Flotation is a unit operation, used in wastewater treatment to
A. Remove the lighter suspended solids
B. Concentrate biological sludge
C. Remove oil and grease
D. Remove the temporary hardness of the water
Choose the correct answer from the options given below:
1
A, B and C only
2
B, C and D only
3
A, B and D only
4
A, B, C and D