Laboratory experiments were carried out to investigate the mechanisms of electrochemical disinfection of artificial wastewater contaminated by Escherichia coli culture (5 105 UFC/100mL) using electrocoagulation. In order to go deeply into the mechanism of the process, the behaviors of two dissolved-type electrode (ordinary steel and aluminum) and a non dissolved-type (carbon graphite) were compared. The ordinary steel electrode was found more efficient for Escherichia coli cells destruction compared to aluminum and carbon graphite electrodes. In order to determine the most favorable condition for the treatment, the effect of various supporting electrolytes including: sodium chloride, sodium sulfate and sodium nitrate was scrutinized. Escherichia coli is inactivated by 5 log units for a charge loading of 37.30 F/m3 for sodium sulfate, 24.87 F/m3 for sodium nitrate, and 12.43 F/m3 for sodium chloride. It thus appear that the most favorable supporting electrolyte type for this method of disinfection is sodium chloride, a fact which can be explained by the formation of disinfectant by-products such as chlorine dioxide, hypochlorite ions and perchlorate ions. From the results obtained, electrocoagulation applied to the elimination of E. coli proceeds through three combined effects: the electric field, the actions of oxidants electro-generated during the process and the adsorption by the metallic hydroxides formed in solution.