Plutonium (Pu), an anthropogenic actinide with extreme radiotoxicity and chemotoxicity, derives mainly from nuclear weapons testing, accidents, and legacy waste disposal. Its environmental mobility and long-term fate are controlled by coupled interfacial reactions and biogeochemical cycling in soils, sediments, and aquatic systems. This review integrates recent advances in Pu sources, speciation, and distribution, with emphasis on adsorption-desorption at mineral-water interfaces, redox transformations across Pu(III/IV/V/VI) states, and colloid/nanoparticle-facilitated transport. Critical controls (pH, redox potential (Eh), dissolved organic matter, Fe/Mn (hydr)oxides, and microbial activity) are systematically evaluated. Microbial redox cycling, biological uptake, and immobilization pathways are shown to profoundly influence Pu speciation and transfer across environmental compartments. A unified conceptual model is presented to link interfacial processes with biogeochemical cycling under varying geochemical and climatic conditions. Current remediation technologies are critically assessed, revealing limitations and emerging interface- and microbe-targeted strategies. This synthesis provides a mechanistic framework for enhanced predictive modeling, risk assessment, and sustainable management of Pu-contaminated sites worldwide.
Zhang et al. (Tue,) studied this question.