Sewage Sludge

Autothermal Thermophilic Aerobic Digestion (ATAD)

A case study from Poland

The ATAD plant in Poland was taken into operation in 2009. The sludge comes from an SBR-plant treating municipal wastewater and faecal sludge.

The ATAD plant meets highest treatment objectives regarding biosolids degradation. Thermophilic temperatures of approx. 60°C are easily achieved. Heat retention makes low ambient temperatures in winter no problem. The energy surplus is utilized for water heating and for supporting the space heating system of the plant.

The product of FUCHS ATAD is stabilized, disinfected sludge classified as Class A Biosolids. Due to its special features an excellent organic fertilizer, which is highly welcome in agriculture. Dewatering leads to volatile solids contents exceeding 30 % DS. This keeps transportation costs low. 



Autothermal Thermophilic Aerobic Digestion (ATAD) in Poland

  • Treatment objective is stabilized and disinfected sludge
  • Taken into operation in 2009
  • Plant treats the municipal wastewater of approx. 30,000 p.e. and faecal sludge
  • SBR reactors as biological treatment
  • Low ambient temperatures during winter period
  • At a retention time of only 8 days the ATAD achieves a degradation rate of volatile solids of approx. 38 %
  • A heat exchanger between pre-ATAD and post-ATAD storage tank guarantees thermophilic temperatures of approx. 60°C even at extremely low
    ambient temperatures
  • The product is stabilized and disinfected sludge, classified as Class A Biosolids, with a dry solids content exceeding 30 % 
  • The water for the complete treatment plant is heated by surplus heat from
    the ATAD 
  • The space heating system of the complete treatment plant is supplied with surplus heat from the ATAD
  • No unpleasant odors – the off-gas is treated by photocatalytic oxidation combined with a washer 


Autothermal Thermophilic Aerobic Digestion (ATAD)
Class A Biosolids a valuable fertilizer