Septic Sludge | Activated Sludge Process | Wastewater Treatment Plant

 Septic Sludge

Septic sludge is defined as any sludge that has become anaerobic and emits a foul odour. Sludge can slowly rise to the surface of vessels such as a primary or secondary clarifier due to gases created by anaerobic decomposition.

Causes

• Septic sludge develops when it is allowed to stay stagnant in a vessel or pipe long enough to deplete residual DO..
• If activated sludge is allowed to accumulate in pockets or "dead spots" for too long, it can turn septic due to poorly designed or constructed sludge hoppers, wet wells, flow channels, and pipe systems.
• Septic activated sludge can accumulate on the bottom of aeration tanks due to insufficient mixing..
• Sludge in a secondary clarifier may also become septic as a result of insufficient return sludge rates.

Solutions

• Mix the contents of the aeration tank thoroughly.
• To prevent sludge deposition, maintain a flow velocity of at least 1.5 feet per second in sludge pipelines and channels.
• Increase the return sludge rate to reduce sludge detention time in the secondary clarifier.
• Check that the clarifier collection mechanism is activated so that solids are removed from the draw-off hopper.
• Check that the sludge draw-off lines are not clogged.
• Check that the return sludge pumps and valves are working properly.