Characteristics and applications of controlled-release KMnO4 for groundwater remediation

The new scheme described in this paper uses controlled-release KMnO4 (CRP) as an active component in the well-based reactive barrier system. This scheme operates to control spreading of a dissolved contaminant plume. Prototype CRP was manufactured by dispersing fine KMnO4 granules in liquid crystal polymer resin matrix. Scanning electron microscope data verified the formation of micro-scale (ID = 20-200 μm) secondary capillary permeability through which MnO4- is released by a reaction-diffusion process. Column and numerical simulation data indicated that the CRP could deliver MnO4- in a controlled manner for several years without replenishment. A proof-of-concept flow-tank experiment and model simulations suggested that the CRP scheme could potentially be developed as a practical approach for in situ remediation of contaminated aquifers. This scheme may be suitable for remediation of sites where accessibility is limited or some low-concentration contaminant plume is extensive. Development of delivery systems that can facilitate lateral spreading and mixing of MnO4- with the contaminant plume is warranted.