What does sewage treatment mean?

1 Answer
Aug 18, 2017

It is usually a chemical process designed for the removal of a specific contaminant.

Explanation:

Sewage treatment options may be classified into groups of processes according to the function they perform and their complexity:

Preliminary:
this includes simple processes such as screening (usually by bar screens) and grit removal. (through constant velocity channels) to remove the gross solid pollution. (Mechanical)

Primary:
usually plain sedimentation; simple settlement of the solid material in sewage can reduce the polluting load by significant amounts. (Mechanical)

Secondary:
for further treatment and removal of common pollutants, usually by a biological process. (Biological)

Tertiary:
usually for removal of specific pollutants e.g. nitrogen or phosphorous, or specific industrial pollutants. (Chemical)

http://www.lboro.ac.uk/well/resources/technical-briefs/64-wastewater-treatment-options.pdf

See Also:
http://www.thewatertreatmentplants.com/tertiary-treatment.html