The Tucker method, extended to cope with five-way data, was considered to study the effectiveness of a chosen remediation procedure and the effect of so-called ‘aging’ on the fractionation of heavy metals like Cu, Cd, Zn, Al, Pb, Fe and Mn in contaminated soil. Specifically, the goal was to understand the influence of soil pH (way 1) on the process of immobilization of those heavy metals (way 2) supposedly bound in different forms (way 3) in heavily contaminated soil samples amended with different amounts of organic matter (way 4) over time (way 5). The huge amount of data collected can be seen as a five-way array as — pH×heavy metals×extractions×organic content×time. The results obtained through the use of the five-mode Tucker model of definite complexity showed that the changes in mobility and bioavailability of metals over time are beneficial. In general, the potentially toxic elements that were analysed became less ‘available’ over time. The same tendency was observed with an increase in soil pH. It is worth noting that the amendment of soil with organic matter seems to have no influence on the mobility reduction of heavy metals in this case. This effect was probably masked by the predominant changes in mobility of metals over time.

The aim of this work was to show usefulness of chemometric analysis in processing of the data describing production of drinking water in the Silesian region of Poland. Water samples have been collected within the period of 1 year and the quality of water was characterized by a number of physical, chemical and microbiological parameters. Principal component analysis (PCA) and STATIS (Structuration des Tableaux A Trois Indices de la Statistique) were employed to obtain the knowledge about the complete water treatment process. PCA makes it possible to uncover seasonal changes influencing the water treatment process. In particular, it was found out that the salt content, hardness and conductivity of water tend to obtain higher levels in winter rather than in summer, and the relatively lower acidity is also to be expected in winter. The sensory quality of water is considerably improved over the consecutive purification steps. Complementary information about the individual technological units of the process is gained with the STATIS approach. The obtained results show that the water produced by the two independent filtering branches of the water plant is of similar quality and the prescribed quality characteristics of drinking water are fulfilled.