Potassium Permanganate–Based Controlled Release Beads to Remediate Groundwater Pollution: Alkylbenzene Degradation and Permanganate Release Kinetics

Groundwater pollution is a significant threat to the public health and environment. Existing groundwater remedial approaches include ex situ treatment and conventional in situ chemical oxidation methods. Although these two methods are widely adopted for groundwater cleanup, continual treatment effectiveness is not satisfactory due to several physicochemical challenges, such as tailing, back diffusion, and concentration rebound. Moreover, these two methods require significant energy and chemical inputs. As an alternative to conventional approaches, controlled release materials are able to discharge chemical oxidants in a continual manner with a substantially prolonged release longevity and treatment time. Thus, these materials are characterized as cost-effective and low-maintenance. In this study, controlled release bead (CRB) materials composed of potassium permanganate (KMnO 4 )-paraffin were synthesized and evaluated for their performance in degrading alkylbenzene organics. Both batch and dynamic degradation studies indicate that the fabricated CRBs can gradually release KMnO 4 into the aqueous phase to degrade alkylbenzenes and the eventual effectiveness in pollutant degradation is on par with the aqueous KMnO 4 solution. Furthermore, KMnO 4 -cement CRBs were fabricated and tested for KMnO 4 release kinetics from the CRB surface. It shows that system temperature can considerably influence KMnO 4 release longevity and hence treatment lifetime. This study provides the essential information of the novel CRB materials for groundwater pollution remediation with a reduced energy and chemical consumption and a lower environmental footprint. This study expands our capacity in designing, laboratory testing, and modeling these novel materials to facilitate their potential field remedial application.