NEW ENHANCED EVAPORATION TECHNOLOGY AS A POTENTIAL REMEDIATION STRATEGY FOR ACID ROCK DRAINAGE

Acid rock drainage (ARD) is a global water quality issue at active and historic mine operations, including coal mines and coal processing sites in Appalachia. Low-quality ARD water was sampled from a historic coal processing site in Kentucky to determine the efficacy of a new enhanced evaporation technology by Micronic Technologies, Inc. for the treatment of ARD. Samples were analyzed for pH, dissolved metals, and sulfate prior to treatment and after treatment. Results indicate 84% to >99% removal of dissolved solutes, and an increase in pH from pH 2.35 to pH 6.03. Example dissolved metals that were removed include aluminum (132 mg/L to 0.25 mg/L; 99.8% decrease), cadmium (0.0051 mg/L to <0.0005 mg/L; >90.2% decrease), chromium (0.0902 mg/L to 0.0096 mg/L; 89.4% decrease), cobalt (0.282 mg/L to <0.002 mg/L; >99.3% decrease), iron (150 mg/L to 0.266 mg/L; 99.8% decrease), manganese (5.25 mg/L to 0.01676 mg/L; 99.7% decrease), nickel (0.647 mg/L to 0.008 mg/L; 98.8% decrease), and zinc (1.84 mg/L to 0.05 mg/L; 97.28% decrease). The neutralization of acidity and successful removal of solutes suggests a strong potential for use of the technology for ARD remediation. Future research includes use of the technology to concentrate rare earth elements and other elements that can be recovered for use in batteries and electronics.