Original scientific paper
https://doi.org/10.2478/10004-1254-60-2009-1898
Effect of Organic and Mineral Soil Fractions on Sorption Behaviour of Chlorophenol and Triazine Micropollutants
Sanja Stipičević
orcid.org/0000-0002-2021-9435
; Institute for Medical Research and Occupational Health, Zagreb, Croatia
Sanja Fingler
; Institute for Medical Research and Occupational Health, Zagreb, Croatia
Vlasta Drevenkar
orcid.org/0000-0002-7430-0431
; Institute for Medical Research and Occupational Health, Zagreb, Croatia
Abstract
This article compares the sorption behaviour of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol, chlorotriazine atrazine, methylthiotriazine ametryn, methoxytriazine atratone, hydroxyatrazine, and didelakylated atrazine in a topsoil and an aquifer sediment before and after removal of sorbent organic matter and in humic acid. Freundlich isotherm coeffi cients Kf and 1/n and free energy change (∆G°) were calculated for all compounds in all sorbents. According to sorbent pH values, chlorophenolate anions and uncharged triazine species dominated in all sorption experiments with topsoil and aquifer sediment. In experiments with humic acid, chlorophenols, atrazine, and didealkylated atrazine existed almost completely as neutral species, whereas protonated species dominated for hydroxyatrazine, atratone, and ametryn. In addition to a hydrophobic partition, sorption of all compounds in native soil and sediment sorbents includes specifi c, more polar interactions, which greatly depend on sorbate acidity/ basicity, specifi c properties of the sorbent organic matter and of mineral surface, as well as on the system pH. A signifi cantly greater sorption intensity of all compounds in “organic-free” than in the native aquifer sediment confi rmed the importance and possible dominance of mineral surface in the sorption process. Sorption intensity of chlorophenol and triazine compounds in humic acid was closely related to compound hydrophobicity. Greater sorption of almost completely protonated hydroxyatrazine than of the more hydropohobic but uncharged atrazine indicated different humic acid reaction sites for two compounds and consequently different sorption mechanisms.
Keywords
ametryn; atratone; atrazine; chlorophenolate anions; didealkylated atrazine; Freundlich isotherm; humic acid; hydroxyatrazine; mineral surface; organic matter
Hrčak ID:
34847
URI
Publication date:
27.3.2009.
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