纳米零价铁氮掺杂碳纳米纤维电化学脉冲法分离废水中的铀

邹景兰; 练紫欣; 滑熠龙

doi:10.16026/j.cnki.iea.2025030181

离子交换与吸附 ›› 2025, Vol. 41 ›› Issue (03) : 181 -189. DOI: 10.16026/j.cnki.iea.2025030181

研究论文

纳米零价铁氮掺杂碳纳米纤维电化学脉冲法分离废水中的铀

作者信息 +

Separation of Uranium from Wastewater by Electrochemical Pulsing with Nano Zero-Valent Iron on Nitrogen Doped Carbon Nanofibers

Author information +

文章历史 +

PDF (1979K)

摘要

纳米零价铁 (nZVI) 具有反应活性强、选择性好、易功能化的特点，是一种优良的铀吸附剂，但其在矿区含铀废水的处理中仍然面临着易氧化、稳定性差和活性位点有限的问题。为了提高其稳定性，同时增加其活性位点，本研究制备了纳米零价铁氮掺杂碳纳米纤维 (nZVI@NCNFs)，并结合更有利的电化学供电方法，优化操作参数来提升其除铀性能。结果表明，本研究所制备的nZVI@NCNFs的抗氧化性和稳定性明显提高；采用电化学脉冲法时，在频率为100 Hz、电位为-0.8 V和0 V交替的条件下，实现了矿区废水中铀的高效提取，6 h内电化学脉冲法的铀去除率可达95%，其吸附速率是同等条件下电化学恒电位法的3倍，是物理化学吸附法的6倍；且nZVI@NCNFs具有良好的长期稳定性，15次循环实验后nZVI@NCNFs材料的铀吸附容量可达729 mg/g。本研究提供了一种电极材料和高效电化学技术相结合的策略，也为其他金属资源的回收提供了参考。

Abstract

Nano-zero-valent iron (nZVI) is an excellent uranium adsorbent due to its outstanding reactivity, selectivity, and tunable functionalizational structure. However, the reactive sites of nZVI particle will be occupied and oxidized by co-existed ions which short its longevity during the treatment of uranium mining wastewater. To address these issues, we encompassed nZVI with nitrogen doped carbon fibers (nZVI@NCNFs) and optimize the parameters of the pulse electrocatalytic method to boost the reactivity of nZVI. The results show that nZVI@NCNFs exhibited remarkable resistance to oxidation and enhanced stability. For example, nZVI@NCNFs performed high uranium extraction reactivity at 100 Hz within the voltage range -0.8 V and 0 V. Under the optimized pulse electrocatalytic parameters condition, 95% uranium was immobilized by nZVI@NCNFs within 6 h, which was three or six times higher than that of the constant potential electrochemical method or the physicochemical adsorption processes, respectively. Furthermore, the uranium adsorption capacity by nZVI@NCNFs was 729 mg/g after 15 cycles. This study provides a valuable reference for the recovery of other metal resources.