Factorial Experimental Design to Optimize a Methodology to Analyze Odorous Chemical Mixtures: Effect on a Sensors Array and on Odour Concentration

摘要

The aim of this study is to check the influence of the chemical composition of odorous and non-odorous gaseson the odour concentration and on the sensor responses. Design of experiments (DOE) is used to planmixtures composition for 5 compounds with different levels of concentrations. The synthetic gas experimentsconsist of preparation of samples based on the factorial design consisting of five compounds i.e., TrimethylAmine, Hydrogen Sulphide, Methane, Limonene and n-Butanol. Pareto plots are examined to evaluate themain effects of each sensor on the odour concentration. In addition, the response of each individual gassensor is examined as a function of the chemical composition as well as the odour concentration. Theresponse surface methodology analysis (Peris et al, 2009) is carried out on the experimental design of thesynthetic gases. The stepwise procedure was used to analyse the results which is an automated tool used inthe exploratory stages of model building to identify a useful subset of predictors. All the combinations arecarried out with step wise regression and without stepwise regression. Also BOX-COX transformations withdifferent values of alpha are also considered during the development of the regression model. Afterwards,multivariate analysis is performed to check the performances of a sensors array regarding the fluctuation ofchemicals concentration. Finally, real odorous samples from a municipal solid waste site are measured withthe same array and the results are compared with the ones obtained with the synthetic odorous gases.Index terms– Experimental design, synthetic odorous gases, sensors array, odour concentrations