Business cost concern of solid CO 2 adsorbents has motivated the production of porous activated carbons from waste biomass materials. In this work, porous activated carbons were prepared from sugarcane bagasse using different activating agents (air, CO 2 , H 3 PO 4 and NaOH). Chemically activated porous carbons exhibited better physicochemical properties as compared to the physically activated carbons. Particularly, NaOH-activated carbon (CAC-S) featured a high specific surface area (1149 m 2 /g) and a large pore volume (1.73 cm 3 /g). X-ray photoelectron spectroscopy (XPS) analysis confirmed that the CAC-S adsorbent exhibited enhanced total basicity. The desired CAC-S adsorbent showed superior isothermal CO 2 uptakes of 5.50 and 4.28 mmol CO 2 /g at 0 °C and 25 °C and 1 bar. The isosteric heat of adsorption was predicted as 43.96 kJ/mol from the Clausius-Clapeyron equation and Toth model, which indicated intensified interaction between CO 2 molecules and the basic carbon surface. The excellent CO 2 adsorption performance should be associated with the improved textural properties and enriched surface basicity benefited from NaOH activation. Overall, CAC-S is considered as a promising adsorbent for CO 2 adsorption. The recycling of sugarcane bagasse as solid CO 2 adsorbents presents environmental implications with respect to waste management and pollutants mitigation.
The effective utilization of biomass waste for the fabrication of biochar adsorbents has aroused significant interest. In this work, a novel hierarchical porous biochar (HPBC) was successfully synthesized by dry mixing combined with one-step pyrolysis method using cucumber straw as a raw material and NaOH as an activator. The prepared HPBC was then applied to remove doxycycline (DOX) from aqueous solutions. HPBC comprised hierarchical porous structures with excellent specific surface area (1409.75 m 2 g −1 ), high pore volume (0.6549 cm 3 g −1 ), and small average pore diameter (1.8582 nm). HPBC was found to contain multiple functional groups involving hydroxyl, carbonyl, amine, and aromatic structure. The adsorption kinetics and isotherm of DOX on HPBC were well described by the Avrami fractional order model and Sips model, suggesting that the adsorption process involved multiple kinetics as well as monolayer and multilayer adsorptions. HPBC exhibited an excellent adsorption capacity for DOX with the maximum value of 552.30 mg g −1 at 25 °C (Sips model). The possible adsorption mechanisms of DOX on HPBC included pore filling, π-π interactions, hydrogen bonding, and electrostatic interactions. This study provided a new approach for resource utilization of straw waste and effective removal of antibiotics from water.
危险品化学品经营许可证（带存储）