Adsorption-degradation of malachite green using alkali-modified biochar immobilized laccase under multi-methods

Malachite green (MG) is an environmental persistent pollutant. The excellent adsorption capacity and enzyme carrier potential of alkali modified biochar (A-MB) are potential solutions for the treatment of MG. In this paper, laccase was immobilized onto A-MB via multi-immobilization methods. The batch adsorption equilibrium experiments were conducted to study the adsorption behavior of MG on carrier A-MB. The results showed that the adsorption of MG on A-MB followed the pseudo-second-order equa-tion and the Langmuir isotherm model. In addition, A-MB possessed a relatively high qmax (757.58 mg/g) for MG. The comparative experiment was set up to compare the removal rate of MG on free laccase (FL) and immobilized laccase (adsorption method: A/lac@A-MB; adsorption-crosslinking method: A-C/lac@A-MB; covalent binding method: CB/lac@A-MB), the maximum removal rate of FL was 89.68 %, but the max-imum removal rate of A/lac@A-MB, A-C/lac@A-MB and CB/lac@A-MB was 97.70 %, 98.77 % and 97.86 %, respectively.(c) 2022 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Automated summary

This study investigates the potential solution of using alkali modified biochar (A-MB) for the treatment of Malachite green (MG). Laccase was immobilized on A-MB through multi-immobilization methods, resulting in efficient adsorption of MG. The experimental results showed that A-MB had a high maximum adsorption capacity for MG. Compared to free laccase, immobilized laccase exhibited higher removal rates for MG.