Performance, Kinetics and Correlation Study of a Plug Flow Multimedia Reactor Treating Conventional UASB Effluent

ABSTRACT

The present study aimed to remove nutrients from anaerobically treated effluents using a plug flow multimedia reactor (PFMMR). An Up‐flow Anaerobic Sludge Blanket Reactor (UASB) was used for sewage treatment. This study was conducted for 105 days to investigate the removal of NH ₄ –N and PO ₄ –P from the UASB effluent treating sewage through denitrification using a plastic carrier and activated carbon as a medium in the PFMMR. The results indicated that the removal efficiencies of NH ₄ –N and PO ₄ –P reached 91.2% and 31.0%, respectively. Correlation analysis revealed that the most robust positive correlations were between UASB and PFMMR COD effluents (0.614) and between sewage and UASB NH ₄ ‐N (0.657), signifying consistent treatment behaviors for these parameters. The “Stover–Kincannon” Grau and Monod models were used to assess the kinetic coefficients for the removal of NH ₄ –N, COD, and PO ₄ –P in the PFMMR. The results revealed that the Monod model was the most appropriate and applicable for assessing nutrient concentrations. The PFMMR system was able to remove COD, NH ₄ –N, and PO ₄ –P with high removal efficiency, as shown by the low U _max and high K _d values. In addition, the specific growth of biomass cultivation on the multimedia was characterized by Fourier Transform Infra‐red (FTIR), Dynamic light scattering (DLS), and Scanning Electron Microscopy (SEM) methods.