Elimination of phenol and aromatic compounds by zero valent iron and EDTA at low temperature and atmospheric pressure

Chemosphere. 2007 Jun;68(2):338-44. doi: 10.1016/j.chemosphere.2006.12.059. Epub 2007 Feb 14.

Abstract

This work deals with a new abiotic oxidation process designed as a suitable pre-treatment step within a biological depuration of wastewater containing phenol or its derivatives (o-cresol, 2-chlorophenol and p-nitrophenol) or aniline. The reaction was carried out in a stirred tank reactor at 20 degrees C and atmospheric pressure in presence of the organic compound, 150mgl(-1), zero valent iron particles (10g), ethylenediamine tetraacetic acid (EDTA, 101mgl(-1)) and air. The experimental results show that 85% of phenol conversion can be achieved after 360min. 2-Chlorophenol was found to be more easily degradable and it is completely eliminated after 300min. The oxidation of o-cresol and aniline behaved more closely to phenol obtaining after 360min 70% and 68% of conversion respectively. p-Nitrophenol was a very refractory compound, giving only 28% of conversion after 360min. Moreover, the influence of some operating variables was studied over the following ranges: temperature from 20 to 50 degrees C, initial phenol concentration from 150 to 1000mgl(-1), EDTA concentration from 50 to 200mgl(-1) and iron particles from 5 to 20g. As expected, temperature strongly enhances phenol conversion. Also, an increase of the catalyst to phenol ratio or the iron or EDTA to phenol ratio improves the reaction rate. A preliminary kinetic analysis of the data shown that the rate of phenol disappearance is not first order with respect to the phenol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / chemistry*
  • Atmospheric Pressure
  • Catalysis
  • Chlorophenols / chemistry
  • Cresols / chemistry
  • Edetic Acid / chemistry*
  • Environmental Restoration and Remediation / methods
  • Iron / chemistry*
  • Nitrophenols / chemistry
  • Oxidation-Reduction
  • Phenols / isolation & purification*
  • Temperature
  • Water Purification / methods*

Substances

  • Aniline Compounds
  • Chlorophenols
  • Cresols
  • Nitrophenols
  • Phenols
  • Edetic Acid
  • Iron
  • 2-chlorophenol
  • aniline
  • 4-nitrophenol
  • 2-cresol