Electrochemical oxidation of model compounds and olive mill wastewater over DSA electrodes: 1. The case of Ti/IrO(2) anode.
The electrochemical oxidation of olive mill wastewater (OMW) and model compounds over a Ti/IrO(2) anode was studied by means of cyclic voltammetry and bulk electrolysis. Experiments were conducted at 1300 mg/L initial COD, 0-1.23V vs SHE and 1.4-1.54V vs SHE potential windows, 50 mA/cm(2) current density, 0-25 mM NaCl, 60-80 degrees C temperature and acidic conditions. The reactivity of model compounds decreases in the order phenol approximately p-coumaric acid>cinnamic acid>caffeic acid. Partial and total oxidation reactions occur with the overall rate following zero-order kinetics with respect to COD and increasing with temperature. Oxidation of OMW at 43 Ah/L, 80 degrees C and in the presence of 5mM NaCl leads to complete color and phenols removal, elimination of ecotoxicity but moderate (30%) COD reduction. Similar performance can be achieved at 6 Ah/L in the presence of 15 mM NaCl. In the absence of salt, the respective color and phenols removal (at 6 Ah/L) is less than 10%. Excessive salinity (25 mM), although does not change color, phenols and COD removal, has an adverse effect on ecotoxicity.
Chatzisymeon
E
E
Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, Chania, Greece.
Dimou
A
A
Mantzavinos
D
D
Katsaounis
A
A
D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D052918:Environmental Restoration and Remediation / Q000379:methods; D007220:Industrial Waste / Q000517:prevention & control*; D007495:Iridium; D031658:Olea; D010084:Oxidation-Reduction; D014025:Titanium; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C044458:iridium oxide; D007495:Iridium; D014025:Titanium