Preparation And Study Of Adsorption Properties Of Antibiofouling Uranium Adsorbent ZIF-90

As one of the novel sustainable energy,nuclear energy has been developed rapidly in recent years.However,the process of development and utilization of nuclear energy will produce a mass of nuclear wastewater which contains uranium with strong radioactivity and high biological toxicity.Besides,U（Ⅵ）has a long half-life,which would cause lasting environmental pollution.In addition,once U（Ⅵ）is absorbed by the human body,it will seriously threaten human life and health.Therefore,it is urgent to find a reasonable way to deal with radioactive nuclear wastewater.Adsorption method has been widely applied for the removal of U（Ⅵ）from nuclear wastewater due to its many advantages in recent years.Therein,uranium adsorption materials are the key to remove uranium from wastewater,which requires both high specific surface area and selective coordination groups.In this paper,a series of highly efficient,selective and recyclable uranium adsorption materials were prepared by combining metal organic frameworks with oxime groups and amidoxime groups.1,Oxime-functionalized adsorption material（ZIF-90-OM）was prepared by the reaction of ZIF-90 with hydroxylamine hydrochloride.The synthesized materials were characterized by FT-IR,SEM,TEM,XRD,TG and BET.The results show that the synthesized ZIF-90 has uniform morphologies and the crystal structure of raw ZIF-90 is not damaged during the post-modification process.The results of uranium adsorption experiments show that ZIF-90-OM has a high adsorption capacity for U（Ⅵ）in aqueous solution,and its uranium adsorption capacity reached 485.2 mg·g^-1.The cyclic tests show that the adsorbent ZIF-90-OM has good regeneration performance.In addition,XPS analysis results indicated that the oxime group played an important role in the process of uranium adsorption.The antimicrobial results showed that the MICs of ZIF-90-OM against S.aureus and E.coli was60μg/m L,indicating that ZIF-90-OM had good antibiofouling property.2,We used diaminomeonitrile and malononitrile as reaction materials,and grafted cyanide groups onto ZIF-90 through imidization reaction and Knoevenagel reaction.Then the amidoxime functionalization reaction was carried out to prepare two kinds of highly efficient uranium adsorbents:ZIF-90-AO-1 and ZIF-90-AO-2.The results showed that although the specific surface area of amidoxime functionalized ZIF-90 decreased,they still maintained good pore structure and crystal structure.The adsorption results showed that both adsorbents exhibited excellent uranium adsorption properties(the maximum adsorption capacity was 324.8 mg·g^-1 for ZIF-90-AO-1 and 382.3 mg·g^-1 for ZIF-90-AO-2).In addition,these two adsorbents ZIF-90-AO-1 and ZIF-90-AO-2 also showed good cyclic regeneration performance.XPS analysis results showed that amidoxime groups in adsorbents participated in the coordination with uranyl ion.The antimicrobial experiments showed that both ZIF-90-AO-1 and ZIF-90-AO-2 had good bactericidal effect.More importantly,the adsorption capacity of ZIF-90-AO-1 and ZIF-90-AO-2 for U（Ⅵ）didn’t decrease significantly in the uranium solution containing bacteria.Therefore,ZIF-90-OM,ZIF-90-AO-1 and ZIF-90-AO-2 can be regarded as highly efficient and recyclable uranium adsorbents with good antibiofouling properties,and have good application prospects for the removal of uranium from wastewater.