Study on the Effectiveness of Reactive Circulation Wells for Remediation of Benzene and Toluene Contaminated Groundwater

A static batch test was used to determine the optimal ratio of Fenton's reagent for removing benzene and toluene from contaminated subsurface at a site, followed by a two-dimensional simulation tank experiment, where benzene and toluene were distributed throughout the tank, and then in the groundwater circulation wells.The Fenton's reagent of 0.05 L of 3% H 2 O 2 and 6.12 g of FeSO 4 •7H 2 O was added in the ratio of 0.05 L of 3% H 2 O 2 and 6.12 g of FeSO 4 •7H 2 O, and the reactive circulation wells were initiated at an aeration rate of 15 L/min.The results show:The groundwater circulation close to the circulation wells is highly disturbed, the mass transfer between the gas and water phases is strong, benzene and toluene are preferentially removed, and a remediation area centered on the circulation wells is gradually formed; after 12 h of cumulative aeration, contaminants within a 50 cm radius from the circulation well were below the detection limit.Residual benzene and toluene were concentrated in the area on both sides of the simulation tank, away from the circulation well.The contaminant removal efficiency within the 50-cm radius of influence of the circulation wells was high, and the enhanced remediation of benzene-and toluene-contaminated groundwater by reactive circulation wells using Fenton's reagent as the remediation agent was more effective.