Navigating soil microbiota shifts to organic pollutants: Insights into the roles of nZVI-biochar in soil ecosystem restoration

Abstract

Soil microbial communities are essential for nutrient cycling, contaminant degradation, and ecosystem sustainability. However, increasing contamination from organic pollutants, including polycyclic aromatic hydrocarbons (PAHs), per- and polyfluoroalkyl substances (PFASs), pesticides, and antibiotics, has led to significant disruptions in soil microbiota, reducing microbial diversity, altering community structures, and impairing enzymatic functions. Despite various remediation strategies, challenges persist in restoring soil health while minimizing the adverse ecological impacts. This review highlights the emerging potential of nano-zero-valent iron-supported biochar (nZVI-BC) as a novel remediation approach that offers synergistic adsorption, catalytic degradation, and microbial community restoration capabilities. While previous reviews have predominantly focused on inorganic contaminants, this review uniquely emphasizes the effects and remediation of organic pollutants, filling a critical knowledge gap. Unlike conventional methods, nZVI-BC enhances microbial diversity, enzyme activity, and the abundance of functional genes while mitigating pollutant toxicity. This review systematically explored the mechanisms by which nZVI-BC influences microbial responses and adaptations, emphasizing shifts in community composition, enzymatic activities, and functional gene expression under organic pollutant stress. Furthermore, it evaluated the application of nZVI-BC in remediating pesticides, antibiotics, PFAS, and PAHs, positioning it as a sustainable and efficient strategy for soil ecosystem restoration. Ultimately, this review provides critical insights into the role of nZVI-BC in mitigating the ecological risks of organic contaminants, thereby offering a path toward improved soil health and long-term environmental sustainability.