Reutilization of Porous Sintered Hematite Bodies as Effective Adsorbents for Arsenic(V) Removal from Water

Abstract

A method was developed to enhance the arsenic adsorption capacity of porous bodies of sintered hematite. The method comprised the formation of a coating of 1 wt % iron oxide nanoparticles on the raw material. The nanoparticles showed two distinct habits: spherical habit, likely ferrihydrite, and acicular habit, likely goethite and/or akaganéite. The specific surface area of the hematite raw material increased from 0.5 to 3.75 m2/g, and the adsorption capacity increased from negligible to 0.65 mg of [As]/g as calculated from equilibrium and breakthrough adsorption data. Equilibrium adsorption data of arsenate on the adsorbent from a solution at pH 5 followed the Langmuir model, while breakthrough adsorption data for a 500 μg/L arsenate solution at pH 5 followed the Thomas model. The adsorbed arsenic could be desorbed using distilled water at pH 12. These results show the potential for the reutilization of waste products comprising coarse hematite bodies as adsorbents.

Species-Specific Uptake of Arsenic on Confined Metastable 2-Line Ferrihydrite: A Combined Raman-X-Ray Photoelectron Spectroscopy Investigation of the Adsorption Mechanism

“…Hematite (α-Fe 2 O 3 ), magnetite (Fe 3 O 4 ), goethite (α-FeOOH), and ferrihydrite (Fe 2 O 3 ·0.5H 2 O) are the commonly available polymorphs and are used for various industrial and scientific applications. Hematite (HEM), magnetite (MAG), and ferrihydrite (Fh)-based materials were used extensively in water purification for the removal of heavy metal ions (Pb and As). − Higher surface area of iron oxides favors larger adsorption capacity for arsenate . Iron oxide nanoparticles are also effective for the removal of other metals such as V, Cr, Co, Mn, Se, Mo, Cd, Sb, Tl, Th, and U .…”

“…30−32 Higher surface area of iron oxides favors larger adsorption capacity for arsenate. 33 Iron oxide nanoparticles are also effective for the removal of other metals such as V, Cr, Co, Mn, Se, Mo, Cd, Sb, Tl, Th, and U. 34 Use of nanoadsorbents for the removal of heavy metal ions from water is particularly attractive as they can be altered suitably to achieve greater surface area and stronger binding capacity.…”

Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent (TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study

“…Data on the TiP1 sorption performance of the same closed-mine water, in dynamic mode with a higher flow rate, are shown in the Supporting Information (Figure S2). Although the higher flow rate means faster removal of metal ions and is economically preferred, it is not favorable in this case as the amount of metal ions in the fixed-bed column decreased due to the contact time between the water and sorbent being too short for sorption equilibrium to take place. − The data at a high flow rate also reveal that the affinity trend is preserved along with the preferential sorption of metal ions on the TiP1 surface.…”

Treatment of metal (loid) contaminated solutions using iron-peat as sorbent: is landfilling a suitable management option for the spent sorbent?

“…Arsenic is commonly removed from contaminated water by adsorption onto reactive media. Iron (Fe) oxides have an affinity for arsenates and are known to be effective and potentially inexpensive adsorbents for use in treating As-contaminated water (Carabante et al 2014; Ahmad et al 2017). To avoid clogging of filters (Mohan and Pittman 2007) and to overcome low hydraulic permeability (Theis et al 1992), Fe-containing filters are commonly produced by coating Fe oxides onto a bulk material, such as sand (Devi et al 2014; Wang et al 2017; Callegari et al 2018) or activated carbon (Yurum et al 2014; Mondal and Garg 2017), where there are advantages of using activated carbon instead of sand because it also targets other contaminants.…”