent by surface atom transfer radical polymerization

“…Among them, adsorption has been one of the most extensively used techniques because of its superior qualities such as better performance, ease in operation, low cost/energy consumption, and possibilities for regeneration/ recycle of used sorbent. A wide range of metal or metal oxidebased sorbents have been developed and applied for the adsorptive removal of arsenic; they can be naturally derived or synthesized such as zero valent iron [11,12], iron oxides [13,14], titanium dioxide [15,16], and zirconium [4,17].…”

Waste Treatment and Remediation Technologies for Arsenic

“…As an alternative, GAC may be impregnated with iron and other materials and then placed into permeable treatment columns. Impregnating activated carbon with inorganic materials, such as calcium chloride (CaCl 2 ) or iron, copper, or zirconium salts, can greatly improve the sorption of As(III) and/or As(V) (US EPA, 2002b, 25;(Rajaković, 1992;Mohan and Pittman, 2007;Mondal, Majumder and Mohanty, 2007;Zhang et al, 2007c;Schmidt et al, 2008). The addition of polyanilines ((C 6 H 7 N 4 ) n ) or other organic compounds to activated carbon may also substantially enhance the sorption of As(V) (Yang, Wu and Chen, 2007; Table 7.1).…”

Comparison of arsenic immobilization properties among calcium silicate hydrate, ettringite, and friedel's salt in a slag‐based binder

“…Numerous treatment methods, such as vitrification, acid extraction, adsorption, and solidification/stabilization (S/S), have been developed to prevent arsenic and heavy metal contamination . To date, S/S with ordinary Portland cement is the most common method for arsenic‐containing waste disposal .…”