DEGRADABILITY OF ECF KRAFT EFFLUENT BY A CATECHOL-DRIVEN FENTON REACTION

摘要

The degradation of a highly loaded ECF (elemental chlorine free) Kraft mill effluent was studied and optimized using a Catechol (CAT) driven Fenton reaction in a lab-scale for 2 h at room temperature using a response surface methodology based on a circunscribed central composited design (CCC). Optimal COD removal was achieved at: Catechol 150 ^M.; Fe(III) 800 ^M; H2O2 12000 ^M ; pH 2.5. At these optimal reaction conditions, TOC (Total Organic carbon), AOX (adsorbable organic halogens) and acute toxicity were determined as well. COD, TOC, and AOX removals achieved by the CAT driven Fenton reaction were similar to those obtained by conventional and Fenton type reactions (40 removals, mean value, in all cases). However, the acute toxicity increased during the CAT driven Fenton reaction and the conventional and Fenton type reactions. These results suggest that the CAT driven Fenton reaction would be a more suitable method for effluent oxidation (as a tertiary treatment). For a feasible application, we suggest to immobilize CAT, or to use it as a solid phase with anchored catecholate functional groups i.e an heterogeneous system.