On the crucial influence of some supporting electrolytes during electrocoagulation in the presence of aluminum electrodes.
The influence of some supporting electrolytes on aluminum electrode oxidation and pH variation during electrocoagulation of an unskimmed milk sample and a cutting oil emulsion has been investigated. Among the electrolytes studied, sulfate anions were found to be quite harmful both for electrical consumption and electrocoagulation efficiency. At the opposite, chloride and ammonium ions were particularly benefic respectively for aluminum corrosion and pH regulation, whereas sodium cations were observed to have a neutral role. The results indicate that electrocoagulation can be realized at low anodic potential even in the presence of sulfate ions when the [Cl(-)]/[SO(4)(2-)] ratio is around or greater than 1/10. The detrimental effect of sulfates on electrocoagulation efficiency can be thwarted by the use of the ammonium salt thanks to its related buffer effect.
Trompette
J L
JL
Laboratoire de Génie Chimique UMR 5503, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France. jeanluc.trompette@ensiacet.fr
Vergnes
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H
D000535:Aluminum; D000818:Animals; D002712:Chlorides; D004564:Electrocoagulation / Q000379:methods*; D004566:Electrodes; D004573:Electrolytes; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D008892:Milk; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds; D012964:Sodium; D013431:Sulfates
D002712:Chlorides; D004573:Electrolytes; D004655:Emulsions; D000644:Quaternary Ammonium Compounds; D013431:Sulfates; D012964:Sodium; D000535:Aluminum