Naslov
Potential of natural and modified Mediterranean soil to protect water supplies from triazine herbicide residues

Autori
Drevenkar, Vlasta ; Rožić, Mirela ; Sekovanić, Lavoslav ; Stipičević, Sanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The 36th ISEAC International Symposium on Environmental Analytical Chemistry, Book of Abstracts / Grilli, Maria Luisa ; Artuso, Florinda - Rim : ENEA, 2010, P136-P136

ISBN
978-88-8286-228-2

Skup
The 36th ISEAC International Symposium on Environmental Analytical Chemistry

Mjesto i datum
Rim, Italija, 05.10.2010. - 09.10.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Triazine herbicides ; Mediterranean soil ; sorption/desorption ; hydrophobically modified soil

Sažetak
Sorption/desorption interactions of three structurally different triazine herbicides (atrazine, atratone, and ametryn) and three breakdown products of atrazine (deisopropylatrazine, deethylatrazine, and didealkylatrazine) were studied in native, acidified, and organically enriched forms of two representative Mediterranean soils (terra rossa): a surface soil collected in the area of Izmir in Turkey and a subsurface soil collected at a location on the Istrian peninsula in Croatia. The native soils were of clayey to silty-clayey type and differed significantly in mineral composition and cation exchange capacity. Triazine sorption/desorption experiments were performed using a batch equilibration method [1]. Sorbate equilibrium concentrations in the aqueous phase after sorption/desorption were determined by high performance liquid chromatography using an UV diode-array detector. The results of sorption experiments, evaluated in terms of Freundlich isotherm, were compared with respect to the physicochemical properties of sorbates and sorbents. Sorption intensity of all triazines in native soils was very low (ΔG° ≤ -2 kJ/mol) despite relatively high soil organic carbon content (15 %). Acidification of native soils to pH 4 with hydrochloric acid significantly enhanced sorption intensity of more basic herbicides (atratone and ametryn) and of two most polar atrazine degradation products. Enrichment efficiency of native soils with a cationic surfactant (hexadecyltrimethylammonium) was highly influenced by soil cation exchange capacity. Retention of triazines in organically enriched soils increased significantly with triazine hydrophobicity due to additional hydrophobic interactions. The most intensive sorption of triazines was observed in soils fortified with cationic surfactant in an amount corresponding to 65 % of the native soil cation exchange capacity. Sorption capacity of hydrophobically modified soils was for most triazines greater than the capacity of native and acidified soils. Desorption experiments for each pair of sorbate/sorbent were conducted in a single desorption step. The results indicated partially or almost completely irreversible sorption of most sorbates in soils richer in organic carbon, save for polar degradation products, whose sorption was irreversible to a greater extent in acidified soils. Native Mediterranean soil seems to make no use as a permeable and stabile native barrier for hydrophobic pollutants to reach groundwater. Its acidification and organic carbon enrichment however show a promising potential in preventing water supplies pollution with triazine herbicide residues. [1] Stipiĉević, S., Fingler, S. and Drevenkar, V., Arh. Hig. Rada Toksikol. 60, 43-52 (2009).

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija, Grafička tehnologija

POVEZANOST RADA