A grit chamber of dimension 12 m × 1.5 m × 0.8 m liquid depth has a flow of 720 m3/hour. The surface loading rate and detention time of the grit chamber would be respectively:
1
4000 m3/hour/m2 and 1.2 minutes
2
40000 liters/m2/hr and 40 minutes
3
40 m3/hour/m2 and 12 minutes
4
40000 liters/m2/hr and 1.2 minutes