Electrochemical treatment of aqueous wastes containing pyrogallol by BDD-anodic oxidation.
In this work, the electrochemical oxidation of pyrogallol (1,2,3-trihydroxybenzene) on boron-doped diamond anodes has been studied. The voltammetric results showed that pyrogallol oxidation takes place in the same potential region as that of phenol where the supporting electrolyte is stable. Synthetic wastewaters containing pyrogallol have been treated in a bench-scale electrolysis plant. This plant operates in a discontinuous mode by recirculating the waste continuously through a single-chamber electrochemical flow cell. The complete mineralization of pyrogallol and the electro-generated pollutants is obtained in the electrolytic device. HPLC analyses show the formation of carboxylic acids as the main intermediates. The efficiency of the electrochemical process was found to depend mainly on the pollutant concentration present in the waste and on the applied current density. The high efficiency of this technology can be explained in terms of the direct electro-oxidation at the BDD surface and the oxidation carried out by hydroxyl radicals and other electro-generated oxidants.
Nasr
Bensalah
B
Institut Supérieur des Sciences Appliquées et Technologie de Gabès, Université de Gabès, 6072 Zrig, Gabès, Tunisia. nasr.bensalah@issatgb.rnu.tn
Hsen
Trabelsi
T
Abdellatif
Gadri
G
D018130:Diamond; D004149:Dioxoles; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D004572:Electrolysis; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D010865:Pilot Projects; D013672:Technology / Q000379:methods / Q000639:trends; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D004149:Dioxoles; D007202:Indicators and Reagents; C041398:7,7'-dimethoxy-(4,4'-bi-1,3-benzodioxole)-5,5'-dicarboxylic acid dimethyl ester; D018130:Diamond