摘要
以单宁酸为目标污染物,分析了溶液初始pH、吸附时间以及吸附剂投加量等因素对酸-高温改性海泡石吸附单宁酸的影响,并通过表面电荷、X射线衍射与红外光谱的测定分析,探讨了天然海泡石、酸-高温改性海泡石以及改性海泡石吸附单宁酸后的表面化学特性.结果表明,溶液初始pH=2增加到pH=10时,酸-高温改性海泡石对单宁酸的去除率由35.0%上升到74.8%,吸附量由7.0mg/g上升到15.0mg/g.随着吸附剂投加量的增加,单宁酸的去除率呈上升趋势.当吸附时间为6h时,去除率可达71.0%,吸附量为14.2mg/g,而后去除率与吸附量基本保持不变.海泡石与酸-高温改性海泡石电荷零点所对应的pHZPC分别为7.32±0.1和6.44±0.1,表明酸-高温改性增加了海泡石表面的酸度,形成了更多的表面吸附位;同时酸-高温改性提高了海泡石的纯度和吸附性能,改性海泡石吸附单宁酸后,其红外图谱显示在2 975、2 919和1 629cm-1处出现了吸收峰,表明改性海泡石对单宁酸有较好的吸附作用.
With tannin as target pollutant, the effects of such factors as the initial concentration pH, adsorption time, and adsorbent dosage on the adsorption of acid-thermal modified sepiolite are analyzed. At the same time, the chemical prop- erties of the natural sepiolite, acid-thermal modified sepiolite and adsorption of tannic sepiolite were investigated using surface charge, X-ray powder diffraction and infrared spectroscopy. The removal rate of tannin adsorbed increased from 35.0% to 74.8% for acid-thermal modified sepiolite as the pH increased from 2 to 10. At the same time, the amount of tannin adsorbed increased from 7.0 to 15.0 mg/g. As the adsorbent dosage increased, so did the removal rate. When the adsorption time was 6h, the removal rate was 71.0% and the amount of tannin adsorbed was 14.2 mg/g. Then the re- moval and adsorption capacity of tannin basically remained unchanged. The pHZPC of the natural sepiolite and acid-ther- mal sepiolite were 7.32±0.1 and 6.44±0.1, respectively. This suggested that acid and thermal treatment increased the surface acidity of sepiolite and the surface available sites for adsorption. The acid and thermal treatment improved the ad- sorption capacity and purity of sepiolite. After the acid-thermal modified sepiolite absorbed tannin, the changes in the IR absorption bands of the sample were noted at 2975, 2919, and 1629 cm^-1. This shows that the adsorption of tannin was well on acid-thermal modified sepiolite.
出处
《西安建筑科技大学学报（自然科学版）》
CSCD
北大核心
2012年第2期248-252,共5页
Journal of Xi'an University of Architecture & Technology(Natural Science Edition)
基金
国家科技支撑项目(2009BAC57B03)
广西教育厅科研项目(201010LX069)
关键词
海泡石
酸-高温改性
单宁酸
吸附
sepiolite
acid-thermal modified
tannin
adsorption
