In order to effectively and selectively remove trace concentration of antimony contained in various waste water like that generated in the production of polyester fiber and so on, novel environmentally benign adsorption gel was prepared from orange juice residue. It was found that antimony (Ⅲ and Ⅴ) can be effectively and selectively removed by using iron(Ⅲ)-loaded adsorption gel. Adsorption behaviors of this adsorption gel for antimony (Ⅲ and Ⅴ) was investigated in detail in terms of the effects of pH and other anionic species as well as adsorption isotherms. It was found that nearly quantitative adsorption was achieved at around 2～3 for antimony (Ⅴ) while antimony (Ⅲ) was quantitatively adsorbed over wide pH range 2～6. The adsorption isotherms were expressed in terms of the Langmuir’s adsorption model and the maximum adsorption capacities were evaluated as 1.12 and 1.19 mmol/g for antimony (Ⅲ) and (Ⅴ), respectively, which are much higher than other adsorbents reported to date. It was further found that the adsorption of both antimony species is not affected by excess concentrations of other anionic species like sulfate, chloride and carbonate. Since the selective elution of the adsorbed antimony was found to be difficult by using any kinds of elution reagents, the elution was carried out by hydrochloric acid solution together with the loaded iron. The eluted antimony was selectively separated from iron as precipitate of antimony sulfide by adding sodium sulfide.
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