Fabrication of porous carbon derived from cotton/polyester waste mixed with oyster shells: Pore-forming process and application for tetracycline removal

摘要

Porous carbon was fabricated from cotton/ polyester-based textile wastes as a carbon source coupled with oyster shells for tetracycline removal. The preparation conditions were optimized and detailed characterization was conducted to study the effects of oyster shells on cotton/polyester pyrolysis. The optimal pyrolysis temperature (900 degrees C), pyrolysis time (1 h) and mass ratio (OS/CPW of 1:1) were determined using the Box-Behnken experiment. The best porous carbon reached a surface area of 645.05 m(2)/g. Oyster shells acted as templates to produce cotton/polyester-based porous carbon and a possible poreforming process was proposed. CaO was converted from CaCO3, which played the dominant role in developing the mesoporous structure. CO2 gas released from CaCO3 promoted the creation of micropore structure. In addition, the impurites of oyster shells acted as the dispersing agent inhibiting CaCO3 and CaO aggregation and growth. Fe2O3 and K2O from impurities reacted with the carbon skeleton to increase microporosity. Finally, the well-developed and uniform porous carbon was obtained. The first-pseudo order model and Langmuir isotherms were suitable. The maximum adsorption capacity of PC-OS -900 was 515.17 mg/g which competed with other waste-based adsorbents. The TET adsorption mechanism was related to pore distribution, hydrogen bonds, pi-pi EDA interactions and electrostatic interactions. (C) 2020 Elsevier Ltd. All rights reserved.