Structural identifiability of some biotechnological systems

In this paper we present an algorithm for nonlinear continuous-time model structural identifiability analysis. The method can be included in the transformation of nonlinear models framework of structural identifiability analysis and is based on test functions from distribution theory. So, the nonlinear continuous-time models are transformed in linear in parameters models by replacing the state variables and their derivatives with corresponding functionals obtained using distributions. Depending on particular cases, the problem is split in many sub-problems interconnected, the results of one stage of analysis being used to the next stages. The presented method is applied to analyse the structural identifiability of a wastewater biodegradation process, considering that the unknown parameters appear in rational relations with measured variables.