摘要
随着核电的发展,放射性污染物流入环境,污染水土资源。纳米零价铁(nZVI)材料因还原性强、去除效率高等优势,被广泛应用于水资源污染修复。本研究以海藻酸钠(SA)为碳源,采用一步碳热还原法制备碳载零价铁(Fe-CB)材料,并将其用于水溶液中放射性核素U(VI)的去除。采用微观光谱和宏观实验研究Fe-CB对U(VI)的吸附性能和作用机理。研究发现Fe-CB具有丰富的官能团(如–OH和–COOH)及较高的比表面积,弥补了纳米零价铁(nZVI)分散性差和去除效果低的不足。在298 K时,Fe-CB对U(VI)的吸附去除在3 h内达到平衡,最大吸附量为77.3 mg·g–1,是能够自发进行的化学吸附。X射线光电子能谱分析仪(XPS)分析发现Fe-CB对U(VI)的去除主要是通过吸附和还原的协同作用来实现的,吸附过程是U(VI)与Fe-CB发生表面络合,还原过程是通过零价铁的还原性将U(VI)还原成U(IV)。研究结果表明Fe-CB材料可作为优良的吸附剂,在环境污染治理领域具有良好的应用前景。
With the development of nuclear power, radioactive pollutants discharge into the environment and then contaminate soil and water resources. Nanoscale zero-valent iron(nZⅥ) materials are widely used in water remediation due to their strong reducibility and high removal efficiency. A carbon-based zero-valent iron material(Fe-CB) was prepared in this work. Fe-CB was fabricated using sodium alginate(SA) as a carbon source via one-step carbothermic method and then applied to eliminate U(Ⅵ) from aqueous solution. Its mechanism and adsorption properties of Fe-CB and U(Ⅵ) were studied by spectroscopic analyses and macroscopic experiments. The results illustrated that Fe-CB possessed of ample functional groups(such as –OH and –COOH) and high BET surface area, which made up for the dispersibility and low removal efficiency of nanoscale zero-valent iron(nZⅥ). The removal of U(Ⅵ) by Fe-CB achieved equilibrium in 3 h and the maximum sorption capacity was 77.3 mg·g–1 at 298 K. XPS analyses indicated that the U(Ⅵ) removal by Fe-CB was a synergistic effect of reductive adsorptive processes. Adsorption process resulted from surface complexation and the reduction process was dominated by U(Ⅵ) reduction to U(IV) by nZⅥ. The results show that Fe-CB can be used as an inexpensive and highly efficient pollutant scavenger, which has great potential for environment pollution management.
作者
王佳琦
庞宏伟
唐昊
于淑君
朱洪涛
王祥学
WANG Jiaqi;PANG Hongwei;TANG Hao;YU Shujun;ZHU Hongtao;WANG Xiangxue(Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control,Department of Environmental Science and Engineering,North China Electric Power University,Baoding 071003,China;MOE Key Laboratory of Resources and Environmental Systems Optimization,College of Environmental Science and Engineering,North China Electric Power University,Beijing 102206,China;Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory,Southwest University of Science and Technology,Mianyang 621010,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第3期373-380,共8页
Journal of Inorganic Materials
基金
国家自然科学基金(21876048,21906052,21836001)
中央高校基本科研业务费专项资金(2018ZD11,2018MS114)
核废物与环境安全国防重点学科实验室开放基金(17kfhk01)。
关键词
零价铁
碳材料
铀
吸附
还原
zero-valent iron
carbon material
uranium
adsorption
reduction
