改性沸石对Cr(Ⅵ)与F^-的竞争吸附性能研究  

Competitive Adsorption of Cr(Ⅵ) and F^- Ions by Modified Zeolite

作　　者：程婷[1] 陈晨[2] 谢伟芳[1] 韩承辉[1] 唐荣[1] 

机构地区：[1]江苏城市职业学院城市科学系,南京210017 [2]江苏科技大学生物与化学工程学院,江苏镇江212018

出　　处：《湖北农业科学》2015年第17期4138-4142,共5页Hubei Agricultural Sciences

基　　金：江苏省高校自然科学研究项目(13KJB610005);江苏省高校自然科学研究项目(14KJD610002);国家自然科学基金项目(201407068);江苏省环境工程重点实验室科研开放基金项目(KF2014002);江苏城市职业学院"十二五"规划青年专项项目(13SEW-Q-058)

摘　　要：利用粉煤灰合成改性沸石吸附Cr(Ⅵ)与F-,考察沸石投加量、初始pH、吸附时间对其竞争吸附效果的影响,研究沸石吸附Cr(Ⅵ)与F-的吸附等温线和吸附动力学模型。结果表明,沸石投加量、初始pH与吸附时间均对沸石吸附Cr(Ⅵ)与F-的效果影响显著。沸石对Cr(Ⅵ)与F-吸附去除率随着沸石投加量的增加而提高,而单位质量的沸石吸附剂对Cr(Ⅵ)与F-的吸附容量均不断下降。沸石对Cr(Ⅵ)的吸附去除率随初始pH升高而降低,而对F-的吸附去除率随初始pH升高先下降再上升。沸石对两种离子的吸附去除率随着吸附时间的延长而不断提高,且竞争吸附主要集中在90 min以内完成。在整个吸附过程中,Cr(Ⅵ)在竞争吸附过程中占优势,两种离子的吸附顺序始终为Cr(Ⅵ)>F-。沸石对Cr(Ⅵ)与F-的吸附过程均更符合Freundlich吸附等温模型,且准二级动力学方程能够较好的描述沸石对两种离子的吸附行为。The experiments were conducted to examine the adsorption of Cr（VI） and F- ions through synthesizing modified （K） zeolite from coal fly ash. The adsorbent dosage, the initial pH and the adsorption reaction time were investigated to study the competitive adsorption effect of Cr（VI） and F- ions. The adsorption isotherm and the adsorption kinetics equation were also discussed. The results showed that, the adsorbent dosage, initial pH and had significant effects on the competitive adsorption of Cr（VI） and F- ions. With the increasing of the adsorbent dosage, the adsorption removal rate of Cr（VI） and F- ions by zeolite were all improved, and the saturated adsorption capacity of two ions were decreased gradually. With the increasing of initial pH, the adsorption removal rate of Cr（VI） was decreased, while the adsorption removal rate of F- ion was increased firstly, and then decreased. The adsorption removal rate of Cr（VI） and F- ions by modified zeolite were all improved with the increasing of reaction time, and the competitive adsorption mainly completed within 90 minutes. In the whole process of adsorption, the adsorption of Cr（VI） predominated in the competitive adsorption process. The competitive adsorption sequence of Cr（VI） and F- ions was Cr（VI） ﹥F-. The adsorption process of Cr（VI） and F- ions accorded with Freundlich adsorption isotherm. The adsorption reaction to the Cr（VI） and F- ions matched to the pseudo-second class reac-tion kinetics model.

关 键 词：粉煤灰 六价铬离子 氟离子 竞争吸附 改性沸石 

分 类 号：X52[环境科学与工程—环境工程]