Acid Leachate Active Treatment Pilot System For Cooledge Brook, MA

Burleson, Emma E.; Eastwood, Annemarie N.; Mitchell, Lauren O.; Youngs, Molly W.

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Acid Leachate Active Treatment Pilot System For Cooledge Brook, MA

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This project, in conjunction with MassDEP, focused on designing and testing a pilot treatment system for an acid rock drainage (ARD) contaminated site at Cooledge Brook in Northborough, MA. Cooledge Brook was impacted by runoff from sulfidic fill rock at a nearby property, resulting in a pH of 4.5 and high levels of dissolved metals in both the groundwater and surface water. We designed, built, and operated a pilot-scale batch reactor system to assess the feasibility of a large-scale treatment system at the site. The pilot system was able to successfully increase the pH of the contaminated water from 4.5 to 7.5 using a sodium hydroxide solution and a pH-metered chemical proportioning pump. Additionally, the solution was aerated to encourage coagulation, decreasing the concentration of dissolved metals in the solution. The pilot system drew water from a contaminated well using a solar-powered pump and was treated in a ten-gallon batch reactor. An electric mixer was used in conjunction with a chemical proportioning pump to add diluted NaOH, neutralizing the pH. After settling, the water had a neutral pH and lower levels of dissolved metals and was discharged back to the environment. Sludge was produced from the overall reaction and was collected and disposed of. Future work such as on site testing and automation will further improve the pilot system for scale up.

This report represents the work of one or more WPI undergraduate students submitted to the faculty as evidence of completion of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review.

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