ABSTRACT
Sewage sludge (SS) is a product of modern society, as wastewater treatment has been implemented following a growing awareness of hygiene and water management issues. SS management has evolved from merely disposal of sludge in landfills or on agricultural soil to become a key component in a circular economy for organic and inorganic materials. Highlighted by the increasing urbanization seen in Europe with more than 70% of the population living in urban areas and many other places in the world, aggregated SS is challenged not only by the sheer volumes of biohazardous sludge to treat, but also by the legislative requirements to reuse of fertilizer components (phosphates) as well as to disposal methods [1–3].
