TREATING METALS IN ACID MINE DRAINAGE USING SLOW-RELEASE HYDROGEN PEROXIDE

Metal concentrations from acid mine drainage (AMD) pose a significant threat to aquatic systems worldwide as a result of past and current mining operations. This study tested the viability of using slow-release hydrogen peroxide (SR-HP) to oxidize and remove ferrous iron (Fe²⁺) from AMD. Fenton’s reagent forms from a mixture of hydrogen peroxide (H₂O₂) and Fe²⁺ available from AMD, creating an advanced oxidation process. The SR-HP forms were developed by dispersing sodium percarbonate (Na₂CO₃·1.5H₂O₂) salts in resin matrix. The SR-HP released H₂O₂ in flowing water at a peak release rate of 28 mg/min during the initial hour and continued to release H₂O₂ at a lower, stable release rate. When AMD water collected from an abandoned mine site in Ohio was flown through a glass column containing a SR-HP, Fe²⁺concentrations were reduced by more than 90% (from ~80 mg/L to ~ 8 mg/L). The SR-HP forms can be strategically installed in the field to reduce metal concentrations in AMD.