Removal of Arsenic Using Mesoporous Silicate Media Impregnated Metal Oxides Nano-Particles

Abstract

The highly ordered mesoporous silica SBA-15 was successfully synthesized and incorporated with iron, aluminum, and zinc oxides by use of an incipient wetness impregnation technique. Aluminum 10% impregnation was safely incorporated by an incipient wetness impregnation technique for SBA-15, which had 638.75 m 2 /g of BET surface area and 48 Å of pore diameter, without producing clogging of pore structures. The adsorption capacities of these materials were evaluated with adsorption isotherm and kinetic studies under different batch conditions. Aluminum was the best incorporation metal compound and impregnation of aluminum 10% for SBA-15 had greater than 2 times higher arsenate adsorption capacity and 15 times higher rate than activated alumina under the condition of 0.133 mmol/L arsenate initial concentration and 0.333 g/L of solids concentration. Al 10 SBA-15 showed about 2.2 ~ 2.4 times higher arsenate adsorption capacities than activated alumina in a broad range of arsenate initial concentrations, in which the Freundlich isotherm model was fitted very well. The ratecontrolling step of arsenate adsorption for all adsorbents appeared to be explained by both the exchange reaction and diffusion reaction. These results showed great advantages of Al 10 SBA-15 for POE/POU application due to its rapid and high adsorption capacity.

Surface Properties and Microstructures of Al-SBA-15 under Different Temperature Calcinations in Relation to Adsorption Performance

“…5 Therefore, aluminum can be loaded onto the SBA-15 material to improve the arsenic removal efficiency. 22 In our previous studies, 23,24 Al-SBA-15 had also been confirmed to be efficient adsorbents for arsenate, and the effects of aluminum loading and adsorption behavior were fully studied. Moreover, we found that aluminum oxides with different coordination environments were produced after the incorporation of aluminum onto SBA-15, and these aluminum oxides made a large number of Lewis or Brønsted acid sites, effectively increasing the number of active adsorption centers.…”

“…Moreover, among the arsenic removal materials, alumina is the most widely used . Therefore, aluminum can be loaded onto the SBA-15 material to improve the arsenic removal efficiency . In our previous studies, , Al-SBA-15 had also been confirmed to be efficient adsorbents for arsenate, and the effects of aluminum loading and adsorption behavior were fully studied.…”

Facile Synthesis of Magnetic Activated Carbon Composite for Arsenic Adsorption

“…Mineral weathering and dissolution resulting from a change in the geo-chemical environment to a reductive condition are the possible natural causes for arsenic contamination of water. While human activities like mining wastes, petroleum refining products, sewage sludge, agricultural chemicals, ceramic manufacturing industries and coal fly ash can be considered as some of the major causes of arsenic contamination [14]. Recently, one of the major challenges in developing countries is the removal of toxic metals from water.…”