Wastewater Treatment Plants and Processing Steps

Wastewater treatment results in the generation of sludge, the quantity of which—expressed in kg dry mass (DM) per inhabitant (P) and year (a)—strongly depends on the degree of stabilization: The degree of sludge stabilization carried out varies considerably worldwide. It is influenced by the local possibilities for disposal or agricultural use, the specific costs per ton of dewatered sludge, as well as by official regulations. Thus, the type of stabilization ranges from non-stabilized sludge, which is treated and settled only mechanically and partially biologically, to full digestion with an integrated hydrolysis step.