Role of Oxygen Transfer in Acid Mine Drainage Treatment

摘要

The U.S. Bureau of Mines conducted a series of experiments to evaluate theaccuracy of a new mathematical iron oxidation model. The model was used to predict the rate of ferrous iron oxidation during acid mine drainage, AMD, treatment. It is intended to replace the currently used model, recommended by EPA, for most treatment applications. The new model indicated that the rate of iron oxidation was dependent on a treatment system's rate of oxygen transfer. This was in contrast to the currently used rate model, which expresses the rate of iron oxidation as a function of the iron and oxygen concentrations solution pH. Synthetic AMD was treated in the U.S. Bureau of Mines-patented In-Line Aeration and Neutralization System (ILS). The measured oxidation rates were used to evaluate predicted rates of the two models. Use of the new model required a measurement of the treatment system's oxygen transfer rate. Because the ILS is a flow-through reactor, a new oxygen transfer test was developed and employed. Based on the findings, the proposed model was deemed successful and is recommended for use by treatment plant designers. The work was done as part of the Bureau's program to reduce pollution from mining and clean up the Nation's contaminated waters and lands.