Electro-Fenton decolourisation of dyes in an airlift continuous reactor using iron alginate beads

Environ Sci Pollut Res Int. 2013 Apr;20(4):2252-61. doi: 10.1007/s11356-012-1100-0. Epub 2012 Aug 1.

Abstract

In this study, electro-Fenton dye degradation was performed in an airlift continuous reactor configuration by harnessing the catalytic activity of Fe alginate gel beads. Electro-Fenton experiments were carried out in an airlift reactor with a working volume of 1.5 L, air flow of 1.5 L/min and 115 g of Fe alginate gel beads. An electric field was applied by two graphite bars connected to a direct current power supply with a constant potential drop. In this study, Lissamine Green B and Reactive Black 5 were selected as model dyes. Fe alginate gel beads can be used as an effective heterogeneous catalyst for the degradation of organic dyes in the electro-Fenton process, as they are more efficient than the conventional electrochemical techniques. At optimal working conditions (3 V and pH 2), the continuous process was performed. For both dyes, the degree of decolourisation increases when the residence time augments. Taking into account hydrodynamic and kinetic behaviour, a model to describe the reactor profile was obtained, and the standard deviation between experimental and theoretical data was lower than 6%. The results indicate the suitability of the electro-Fenton technique to oxidise polluted effluents in the presence of Fe alginate gel beads. Moreover, the operation is possible in a continuous airlift reactor, due to the entrapment of iron in the alginate matrix.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / chemistry*
  • Catalysis
  • Coloring Agents / chemistry*
  • Electrochemical Techniques*
  • Gels
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / chemistry
  • Hydrodynamics
  • Hydrogen Peroxide / chemistry*
  • Iron / chemistry*
  • Kinetics
  • Lissamine Green Dyes / chemistry
  • Models, Chemical
  • Naphthalenesulfonates / chemistry
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / instrumentation
  • Water Purification / methods*

Substances

  • Alginates
  • Coloring Agents
  • Fenton's reagent
  • Gels
  • Hexuronic Acids
  • Lissamine Green Dyes
  • Naphthalenesulfonates
  • Water Pollutants, Chemical
  • Glucuronic Acid
  • green 5
  • Hydrogen Peroxide
  • Iron
  • Remazol black B