Gawel Alina, Sühnholz Sarah, Georgi Anett, Kopinke Frank-Dieter, Mackenzie Katrin
Evonik Operations GmbH, Process Technology & Engineering, Paul-Baumann-Str. 1, D-45772 Marl, Germany.
Helmholtz-Center for Environmental Research - UFZ, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany; Intrapore GmbH, Katernberger Str. 107, D-45327 Essen, Germany.
J Hazard Mater. 2023 Oct 5;459:132125. doi: 10.1016/j.jhazmat.2023.132125. Epub 2023 Jul 22.
Nitroaromatic compounds (NACs) are prominent explosives. In this context, these toxic substances were released into the environment and cause long-lasting groundwater contamination. In preparation of a possible in-situ remediation, colloidal Fe-zeolites were investigated for their capabilities as adsorbents and oxidation catalysts. It was shown that the Fe-zeolites FeBEA35 and FeFAU55 are potent inorganic adsorbents for NACs and simultaneously capable of activating HO as Fenton-like oxidation catalysts. Adsorption isotherms of 15 NACs on both zeolites were measured to evaluate the option of coupling adsorptive contaminant enrichment with oxidative degradation. The faujasite-type zeolite FeFAU55 showed a distinct S-type adsorption behaviour and reached significantly higher NAC loadings of > 20 wt%. For FeBEA35, L-type adsorption isotherms and maximum loadings q of about 4 wt% were obtained. Degradation of all NACs, monitored by nitrate formation, was observed. Apparent rate constants of the NACs with hydroxyl radicals in a homogeneous, stoichiometric Fenton reaction were related to the heterogeneous system to examine the role of adsorption on the oxidative degradation. Beneficial influence of the adsorption on the oxidation rates was identified. The results of this work open up promising prospects for future application of Fe-zeolites for the in-situ remediation of NAC-contaminated groundwater.
硝基芳香族化合物（NACs）是一类重要的炸药。在这种情况下，这些有毒物质被释放到环境中，导致地下水长期污染。在准备可能的原位修复时，研究了胶体铁沸石作为吸附剂和氧化催化剂的性能。结果表明，铁沸石FeBEA35和FeFAU55是NACs的有效无机吸附剂，同时能够作为类芬顿氧化催化剂活化羟基自由基（HO）。测定了15种NACs在两种沸石上的吸附等温线，以评估将吸附性污染物富集与氧化降解相结合的可能性。八面沸石型铁沸石FeFAU55表现出明显的S型吸附行为，NAC负载量显著更高，超过20 wt%。对于FeBEA35，获得了L型吸附等温线和约4 wt%的最大负载量q。通过硝酸盐生成监测，观察到所有NACs的降解。在均相、化学计量的芬顿反应中，NACs与羟基自由基的表观速率常数与非均相体系相关，以研究吸附在氧化降解中的作用。确定了吸附对氧化速率的有益影响。这项工作的结果为铁沸石未来用于原位修复受NAC污染的地下水开辟了广阔前景。
