The use of hydroxyl-radical-generating systems for the treatment of olive mill wastewaters.

Three hydroxyl-radical producing biomimetic systems, composed of CuII, hydrogen peroxide and pyridine, glucaric or succinic acid, were able to perform decolorization of olive mill wastewaters (OMW) >85 % within 3 d combined with a significant removal of total phenols (>75 %). The systems consisting of 50 mmol/L succinic acid, 5-10 mmol/L CuSO4 and 100 mmol/L H2O2 were the most effective at OMW treatment, and led to the reduction of phenol contents to <1 % along with high decolorization (>88 %) and acceptable values of chemical oxygen demand.