Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA.
Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, Tempe, AZ, USA.
J Hazard Mater. 2022 Feb 5;423(Pt A):127055. doi: 10.1016/j.jhazmat.2021.127055. Epub 2021 Aug 31.
Nitrated energetics are widespread contaminants due to their improper disposal from ammunition facilities. Different classes of nitrated energetics commonly co-exist in ammunition wastewater, but co-removal of the classes has hardly been documented. In this study, we evaluated the catalytic destruction of three types of energetics using palladium (Pd) nano-catalysts deposited on H-transfer membranes in membrane catalyst-film reactors (MCfRs). This work documented nitro-reduction of 2,4,6-trinitrotoluene (TNT), as well as, for the first time, denitration of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and pentaerythritol tetranitrate (PETN) over Pd at ambient temperature. The catalyst-specific activity was 20- to 90-fold higher than reported for other catalyst systems. Nitrite (NO) released from RDX and PETN also was catalytically reduced to dinitrogen gas (N). Continuous treatment of a synthetic wastewater containing TNT, RDX, and PETN (5 mg/L each) for more than 20 hydraulic retention times yielded removals higher than 96% for all three energetics. Furthermore, the concentrations of NO and NH were below the detection limit due to subsequent NO reduction with > 99% selectivity to N. Thus, the MCfR provides a promising strategy for sustainable catalytic removal of co-existing energetics in ammunition wastewater.
硝态含能物质是广泛存在的污染物，因为它们在弹药设施中的不当处理。不同类别的硝态含能物质通常共同存在于弹药废水中，但对它们的共同去除很少有文献记载。在这项研究中，我们评估了钯（Pd）纳米催化剂在膜催化剂-膜反应器（MCfR）中沉积在 H 转移膜上对三种含能物质的催化破坏。这项工作记录了 2,4,6-三硝基甲苯（TNT）的硝基还原，以及六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）和季戊四醇四硝酸酯（PETN）在环境温度下首次进行的脱氮。催化剂的比活性比其他催化剂体系报道的高 20 到 90 倍。RDX 和 PETN 释放的亚硝酸盐（NO）也被催化还原为氮气（N）。连续处理含有 TNT、RDX 和 PETN（每种 5mg/L）的合成废水超过 20 个水力停留时间，所有三种含能物质的去除率均高于 96%。此外，由于随后的 NO 还原具有>99%的 N 选择性，NO 和 NH 的浓度均低于检测限。因此，MCfR 为可持续催化去除弹药废水中共存的含能物质提供了一种有前途的策略。
