Comportamento de dois reatores em batelada seqüenciais aeróbios com diferentes idades do lodo e retorno total do lodo em excesso após desintegração com ultra-som / Behavior of two aerobic sequential batch reactors with different sludge ages and total return of excess sludge after disintegration by ultrasound
AUTOR(ES)
André Luís de Oliva Campos
DATA DE PUBLICAÇÃO
2002
RESUMO
The study aims to reduce the sludge generation in aerobic systems by recirculation of the excess sludge after disintegration with a ultrasound set. Two aerobic sequential batch reactors (A and B) were utilized operating with two different sludge ages: 12 and 8 days respectively. The reactors were operated in two stages. In the first stage, called control, the reactors were operated for 130 days, without total sludge recirculation, to promote an assessment and compare with the next stage, called test. In the control stage the behavior of COD, solids and nutrients were analyzed, and tests with ultrasound were performed. The reactor A presented a good COD removal, but not a good nitrification, and a phosphorus removal of 60%. The reactor B presented a good COD removal and a good nitrification, but not complete, and a phosphorus removal of 57%. The test stage the reactors were operated for 90 days, with sludge recirculation after disintegration by ultrasound. There was an increase in influent COD, nitrogen and phosphorus because of sludge recirculation. There was an increase in MLVSS, but reactor A presented a greater increase. Both reactors presented good results in COD removal comparing with control stage. The reactors present a good improvement in nitrification, but not good phosphorus removal regarding to control stage. The analysis showed that sludge disintegration and recirculation to aeration tank not caused any problem in the behavior of the reactors. Comparing to transport, treatment and final disposal problems, the study of sludge reduction is a great alternative that deserves attention.
ASSUNTO(S)
ultra-som desintegração sludge minimization batelada disintegration batch lodos ativados activated sludge ultrasound minimização de lodos
