Part A: Sanitization and use of sewage sludge in soil Technical Note 4 - Sludge sanitization by alkaline stabilization

Abstract

Alkaline stabilization (AS) is one of the most widespread processes in the world for the sanitization of sludge produced in sewage treatment, although in Brazil it is used by only a few sanitation companies. The fact that an environmentally sustainable destination for sewage sludge is not mandatory, as well as a series of economic, technical and operational factors, end up limiting the AS process application. The increase of AS practices are expected due to the the Brazilian CONAMA Resolution nº 498/2020, which aims to increase the use of biosolids in agriculture and to further deepen technical and operational knowledge related to this practice. This technical note (TN) presents the main forms of the storage and application of lime, as well as the minimum parameters required for designing maturation and curing yards. In this TN, the intrinsic AS costs and best engineering practices used are discussed, in view of reducing possible problems and maximizing its usage throughout the national territory.