酸化蒙脱石对挥发性有机物的吸附研究

Preparation and Characterization of Acid Activated Montmorillonites for VOCs Removal

通过对蒙脱石矿物表面与结构改性优化处理,增大其比表面积,扩大有效吸附孔洞,增强表面疏水性能,从而提高其对挥发性有机物(VOCs)的吸附能力。本研究通过酸化法对蒙脱石(Mt)进行活化,在固定活化的温度、时间、固液比和搅拌速率的条件下,探讨不同浓度硫酸活化对Mt结构的影响,并研究相应酸化产物对作为指示VOCs的甲苯、二氯甲烷的吸附效果,进而推断酸活化产物与VOCs的构-效关系。结果表明,Mt经过酸活化后,其BET比表面积达到373.8 m2/g,孔体积为0.52 cm3/g。酸活化产物对甲苯、二氯甲烷的饱和吸附容量最高分别达到156.6、119.7 mg/g,相比原土的吸附量分别提高了1.46和1.62倍。吸附容量与吸附剂的BET比表面积和孔体积并非简单线性正相关关系,VOC分子的尺寸也有一定的影响。

Montmorillonite（Mt） was activated by acid treatment with different concentrations of sulfuric acid, under the condition with a fixed activation temperature, time, solid-liquid ratio and stirring speed. Acid activation resulted in the high BET specific surface area（ca.373.8 m2/g） and high pore volume（ca.0.52 cm3/g）. The saturation capacity of acid activation product for toluene and dichloromethane are 156.6 and 119.7 mg/g, which were 1.46 and 1.62 times larger than those of raw Mt, respectively. Adsorption capacity is not positively correlated with BET specific surface area and pore volume, while the size of the VOC molecules has a certain effect on montmorillonite＇s adsorption capacity.