Fermentação alcalina para recuperação de fósforo e produção de biogás de lodo aeróbio

Abstract

In order to recover resources such as phosphorus and aerobic sludge water, two types of substrates were subjected to alkaline fermentation: sludge 1 from a conventional activated sludge system and sludge 2, sequential batch reactor sludge (RBS) programmed for removal phosphorus. On a laboratory scale, the sludge was subjected to three different treatment conditions: A, control, fermentation without adding alkali; B fermentation in alkaline condition of pre-solubilized sludge and C fermentation in alkaline condition of raw sludge. The results showed that sludge solubilization occurred with a substantial reduction in SSV concentrations of 58% and 60% in sludge 1 and 2, for treatment B, respectively. While for treatment C, 50 and 53%, respectively for sludge 1 and 2. Under treatment conditions B and C, higher values of biogas production were also observed, about 3.14 and 2.35 times higher than the control A, respectively for treatment conditions B and C. There was an increase in the concentrations of soluble phosphorus with 200 and 397 mg.L^-1 in treatment condition B and 170 and 383 mg.L^-1 in treatment condition C, in sludge 1 and 2, respectively. All of these values are between 2 and 2.5 times higher than the phosphate release observed in the control treatment A. These results indicate that fermentation in alkaline condition can be a potential way to recover resources in sources such as aerobic sewage sludge.