Pyrolusite Process to Remove Acid Mine Drainage Contaminants from Kimble Creek in Ohio: A Pilot Study

摘要

Th e Kimble Creek abandoned coal mine site, located on Wayne National Forest in southeastern Ohio, is among several abandoned coal mine sites that have been responsible for the acid mine drainage (AMD) polluting ground and surface water. Materials released by AMD include iron, aluminum, manganese, other hazardous substances, and acidity that are harmful to aquatic life. We tested at the Kimble Creek site the Pyrolusite Process, a microbiological water treatment system that employs metal-oxidizing bacteria adsorbed on limestone rocks. Th e pilot treatment plant constructed was inoculated with a mixture (fi ve strains) of metal-oxidizing bacteria. Water was examined at regular intervals for pH, concentrations of metals (Fe, Al, Mn, Mg, Zn, Ca), dissolved oxygen, temperature, conductivity, hardiness, sulfate and chloride contents, acidity, alkalinity, and dissolved solids. Results showed that the Prylosite Process consistently increased the pH of effl uent water to above-neutral levels. Th e iron and aluminum contents, which were as high as 72 mg/L and 50 mg/L, respectively, were below detectable levels in the effl uent water. Scanning electron microscope (SEM) and DNA analyses of rock samples showed growth and density increases of inoculated bacteria. Th e sludge contained iron (predominantly Fe+3), aluminum, and small amounts of zinc, magnesium, and manganese. Based on the performance of the pilot system, a full-fl edged system was constructed at the Kimble Creek site which is functioning as expected based on preliminary tests.