Project description

Considerable amounts of chlorinated hydrocarbons (>> 100 mg / L) have been detected in the groundwater and soil at the location of a former dry cleaning facility. From a range of offered remediation solutions, in-situ chemical oxidation was chosen. The process was based on the introduction of sodium permanganate combined with the application of a hydraulic anti-surge device. Large-scale distribution of the oxidizing agent was executed both directly into the contaminated area and around the nearby surroundings of the plume. The outcome was a substantial decrease in CHC accumulation. The entire procedure required continuous monitoring and process adjustments such as chemical degradation, displacement and desorption of the chlorinated hydrocarbons as well as formation of birnessite (Manganese oxide deposits). Finally, follow up monitoring confirmed the long-term remediation goal of the site, which was CHC concentration in ground water below 1 mg / L.

 

Technology / Features

During in-situ chemical oxidation, contaminants dissolved in the ground water are decomposed by chemical oxidation. Hydrogen peroxide, persulfates or permanganates are used as oxidizing agents. Direct contact between the oxidant and contaminants are basic requirement for effective application of this process for ground water treatment. The distribution of the oxidant is achieved by actively guided circulation cells which require delivery, distribution, dosing of the oxidizing agent, infiltration and monitoring elements for groundwater treatment, all of which are managed by a qualified plant engineer. The operation is cyclic and includes measuring, distribution, and reaction cycles controlled by an in-situ conductivity sensor array measured as biomass propagation.