Energy saving in biological sewage treatment - by heat pumps and heat exchangers

摘要

In a biological sewage treatment plant, consisting of a mechanical cleaning section with a preclarification basin, an activated sludge basin, a reclarification section and a digestion tower for the sludge, the consumption of extraneous energy is reduced by applying heat exchangers, heat pumps and solar heat collectors. Heat is recovered from the liquid leaving the reclarification section and/or from the pulp leaving a thickener for the digested sludge and/or from the influent sewage. This reduces the amount of extraneous energy required without detrimental effect on the optimum digestion of the sludge in the digestion tower.