The Box-Benkhen experimental design for the optimization of the electrocatalytic treatment of wastewaters with high concentrations of phenol and organic matter

Water Sci Technol. 2009;60(11):2809-18. doi: 10.2166/wst.2009.705.

Abstract

In this work, the Box-Benkhen experimental Design (BBD) was applied for the optimization of the parameters of the electrocatalytic degradation of wastewaters resulting from a phenolic resins industry placed in the suburbs of Medellin (Colombia). The direct and the oxidant assisted electro-oxidation experiments were carried out in a laboratory scale batch cell reactor, with monopolar configuration, and electrodes made of graphite (anode) and titanium (cathode). A multifactorial experimental design was proposed, including the following experimental variables: initial phenol concentration, conductivity, and pH. The direct electro-oxidation process allowed to reach ca. 88% of phenol degradation, 38% of mineralization (TOC), 52% of Chemical Oxygen Demand (COD) degradation, and an increase in water biodegradability of 13%. The synergetic effect of the electro-oxidation process and the respective oxidant agent (Fenton reactant, potassium permanganate, or sodium persulfate) let to a significant increase in the rate of the degradation process. At the optimized variables values, it was possible to reach ca. 99% of phenol degradation, 80% of TOC and 88% of COD degradation. A kinetic study was accomplished, which included the identification of the intermediate compounds generated during the oxidation process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Electrochemistry
  • Electrodes
  • Equipment Design
  • Graphite
  • Kinetics
  • Organic Chemicals / analysis*
  • Oxidation-Reduction
  • Phenols / analysis*
  • Titanium
  • Waste Disposal, Fluid / instrumentation
  • Waste Disposal, Fluid / methods*

Substances

  • Organic Chemicals
  • Phenols
  • Graphite
  • Titanium