Read the following statements regarding waste-water
treatment plant with one or two blanks. Select the
option that correctly completes any two statements.
(i) ________ process allows settling of sand in the chambers.
(ii) The solid waste called _______settles down and lighter waste called ________ floats on the surface.
(iii) Secondary treatment involves use of_______.
(iv) ________ and ________ are used in tertiary treatment.
A (ii) sluge, scum; (iii) chemicals
B (iii) grit removal; (iv) chlorine, UV rays
C (ii) scum, sludge; (iii) bacteria
D (i) screening; (iv) aerobic, anaerobic bacteria
What is the answer for the fourth statement?