石墨烯气凝胶对四溴双酚A的吸附研究

为了解决石墨烯吸附剂在水中易团聚、流失及难以回收利用的问题，以NaHSO3为还原剂，通过化学还原自组装的方法制备了石墨烯气凝胶吸附剂（S-RGA）. 采用SEM和BET对S-RGA和其孔径进行了表征，结果表明S-RGA是具有细密均匀多孔的块状结构体，比表面积达到98.37m2/g，平均孔径为7.48 nm. S-RGA对四溴双酚A（TBBPA）的吸附研究结果表明，S-RGA对TBBPA有较高的吸附容量和较好的重复利用率，在初始TBBPA质量浓度为0.25 mg/L时，随吸附剂的量增加，S-RGA的吸附容量先增加后减少，当吸附剂的量为15 mg/L时，达到最大吸附效率；当溶液pH＞7，随着pH的增大，由于S-RGA与TBBPA之间的静电斥力作用，其吸附容量随之减少；S-RGA对 TBBPA的吸附也受离子强度影响，随着离子强度的增大，其吸附容量呈现先减少后增加的趋势. S-RGA对TBBPA吸附过程符合准二级动力学和Freundlich吸附等温线，经过5次循环吸附试验，S-RGA对TBBPA吸附容量仅损失6.83%.

Adsorption of Tetrabromobisphenol-A by Graphene Aerogels

In order to solve the problem that the graphene adsorbent was easy to be agglomerated, lost and difficult to be recycled in water, graphene aerogels adsorbent (S-RGA) was prepared by chemical reduction self-assembly with NaHSO3 as reductant. S-RGA and its pore size were characterized by SEM and BET. The results showed that S-RGA was a massive, homogeneous porous structure with a specific surface area of 98.37 m2/ g and an average pore size of 7.48 nm. The adsorption of tetrabromobisphenol A (TBBPA) by S-RGA was studied by parallel adsorption test. The results showed that S-RGA had higher adsorption capacity and better recycling of TBBPA. The adsorption capacity of S-RGA increased first and then decreased with the increase of the amount of adsorbent at the initial TBBPA concentration of 0.25 mg/L. When the amount of adsorbent was 15 mg/L, the maximum adsorption efficiency was obtained. When the solution pH 7, the adsorption capacity decreased with the increase of pH, due to the electrostatic repulsion between S-RGA and TBBPA. The adsorption of TBBPA by S-RGA was also affected by the ionic strength. With the increase of ionic strength, the adsorption capacity of S-RGA increased first and then increased. The adsorption of TBBPA by S-RGA was in accordance with pseudo-second-order kinetics and Freundlich adsorption isotherm. After five cycles of adsorption, S-RGA lost only 6.83% of TBBPA adsorption capacity.