Mineral-catalyzed peroxidation of tetrachloroethylene

The treatment of perchloroethylene (PCE) was investigated by the promotion of Fenton-like reactions using the iron oxyhydroxide goethite (α-FeOOH) as the sole source of the iron catalyst. A silica sand-goethite matrix was contaminated with 5 mg L^?1 PCE and the oxidative treatments were conducted with 0.15 mM, 2 mM, 5mM, 10mM, 20mM, and 30mM H₂O₂. Perchloroethylene was effectively degraded within 96 hr and the most efficient treatment stoichiometry was observed using 0.15 mM H₂O₂ at pH 3. The degree of heterogeneous catalysis was evaluated by conducting oxidation reactions in parellel systems with an equivalent concentration of soluble iron. The results showed that, within the first 24 hr, up to 94% of the PCE degradation was attributed to heterogeneous catalysis. This modified Fenton's process, when used to treat 5 mg L^?1 PCE in natural subsurface materials with 2 mM H₂O₂ at pH 3, resulted in a residual of 0.20 mg L^?1 PCE after 96 hr.