EFICIENCIA DE REMOCIÓN DE DBO5 Y SS EN SEDIMENTADOR Y LECHO FILTRANTE PARA EL TRATAMIENTO DE AGUAS RESIDUALES DEL BENEFICIO DE CAFÉ (coffea Arabica)

In order to evaluate the current operating conditions of wastewater treatment systems of small scale coffee growers in the south of Huila a lab-scale prototype (S 1:25) was constructed. It was composed of both a sediment tank and a filter fit in series, simulating similar operating conditions used by coffee producers. Removal of biological oxygen demand (BOD 5 ) and suspended solids (SS) was performed in wastewater from coffee bean processing. A 23 factorial experimental design for the evaluation of the type of sedimentation tank, type of filter and hydraulic retention time (HRT) in the sedimentation tank was employed. The results showed high removal efficiencies of suspended solid concentrations (more than 95%), and low removal efficiencies in BOD 5 (about 20%). The combination of tank type 1 (square with a lower area), filter type 1 (upflow anaerobic filter – UAF) and HRT of 30 hours had the highest removal efficiency.