Question

Fill in the blanks with suitable words.
(a) The ______________ removes solid insoluble matter.
(b) The insoluble matter that settles at the bottom of the settlement tank is _______________.
(c) In the secondary stage, sewage is treated with _____________.
(d) ________________ percent of pollution is removed in the secondary stage.
(e) In the tertiary stage, _________________ is carried out.

Answer 1

(a) The primary treatment removes solid insoluble matter.
(b) The insoluble matter that settles at the bottom of the settlement tank is sludge.
(c) In the secondary treatment, sewage is treated with bacteria.
(d) 85 percent of pollution is removed in the secondary stage.
(e) In the tertiary stage, disinfection is carried out.