PRINCIPAL COMPONENT ANALYSIS (PCA) TO THE VOLUME OF BIOGAS GENERATED IN LANDFILL AND THE CORRELATION WITH PHYSICO-CHEMICAL PARAMETERS

Abstract

This study aimed to evaluate the correlation structure of the biogas volume generated with the physical and chemical variables moisture, pH, alkalinity, chemical oxygen demand (COD) and total volatile solids (STV), through a principal component analysis (PCA). The replicates of each treatment, for both the inoculum and for the substrate were subjected to Pearson correlation analysis to determine if they could be treated as replicas. To this end, we used 92 sampling units (number of daily measurements on the production of biogas). The biogas production of the two treatments (inoculum and substrate) was evaluated for 91 days and between treatments using an analysis of variance (ANOVA). The treatments were nested within time, constituting an ANOVA with hierarchical design, with 5% significance. The results showed that the generation of biogas was more related to the pH, followed by STV, moisture and COD. The sum of the ACP 1 and 2 explained 98% of the biogas production data.