苯蒸气在有机膨润土上的吸附性能及机理研究

Sorption properties and mechanisms of benzene vapor onto organobentonites.

对比研究了膨润土和有机膨润土的结构及其对苯蒸气的吸附性能.绘制了不同温度下苯蒸气在有机膨润土(空气中干燥)上的吸附等温线,计算出苯蒸气的吸附系数及吸附热,并初步推测其吸附机理.结果表明,苯蒸气在原土上的等温吸附曲线呈非线性,其吸附热为-30.6kJ/mol,主要吸附机理为矿物质表面吸附.表面活性剂改性后,膨润土的吸附能力远大于原土,苯蒸气在有机膨润土上的吸附等温线呈线性,其吸附热在-29.7~ -20.8kJ/mol之间,吸附作用中有机质的分配作用贡献率较大,吸附系数(Kd)与有机碳含量(foc)成正相关.

The structure of natural bentonite and air-dried organobentonites as well as their sorption properties were investigated. The sorption isotherms of vapor phase benzene onto air-dried organobentonites were determined; the sorption heats and coefficients were calculated; and its sorption mechanism was inferred preliminarily. Results indicated that the sorption isotherm of vapor phase benzene on natural bentonite was nonlinear; its sorption heat was -30.6kJ/mol with its mechanism mainly mineral surface sorption. The sorption isotherms of vapor phase benzene onto organobentonites were linear and its sorption heats were -29.7 [similar to] -20.8 kJ/mol; the sorption coefficients (Kd) were positively correlated with the organic carbon contents(foc); and the sorption of benzene vapor by organobentonites occurs essentially by vapor partition into organic-matter fractions of the samples.