State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China.
J Environ Sci (China). 2021 Oct;108:96-106. doi: 10.1016/j.jes.2021.02.015. Epub 2021 Mar 2.
Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene (TCE). In this work, the liquid-phase hydrogenation of TCE by Raney Ni (R-Ni) and Pd/C under an open system have been studied, in which nascent H (Nas-H) generated in situ from the cathode acted as a hydrogen source. Experimental results showed that TCE was completely eliminate from the solution through the synergistic effects of hydrodechlorination and air flotation due to the formation of continuous micro/nano-sized Nas-H bubbles from the cathode. Furthermore, the effects of inorganic anions and organic solvents on R-Ni and Pd/C hydrogenation activity were investigated, respectively. The results showed that NO and acetonitrile can form a competitive reaction with TCE; Sulfur with lone-pair electrons will cause irreversible poisoning to these two catalysts, and have a stronger inhibitory effect on Pd/C. This work helps to realize the separation of volatile halogenated compounds from water environment and provides certain data support for the choice of catalyst in the actual liquid-phase hydrogenation system.
水相氢解脱氯是一种很有前途的技术，可用于修复三氯乙烯（TCE）污染的水体。在这项工作中，研究了在开放体系中，Raney Ni（R-Ni）和 Pd/C 对 TCE 的液相氢化作用，其中由阴极原位生成的新生氢（Nas-H）作为氢源。实验结果表明，由于从阴极形成连续的微/纳米级 Nas-H 气泡，协同氢解和空气浮选作用可将 TCE 完全从溶液中去除。此外，还分别研究了无机阴离子和有机溶剂对 R-Ni 和 Pd/C 氢化活性的影响。结果表明，NO 和乙腈可以与 TCE 形成竞争性反应；具有孤对电子的硫会对这两种催化剂造成不可逆的中毒，并且对 Pd/C 的抑制作用更强。这项工作有助于实现挥发性卤代化合物从水环境中的分离，为实际液相氢化体系中催化剂的选择提供了一定的数据支持。
