Aerated submerged bio-film (ASBF) pilot plant has been developed to optimize an inexpensive method of enhanced wastewater treatment. This study describes pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. These structures are designed to encourage the growth of a nitrifying bacterial bio-film on a submerged surface. These structures also force the direct contact of rising air bubbles against the submerged bio-film. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research investigated the efficiency of dissolved organic matter and ammonia nitrogen removals at cold temperatures. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min. (C) 2009 Elsevier B.V. All rights reserved.