da Silva Oliveira, Aline, et al. “The Relevance of Sludge Generated in Wastewater Biological Treatment Systems, With an Emphasis on Ribeirão Preto, São Paulo, Brazil”. O Mundo Da Saúde, vol. 30, no. 4, June 2020, pp. 634-43, doi:10.15343/0104-7809.200630.4.15.