Metal removal efficiencies of substrates for treating acid mine drainage of the Dalsung mine, South Korea

A pilot reactor system for testing acid mine drainage treatment was designed, operated at the Dalsung mine, and then evaluated for operating problems. Field analyses of pH and Eh (redox potential) were made. In the laboratory, analyses were made of Cd, Pb, As, Zn, Cu, Fe, Al and Mn. The reactor, containing a mixture of rice stalks, cow manure, and limestone, initially showed decreases of 98% Cu, 100% Zn, 99% Fe, 100% Cd, 97% Al, 61% Mn and 100% Pb when the effluents from the reactor had a pH of 6 and an Eh of about -300 mV. However, as time passed, the Eh rose and the amount of metals removed decreased, except Al. This indicated that maintaining reducing conditions was very important for continued metal removal. During the operating period, there were some problems such as a volume change in the substrate within the reactor and scaling on pipes. These problems appeared to reduce the flow of mine drainage in pipes and the reactor over time. (C) 1998 Elsevier Science B.V. All rights reserved.