Radon removal using point-of-entry water-treatment techniques. Final report, October 1988-June 1990

The purpose of the EPA Cooperative Agreement was to evaluate the performance of POE granular activated carbon (GAC), and diffused bubble and bubble place aeration systems treating a ground water supply containing radon (35,620 + or - 6,717 pCi/L). The pattern of loading to the units was designed to simulate daily demand in a household. Each of the systems was evaluated with respect to three primary factors: radon removal efficiency, potential problems, and economics. The radon removal efficiencies of the POE GAC units gradually deteriorated over time from 99.7% to 79% for the GAC without pretreatment and 99.7% to 85% for the units preceded by ion exchange. The bubble plate and diffused bubble POE units were very efficient (99%) at removing radon from the water. The resilience is primarly due to the high air to water ratios supplied by the aeration blowers. One major problem associated with the aeration techniques is iron oxidation/precipitation