EFFECTS OF LOW DIRECT ELECTRIC CURRENT ON AEROBIC BIOLOGICAL TREATMENT OF URBAN WASTEWATER

Wastewater is one of the principal source of organic and inorganic contamination of the environment. It is because of its complex composition (proteins, carbohydrates, oils, urea and synthetic organic compounds). Application of electric current in wastewater treatment processes has become, nowadays, a phenomenon of increasing importance. In this work, we proposed to study, in vitro, the effect of low electric current treatment on the performances of the microorganisms present in activated sludge obtained from the aeration basin of a wastewater treatment plant located in Tizi-Ouzou (Algeria). The trials were carried out by varying two parameters: The distance between electrodes (d = 2 cm, d = 6 cm) and the density of the electric current (D =1.4 mA/cm2, D =3.8 mA/cm2, D = 7 mA/cm2). The results obtained showed a significant improvement in the abatement rate of the two following parameters: turbidity and suspended matters, demonstrating the effectiveness of the approach used in this study. Regarding the results inherent to the bacteriological parameters, it was apparent that electric current affected the composition of the microbial flora of the activated sludge used. Indeed, with the exception of sulfite-reducing clostridia count, it was observed that the numbers of the whole germs under consideration, significantly decreased as a result of direct electric current application.