The Sequential Tests about Passive Treatment for Acid Mine Drainage Using Sulfate Reducing Bacteria

In order to prevent the mine pollution caused by the acid mine drainage (AMD) from abandoned metal mines in Japan, the treatment of AMD has been conducted with neutralization using a significant number of reagents. Passive treatment processes are attractive as an alternative because of an energy and cost saving one. Although the passive treatment processes using sulfate-reducing bacteria (SRB) have been investigated widely in the United States and Europe, many of those processes require a huge area that is necessary for a long hydraulic retention time (HRT). So, in this research, the mechanism, influential factors and performance of metal removal using SRB have been investigated in the column test to develop it as a prospective, effective and compact process. The results showed that sulfate reduction by SRB had continued for 140 days under the condition of a 50-hour HRT, and that metals had been removed as sulfides in a column. In addition, it is apparent that the positions where each metal sulfide was precipitated were different. This means that the quality of AMD is an important factor when the treatment facility is designed.