| Abstract | Korištenje velikih količina pesticida, kao i njihova visoka topljivost u vodi predstavljaju popriličnu opasnost za okoliš, u vidu onečišćenja voda, zagađenja tla, zraka te narušavanja homeostaze ekosustava. Iz toga razloga, cilj istraživanja bio je ispitati utjecaj karakteristika tla s lokaliteta Grobnik, Matulji, Međimurje i Otočac uz poseban naglasak na utjecaj organske tvari tla na sorpcijsko ponašanje dimetoata. Izvršena su određivanja aktualne, supstitucijske i hidrolitičke kiselosti tla, količine i sastava humusa, određivanja ugljika u ekstraktu, huminskim i fulvinskim kiselinama te spektrofotometrijsko određivanje prirode građe huminskih kiselina pri valnim duljinama od 465 i 665 nm. Određivanje sorpcijskog kapaciteta tla za dimetoat provedeno je pomoću tekućinskog kromatografa visoke djelotvornosti (HPLC). Reakcija tla bila je neutralna i alkalna (pH=6,73-7,40), a udio organske tvari u tlu se nalazio u rasponu od 1,21-3,47% te svrstava tla u slabo humozna i dosta humozna tla. Prema Freundlichovom modelu opisa procesa sorpcije organskih spojeva na tlu dobivene su sorpcijske izoterme C oblika kod uzoraka GR, M2 i L1, L oblika kod uzorka MEĐ te S oblika kod uzorka M1, a vrijednosti koeficijenta KF su bile u rasponu od 0,20-6,91 (mg/kg)(mg/L)1/n. Rezultati ukazuju kako sorpcijsko ponašanje dimetoata u tlu nije uvjetovano samo organskom tvari tla, već zajedničkim učinkom svih karakteristika tla. |
| Abstract (english) | The use of large pesticide quantities, as well as their high water solubility, represent a significant environmental hazard, in the form of water, soil, air pollution and disruption of the ecosystem homeostasis. For that reason, the aim of this study was to investigate the effect of soil characteristics from following locations: Grobnik, Matulji, Međimurje and Otočac with the main emphasis on the effect of organic carbon soil characteristics on the sorption behavior of dimethoate. Actual, exchangeable and hydrolytic acidity of soil, character and humus content, amount of carbon in extract, humic and fulvic acids and spectrophotometric determination of the natural humic acid structure at wavelengths of 465 and 665 nm were performed. Determination of the soil sorption capacity for dimethoate was performed using a high performance liquid chromatograph (HPLC). The soil reactions were neutral and alkaline (pH=6.73-7.40) and the proportion of organic matter content in soil ranged from 1.21-3.47% classifying soils as poorly and fairly humus soils. According to Freundlich's model for describing the sorption process of organic compounds in soil, sorption isotherms were classified as C type for the samples GR, M2 and L1, L type for the sample MEĐ and S type for the sample M1. Furthermore, the values of the KF coefficient varied from 0.20-6.91 (mg/kg) (mg/L)1/n. The results of the study indicate that the sorption behavior of dimethoate in soil is not only caused by soil organic matter content, than by the combined effect of all soil characteristics. |
