Column Adsorption of Chromium(VI) by Strong Alkaline Anion-Exchange Fiber

摘要

The removal of chromium(VI) from saturated sodium chloride (NaC1) solution by strong alkaline anion-exchange fiber (SAAEF) was achieved with column experiments. Factors affecting the adsorption, such as the pH value, loading density, flow rate, and operational temperature, were investigated. The results show that Cr(VI) removal was remarkably pH dependent. The optimal operational conditions were as follows: pH value = 2.0, loading density = 0.12-0.19 g/cm3, room temperature, and flow rate = 6-12 BV/h. The SAAEF column could be regenerated completely by 2% NaOH in saturated NaCl or 2% KOH in 15% KC1 as an eluent. Cr(VI) was recycled as Na_2Cr_2O_7 and K_2Cr_2O_7, respectively. The desorption rate of Cr(VI) reached 98.09%. The adsorption ability of the SAAEFs was stable after repeated use. Overall, the results indicate that SAAEF proved to be an effective material for the adsorption of high concentrations of Cr(VI) from a saturated NaCl solution.