engineering recuitment TSPSC AEE Civil Mock Test 2022 Environmental Engineering Water Treatment Disinfection
Permanent hardness is removed by :
(a) Lime soda process
(b) Boiling
(c) Demineralisation process
(d) Base exchange process
1
(a) only
2
(b) only
3
All of the above
4
(a), (c) and (d) only