Integrated Fenton's reagent-coagulation/flocculation process for the treatment of cork processing wastewaters

In the present work two methods were tested for the treatment of cork processing wastewaters. In a first phase, a coagulation/flocculation method was applied using FeCl3 as flocculating agent and Ca(OH)2 as base-precipitant. One cycle of the treatment (1000 ppm of FeCl3) reduced chemical oxygen demand (COD), total polyphenols and aromatic compounds of the effluent by 45, 71 and 58%, respectively. Two cycles of treatment (2x 1000 ppm of FeCl3) increase these reductions until values of 67, 92 and 85%, respectively. In a second phase, an integrated Fenton-coagulation/flocculation process was applied (this second method only requires the addition of H2O2). One cycle of the integrated process (1000 ppm of FeCl3 and 0.5 mol/l of H2O2) reduced the COD, total polyphenols and aromatic compounds of the effluent by 74, 99 and 98%, respectively, which supposes a considerable improvement compared with the first method.