Sensitivity analysis in the WWTP modelling community – new opportunities and applications

A mainstream viewpoint on sensitivity analysis in the wastewater modelling community is that it is a first-order differential analysis of outputs with respect to the parameters – typically obtained by perturbing one parameter at a time with a small factor. An alternative viewpoint on sensitivity analysis is related to uncertainty analysis, which attempts to relate the total uncertainty in the outputs to the uncertainty in the inputs. In this paper we evaluate and discuss two such sensitivity analysis methods for two different purposes/case studies: (i) Applying sensitivity analysis to a plant design (BSM1 plant layout) using Standardized Regression Coefficients (SRC) and (ii) Applying sensitivity analysis to help fine-tuning a fuzzy controller for a BNPR plant using Morris Screening. The results obtained from each case study are then critically discussed in view of practical applications of sensitivity analysis in day-to-day engineering projects.