In the municipal or industrial wastewater treatment plants often the sludge is subjected to an anaerobic digestion treatment. This type of digestion is preferred with respect to the aerobic one due to a so definite energy save. The aerobic digestion is considered acceptable only for limited capacity plants where, often, realization costs for this treatment phase are not bearable and justified due to the dimension of the plant.
In the other cases the anaerobic digestion is recommended: in fact it can supply the heat energy required to keep the sludge at the temperature condition suitable for the development of the anaerobic digestion processes. Moreover, in the big plants, it is possible to use also the produced residual biogas for the district heating and electric power generation.
CGE – Gasometric bell with helical guides
CGT – Gasometric bell with telecopic guides
DACS – Anaerobic sludge digester SCF – Sludge heat exchanger