Resumo

CASTILLO-BORGES, Elba R. et al. Use of a rotating biological contactor system for treatment of septic tank effluents. Tecnol. cienc. agua [online]. 2013, vol.4, n.3, pp.125-134. ISSN 2007-2422.

Although septic tanks is the most common wastewater treatment device used in the State of Yucatan, Mexico, it is a deficient purification process and therefore further treatment is needed. This work presents the results from a pilot-scale rotating biological contactor (RBC) process used to treat septic tank effluent. The RBC was operated with three organic loading rates (5.2, 15.9 and 17.2 g BOD₅/m²·d) and two rotation velocities (15 and 30 rpm). COD, BOD₅, TKN and NH₃-N removal efficiencies were measured and a factorial analysis was carried out to determine the best operating conditions. The organic loading rate was shown to be the variable that had the greatest effect on the process, with lower loads and better efficiency (roughly 90% for COD and BOD₅). Rotation velocity was significant for the removal nitrogenous matter. The most efficient combination was found to be 5.2 g DBO₅/m²·d at 30 rpm, which is equivalent to a tangential velocity of 16.49 m/min.

Palavras-chave : septic tank; organic loading rate; rotation velocity; rotating contactor biological.