Use of EAF dust as heterogeneous catalyst in Fenton oxidation of PCP contaminated wastewaters

In this study, chemical oxidation tests using H2O2 were performed on a solution contaminated with 100 mg l(-1) of pentachlorophenol (PCP). The effectiveness of electric arc furnace dust and hematite as heterogeneous catalysts was evaluated. Reactions were conducted at pH 2 for 24 h. Either H2O2 stabilized with KH2PO4 or un-stabilized H2O2 was used. Total organic carbon (T.O.C.) removal and chloride release from PCP molecule were monitored. Results showed that the maximum removal yields for electric arc furnace (EAF) dust (49.2% T.O.C., 56.7% Cl) were achieved when H2O2:PCP ratio was 10:1 and Fe:H2O2 = 1:5 for unstabilized H2O2 and when H2O2:PCP = 10:1 and Fe:H2O2 = 1:1 for stabilized H2O2 (48% T.O.C., 60.6% Cl). The maximum yield using hematite (45.2% T.O.C., 55.2% Cl) was obtained when H2O2:PCP ratio was 10:1 and Fe:H2O2 was 1:2. When EAF dust was used and Fe:H2O2 > 1:5, Cl release was higher than the one expected from T.O.C. removal.