Electrochemical oxidation of model compounds and olive mill wastewater over DSA electrodes: 1. The case of Ti/IrO(2) anode

J Hazard Mater. 2009 Aug 15;167(1-3):268-74. doi: 10.1016/j.jhazmat.2008.12.117. Epub 2008 Dec 31.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrochemical Techniques / instrumentation
  • Electrochemical Techniques / methods*
  • Electrodes
  • Environmental Restoration and Remediation / methods
  • Industrial Waste / prevention & control*
  • Iridium
  • Olea*
  • Oxidation-Reduction
  • Titanium
  • Water Pollutants, Chemical / chemistry*

Substances

  • Industrial Waste
  • Water Pollutants, Chemical
  • iridium oxide
  • Iridium
  • Titanium