Biogene-derived aerogels for simultaneously selective adsorption of uranium(VI) and strontium(II) by co-imprinting method

Recovery of multiple radionuclides from radioactive effluents is extremely important for either environmental protection or sustainable development of nuclear energy. In this work, we report a strategy of simultaneously selective removal of uranium(VI) and strontium(II) from simulative highly saline low level radioactive effluents employing co-imprinting method. Specifically, a novel aerogel (U/Sr-IP) is imprinted with uranium(VI) and strontium(II) from biogenic dopamine and sodium alginate. The aerogel shows better selectivity for uranium(VI) and strontium(II) against other cations compared with non-imprinted polymer. The maximum adsorption capacities are calculated from Langmuir models to be 317 and 160 mg/g for uranium(VI) and strontium(II), respectively. Simultaneously selective adsorption of uranium(VI) and strontium(II) saves the time and space in dealing with complex radioactive wastewater. Noteworthily, when the concentration of sodium chloride (1 mol/ L) is five times than that of radioactive effluents, 83% of the adsorption capacity is maintained even after 5 recycles. After the adsorption, uranium(VI) and strontium(II) are eluted by Ca(NO3)2 and Na2CO3 successively, which makes the aerogel more practical by sequential elution. The prepared U/Sr-IP is an efficient and competitive adsorbent in harsh environment, displaying a promising application in removal of radionuclides from highly saline low level radioactive effluents. This work demonstrates a concept of simultaneously selective adsorption of two or more radionuclides for the first time.

Automated summary

The study developed an aerogel using a co-imprinting method for the simultaneous selective removal of uranium(VI) and strontium(II) from radioactive effluents. The aerogel showed excellent adsorption performance in highly saline low level radioactive effluents, and has promising applications in the field.