香蒲基生物炭的活化及对VOCs吸附的应用

以香蒲为原料制备生物炭(Biochar), 并用不同试剂进行活化. 活化前的Biochar比表面积和孔体积很小, 分别为1.71 m²/g和0.00421 cm³/g, 而活化后的Biochar比表面积和孔容均增大, 其中经碳酸钠（Na₂CO₃）活化后的Biochar比表面积和孔容最大. 研究了Na₂CO₃与Biochar的质量比对其活化的影响, 确定了Na₂CO₃/Biochar最佳质量比为3∶1条件下， 得到的样品Biochar-Na₂CO₃-3具有最优的表面积和孔容, 分别为624 m²/g和0.211 cm³/g, 并具有优异的挥发性有机化合物(VOCs)吸附性能, 其正己烷、 甲苯和92号汽油的静态吸附容量分别为1.03, 0.814和0.751 g/g, 正己烷和甲苯的动态吸附容量分别为1.00和0.796 g/g, 且吸附稳定性相对较高, 优于商业用活性炭(AC)和硅胶(SG).

Activation of Biochar from Cattail and the VOCs Adsorption Application

Biochar was achieved by using cattail as raw material and activated with different agents. The specific surface area and pore volume of biochar before activation was very small， 1.71 m²/g and 0.00421 cm³/g， respectively， and they were greatly increased after activation. The biochar activated by Na₂CO₃ has the best surface area and pore volume. At the same time， the effects of different mass ratios of Na₂CO₃ and Biochar on the activation of Biochar were studied， and the optimal mass ratio of activation was determined. When mass ratio of Na₂CO₃/Biochar is 3∶1， the synthesized dample（Biochar-Na₂CO₃-3） has the biggest specific surface area and pore volume（624 m²/g and 0.211 cm³/g）， which has excellent adsorption performance of volatile organic compounds（VOCs）. The static n-hexane， toluene and No.92 gasoline adsorption capacities of Biochar-Na₂CO₃-3 are 1.03， 0.814 and 0.751 g/g， respectively. The dynamic n-hexane and toluene adsorption capacities of Biochar-Na₂CO₃-3 are 1.00 and 0.796 g/g， respectively. The adsorption performance is stable， which is better than the commercial activated carbon（AC） and silica gel（SG）.