Análise multivariada da influência das variações dos parâmetros de qualidade da água da rede na qualidade da água desmineralizada produzida na Central Termoeléctrica de Maputo

Abstract

This internship report addresses the multivariate analysis of the influence of variations in the quality parameters of the mains water on the quality of the demineralized water produced at the Maputo Thermoelectric Power Plant (CTM). The water demineralization process at CTM involves several steps, from pretreatment, where larger impurities are removed, and main treatment, which is done through reverse osmosis and ion exchange. The analysis was performed using multivariate regression models to predict how the quality parameters of the mains water, supplied by Águas da Região Metropolitana de Maputo (AdRMM), influence the quality of the demineralized water produced. The study included the collection of experimental data, followed by the processing and interpretation of these data with the aid of IBM® SPSS Statistics 26 and Microsoft Excel 2021 software. Several laboratory tests were carried out to assess the quality of the demineralized water and the mains water. These tests included measurements of pH, electrical conductivity (EC), iron concentration (Fe), among other parameters. The collected data were then used to build regression models that allowed the evaluation of the relationship between the parameters of the tap water and the quality of the demineralized water. The results showed that the regression models are effective in predicting the variability of the pH and electrical conductivity parameters of the demineralized water, with coefficients of determination (R²) of 85.5% and 94.2%, respectively. However, for the Log(Fe_D) parameter, the model demonstrated lower effectiveness, explaining only 52.1% of the variability. The inclusion of new parameters can improve the accuracy of the models, especially for Log(Fe_D). The detailed analysis of the data allowed the construction of a model based on the tap water parameters, as well as the combination of these that most influence the pH, EC and Fe of the demineralized water produced, enabling preventive actions to be taken to ensure the continuity of production with the desired quality.