Occurrence sources and remediation strategies of uranium contamination in water
摘要
Uranium (U) is a naturally occurring radioactive element extensively used in nuclear fuels and industrial processes. However, its dual radiological and chemical toxicity poses severe risks to ecosystems and human health, with strong associations with bone and liver cancer. The growing reliance on nuclear energy has increased the demand for efficient uranium recovery and remediation strategies to ensure both environmental safety and sustainable energy supply. This review assessed the sources of uranium contamination and examined conventional with emerging removal technologies, integrating quantitative performance with mechanistic understanding. Adsorption remains the most widely investigated approach, with phosphate-functionalized layered double hydroxides (~ 925 mg/g), functionalized graphene oxide (~ 935 mg/g), and modified Mg/Al-LDH (~ 330 mg/g). Metal-organic frameworks offer optimizable surface functionalities and photoactive removal, utilizing TiO2 nanotubes with an 89% reduction of U(VI) to U(IV) under visible light. Electrocoagulation using iron anodes modified with organic ligands removed 99.65% U(VI). Membrane-based processes (nanofiltration, reverse osmosis) achieve > 95–99% removal. Bioremediation approaches (bioleaching, biosorption, and microbial bioreduction) also exhibit high efficiencies, with chitin- and chitosan-based sorbents achieving ~ 312 mg/g, algae and fungi exceeding 500 mg/g removal capacity, microbial biofilms enabling > 95% U(VI) reduction, and plants demonstrating substantial uranium uptake. These findings underscore laboratory-scale progress, yet highlight challenges in fouling, geochemical stability, and scalability. Future research should address the safe management of transformed uranium, the impacts of toxicity, bioleaching kinetics, microbial bioreduction, and phytoremediation pathways, as well as mitigate toxic byproducts like uraninite, to achieve sustainable field-scale remediation.