engineering recuitment OPSC Assistant Industries Officer Mock Test 2025 Environmental Engineering Water Treatment Filtration
Which of the following is a characteristic of rapid sand filters in drinking water treatment?
1
Backwashing by water and compressed air for cleaning
2
The effective size of fine sand of 0.2 to 0.35 mm with uniformity coefficient of 2 to 2.75
3
Requiring large area
4
Highly efficient in removing bacteria