Abstract
This study was conducted to investigate the influence of iron corrosion products on the removal precipitation of uranium (VI) from aqueous solutions by zero valent iron (ZVI). Batch experiments were conducted with solutions containing 20 mg /L U(VI) (0.084 mM) at room temperature with washed and untreated scrap iron.
The results show significant decrease of the immobilization efficiency of ZVI for uranium in the presence of both atmospheric corrosion products and those generated in situ. Among the relevant groundwater components, those who promote the iron corrosion e.g. SO42−, Cl− produce more corrosion products and have a stronger negative effect on the immobilization process. Carbonate ions also have a negative effect on the immobilization efficiency since they form stable complexes with uranium and reduce the adsorption on the iron surface which is the first step to immobilization. Humic substances didn’t show any negative effect but rather a slight enhancement of the immobilization rate. These results show that washing ZVI materials with hydrochloric acid before testing will overestimate their efficiency in practical use.
