Butler, S.C., J. Pope, S.R. Chaganti, D.D. Heath, and C.G. Weisener.
Geosciences 9(1):50(2019)

A laboratory mesocosm study investigated the physio-chemical and biological influence of anoxic storage (burial deep within a waste rock dump) and exposure to oxic environments (use of sludge on the surface of the mine) on sludge material created by a mussel shell bioreactor treating acid mine drainage (AMD). Microbes in an oxic environment increased the formation of oxyhydroxides, and acidic conditions increased metal mobility. In an oxic and circumneutral environment, the AMD sludge may be repurposed to act as an oxygen barrier for mine tailings or soil amendments. Anoxic conditions would likely promote the biomineralization of sulfide minerals in the AMD sludge by sulfate-reducing bacteria, which were abundant in the system. The anoxic conditions reduced the risk of Zn associated with oxides, but increased Fe associated with organic material. Fewer risks were associated with anoxic burial but repurposing in an oxic condition may be appropriate under favorable conditions. https://scholar.uwindsor.ca/cgi/viewcontent.cgi?article=1205&context=glierpub