Nitrogen Compounds Removal in a Rotating Electrobiological Contactor

Abstract

The goal of this work was to determine the impact of electric current on the efficiency of removal of nitrogen compounds from waste water. The experiments were run at bench scale, in a rotating electrobiological contactor (REBC) under both conventional conditions (i.e., without electric current) and with electric current passage at the following densities: 0.2, 0.8, and 1.5 A/m². The cathode comprised stainless steel discs with immobile biofilm, and the anode a stainless steel electrode, submerged in waste water contained in the flow tank of the contactor. In the experiment, use was made of waste water containing nitrogen in organic, ammonium, and nitrate form. The process of nitrogen removal was the most effective with electric current passage at the density of 0.2 A/m². Over 83% efficiency of the denitrification was observed at a nitrification efficiency of 68.9%.