Biological nutrient removal using intermittent aeration in a hybrid moving bed biofilm reactor

The paper presents an experimental study on a lab scale pilot plant in a Hybrid Moving Bed Biofilm Reactor. The pilot plant was fed with synthetic wastewater and was in operation considering two different operating conditions: continuous aeration and intermittent aeration. Both continuous and intermittent aeration were monitored and compared in order to seek the best conditions for carbon and nitrogen removal. At the beginning of the experimentation, an initial period of about 90 days was considered during which the pilot plant worked in bench scale configuration for allowing the formation of biofilm on the carriers. Once the biofilm growth was accomplished, the pilot plant worked for a first period in continuous aeration and in a second period in intermittent aeration. The efficiency of organic matters removal was similar between the two periods. Contrarily, the efficiency of N-removal improved by 50 % and more. More specifically, the efficiency to remove the carbon and nitrogen using intermittent aeration were about 93% and 90%, respectively.