Optimization Measures and Results of a Full-Scale Potassium Permanganate Application (Abstract)

摘要

A full-scale in situ chemical oxidation (ISCO) application using potassium perman- ganate (KMnO4) was implemented for the treatment of chlorinated ethenes in groundwa- ter at a site in Myrtle Beach, South Carolina. A total of 52 injection wells were installed throughout a narrow 60-ft plume with an approximate 420-ft length. Approximately 25,200-lbs of potassium permanganate were injected as 127,000 gallons of solution ranging in concentration from 3 percent to 0.2 percent. Multiple innovative optimization measures were implemented to enhance the delivery, distribution, and overall effective- ness of the technology in achieving site remediation. First, the screened interval length and depth of the injection wells was adjusted across the site to specifically target the sandy contaminated zone, which varied in thickness and depth. Second, a mixing and injection system was designed to allow for continuous injection of permanganate solution without interruption during the mixing process. Third, the concentration of the perman- ganate solution was varied with time within each injection phase to enhance subsurface distribution. A computer model code was developed to calculate the necessary change in permanganate concentration with time by accounting for the injection rates, hours of injection per day, total soil oxidant demand, spacing between injection wells, and most notably the kinetics of permanganate consumption. This approach ensured a more uni- form distribution of permanganate, minimizing the potential for permanganate residuals around the injection wells. Lastly, the injection process was combined with groundwater extraction to contain and capture the displaced groundwater, maintain hydraulic control of the permanganate solution, and further facilitate the distribution of the injectant.