Invasive plant-derived biochar for sustainable bioremediation of pesticide contaminated soil

Managing invasive plant presents a significant challenge to both the environment and the economy. There is an opportunity to address this issue by utilizing invasive plants as a sustainable and cost-effective source of valuable functional materials for environmental remediation. In this study, a promising Mikania micrantha biochar (MB) was synthesized by pyrolyzing an invasive plant, which was utilized for bacterial immobilization and adsorption of contaminants. By embedding Proteus terrae ZQ02-MB within a polyvinyl alcohol-sodium alginate gel to create a biochar-modified bacterial microsphere (BBM), the superior degradation of pesticide contaminants was observed. Taking chlorothalonil (CHT) as an example, field experiments demonstrated that BBM achieved a removal efficiency of 59.8% by the third day. Additionally, BBM not only improved the richness and diversity of soil bacteria but also enhanced the microbial community structure by the seventh day. On this basis, the adsorption capacity of MB, biofilm growth promoting ability of BBM, and the CHT mineralization ability of strain ZQ02 were validated as a joint mechanism to promote efficient CHT removal. Overall, this study proposes a composite model of invasive plant-derived biochar loaded microorganisms, which has great potential in eliminating pollutant residues and paves new paths to develop strategies for reusing invasive species resources.