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.