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  • Influence of chemical charg...
    Holzmann, Hannah; Simeoni, Andrea; Schäffer, Andreas

    Chemosphere (Oxford), February 2021, 2021-Feb, 2021-02-00, Letnik: 265
    Journal Article

    In order to investigate the influence of differently sized particle fractions on the fate of ionic chemicals in water-sediment systems, we performed simulation studies following OECD guideline 308. We used 14C-labelled anionic (4-n-dodecylbenzenesulfonic acid sodium salt, ‘14C-DS-’), cationic (4-n-dodecylbenzyltrimethyl ammonium chloride, ‘14C-DA+‘) and non-ionic (4-n-dodecylphenol, ‘14C-DP’) organic chemicals. The sediment was subjected to particle size fractionation. For each particle fraction and test compound, water-sediment systems were prepared and incubated for 14 days. Across all particle fractions, higher amounts of applied radioactivity (AR) of 14C-DS- (in sand 60.1%, in silt 45.1%, in clay 57.0%) and of 14C-DP (sand: 31.8%, silt: 24.4%, clay: 29.2%) were mineralised compared to 14C-DA+ (sand: 5.1% AR, silt: 3.5% AR, clay: 2.4% AR). The highest bioavailability was observed for 14C-DS- followed by 14C-DP and 14C-DA+ across all particle fractions. Formation of non-extractable residues (NER) of 14C-DS- did not substantially differ between the particle fractions, whereas NER formation of 14C-DA+ was higher in the clay fraction (24.3% AR) than in silt (15.9% AR) and sand (8.4% AR). The same trend was observed for 14C-DP. We showed that differently sized particle fractions have an influence on the fate of ionic chemicals in water-sediment systems and conclude that this should be considered when simulation studies in soils and sediments with different textural compositions are performed. Since a positive charge of organic chemicals tends to form higher portions of NER in the clay fraction of sediments, these NER should be further investigated in terms of their nature and types of binding. Display omitted •Mineralisation of both ionic and non-ionic compounds was highest in sand fraction.•Extractability of cationic compound increased with increasing sand content.•NER formation of anionic compound less affected by particle size fractions.•Highest amounts of NER in clay fraction for cationic compound.•Degradation pathway of cationic compound was influenced by particle size fractions.