ELECTROCATALYTIC DEGRADATION OF PHENOL IN ACIDIC AND SALINE WASTEWATER

ABSTRACT The electrocatalytic degradation of low concentration of phenol (100–800 mg L−1) as a model contaminant for wastewater treatment was studied on modified β-PbO2 anode. Various affected factors such as current density (7.5–30 mA cm−2), reaction temperature (5–60°C), pH (2–6), salinity of the electrolyte (0.5–10 g L−1 K2SO4), and circulation rate (100–2400 mL min−1) were investigated. Phenol at a concentration level of 100 mg L−1 could be completely degraded within 30 min under the current density of 7.5 mA cm−2 with the addition of K2SO4 (1.0 g L−1) at pH 5.6 and temperature 60°C. The method showed promising application for treating phenolic wastewater of high salinity and acidity. Analysis of the intermediates of the phenol degradation products indicated good catalytic characteristics of the anode for breaking down the aromatic compounds to organic acids. The overall degradation of phenol was considered a controlled process of mass-transfer. According to the proposed model and Arrhenius's Law, the activation energy was calculated 23.8 kJ mol−1.

[1]  Zucheng Wu,et al.  Partial degradation of phenol by advanced electrochemical oxidation process. , 2001, Environmental science & technology.

[2]  N. Abuzaid,et al.  Electrochemical Oxidation of Phenol Using Graphite Anodes , 1999 .

[3]  A. Savall,et al.  Mechanistic Aspects of Phenol Electrochemical Degradation by Oxidation on a Ta / PbO2 Anode , 1998 .

[4]  I. Ortiz,et al.  Extraction of Phenol Using Trialkylphosphine Oxides (Cyanex 923) in Kerosene , 1997 .

[5]  C. Philippopoulos,et al.  Homogeneous oxidation of phenols in aqueous solution with hydrogen peroxide and ferric ions , 1997 .

[6]  M. Smyth,et al.  Phenol Removal by Modified Peroxidases , 1996 .

[7]  C. Comninellis,et al.  Anodic oxidation of phenol in the presence of NaCl for wastewater treatment , 1995 .

[8]  K. Rajeshwar,et al.  Electrochemistry and the environment , 1994 .

[9]  Christos Comninellis,et al.  Electrochemical detoxification of a 1,4-benzoquinone solution in wastewater treatment , 1994 .

[10]  G. Nakhla,et al.  Dissolved oxygen effects on equilibrium and kinetics of phenolics adsorption by activated carbon. , 1994, Environmental science & technology.

[11]  K. Nobe,et al.  Hydroxylation of chlorobenzene and phenol in a packed bed flow reactor with electrogenerated Fenton's reagent , 1993 .

[12]  Dennis C. Johnson,et al.  The Importance of Anodic Discharge of H 2 O in Anodic Oxygen‐Transfer Reactions , 1992 .

[13]  C. Pulgarin,et al.  Anodic oxidation of phenol for waste water treatment , 1991 .

[14]  M. Gattrell,et al.  The electrochemical oxidation of aqueous phenol at a glassy carbon electrode , 1990 .

[15]  B. Fleszar,et al.  An attempt to define benzene and phenol electrochemical oxidation mechanism , 1985 .

[16]  J. Stickney,et al.  Electrochemical oxidation of aromatic compounds adsorbed on platinum electrodes , 1983 .

[17]  A. Watkinson,et al.  Anodic oxidation of phenol for waste water treatment , 1980 .

[18]  R. D. Evans,et al.  Calculation of the total anthropogenic lead in the sediments of a rural Ontario lake , 1980 .