Every community produces both of liquid and solid wastes and air emissions. The liquid waste (wastewater) is essentially the water supply of the community after it has been used in a variety of applications. The sources of wastewater may be defined as a combination of the liquid of water-carried wastes removed from recidences, institutions, commercial and industrial establishment. When untreated wastewater accumulates in the septic, the decomposition processes of the organic contains.
The wastewaters containning biodegradable constituens. With proper analysis and environmental control, it can be treated biologically. The emvironmental engineer have to understand the characteristics of each biological process to ensure that the proper environment is produced and controlled effectively.
The biological treatment are to transform anf particulate biodegradable constituens into acceptable end product, capture and incorporate suspended and nonsetletable colloidal solids into a biological floc, transform or remove nutriens (such as nitrogen and phosphorus), remove spesific trace organic constituens and compounds.
The principal process used for the biological treatment of wastewater can be classified with respect to their metabolic function as aerobic processes, anaerobic processes, anoxic processes, facultative processes, and combined processes.