Application of Data Exploration Methods for Evaluating Relationships between Elements in Incineration Bottom Ash

The study presents a comprehensive statistical analysis of incineration bottom ash (IBA) to uncover relationships between elemental components using multiple regression, spline models, and hierarchical clustering. Results revealed strong correlations between specific elements, notably Cu-Zn, Co-Ni, and HREE-LREE, indicating common sources and geochemical affinities. Spline regression models outperformed linear models for elements with complex, non-linear relationships such as Cr, Co, Ni, and rare earth elements. Cluster analysis consistently identified three major groups of elements, supporting their joint behavior in the ash matrix. The high variability of element concentrations across samples underscores the need for long-term monitoring and highlights the potential for targeted recovery of valuable elements.