Aerobic Digesters

Aerobic digestion is a sludge stabilization process
designed to convert waste activated sludge solids to carbon dioxide, water, residual cell debris and other end products. The oxidation of cellular material is referred to as endogenous respiration and is typically the dominant reaction in aerobic digestion. The detention time in the digester is normally about 20 days to achieve satisfactory solids stabilization. Aerobic digestion stabilizes the sludge solids more rapidly than anaerobic digestion, even though a less complete breakdown of cells is typically achieved. Oxygen can be supplied by mechanical aerators or by diffused aeration

  • Advantages
  • Sludge is stabilized (made odor-free)
  • Methane gas is produced and can be reused
  • Volume of activated sludge tanks is reduced by approx. 60 %
  • Electrical energy is generated
  • Electric energy for aeration system is reduced by approx. 30 % at an energy production of 80 % of the theoretical available energy of the biogas
  • Improved dewatering of sludge
  • Pasteurization occurs possible when digestion is operated under thermophilic conditions
  • Valuable fertilizer produced for agriculture and forestry
  • Co-digestion using anaerobic materials e.g. waste

Anaerobic Digesters

The modern waste water treatment plants of today have significantly lower amounts of solids in the effluent. Early on, Passavant-Roediger recognized that these solids must be properly treated and disposed of. For this purpose, we can offer you mature plants and processes. In digestion tanks, sludge is anaerobically
stabilized, meaning that its organic mass is
converted into methane gas and water.