Design and optimization of molasses-based wastewater treatment plant at Agro-Chemical and Food Company Limited (ACFC), Muhoroni, Kenya

The study aimed to design and optimize a treatment train for molasses-based wastewater at the Agro-Chemical and Food Company Limited (ACFC) in Muhoroni, Kenya. Raw influent parameters in the system were: Biochemical Oxygen Demand (BOD)-43,000mg/l, Chemical Oxygen Demand (COD)-120,000mg/l, Total Suspended Solids (TSS)-95,000mg/l, pH-4.25, and Temperature-40°C. The existing wastewater treatment plant comprises of an Anaerobic Digester, Bulk Volume Fermenter and Aerated lagoons. Optimization of anaerobic digester is done through design based on Hydraulic Retention Time (HRT) and is expected to achieve a biogas production rate increase of 49.71% on average. To ensure the plant complies with National Environment Management Authority (NEMA) standards, an upgrade of the existing system will be done by retrofitting Aeration Tanks and Secondary Clarifiers. These findings support scale-up and offer a replicable framework for agro-industrial wastewater management. The results of the study showed that implementing the optimal conditions and incorporating the aeration tanks and secondary clarifiers will result in about a 50% reduction of fuel cost by utilizing the biogas produced and meeting the wastewater effluent standards respectively.