Part A: Sanitization and use of sewage sludge in soil Technical Note 1 – Topics of interest

Sewage treatment plants (STPs) generate solid by-products that need to be managed safely so as not to compromise the environment and public health. Among these by-products, of special interest is the sludge generated in the primary, biological and physical-chemical treatment units, which concentrates a large amount of the pollutants and contaminants removed during sewage treatment. However, the sludge is also a reservoir of compounds that can be recovered or reused (e.g.: organic matter, phosphorus, and nitrogen), which are of agronomic interest and can be used for the recovery of degraded areas. This technical note (TN), the first of the collection “Valorization and management of solid by-products of sewage treatment. Part A: Sanitization and use of sewage sludge in soil”, presents topics of interest related to modern management of the sludge generated in STPs, with emphasis on the legal aspects and forms of treatment for its transformation into biosolid for use in soils and other possibilities. The other TNs that are part of this collection deepen the topics briefly addressed in this first TN.