Evaluation of Process Performance for Lipid-rich Wastewater Treatment Using a Combination System of an Anaerobic Baffled Reactor and an Aerobic Trickling Filter

Abstract

ABSTRACT Laboratory-scale reactor experiments for the treatment of lipid-rich wastewater were conducted us- ing a combination system consisting of an anaerobic baffled reactor (ABR) and an aerobic trickling filter (ATF). Lipid-rich wastewater was collected from the school cafeteria at the National Institute of Technology, Kure College. A water bath was installed to heat the bottom portion of the ABR to 35°C to help separate the lipids from the wastewater. The chemical oxygen demand (COD), total suspended solids, and lipid concentration of the wastewater were 88.6, 23.9 and 11.2 g/L, respectively. The ABR removed 94.4% of the COD during the continuous experiment at a maximum organic loading rate of 9.2 kgCOD/(m3·d). Finally, 96.8% of the COD was removed by the whole system. Next, 57.8% of inlet COD was converted to methane in the ABR. In contrast, 16.3% of the COD removed had accumulated as scum at the top of each compartment of the ABR and the accumulated scum was found to self- combust. Therefore, the ABR can achieve a high-rate treatment of lipid-rich wastewater with energy recovery by converting degradable substances to methane and persistent substances to scum.