Hao Li,Ningning He,Chong Cheng,Hao Dong,Jun Wen,Xiaolin Wang
Uranium extraction from seawater is a long-term process, in which biofouling caused by marine bacteria drastically decreases the properties of adsorbents. All reported antimicrobial uranium adsorbents are prepared with inorganic nanoparticles or single-molecule antibiotics, which possess poor antimicrobial, durability and adsorption performances. Herein, an antimicrobial polymer contained uranium adsorbent is prepared for the first time. The introduction of antimicrobial polymer endows the adsorbent with efficient and stable antimicrobial activity, as well as enhanced adsorption performance and good hydrophilicity attributed to plentiful amine groups. It possesses an inhibition rate up to 99.46% against marine bacteria at a high concentration (10 8 CFU mL −1 ), and a saturation uranium adsorption capacity of 684.3 mg g −1 (pH 8.0, 25 °C). Note that negligible degradation is observed in antimicrobial (>99%) and adsorption (>92%) tests after five cycles, indicating its great durability. Furthermore, as the first antimicrobial adsorbent used in marine tests, the kilogram-grade adsorbent performs excellent comprehensive property in 40-day marine tests. These results suggest that antimicrobial polymer contained adsorbent is a promising candidate for efficient uranium extraction from seawater.
Wangzhi Chen,Jieyao Wang,Xiaogeng Lin,Xingyu Ma,Bo Lin,Xiaoxuan Dai,Lei Li
The preparation of highly selective and cost-effective uranium adsorbents still remains challenging. Amidoxime-based adsorbents are well known for their targeting effects on uranyl ions. However, the formation of amidoxime groups requires the use of toxic cyanides. In this work, a family of amidoxime-based uranium adsorbents derived from asphalt has been prepared successfully with a cyanide-free strategy. Hypercross-linked asphalt polymers (HAPs) were prepared by using formaldehyde dimethylacetal as the external cross-linker. Then, cyano groups were grafted onto HAPs via the reaction with dichloromethyl methyl ether, followed by the treatment with aqueous ammonia and iodine. Eventually, the cyano groups were converted into amidoxime groups with hydroxylamine to obtain uranium adsorbents (HAP-AOs). The optimum cyanation reaction parameters and HAPs have been screened, and the optimal HAP-AO exhibits a maximum absorption capacity of 485 mg g–1 with high selectivity and excellent recyclability. It should be noted that this preparation procedure of uranium adsorbents can be further extended to other raw materials containing aromatic rings, including coal tar, coumarone-indene resin, and toluene. This work not only provides a cyanide-free strategy for preparing amidoxime-based adsorbents but also sheds light on the value-added utilization of massive byproducts of the petrochemical industry in a sustainable development protocol.
危险品化学品经营许可证（带存储）