Optimizing the Integration of Anaerobic and Aerobic Reactors for Enhanced Treatment of Pulp and Paper Mill Wastewater

Pulp and paper mill wastewater poses a significant environmental challenge due to its high concentrations of organic pollutants, which require efficient treatment methods. This study addresses this issue by optimizing the integration of an Anaerobic Baffled Reactor (ABR) and an Activated Sludge Reactor (ASR) for effective wastewater treatment. The research focuses on optimizing key operational parameters hydraulic retention time (HRT) and organic loading rate (OLR) to maximize the removal of chemical oxygen demand (COD) and biochemical oxygen demand (BOD). The study identified the optimal conditions for the ABR at an OLR of 6.2 g/L/d and an HRT of 3.2 days, achieving 92% COD and 95% BOD removal efficiencies. Additionally, the integrated ABR-ASR system showed significant removal rates for total suspended solids (TSS), turbidity, and color, reaching 92%, 98%, and 92%, respectively, under optimal conditions. These results demonstrate the system’s robustness and versatility in handling complex wastewater matrices. The kinetic modeling using the modified Stover-Kincannon model further revealed high substrate utilization rates, indicating efficient degradation capacity. Future research should expand on this work by exploring energy recovery from biogas production to improve the system’s sustainability and broader applicability.