Raven Activated Sludge Process Settleometer Kit

Raven Activated Sludge Process Settleometer Kit - Observe Settling Characteristics to Troubleshoot Slow Sludge

Settling of sludge in the secondary clarifier is a critical part of the activated sludge process. Poorly settling sludge is a strong indication of process problems and solids loss in final effluent. The Settleometer is  primarily used in wastewater plants for four applications: 

1. Settling Characteristics – Determine Rapid, Normal or Slow settling. 
2. Settled Sludge Volume (SSV) is used in calculating return sludge flow rates. 
3. Troubleshoot settling problems to determine a density or a concentration issue.
4. Determine timing when denitrification occurs and sludge rises to surface.

Normal sludge forms a floc and gently squeezes the water out of the blanket forming on the bottom. Settles between 800 and 700 in five minutes.

Rapid sludge settles like dark grains of sand leaving behind a turbid supernatant with suspended solids. Settles to 700 or less in five minutes.

Slow sludge appears to be stuck in the settling process with little or no progress but with very clear supernatant. Does not settle to 800 in five minutes. Slow settling sludge can be caused by high density sludge or high concentrations of sludge.