Implementation of the IWA anaerobic digestion model No.1 (ADM1) for simulating digestion of blackwater from vacuum toilets

The IWA anaerobic digestion model No.1 (ADM1) is applied to the blackwater anaerobic digestion (BWAD) plant in this work. In order to verify the biochemical kinetics, batch experiments were executed. According to the Monod type kinetics, the maximum uptake rates (k_m) of butyric acid (HBu), propionic acid (HPr) and acetic acid (HAc) are testified as 18, 14, 13 d⁻¹, and their half saturation concentrations (K_S) are 110, 120, 160 g COD/m³, respectively. Afterwards, the model was calibrated based on the performance of a laboratory scale BWAD plant (under mesophilic conditions) by three scenario studies, i.e. the reference conditions, different feeding frequencies and high NH₄⁺ concentration. The model successfully simulated three scenarios. The further two virtual scenario studies were achieved based on the calibrated model. First, the performance of BWAD plant was predicted with different hydraulic retention times (HRT); second, the kitchen refuse (KR) was added into the BWAD plant as additional organic loading. The model predicted the perspective of BW plus KR digestion and generated valuable suggestions for the operation of the real BWAD plant.