caa a22 4500 605511918 CHVBK 20210128100653.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00894-015-2603-7 doi (NATIONALLICENCE)springer-10.1007/s00894-015-2603-7 Analysis of degradation mechanism of disperse orange 25 in supercritical water oxidation using molecular dynamic simulations based on the reactive force field [Elektronische Daten] [Jinli Zhang, Jintao Gu, You Han, Wei Li, Zhongxue Gan, Junjie Gu] 4-[N-(2-cyanoethyl)-N-ethylamino]-4′-nitroazo-benzene (disperse orange 25, DO25) is one of the main components in dyeing wastewater. In this work, supercritical water oxidation (SCWO) process of DO25 has been investigated using the molecular dynamic simulations based on the reactive force field (ReaxFF). For the SCWO system, the effects of temperature, the molecular ratio of DO25, O2 and H2O as well as the reaction time have been analyzed. The simulated results showed that the aromatic rings in DO25 could be attacked by hydroxyl radical, oxygen molecule, and hydroxyl radical together with oxygen molecule, respectively, which caused the aromatic ring-opening reaction to happen mainly through three different pathways. The hydroxyl radicals were mainly from water clusters and H2O2 (which was produced from oxygen molecules reacting with water clusters). However, for the SCW system as comparison, the aromatic rings in DO25 could be attacked by hydroxyl radical only, and the OH radicals just come from water clusters. During the DO25 SCWO degradation process, we also found that N elements in one DO25 molecule were difficult to be converted into environmentally friendly N2 molecules because of steric hindrance, but increasing the number of DO25 molecules could improve the possibility for the connection of N elements, thus promoting N element converting into N2. Extending reaction time could also improve N elements in DO25 to transform into N2 rather than carbonitride. Graphical Abstract The processes of making DO25 wastewater by SCWO into clean water Springer-Verlag Berlin Heidelberg, 2015 Dyeing wastewater nationallicence Molecular dynamics nationallicence Reaction mechanism nationallicence ReaxFF nationallicence Supercritical water oxidation nationallicence Zhang Jinli School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut Gu Jintao School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut Han You School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut Li Wei School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut Gan Zhongxue State Key Laboratory of Low Carbon Energy of Coal, ENN Group, 065001, Langfang, Hebei Province, China aut Gu Junjie Mechanical and Aerospace Engineering, Carleton University, 1125 Colonel By Drive, K1S5B6, Ottawa, Ontario, Canada aut Journal of Molecular Modeling Springer Berlin Heidelberg 21/3(2015-03-01), 1-13 1610-2940 21:3<1 2015 21 894 https://doi.org/10.1007/s00894-015-2603-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00894-015-2603-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhang Jinli School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut NATIONALLICENCE 700 1- Gu Jintao School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut NATIONALLICENCE 700 1- Han You School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut NATIONALLICENCE 700 1- Li Wei School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, China aut NATIONALLICENCE 700 1- Gan Zhongxue State Key Laboratory of Low Carbon Energy of Coal, ENN Group, 065001, Langfang, Hebei Province, China aut NATIONALLICENCE 700 1- Gu Junjie Mechanical and Aerospace Engineering, Carleton University, 1125 Colonel By Drive, K1S5B6, Ottawa, Ontario, Canada aut NATIONALLICENCE 773 0- Journal of Molecular Modeling Springer Berlin Heidelberg 21/3(2015-03-01), 1-13 1610-2940 21:3<1 2015 21 894