离子交换纤维对Cr(Ⅵ)的交换性能研究

Study on characteristic of ion-exchange for chromium(Ⅵ) by polypropylene anion exchange fiber

研究了苯乙烯系聚丙烯基阴离子交换纤维对Cr(Ⅵ)的交换性能,考察了酸度、温度和流速等因素对交换性能的影响。实验结果表明,在 pH 值为 3时交换性能最好。离子交换纤维对 Cr(Ⅵ)的交换以液膜扩散为主,交换速度很快,8min 即可达到交换饱和,交换反应速率常数为0.015s-1,离子交换过程服从Freundlish等温式。测定了纤维静态饱和交换量为257.6mg/g。温度和流速影响动态交换性能,使得穿透曲线和穿透时间发生改变。与离子交换树脂相比具有交换速度快、交换量大的优点,是一种交换性能优良的分离材料。

The ion-exchange capability of polypropylene anion exchange fiber for Cr(Ⅵ) was studied. The effects of acidity, temperature and flow speed on ion-exchange capability were observed. The results show that the optimum pH was 3. The main exchange action of the fiber is the expansion of the liquid surface .The exchange is fast and it can be saturated in 8 min .The exchange rate constant is 0.015/s .The processes of ion-exchange were consistent with Freundlish′s equation. The effects of flow speed and temperature on dynamic exchange capability were large, so the breakthrough curve and breakthrough time were changed. The static saturated ion-exchange capacity was 257.6mg/g. Compared with ion-exchange resin, the polypropylene anion exchange fiber had higher exchange speed and larger exchange capacity.