The Fukushima Daiichi nuclear disaster, triggered by the earthquake and tsunami on March 11, 2011, resulted in a severe release of radioactive materials, including cesium, from the damaged nuclear reactors. This catastrophe led to partial meltdowns in the reactor cores, releasing a substantial amount of cesium-137 (Cs-137) and cesium-134 (Cs-134) into the environment. Cs-137, with its long half-life and high mobility, poses significant environmental and human health hazards. It contributes to radioactive contamination, leading to soil degradation and ecosystem disruption. At the same time, prolonged exposure increases the risk of cancer, particularly affecting the thyroid, and may cause chronic radiation damage to the immune and reproductive systems.
Removing cesium from radioactive wastewater is challenging due to various factors, including the complex chemical nature of cesium and the large volume of contaminated water generated post-disaster. The choice of removal method must consider factors such as efficiency, cost, and environmental impact. In a recent study by Prof. Shuting Zhuang and Prof. Jianlong Wang, two standard methods for cesium removal, adsorption, and membrane separation, have been extensively reviewed.
Adsorption, mainly using advanced adsorbents, has shown promise in treating radioactive wastewater with low radionuclide concentrations but large volumes. Various materials, including inorganic and organic substances and biological materials, have been explored for Cs+ removal, with hexacyanoferrate notable for its exceptional adsorption capacity and selectivity.
Membrane separation, incredibly reverse osmosis (RO), has emerged as an effective technique for cesium ion separation. RO membranes with smaller pores efficiently retain cesium ions, offering advantages like commercialization, high efficiency, and water fluxes. However, membrane methods generate concentrated retention liquid that requires treatment due to higher concentrations of radioactive nuclides, and prolonged operation poses challenges to the radiation stability of membrane materials.
Continuous research and technological advancements are crucial to developing sustainable and cost-effective methods for treating contaminated water and mitigating the environmental impact of cesium discharge. This ongoing effort aims to address the complex challenges of cesium contamination and contribute to ecological restoration and human health protection.
More information: Shuting Zhuang et al, Cesium removal from radioactive wastewater by adsorption and membrane technology, Frontiers of Environmental Science & Engineering. DOI: 10.1007/s11783-024-1798-1
Journal information: Frontiers of Environmental Science & Engineering Provided by Higher Education Press
