Modelación operacional de digestores en planta de tratamiento de aguas servidas.

Abstract

The objective of this paper is the development of a mathematical model of anaerobic digestion that simulates the principal control variables in the process, and helps the planning and operational phases in normal and particular situations of operation in the 15,000 m3 digesters of La Farfana WWTP, in Santiago, Chile. This work was carried out jointly by the engineers of La Farfana and the School of Biochemical Engineering of the Pontifical Catholic University of Valparaiso, Chile. The model, called AM3, corresponds to a three stage process: hydrolysis, acidogenesis and methanogenesis, the action of external inhibiting agents being considered. The calibration process was carried out using available operational data of the plant, with support from laboratory experiments. The results made it possible to represent satisfactorily and reliably the process of digestion within the plant anaerobic reactors, simulating the patterns of the principal control variables of the process during normal and particular periods of operation, the latter using an inhibiting factor of continuous adjustment, turning out in this way a highly flexible tool to variable conditions. Finally, the reliability of the model allows its use in industrial processes, as a tool for operational support of processes within a treatment plant. It helps to take operational decisions, being possible to improve the knowledge and application of this type of model.