Submerged system and method for removal of undesirable substances from aqueous media

A system and method are provided for removal of undesirable substances from a body of liquid. The system can include an aeration structure (10) having a continuously inclined surface (14) configured to provide an interaction of air bubbles (22) against substantially an entire length of the continuously inclined surface (14) while the air bubbles are moving toward a top of the body of liquid. The continuously inclined surface (14) can be substantially submerged in the body of liquid. A bio-film of diverse bacteria colonies (16) is disposed on the continuously inclined surface (14), and a high surface area-to-volume structure (102) is located in proximity to the aeration structure (10), upon which a bio-film of bacteria colonies (16) can be formed. An aeration system (18) is coupled to an air supply system (26) which releases the air bubbles (22) toward a bottom of the continuously inclined surface (14), such that the air bubbles (22) move along the continuously inclined surface (14) as they rise so as to (i) create a variety of aerobic-anaerobic conditions at the bio-film (16) and (ii) engage the air bubbles (22) in a continuous mixing of a micro climate for the bio- film (16) in response to an orientation of the continuously inclined surface (14) and (iii) provide airlift circulation of water from bottom to top of the aeration structure.