Behavior of a Ti/RuO2 anode in concentrated chloride medium for phenol and their chlorinated intermediates electrooxidation

Display Omitted a- Phenol and its intermediate compounds in NaCl solution were electrooxidized. a- Increasing amounts of NaCl favors phenol and their intermediates electrooxidation. a- Treated solution contained less than 0.002% of the initial phenol concentration. a- The energy consumption for total COD removal was 34.41kWhkga degree 1. The electrooxidation of phenol and its intermediate compounds in concentrated sodium chloride solutions on a Ti/RuO2 anode was studied with electrochemical techniques allied to UV-vis spectrometry, Gas Chromatography/Mass Spectroscopy (GC/MS) and chemical oxygen demand (COD) analysis. Results have shown that although the increase of chloride ion concentration favors initially the chlorophenols formation, it also favors both the phenol and chlorophenols degradation through an indirect oxidation mechanism. Increasing amounts of chloride ion led to a decrease in the specific energy consumption for both phenol and COD removal from solution. CG/MS analysis indicated that after a 30-min electrolysis in the presence of 20gLa degree 1 NaCl, with a current density of 10mAcma degree 2, the treated solution contained less than 0.002% of the initial phenol concentration (100mgLa degree 1). A substantial reduction in the chlorophenols concentration was also achieved under the same electrolysis conditions.