Study On Amidoxime Based Charge Balance Anti-fouling Adsorbent For Uranium Extraction From Seawater

As the demand for clean energy transition continues to increase,the installed nuclear power capacity has also increased.The nuclear energy industry is currently one of the most important energy supplies,and uranium is a key basic raw material for the nuclear energy industry.One of the key driving factors affecting the development of nuclear power is the long-term price of fuel,and the long-term price of fuel depends on the supply of uranium.Due to the increase in consumption of onshore uranium resources,the reserves of onshore uranium mines are rapidly decreasing,and onshore uranium resources are very limited.There are about 4.5 billion tons of uranium in the world’s seawater.Obtaining uranium from seawater is considered one of the potential strategies to meet the growing demand for nuclear energy.In recent years,amidoxime-based materials have a special affinity for uranium and have been extensively studied as high-efficiency adsorbents.The adsorbent has the characteristics of large specific surface area,high mechanical strength,and high uranium extraction efficiency.It can be modified by reasonable functional groups and designed into a material with a unique structure.However,in terms of economic benefits and performance,amidoxime-based materials still have much room for improvement.At present,factors such as low uranium concentration in the ocean,competitive metal ions,high salt environment,the form of uranium in seawater,and serious marine pollution have greatly restricted the extraction capacity of uranium.Due to the above factors,the demand for economically and efficiently extracting uranium from seawater cannot be met,and the existence of marine pollution has severely reduced the ability of the adsorbent to extract uranium.Therefore,efforts to resist marine pollution and adhesion have become a key method to improve the efficiency of uranium adsorption.In this study,different ratios of four ethylene five tetraethylenepentamine（TEPA）and negatively charged polyacrylamidoxime（PAO）were crosslinked,and the adsorbent for marine uranium extraction with marine biofouling fouled hydrogel membrane was prepared by coating method.Due to the reduced charge attraction between adsorbent and charged contaminants,the PAO-CB hydrogel film exhibits high resistance to marine fouling,including biological fouling and non-biological fouling.The PAO-CB hydrogel film has higher mechanical strength and exhibits a tensile strength of 18.91 MPa at break.This high mechanical strength is higher than most PAO based adsorbent,which will be beneficial to the practical application of PAO-CB in the ocean.Due to the stable covalent bond structure between PAO and TEPA,PAO-CB adsorbent also has high reusability and anti adhesion ability.The PAO-CB hydrogel membrane showed a high uranium extraction capacity of 8.4 mg g^-1 in real seawater,which was 44.59%higher than that of PAO hydrogel membrane.The results show that the construction of charge balance adsorbent is an effective method to control the complex marine fouling in the process of uranium extraction from seawater,which provides a new research method in the field of uranium extraction from seawater.