Enhanced Microbial Degradation of Herbicides by Modified Biochar: A Review

The extensive application of herbicides in modern intensive agriculture has led to their persistent residue across multimedia environments, posing severe risks to ecosystem and human health. Among the current methods for removing herbicides, the single microbial remediation approach is often constrained by environmental fluctuations and the toxicity of high-concentration substrates, while the physical adsorption technology has the risks of desorption and secondary pollution. Modified biochar-assisted microorganisms are considered a useful method for efficient degradation of herbicides. This review provides an integrated overview of modified biochar-microbe synergistic remediation systems, covering four major herbicide classes: triazines, glycines, chloroacetanilides, and sulfonylureas. It explicitly proposes an “adsorption-biodegradation” coupling mechanism: modified biochar mitigates microbial toxicity by rapidly reducing herbicide bioavailability through adsorption, while simultaneously serving as a carrier and nutrient source to enhance the degradative activity. Furthermore, the study explores ecological functions such as the improvement of soil microenvironments, the regulation of microbial communities, and the promotion of functional gene expression, providing a theoretical foundation for the green in situ remediation.