Effects of co-modified biochar immobilized laccase on remediation and bacterial community of PAHs-contaminated soil

Considering the stability and economy of immobilized enzymes, this study prepared co-modified biochar immobilized laccase product named Fe 3 O 4 @ [email protected] @LC via orthogonal experimental design and explored its possibility of remediating polycyclic aromatic hydrocarbons (PAHs) contaminated soil in steel plants. Compared with the free laccase treatment, the relative activity of Fe 3 O 4 @ [email protected] @LC remained 60 % after 50 days of incubation at room temperature. The relative activity of Fe 3 O 4 @ [email protected] @LC could still retain nearly 80 % after five reuses. In the process of simulating the PAHs-contaminated site treatment experiment in Hangzhou Iron and steel plant, immobilized laccase exhibited efficient adsorption and degradation performances and even the removal rate of 5-ring PAHs reached more than 90 % in 40 days, resulting in improving urease activity and dehydrogenase in the soil and promoted the growth of a PAH degrading bacteria ( Massilia ). Our results further explained the efficient degradation effects of Fe 3 O 4 @ [email protected] @LC on PAHs, which make it a promising candidate for PAHs-contaminated soil remediation.