Degradation and toxicity reduction of phenol by ultrasound waves

  • A. Maleki Health Faculty, Kurdistan University of Medical Sciences, Sanandaj, Iran
  • A.H. Mahvi School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
  • A. Mesdaghinia School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
  • K. Naddafi School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Keywords: Phenol, Ultrasound, Sonochemistry, Toxicity assay

Abstract

The effects of parameters such as pH, kinetic constants and initial phenol concentration on the sonochemical degradation of phenol and toxicity assay were studied. The experimental results showed that lower pH and lower concentration of phenol favor the phenol degradation. But the rates of phenol degradation under sonication have always been quite low. It is found that the rate of ultrasonic degradation of phenol for initial concentration of 1 mg/L is 0.018 min-1 but later it reduces with increasing of phenol initial concentration substantially and the experimental data fitted well with pseudo first-order reaction rate equation. Bioassay tests showed that phenol was toxic to Daphnia magna and so resulted in quite low LC50 values. Comparison of toxicity units (TU) between phenol and effluent toxicity showed that the TU value for effluent was 1.21 times lower than that obtained for phenol solely. Thus, the toxicity of metabolites formed during the degradation of phenol is lower than the toxicity of phenol itself.

 

KEY WORDS: Phenol, Ultrasound, Sonochemistry, Toxicity assay

 

 

Bull. Chem. Soc. Ethiop. 2007, 21(1), 33-38.

Section
Articles

Journal Identifiers


eISSN: 1726-801X
print ISSN: 1011-3924