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Updated: Jan 6, 2026
Physical, Chemical and Biological Characterization of Six Biochars Produced for the Remediation of Contaminated Sites
Published on: November 28, 2014
Magnetic biochar derived from biosolids via hydrothermal carbonization: Enzyme immobilization, immobilized-enzyme
1College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, PR China; Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
Abstract:
Magnetic and nonmagnetic biochar (MBC & BC) were produced from biosolids under hydrothermal conditions and characterized in order to understand surface chemistry impacts on enzyme immobilization and activity. Peak surface pore size of MBC was 180 nm and that of BC was 17 nm. Despite similar surface area (≈ 49 m2/g) MBC immobilized more laccase (99 mg/g) than biochar (31 mg/g). For horseradish peroxidase (HRP), the two biochars had similar immobilization capacity (≈ 65 mg/g). Laccase and HRP on MBC had 47.1 and 18.0% higher specific activity than on BC, respectively. The matrix activity of MBC-laccase (33.3 U/mg support) was 3.7-fold higher than BC-laccase (8.8 U/mg support) and higher than the same amount of free laccase (30.2 U) at pH 3.0 (P < 0.05). Although MBC had its own peroxide oxidation activity (104.1 and 165.9 U/mg biochar at pHs 5&6) this only accounted for 16.7 and 20.4% of the total MBC-H RP activity respectively. After 10 wash cycles, MBC still retained 79.3% and 60.3% of laccase and HRP activity, respectively. Additionally, MBC had lower acute toxicity, suggesting that it is relative benign from an environmental perspective.
