MERCURY CAPTURE DURING ARTISANAL AND SMALL-SCALE GOLD MINING (ASGM) USING LOW-COST SULFURIZED CARBON

Artisanal and small-scale gold mining (ASGM) is the largest anthropogenic source of mercury to the atmosphere worldwide, largely in developing countries. During the mining process, liquid mercury is added to river sediment and soil to create a gold-mercury amalgam. The amalgam is then burned in the field or in gold shops, exposing miners to high concentrations of mercury and releasing it to the environment. This research examines a novel mercury capture system using low-cost, sulfur-impregnated carbon. Low-cost, sulfur-impregnated carbon was compared to virgin activated carbon and industrially synthesized impregnated carbon for material properties (e.g. break through, sorption capacity, BET, and particle density) and characterized using spectroscopy (XPS and FTIR). In a laboratory mercury flow through system, sulfur-impregnated carbon reduced mercury concentrations nearly 50% more efficiently compared to virgin activated carbon. Further, leachable mercury decreased dramatically with sulfur-impregnated carbon compared to activated carbon alone. In an effort to understand mercury reactivity in sulfurized carbon, sediment microcosms were amended with carbon loaded with mercury. Sulfur-impregnated carbon had a drastic impact on mercury reactivity and methylation potential compared to activated carbon alone. Our on-going work examines mercury reactivity and methylation potential of both industrially used and sulfurized carbon during disposal. Future work will optimize conditions to implement sulfurized carbon capture systems for ASGM in developing countries.