Wastewater management is an important part of sanitation.
The essential components of wastewater management are collection (see sewage collection) and wastewater treatment.
Wastewater can generally be divided into sewage (or blackwater), greywater, and industrial wastewater. These have some differences in level of hazard to public health, and in wastewater treatment requirements, but many of the processes are the same.
The stages in wastewater treatmentare:
- Primary wastewater treatment - sieving and sedimentation.
- Secondary wastewater treatment - digestion of biological matter, usually through oxidation, although anaerobic digestion is also possible.
- Tertiary wastewater treatmentW - an additional treatment stage to improve effluent quality its discharge into the environment. This covers additional removal of suspended solids, refractory organics, heavy metals and dissolved solids
- "Advanced wastewater treatment" may be considered part of tertiary treatment, or may be considered separately - this is a matter of terminology. It includes nutrient removal - i.e. biological removal of nitrogen and phosphorus to avoid eutrophication of the receiving water body.