COMPARISON OF THE EFFICIENCIES OF ORGANIC AND CELLULOSIC SUBSTRATES IN REMOVING SULFATES AND METALS FROM ACID MINE DRAINAGE USING CONTINUOUS SULFATE REDUCING BIOREACTOR

摘要

The present study deals with the biological treatment of the acid mine drainage using an anaerobic sulfate-reducing bioreactor with waste materials like sawdust and wood chips (cellulosic materials), cow manure and compost (organic materials), which have been used as possible carbon sources for sulfate-reducing bacteria. The efficiency of all these materials was investigated in the removal of metals and sulfates from synthetically prepared acid mine drainage. The bioreactor was run in continuous mode for 182 days and the effluent was sampled out from all the six reactors at time intervals of 1,3,5,8,10,20,30,45 and 60 days. There was a rapid decrease in the redox potential for compost, cow manure, sawdust mix and wood chips mix showing the survival of Sulfate-Reducing Bacteria, while it remained almost the same as the initial value in case of sawdust and wood chips showing the non-survival of the SRB. The retention time was optimized to 10 days. Thus compost and cow manure as substrates for the removal of metals and sulfates proved to be more efficient than sawdust and wood chips, while sawdust mix and wood chips mix have shown near similar behavior of organic substrates.