Rapid and efficient degradation of tetrahydrofurfuryl alcohol and polyvinyl alcohol in complex organic low-level radioactive wastewater by Fenton oxidation

During the production of UO₂ core fuel elements for high-temperature gas-cooled reactors, a complex organic low-level radioactive wastewater (OLLRW) containing large amounts of tetrahydrofurfuryl alcohol (THFA), polyvinyl alcohol (PVA), and other organics is generated. So it’s urgent to have a pretreatment method to efficiently degrade the large and small molecular organic matters. Therefore, the Fenton continuous oxidation method developed in this study cleverly utilizes the secondary enhanced oxidation of H₂O₂. Compared with the conventional advanced oxidation method, the degradation efficiency of organic matter in simulated wastewater by continuous Fenton oxidation can be doubled, reaching 99.5%. The chemical oxygen demand (COD) of real complex uranium-containing OLLRW was reduced from 18,480 to 979.0 mg L⁻¹. After further oxidative degradation of organic compounds in simulated OLLRW, the COD of wastewater can be reduced to 88.9 mg L⁻¹. This method can effectively mitigate the "toxic" effect of organic matter on adsorption process, thus providing a new idea for the pretreatment of complex OLLRW in high-temperature gas-cooled reactors.