Caryl Ann Becerra
cbecerra@microbio.umass.edu

RESEARCH

Acid mine drainage (AMD) is one of the largest widespread environmental problems exarcerbated by mining activities. Methods to remediate and prevent AMD are both time consuming and expensive. Promoting the natural attenuation of sites affected by AMD offers a more cost-effective strategy for the mining industry.

Davis Mine in Rowe, Massachusetts is an AMD site where natural attenuation is occurring. The natural attenuation at this site may be due to the dilution of unpolluted water into the area and/or microbial activity such as sulfate reduction. In previous studies, sulfate-reducing bacteria (SRB) were found.

The main goal of this study is to determine the contribution of microbial sulfate reduction and iron reduction to the natural attenuation observed at Davis Mine under different sampling seasons by using several techniques to measure sulfate reduction activity.

Microbial sulfate reduction rates will be determined first through microcosm studies with amended Davis Mine water and SRB media buffered at the local pH. A sediment core depth analysis of sulfate reduction rates will be resolved using radio-isotopes of sulfate for an AMD generating zone, an AMD attenuating zone, and downstream from the tailings pile in the hyporheic zone where due to geochemical properties, SRB’s are likely to be found.

Microbial community analysis at these collection sites will be used to determine who the major contributors are in the process of sulfate reduction and iron reduction. Eventually, attempts will be made to isolate an active SRB and compare sulfate reduction rates of a pure culture to enrichments with environmentally abundant substrates.

By determining the rate of sulfate reduction and the abundance and diversity of SRB’s at Davis Mine , we can provide estimates of their likely importance in other global settings as well as an application in industrial waste streams.

A view of the smapling site at Davis Mine