Ethanol-Fed or Solid-Phase Organic Sulfate Reducing Bioreactors for the National Tunnel Drainage, Clear Creek/Central City Superfund Site?

Abstract

Abstract:The Peerless Jenny King treatment system is a series of four sulfate reducing bioreactor cells installed to treat acid mine drainage in the Upper Tenmile Creek Superfund Site located in the Rimini Mining District, near Helena MT. The system consists of a wetland pretreatment followed by the four cells connected in a serpentine manner. The mining impacted water flows from the wetland through each cell before discharge. Sulfate reducing bioreactors mitigate acidity and metal contamination through the microbial production of sulfide. The produced biogenic sulfide precipitates metals, and the microbial process of reducing sulfate to sulfide produces alkalinity.The health of the entire microbial community present in such systems is important for remediation to be effective. Classes of microbes generally present in such systems include fermenters, methanogens and sulfate reducers. The health can be measured in terms of active microbial populations and positive interactions between populations for the support of sulfate reduction. The goal of this research is to measure the activity of each class utilizing analyses that quantify the groups by their function, as opposed to the traditional molecular techniques of identifying bacteria. Gas chromatography, HPLC-DAD, and ICP-AES are used to identify and quantify the end products of metabolism. The microbial activity can then be characterized and changes can be monitored over time. Results from 2005 sampling of Cell 3 within the system indicate that the activity of sulfate reducing bacteria is much higher than the numbers present would indicate. These results combined with those from 2006 sampling indicate that methanogenesis is a minor process within this cell. The calculation of the stoichiometry of carbon utilization by SRB is much higher than what would be predicted from known stoichiometric ratios of carbon used per sulfate reduced.

Effect of Organic Substrate Composition on Microbial Community Structure of Pilot-Scale Biochemical Reactors Treating Mining Influenced Water

“…Interestingly, the performance of the six BCRs was comparable (Buccambuso et al, 2007), though the ETOH BCRs offered some advantage in terms of overall sulfate and metals removal.…”

“…In this study, six pilot-scale BCRs were operated in Black Hawk, Colorado, and were fed with discharge from the National Tunnel, which is a major contributor of contaminants to this area (Buccambuso et al, 2007). Three organic substrate conditions were compared in duplicate:…”

Comparing Chitin and Organic Substrates on the National Tunnel Waters in Blackhawk, Colorado for Manganese Removal

“…It is a brownish material of less than 1 mm in size. The material was packed into 120 liter nonmetal barrels in a downflow configuration the same as the other reactors that were built in 2006 (Buccambuso, et al, 2007). The reactors were started in May of 2007 and were designed to receive 23 liters of National Tunnel water per day in 4 increments.…”

“…For the influent and effluent, field measurements include temperature, pH, alkalinity, specific conductance, oxidation/reduction potential (ORP); samples were taken and analyzed for, Zn, Cu, Mn total Fe, and total S. Tables 2 gives the sampling conditions and Table 3 gives the analytical information on the water constituents that were analyzed (Buccambuso, et al, 2007).…”

“…Since 2006, the researchers at the Colorado School of Mines (CSM) in conjunction with the US Environmental Protection Agency (EPA) Office of Research and Development (ORD) and Region 8, and Golder Associates have been conducting comparison studies on how well different substrate recipes used in sulfate-reducing bioreactors (SRBRs) performed in removing contaminants from the National Tunnel water in Blackhawk, Colorado , Buccambuso, et al, 2007. Pairs of reactors in a downflow configuration included an ethanol based configuration designed by the EPA and CSM, an organic substrate designed by EPA and Golder, and a corn stover substrate designed by CSM.…”