Arsenic, the twentieth richest element in the earth’s crust, is widely dispersed into water due to mining, natural weathering process, dissolution of minerals, agricultural pesticides and other natural and anthropogenic activities. Long-term use of such arsenic contaminated water during human’s daily life, such as drinking, cooking and irrigation, would pose danger to human health, including skin, lung cancers, cardiovascular diseases, non-pitting swelling and other diseases. Consequently, arsenic contamination of ground water has drawn attention all over the world and the WHO (World Health Organization) and EPA (Environmental Protection Agency) regulations set 10 ug/L as the maximum contaminate level of arsenic in drinking water. Arsenic in natural water sources exist predominately in two forms of arsenite (As(III)) and arsenate (As(V)).<br/>In recent years, adsorption is considered one of the most competitive methods for arsenic remediation from water due to its high efficiency, economy, and simple operation. There are various adsorbents made for arsenic removal including natural and composite materials. However, none of them is found to be completely applicable. Therefore, improved, and tailor-made materials are sought. Substitutes should be easily available, cheap and, above all, be readily regenerated, providing quantitative recovery.<br/><br/>RTI’s ultra-high reactive surface solid sorbents (e.g., Fe-and Mn-based sorbents), for optimum removal of metals from drinking water at maximum water productivity and reduced cost was developed to remove As through a novel chelating mechanism. Practical As removal by RTI’s sorbent was achieved through high As removal efficiency at low sorbent loadings. As demonstrated from our recent data, both Fe-and Mn-based sorbents adsorb selectively As (III) and As(V). The As capacity of the sorbent is directly tied to the Fe oxide content as well as Mn oxide, which is dependent on the sorbent’s amine formulation. It was also found that the both sorbents showed greater adsorption capability and selectivity for As(V) and As(III) over other contaminants. Furthermore, X-ray absorption spectroscopy (XAS) determined that Fe-based sorbents are primarily a lepidocrosite like phase and Mn-based sorbents are mostly a feitnechtite phase. More insights on the mechanisms of adsorption of these adsorbents will be presented using several spectroscopy techniques including operando X-ray Absorption Near Edge Spectroscopy (XANES).

Synthesis, characterization and mechanisms of arsenic uptake from aqueous solution by interaction with iron-and manganese-based solid sorbents

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.