North China Electric Power University’s innovative solutions for Fukushima radioactive water crisis

Japan's recent announcement of its plan to release more than 1.2 million tons of radioactive water into the Pacific Ocean has triggered global environmental concerns. The radioactive water in question was generated by the cooling process employed to decommission the Fukushima Daiichi nuclear power plant, in the aftermath of the catastrophic 2011 Fukushima nuclear incident. Despite being treated by an advanced liquid processing system (ALPS), the water is still reported to carry hazardous radioactive materials or radionuclides which may be active and have long half-lives (effectively taking a long time to disintegrate), thereby posing a significant threat to ecosystems and human health globally.

Conventional materials like clay minerals, activated carbon, carbon nanotubes, and resins have been used for radionuclide removal, but are limited by their slow adsorption kinetics, poor selectivity, and low adsorption capacity. As a result, researchers are now exploring advanced nanomaterials like porous organic polymers (POPs), metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and porous aromatic frameworks (PAFs) for this purpose. These materials possess a high specific surface area, abundant pore structures, exceptional stability, and design flexibility, making them promising candidates for radionuclide removal.

Taking this forward, a research team led by Professor Xiangke Wang from North China Electric Power University, Beijing, P. R. China is at the forefront of these efforts to design nanomaterials and technologies that can remove radionuclides from the environment. In their recent review article published in the journal Eco-Environment & Health, they shed light on this emerging research, higher requirements for nanomaterial design, and the implementation of strategies and strengthened cooperation required to mitigate any harm caused to aquatic and land ecosystems. Speaking about the motivation behind their extensive review, Prof. Wang says, “We intend to create high-performance porous materials and technologies for the efficient removal of radionuclides from practical environments, as well as a reserve of advanced materials and technologies that can be used or further developed to deal with future nuclear accidents.”

Of the various technologies being explored, electrocatalysis has emerged as a next-generation solution that offers a continuous extraction of radionuclides through reduction or oxidation using electric fields. It is considered a promising approach for sewage treatment owing to its controllability, efficiency, and environmental friendliness. This technology has also been shown to effectively extract uranium from seawater, thereby highlighting its promise. Adsorption also stands out due to its low cost, simplicity, and practicality. The key to successful adsorption is the design of efficient adsorbents with rich functional sites, large specific surface areas, and high stability. Additionally, adsorption-photocatalysis systems have emerged as a viable approach for selective and efficient radionuclide removal. Photocatalytic technology activates catalysts through light field resources, offering an eco-friendly, low-cost, and efficient solution. Researchers have achieved impressive uranium extraction capacities under visible light irradiation by introducing photo-active sites into nanomaterials such as COFs.

While these technologies and materials look promising, there are several challenges that must be addressed to fully harness their potential. These include the complexities of radionuclide forms in practical environments, the need for simpler and eco-friendly material preparation processes, the exploration of collaborative technology systems, a need for deeper understanding of material structures and radionuclide capture mechanisms, and the recycling of resource nuclides.

Looking ahead, Prof. Wang hopes that this research will attract the interest of a wide range of researchers and raise concerns about material design and technology improvement for radionuclide removal. “The ultimate goal is to apply these nanomaterials and technologies in real-world environmental conditions to promote sustainable development and safeguard our planet from the threats of radioactive contamination” Prof. Wang concludes.

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Reference

DOI: https://doi.org/10.1016/j.eehl.2023.09.001

Authors: Xiaolu Liu, Muliang Xiao, Yang Li, Zhongshan Chen, Hui Yang, and Xiangke Wang

Affiliations: MOE Key Laboratory of Resources and Environmental System Optimization, North China Electric Power University, Beijing, P. R. China

About Professor Xiangke Wang from North China Electric Power University (NCEPU)

Dr. Xiangke Wang has authored 500+ peer-reviewed articles, including 30+ invited reviews in professional journals. Dr. Wang's research covers radionuclide environmental behavior, heavy metal and organic pollutant management, and wastewater treatment using nanomaterials and clay minerals. His current work explores plasma techniques and nanomaterials for radioactive pollution control.