3차원 지하수 유동과 반응성용질이동 모델을 활용한 우라늄 흡착 및 이동에 관한 개념 모델링

Abstract

In this study, the speciation, adsorption, and transport of uranium in groundwater environments were simulated using geochemical models. The retarded transport of uranium by adsortption was effectively simulated using 3-D groundwater flow and reactive transport models. The results showed that most uranium was adsorbed(up to 99.5%) in a neutral pH(5.5<pH<8) under low pCO2(10-3.6 atm) condition. Under the higher pCO2(10-2.5 atm) condition, however, the pH range where most uranium was absorbed was narrow from 6 to 7. Under very low pCO2(10-4.5 atm) condition, uranium was mostly absorbed in the relatively wide pH range between 5.5 and 8.5. In the model including anion complexes, the uranium adsorption decreased by fluoride complex below the pH of 6. The results of this study showed that uranium transport is strongly affected by hydrochemical conditions such as pH, pCO2, and the kinds and concentrations of anions(Cl-, SO42-, F-). Therefore, geochemical models should be used as an important tool to predictthe environmental impacts of uranium and other hazardous compounds in many site investigations.