LAUSR

Abstract Removal of toxic organic compounds from the subsurface with meso zero-valent iron particles (mZVI) emplaced in porous media overcomes the concerns associated with in situ groundwater remediation technologies. The results of the continuous column experiments with mZVI is first of its kind and provide a sound basis on Fenton reaction mediated remediation of contaminated groundwater. Columns with different configurations varying in ZVI distribution and location of H2O2 were investigated for factors influencing sustainable phenol removal. The performance of columns were in the ascending order of C > A > B > D where columns A and B had full-length ZVI distribution, C and D had half-length ZVI distribution, with H2O2 injection at initial conditions in A and C and at intermittent points in B and D. Conditions maintained in column C resulted in 61–84% more interaction between Fe2+ ions and H2O2, promoted continuous corrosion, invigorated effective Fe2+-Fe3+ cycling, retained active iron surface area and circumvented precipitation and secondary sludge production. The breakthrough curves showed that mZVI particles extended the active corrosion stage by 5–8 times and resulted in 3–7 times increment in mg phenol removed/mg mZVI along with 80–99.8% utilization of mZVI. Additional sand-only columns proved that Fenton’s oxidation in in situ porous media can be improvised by 14–34% without incumbent addition of ZVI particles.