Removal of Selenium from Aqueous Sample using Calcium Alumino-zincate

摘要

Aiming to apply in a removal of selenium from contaminated waste water, we have studied the immobilization of Se(IV) and Se(VI) into the hydrate of calcium alumino-zincate (14CaO.5Al_2O_3.6ZnO, shown as C_(14)A_5Z_6). By adding 2 g of C_(14)A_5Z_6 to 1 L of 5 mg/L Se(VI) solution, the concentration of Se(VT) was decreased to less than 0.01 mg/L within 60 minutes. In the case of using 1 g of calcium hydroxide with 2 g of C_(14)A_5Z_6, the Se(VI) concentration reached to 0.01 mg/L within 30 minutes. On the other hand, the concentration of Se(IV) was decreased from 5 mg/L to 0.16 mg/L in 60 minutes whilst it reached to 0.041 mg/L by adding calcium hydroxide in the same reaction period. The immobilization capacities of selenium were 222 and 127 mg/g for Se(IV) and Se(VI), respectively. By adding calcium hydroxide, the immobilization capacity of C_(14)A_5Z_6 was increased to 240 and 200 mg/g for Se(IV) and Se(VI), respectively.