Functional Polypropylene Nonwoven Fabric Sorbents For Sorption Of Uranyl Tricarbonate Complex

Uranium is the main source for the production of nuclear electricity in the world.It is noticed that uranium sources on land would be exhausted by the end of this century.Meanwhile,there is more than 1000 times of uranium in the oceans than that in the terrestrial ores.It will be enough to supply nuclear power production over the next few centuries if extracted economically.Hence,it is strategically important to develop new materials and techniques for efficient uranium extraction from seawater to guarantee the supply in the future.However,the relatively higher concentration of other coexisting ions than uranium in seawater,and the strong competition of vanadium may diminish the available active sites for uranium,which will reduce the cycle efficiency.In addition,biofouling is another adverse factor influencing the amount of uranium binding to the sorbents,thereby leading to the decrease of sorption capacity.Aiming at these problems,we designed the surface ion-imprinted polypropylene nonwoven fabric for the enhanced selectivity for uranium and efficient antifouling polypropylene nonwoven fabric for potential uranium seawater extraction.Specific studies of this paper are as follows:(1)Surface Ion-Imprinted Polypropylene Nonwoven Fabric for Potential Uranium Seawater Extraction with High SelectivityA novel surface ion-imprinted polypropylene nonwoven fabric was prepared for potential uranium seawater extraction with high selectivity.Specifically,surface ion-imprinted polypropylene nonwoven fabric is prepared by copolymerization of 4-vinylbenzyl chloride and 1-vinylimidazole in the presence of uranyl tricarbonate complex.The sorption can reach the equilibrium with large capacity of 133.3 mg/g within 15 h at pH 8.0 and 298.15 K.The imprinted fabric shows more excellent selectivity towards uranium over vanadium and the other coexisting ions in seawater compared with non-imprinted fabric.In addition,it exhibits good salt-resistant stability and can be regenerated efficiently after five cycles.Therefore,the imprinted fabric may be a promising sorbent for potential uranium seawater extraction.(2)Guanidine-modified Polyamidoxime-functionalized Polypropylene Nonwoven Fabric for Potential Uranium Seawater Extraction with Antifouling PropertyGuanidine-modified Polyamidoxime-functionalized polypropylene nonwoven fabric for potential uranium seawater extraction with antifouling property was reported here.Specifically,glycidyl methacrylate was first grafted onto polypropylene nonwoven fabric under γ-ray irradiation,and then reacted with dicyandiamide,and followed by amidoximation to give the functionalized sorbent.The effect of sorbent dose,contact time and coexisting ions on uranium sorption and antibacterial assay were investigated.0.25 g/L of sorbent dose was selected as the optimum value from the economical point of view.The sorption equilibrium could be reached within 5 h.And the sorption amount for uranium was up to 1.84 mg/g after 4 days exposure in simulated seawater.Antibacterial assay indicated guanidine-modified fabric could efficiently inhibit the adhesion of Gram-negative E.Coli and have the bactericidal function.In addition,it could be regenerated with high efficiency after five cycles.This work indicates that guanidine-modified polyamidoxime-functionalized polypropylene nonwoven fabric may be a promising material for real uranium seawater extraction.