铁活化斜发沸石吸附水中氟的热力学研究  

Thermodynamic Study on Adsorption of Fluoride Ions in Water by Iron-active Clinoptilolites

作　　者：李颖[1] 李曼尼[1] 刘晓飞[1] 

机构地区：[1]内蒙古大学化学化工学院,呼和浩特010021

出　　处：《内蒙古大学学报（自然科学版）》2005年第4期405-410,共6页Journal of Inner Mongolia University：Natural Science Edition

摘　　要：经2%NaOH溶液预处理的白庙子斜发沸石分别用5%FeCl3溶液静态热浸渍和动态热浸渍制得的3#和4#铁活化斜发沸石,其比表面积、孔体积及微孔分布有了明显改善,对水中氟离子静态吸附容量有了明显提高.3#矿样上呈指数型吸附等温线,可用Freundlich等温方程描述.4#矿样上呈S型吸附等温线,有多分子层吸附特征.热力学分析表明,两矿样对氟的校正选择商KC随温度和氟离子浓度提高而增大,选择能力增强.△exH0-m、△exS0-m和△exG0-m结果表明,吸附行为是吸热的熵增大过程,提高温度和浓度时矿样对氟的化学亲和力增强.3#矿样对氟离子的化学亲和力较强,静态吸附容量较大.Iron-active clinoptilotites of 3~# and 4~# samples were prepared by the static and dynamic impregnation with 5% FeCl_3 solution after pre-impregnation with 2%NaOH solution,respectively.Their S_(BET),pore volumes and the micropore distributions were improved obviously, and the static adsorption capacities of fluoride ion in water were enhanced obviously also.An exponent isotherm of adsorption on the 3#sample was obtained.The result can be described by the Freundlich isothermic equation.The S-type isotherm of adsorption on the 4~# sample was of the characterization of multi-layer adsorption related to the distribution of micropores,not agreeing to the Freundlich isothermic equation. Thermodynamic study showed that the modified selectivity quotient K_C was enhanced with the increasing of temperature and concentration of fluoride ions,and the selectivity of samples for fluoride ions increased also.The results of △exH^(0-)_m,△exG^(0-)_m and △exS^(0-)_m of the ion exchange process showed that the adsorption and ion exchange behaviors were the endothermic process with entropy increase, and the chemical affinities of samples for fluoride ions were enhanced with the increasing of temperature and concentration of fluoride ions.Because of the difference of adsorption behavior,the chemical affinity and static adsorption capacity for fluoride ions of 3# sample was stronger than that of 4~# sample.

关 键 词：铁活化斜发沸石 氟吸附容量 吸附等温线 吸附热力学 

分 类 号：P578.974[天文地球—矿物学]