Phytoremediation of organic pollution using leguminous plants and auxiliary additives: principles and advantages

Organic pollution, particularly persistent organic pollutants (POPs), pose significant threats to the natural environment and human health. Bioremediation, especially phytoremediation, has emerged as a promising approach for degrading organic pollutants due to its cost-effectiveness and environmental sustainability. Legumes are widely used in phytoremediation because of their well-developed root systems and symbiotic rhizosphere microorganisms. This review provides a comprehensive overview of the efficiency and mechanisms of legume-based phytoremediation, along with the role of auxiliary additives in addressing organic pollution. These additives include microorganisms, other plants, and additional substances (including bioactive substances, secondary metabolites and inactive additives). Legumes can effectively increase degradation rates, especially for pesticides and polycyclic aromatic hydrocarbons (PAHs), across various timeframes (15–180 days) and environmental conditions (water, synthetic soil, or field soil). Auxiliary additives further facilitate this process through different mechanisms. Intercropping systems that integrate legumes with other plants promote soil health and enable gradual yet cost-effective biodegradation. Microorganisms and plants can work synergistically to achieve co-degradation through three potential pathways, while additional substances contribute to soil health and simultaneously enhance pollutant biodegradation. Each of these approaches offers specific advantages. Additionally, a sustainable cycle involving legumes, crops, and additional substances could be established for long-term reuse. These findings provide valuable evidence and guidance for legume-based phytoremediation, offering insights and hypotheses for future research on biodegradation mechanisms.

Graphical Abstract