Estudo da associação em série de reator UASB e filtros anaeróbios para o tratamento de esgotos sanitários

Abstract

This present work alms to evaluate the treatment systems performance by using anaerobic filters as post-treatment units of the effluent form which is treating Belo Horizontes sanitary sewages. The research was developed in pilot plant laboratory of DESA- UFMG from june 96 to july 97. It had been used a UASB reactor (volume: 416 L; helght: 4,20 m)as a pilot unit and two fiber glass anaerobic filters (volume: 102,4 L; helght: 1,50 m). Both filters used blast furnace cinder as a packing material.The upflow and downflow anaerobic filters (UF and DF) operated as two distinctive systems: UASB/UF and UASB/DF. The UASB reactor was operated at a hydraulic detention time (HDT) of 6 and 4 hours under a permanent hydraulic rate. The anaerobic filters were operated wth HDTs varying from 24 to 1,0 hour under a permanent hydraulic rate as well. These different operational conditions characterize eight phases in the research. After monitoring during about one year, the systems UASB/UF and UASB/DF presented excellent results in terms of COD and BOD removal and very low concentrations of wastewater suspended solids on the final effluent. The COD and BOD removal medium results varied from 78 to 91% and 76 to 91%, making it possible the maintenance of the COD concentrations in the final effluent at the rate from 60 to 90 mg/L, and BOD values systematically under 40 mg/L. The global averages of the SS on the final effluent were kept near 30 mg/L during at almost phases in the research. It believed that the anaerobic filter may become an attractive for the post-treatment of effluents from UASB reator in Brazil. The systems UASB/anaerobic filter can be projected with short HDTs, resulting in very compact and cheap treatment units.