Abstract:
Activated carbon adsorbents with rich mesopore were prepared by H
3PO
4 activation method using waste
Zanthoxylum bungeanum branches as biomass raw materials and (NH
4)
2HPO
4 as additive. The physicochemical properties of the prepared activated carbon adsorbents were characterized by SEM, BET, FT-IR, and XRD. The prepared activated carbons were used to evaluate the toluene adsorption-desorption performances in air, and its renewable performance was also evaluated by toluene adsorption-desorption cycles. The addition of (NH
4)
2HPO
4 additive enhanced the pore-forming effects. The abundant gas products in process of the activation pore-forming can open the closed pores to promote pore expansion, and promote the mesoporous structure to be formed in the prepared activated carbon adsorbents. When the addition amount of (NH
4)
2HPO
4 is 1.0%, the specific surface area of the prepared AAC10 adsorbent was 1 082.2 m
2·g
-1, the toluene adsorption amount reached 353.10 mg·g
-1, and the mesopore rate increased by 16.91%. The rich mesoporous structure effectively reduced the toluene desorption resistance, which allowed the corresponding activated carbon adsorbent to achieve the regeneration of toluene adsorption performances at 40 ℃ or even room temperature, and showed good renewable performance.