Multiparametric study of a filter bed from a swimming pool water treatment system

The principal objective of this paper is to present the results of a multi-parametric study of a filter bed used in a swimming pool water treatment system for the past 20 years, with only the anthracite layer being replaced after 14 years of operation. The influence of the age of the bed on the efficiency of the filtration process was investigated, as well as the relationship between different parameters of the filter bed. The possibility of reusing the waste obtained after replacing the filter bed was also assessed. The study encompassed a range of analytical techniques, including basic physicochemical analysis (total organic carbon, nitrates, and phosphates) of filter bed extracts, microbiological analysis (Escherichia coli, Pseudomonas aeruginosa, most probable number (MPN) of mesophiles, psychrophiles, and coliforms), chromatographic analysis of micropollutants, analysis of extract ecotoxicity, and bed structure using scanning microscopy. The multiparametric analysis of the bed extracts demonstrated the adsorption of a diverse range of contaminants (chemical and microbial) and their high concentrations. The test samples exhibited heterogeneous adsorption of contaminants in the vertical and horizontal layers of the bed, accompanied by high toxicity. The wide range of studies provided a complementary view of the quality of the filter bed, its impact on the efficiency of the filtration process, and the possibility of reusing this waste.