Efficiency of removal of bod5 and ss in sedimentation tanks and filters in wastewater treatment systems for coffee bean (Coffea arabica) processing

Abstract

n 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 (BOD5) 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 BOD5 (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.

Keywords

• Aguas residuales
• Beneficio húmedo de café
• Remoción