EFEITOS DA ESCÓRIA KR NA HIGIENIZAÇÃO DO LODO DE ESGOTO: ELIMINAÇÃO DE PATÓGENOS E PRODUÇÃO DE BIOSSÓLIDOS PARA USO AGRÍCOLA

Abstract

The usage of sewage sludge in agriculture is conditioned to significant reductions on the concentration of pathogens, turning it into a biosolid. This research intends evaluate ETE Mulemba sewage sludge sanitation through usage of KR slag, from desulphurization of pig iron from a steel mill. The Multiple Tube Technique verified the most probable number (NMP) of thermotolerant coliform and total coliform. Presence of Salmonella in samples was determined through analyzing the growth of colonies that are compatible with the genus Salmonella in selective medium XLD agar and BGA. After homogenization of sewage sludge with KR slag, the pH level raise did not respect the requirements of CONAMA Resolution 375/06, which validates the biosolid use in agriculture. However, the measurement performed was semiquantitative. The analysis of total coliforms and thermotolerant coliforms in the sewage sludge indicated amounts greater than 1,6x104 MPN/g DW for both parameters. The result was reduced to less than 18 MPN/g after 15 days of sanitizing in T3, showing itself consistent with the required by CONAMA Resolution 375/06 for the expected use. However, it was not possible to affirm reduction on the presence of Salmonella by biochemical tests in this research, thus, the result is inconclusive for Salmonella.