Question

The stage in which sewage water is treated biologically is called

• A. secondary sewage treatment
• B. primary sewage treatment
• C. both
• D. none

Answer 1

The correct option is A

secondary sewage treatment

Secondary treatment is a biological process where the sewage water is treated to remove suspended and dissolved organic compounds using a mass of aerobic bacteria which can degrade the organic compounds aerobically. The bacteria associate with fungi to form a meshlike network called flocs.