Exploitation of the ADM1 in a XXI century wastewater resource recovery facility (WRRF): The case of codigestion and thermal hydrolysis.

The aim of this study is to test the capability of the anaerobic digestion model n1 (ADM1) to reproduce data from full-scale digesters operated in a wastewater resource recovery facility (WRRF) where both thermal hydrolysis and codigestion with industrial waste are carried out. Furthermore, the potential uses of the model in a WRRF are also described, with particular relevance for plant engineers/operators. The model capability was calibrated and validated with data from full-scale digesters from the Mapocho-Trebal WRRF (Biofactoría) in Santiago, Chile. A success simulation rate, defined as the percentage of experimental values of a certain variable that lies within the simulation band given by a simulation tolerance established by the user/operator, was established to test the capability of the model as objectively as possible. Regarding the full-scale digester fed with thermally pretreated mixed sludge, success rates of 65% for biogas production and 60-100% for other variables were achieved. Regarding the full-scale digester in codigestion mode, the model had a success rate of approximately 60% for predicting the biogas flow for the whole evaluation period, while for the other variables, values between 70 and 100% were attained. The lowest success rates were observed for the volatile fatty acid (VFA) concentration in the digestate. Despite the lack of available data and the number of assumptions that had to be made, the model was demonstrated to be capable of reproducing the behavior of the full-scale reactors. A proper, up-to-date, calibrated and validated model can aid in the decision-making process in a WRRF, for instance, in determining some unmeasured inlet conditions, in improving the resilience of the process and in managing the incorporation of a new cosubstrate into the plant, among others.