Parameter analysis of the IWA Anaerobic Digestion Model No. 1 for the anaerobic digestion of blackwater with kitchen refuse

The IWA anaerobic digestion model No.1 (ADM1) had been successfully applied to the lab-scale mesophilic blackwater anaerobic digestion (BWAD) plant for cases of only blackwater (BW) feeding and of BW plus kitchen refuse (KR) feeding. In this paper, the simulation results of BW+KR anaerobic digestion are presented and discussed, followed by the analyses and discussion of the critical and important parameters as well as the performance of ADM1 based on these results. The raw BW can contain up to 30% short chain fatty acids (SCFA) which severely impact the performance of the model. The model proved that the disintegration/hydrolysis rate of BW is around 4.5 d⁻¹, which is about ten times higher than that of KR (K_dis,KR=0.5 d⁻¹). ADM1 is not sensitive to the distribution ratio among carbohydrates, proteins and lipids. For BWAD the C₄ metabolism can be integrated in the uptake of LCFA. The uptake delay phenomenon was observed and cannot be simulated by ADM1, but it is tolerable. No unique K_I,NH3,ac is found out for all investigated ammonia concentration ranges. Meanwhile, ADM1 is not sensitive to K_La and k_p, so they can easily be set up.