Highly efficient and ultra-rapid adsorption of malachite green by recyclable crab shell biochar

In this study, waste crab shell was hydrothermally carbonized and then activated to prepare an effective and recyclable adsorbent. The adsorption performance of the adsorbent for different dyes was investigated through adsorption experiments, and the results showed that it had the largest adsorption performance for malachite green. Furthermore, the adsorption performance and mechanism of malachite green were investigated by static and dynamic adsorption method. The crab shell biochar could remove 6142.5 mg g(-1) of malachite green within 3 minutes, indicating that the crab shell biochar could ultrarapid and highly efficient adsorb malachite green. In addition, the malachite green adsorbed on the crab shell biochar could be removed by calcination, which achieved the entire regeneration of the crab shell biochar. The adsorption of malachite green by crab shell biochar adsorbent conformed to the pseudo-second-order kinetic model, the Dubinin-Radushkevich and Langmuir isotherm adsorption model. Physical and chemical characterization indicated that the adsorption mechanism of malachite green included alkaline fading effect, hydrogen bonding and pi-pi interaction. (c) 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, waste crab shell was hydrothermally carbonized and activated to prepare an effective and recyclable adsorbent. The adsorbent exhibited the highest adsorption performance for malachite green. The adsorption mechanism involved alkaline fading effect, hydrogen bonding, and pi-pi interaction, and the adsorption process followed the pseudo-second-order kinetic model and the Dubinin-Radushkevich and Langmuir isotherm adsorption model. The crab shell biochar could rapidly and efficiently adsorb malachite green and could be regenerated through calcination.