Define the Types of Sedimentation
1. Type I
- Particles that settle discretely (settle as individual particles)
- sand, grit
- Pre-sedimentation for sand prior to coagulation
2. Type II
- Particles that flocculate during sedimentation
- Size constantly changing, thus settling velocity
- Generally settling velocity increasing
- Alum or Iron coagulation, in primary sedimentation
3. Type III or zone sedimentation
- Particles or at high conc. (>1000 mg/l)
- Particle settle as a mass and a distinct clear zone and sludge zone are present
- Lime softening sedimentation, activated sludge sedimentation and sludge thickeners