The Role of Bioflocculation on Suspended Solids and Particulate COD Removal in the Trickling Filter Process

Understanding that there is a significant presence of extracellular polymeric substances at the biofilm/wastewater interface and that the primary constituent of chemical oxygen demand (COD) in domestic wastewaters is organic particulates, this research describes the kinetics of particulate removal in a pilot-scale trickling filter (TF) and the role of bioflocculation in the removal process. Recent research has described the role of bioflocculation on particulate COD (PCOD) removal in suspended growth biological wastewater treatment systems. However, no research pertaining to PCOD removal by bioflocculation in attached growth systems was identified prior to this study. For this study, experiments were conducted using both bench- and pilot-scale biofilm reactors and provided evidence that the removal of organic and inorganic particulate matter in a TF bioreactor follows a first-order bioflocculation rate equation. The statistical analysis of data obtained from the pilot TF fits the dispersion model to suspended solids and PCOD remaining in the pilot TF.