Silica gel as an Adsorbent in the Removal of Cationic Blue X-Bl From Aqueous Solutions and its Regeneration by UV-Fenton Oxidation

摘要

The removal of cationic Blue X-BL in aqueous solution by adsorption of silica gel was investigated. Effects of pH, initial concentration of dye solution and temperature on the adsorption of Cationic Blue X-BL onto silica gel were studied. When the initial concentration of the blue dye was 100 mg/dm~3, silica gel is 0.6 g at pH 9.3 and at 303 K, adsorption reached equilibrium after 2 h with the final adsorption quantity 16.38 mg/g. Fenton reaction with UV light was applied in the regeneration operation of silica gel which can transmit most of the UV light. The concentration of Fe~(2+) and H_2O_2 was evaluated and when the concentration of Fe~(2+) and H_2O_2 were 0.05 mmol/dm~3 and 0.132 mol/dm~3, the first, second, third and forth regeneration efficiency were 84.68%, 82.05%, 65.26% and 50.73%, respectively. In order to improve the regeneration capacity and silica gel's reuse times, acid washing was introduced in the forth regeneration after Fenton reaction, which can enhance the regeneration efficiency to 92.19%.