REMOVAL OF ARSENIC(Ⅴ) ION FROM UNDERGROUND WATER BY CERIUM(IV) BASED ADSORBENT

摘要

A rare earth metal based inorganic adsorbent was developed by incorporating cerium (Ⅳ) into iron oxide crystals, and its performance for removal of arsenate from both synthetic and natural underground water was evaluated. Physico-Chemical characteristics of cerium and iron adsorbent (CFA) were studied. The performance of the inorganic adsorbent for arsenic (Ⅴ) removal was compared with that of activated alumina, a conventional adsorbent for arsenic (Ⅴ) removal. Experimental results show that the capacity of rare earth metal based absorbent was almost constant around a value of 16.0 mg As (Ⅴ) · g -1over a wide final pH range of 3-8, while the maximum adsorption capacity of activated alumina of 8.3 mg As (Ⅴ) ·g~(-1) was obtained around final pH of 5 to 6. The results shows that the adsorption of arsenic (Ⅴ) on CFA adsorption follows Freundlich and Langmuir isotherm in the tested range of arsenic concentrations at 20℃. Salinity, hardness, fluoride and other anions such as Cl-, NO_3 -,SO_4~(2-) did not interfere with the adsorption of arsenic, but phosphate inhibited the removal of arsenic (Ⅴ) seriously. The method was applied for the removal of arsenic from underground water in Inner Mongolia of China. The above results demonstrate the effectiveness of the new adsorbent for arsenic removal.