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Rudnik Idrija u Sloveniji bio je drugi najveći rudnik žive na svijetu i značajan antropogeni izvor žive. Tlo u okolici rudnika još uvijek sadrži od 10 do čak 10 000 mg Hg/kg na drevnim mjestima pečenja rude. Budući da je Idrija krško područje postoji opasnost od infiltracije žive oborinskim vodama u dublje slojeve tla te u konačnici i u podzemne vode. Kako bi se procijenio utjecaj žive na okoliš u području rudnika Idrija i šire, potrebno je ispitati njeno potencijalno ispiranje iz tla. Eksperimenti ispiranja žive iz onečišćenog tla sa sadržajem žive od 1347 mg Hg/kg provedeni su standardnom šaržnom metodom prema normi DIN 38414 S4 u ultračistoj vodi različitih početnih pH o vrijednosti u rasponu od 3,00 do 11,46 tijekom 24 h. Ukupna koncentracija izlučene žive nakon 24 h bila je vrlo niska i iznosila od 0,33 do 17,43 µg/L, što ukazuje na vrlo visoki afinitet žive prema organskim i anorganskim tvarima u tlu. Međutim, gotovo sve izmjerene koncentracije bile su iznad maksimalno dopuštene koncentracije za vode za ljudsku potrošnju prema hrvatskim i slovenskim zakonima, kao i prema Direktivi Vijeća Europske zajednice. Praćenjem ukupne koncentracije otopljene žive u odabranim vremenskim intervalima tijekom 24 h dobivene su značajno veće koncentracije ukupno izlučene žive od 102,86 do čak 488,02 µg/L, i to nakon 2,5 do 7,0 sati od početka eksperimenta. Dobiveni rezultati ukazuju na nužnost daljnjeg praćenja kakvoće tla na drevnim mjestima pečenja rude u okolici Idrije, detaljnijeg istraživanja izlučivanja žive u prvih nekoliko sati ispiranja tla te određivanja oblika u kojemu se živa nalazi u tlu i vodi. The Idrija mine in Slovenia was the second largest mercury mine in the world and significant anthropogenic source of mercury. The soil in surrounding the mine still contains from 10 to even 10.000 mg Hg/kg at ancient roasting sites. Since Idrija is karst area there is dangerous of mercury infiltration by rain water into deeper soil layers and thus into groundwater. In order to assess the impact of mercury onto environment in Idrija district and beyond, it is necessary to examine its potentially leaching from the soil. Leaching experiments of mercury contaminated soil with 1347 mg Hg/kg were performed by standard batch method according to DIN 38414 S4 in ultrapure water of different initial pH o values in the range of 3.00 to 11.46 for 24 h. The total leached mercury concentration after 24 h was very low and ranged from 0.33 to 17.43 µg/L, indicating very high affinity of mercury toward organic and inorganic substances in the soil. However, almost all measured concentrations were above the maximum permissible levels for waters for human consumption according to Croatian and Slovenian legislations as well as to the Directive of the European Community Council. By monitoring the total leached mercury concentration in time intervals within 24 h, the concentrations were significantly higher, and after 2.5 to 7.0 hours from the beginning of the experiment ranged from 102.86 to even 488.02 µg/L. The obtained results indicate the need for further monitoring of the soil quality at ancient roasting sites of the Idrija district. A more detail study of mercury leaching in the first few hours of the experiment is necessary with determination of the form in which the mercury is present in the soil and the water.

Rudnik Idrija u Sloveniji bio je značajan antropogeni izvor žive. Iako je još 1995. godine proizvodnja u rudniku prestala, zbog neučinkovitog pečenja rude tlo u okolici Idrije je vrlo onečišćeno živom čija koncentracija doseže i do 10 000 mg Hg/kg. U tako krškom području živa se površinskim i oborinskim vodama može isprati u dublje slojeve tla te može doći do podzemnih voda. Budući da je živa jedan od najtoksičnijih metala, nužno je pronaći učinkovitu, a isplativu metodu za uklanjanje žive iz onečišćenih voda. U ovome radu ispitana je učinkovitost prirodnog zeolita klinoptilolita veličine čestica 0,6 - 0,8 mm u obradi eluata dobivenog ispiranjem živom onečišćenog tla s područja Idrije. Najveći učinak uklanjanja dobiven je u eluatima s najnižom koncentracijom ukupne žive, koja se smanjila do ispod maksimalno dopuštenih koncentracija. Najveća ravnotežna količina vezane ukupne žive po jedinici mase zeolita postignuta je u eluatima s najvećom koncentracijom ukupne žive te opada smanjenjem početne koncentracije. Prirodni zeolit klinoptilolit može se uspješno primjeniti u obradi voda onečišćenih živom, posebice u slučaju niskih početnih koncentracija ukupne žive. Međutim, u svrhu povećanja učinkovitosti prirodnog zeolita za uklanjanje ukupne žive nužno je poboljšati njegova površinska svojstva za adsorpciju različitih ionskih i organskih vrsta, što se najčešće postiže modifikacijom organskim surfaktantima. The Idrija mine in Slovenia was a significant anthropogenic source of mercury. Although the production in the mine stopped in 1995, the soil in surrounding of Idrija is highly polluted with mercury due to the inefficient ore roasting, so the concentration reaches even up to 10 000 mg Hg/kg. In such karst area, surface and rain waters can leach mercury from contaminated soil to deeper soil layers and then into groundwater. Since mercury is one of the most toxic metals, it is necessary to find an efficient, cost- effective method for its removal from contaminated waters. This paper investigated the efficiency of the natural zeolite clinoptilolite of particle size 0.6 - 0.8 mm in the treatment of the leachate obtained by leaching the mercury contaminated soil of Idrija district. The highest removal efficiency has been obtained in leachates with the lowest concentration of total mercury, which has been decreased to below the maximum permissible concentration. The highest equilibrium quantity of removed total mercury per unit of the zeolite mass has been achieved in the leachates with the highest concentration of total mercury, and decreased by decreasing in initial concentration. The natural zeolite clinoptilolite can be successfully applied for the treatment of mercury contaminated waters, especially in the case of low initial total mercury concentrations. However, in order to increase the efficiency of natural zeolite for total mercury removal, it is necessary to improve the surface properties of zeolite for adsorption of various ionic and organic species, which is most commonly achieved by modification with organic surfactants.