Aerobic lagoons use aerobic bacteria and/or algae to treat wastewater
in oxygen-adequate condition which is accomplished by
either constructing the lagoons shallow so that air and sunlight can
transfer into the system or relying on proper aeration. Facultative
ones are between aerobic and anaerobic lagoons and the treatment
occurs with the aid of facultative microorganisms. Anaerobic lagoons
are oxygen free system in which anaerobic microorganisms
play significant role in the treatment process. In fact, apart from
microorganism function, settling, filtration, and chemical reaction
could simultaneously exist in lagoon wastewater treatment