Effect of dynamic loading on biological nutrient removal in a pilot-scale liquid-solid circulating fluidized bed bioreactor

A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was employed for biological nutrient removal from municipal wastewater at the Adelaide Pollution Control Plant, London, Ontario, Canada. Lava rock particles of 600 μm were used as a biomass carrier media. The system generated effluent characterized by <1.0 mg NH₄ N/L, <6.0 mg NO₃ N/L, <1.0 mg PO₄ P/L, <10 mg TN/L, and <10 mg SBOD/L at an influent flow of 5 m³ /d, without adding any chemicals for phosphorus removal and secondary clarification for suspended solids removal. The impact of the dynamic loading on the LSCFB effluent quality and its nutrient removal efficiencies were monitored by simulating wet weather condition at a maximum peaking factor of 3 for 4 h. The achievability of effluent characteristics of 1.1 mg NH₄ N/L, 4.6 mg NO₃ N/L, 37 mg COD/L, and 0.5 mg PO₄ P/L after 24 h of the dynamic loading emphasize the favorable response of the LSCFB to the dynamic loadings and the sustainability of performance without loss of nutrient removal capacity.