Reactivity and Control of Mercury Released From Artisanal and Small-Scale Gold Mining

EPA Grant Number: FP917787
Title: Reactivity and Control of Mercury Released From Artisanal and Small-Scale Gold Mining
Investigators: Diringer, Sarah Elisa Axelroth
Institution: Duke University
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2015 through August 31, 2018
Project Amount: $132,000
RFA: STAR Graduate Fellowships (2015) RFA Text |  Recipients Lists
Research Category: Academic Fellowships

Objective:

This research focuses on mitigating direct release of mercury during amalgam burning and decreasing methylmercury production during disposal, thereby decreasing accumulation in fish. This will be accomplished through two specific aims. First, I will develop a sulfur-impregnated charcoal sorbent using inexpensive, locally available materials to improve gaseous mercury capture during ASGM processes. Second, I will examine the mercury reactivity of contaminated sorbents under conditions relevant to solid waste disposal scenarios.

Approach:

Sulfurized charcoal will be synthesized in the lab using elemental sulfur and activated carbon and biochar. A laboratory flow through system will be set up to determine the Hg capture efficiency for varying mercury vapor concentrations and total air flow. The synthesized carbons will be compared with commercial sulfurized charcoal for mercury sorption capacity, breakthrough, and particle characterization. In order to understand disposal scenarios, sediment microcosm slurry experiments will determine the stability of Hg within the carbon, the potential for leaching from the carbon matrix, and methylmercury production.

Expected Results:

Sulfurized carbons are expected to capture mercury more efficiently than non-impregnated carbons. Further, the microcosms amended with sulfurized-carbon and Hg are expected to show decreased MeHg production and ‘bioavailable phase’ leaching as compared to both non-sulfurized carbon and no carbon amendments. This result will provide exciting insight into reactivity of Hg released from ASGM.

Supplemental Keywords:

ASGM, mercury, activated carbon, carbon sorbent, sulfur

Progress and Final Reports:

  • 2016
  • 2017
  • Final