Remediation of BTEX plume in a continuous flow model using zeolite-PRB

Abstract

Adsorption is a well-known phenomenon that causes the remediation of BTEX (Benzene, Toluene, Ethylbenzene, and Xylene). Zeolite is typically useful for the removal of BTEX from groundwater. In this study, the migration of the BTEX plume was investigated in a bench-scale tank model as a shallow aquifer. The objective of this research was to analyze the performance of a natural zeolite in-situ PRB remediation technique. Natural zeolite was applied as a physical permeable reactive barrier. In the first part of the experiment, 40 ml of BTEX as a contaminant was injected at the injection point (BI) into the sand tank. Samples were taken periodically via 14 boreholes for BTEX test for 23 days and analyzed using a GC-FID instrument. The results indicated high removal rates of BTEX by passing through the zeolite barrier. Zeolite barrier reduced the BTEX concentration up to 90% of the initial value. However, the barrier efficiency started to decrease after 132 h since pollution injection reached a minimum amount (%53 of the initial value) due to occupying the free space and grain pore where BTEX was adsorbed onto the surface of zeolite, thereby decreasing the barrier efficiency.