Lagoons are one of the oldest means of wastewater treatment and still extensively used due to the fact that they are easy to operate, facile to maintain, cheap to build, and less sludge production.
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. Generally, lagoons can provide expected stabilized effluent without offensive odor emission; however, when the system is upset due to certain changes, for example large quantity wastewater abruptly enters the lagoons, consequently nuisance odor emission will occur