PERFORMANCE OF ANAEROBIC-AEROBIC PACKED-BED REACTOR IN THE TREATMENT OF DOMESTIC SEWAGE

This paper reports on the performance evaluation of an upflow anaerobic-aerobic reactor, filled with polyurethane matrices, for domestic sewage treatment. Initially, different hydraulic retention times were assayed with the reactor operating exclusively in anaerobic condition. Afterwards, anaerobic-aerobic combined reactor was operated. The anaerobic operation with HRT of 10 h provided the best organic matter removal with COD reduction from 389 +/- 70 mg/L to 137 +/- 16 mg/L. Under anaerobic-aerobic condition, the COD dropped from 259 +/- 69 mg/L to 93 +/- 31 mg/L with HRT of 12 h ( 6 h in anaerobic and 6 h in aerobic stages). Finally, comparing all the obtained results, it was possible to verify the importance of the aerobic post treatment in the removal of part of the organic matter not removed in an exclusively anaerobic treatment.