Treatment of penicillin with supercritical water oxidation: Experimental study of combined ReaxFF molecular dynamics

Review on Mechanisms and Kinetics for Supercritical Water Oxidation Processes

“…However, with the continuous development of molecular force fields, molecular dynamics simulations can give dynamic information about the system, and larger simulated systems can be processed quickly and efficiently. The current force fields used in molecular dynamics simulations are mainly ReaxFF [151,[163][164][165] and COMPASS [166,167].…”

“…The active radicals and their sources during the SCWO process were investigated in previous studies [163,165]. Zhang et al [163] clarified the reaction mechanism of SCWO by tracing the changes of water and oxygen in SCW.…”

“…Finally, the H 2 O 2 molecule was decomposed into two OH• radicals. In addition, Ma et al [165] used H 2 O 2 as an oxidant to expound the sources of radicals and oxygen by tracing the changes of water and hydrogen peroxide. The transformation path between free radicals and oxidants is shown in Figure 17.…”

“…Both the OH• radical and O atom promote the ring-opening by weakening the C-C bond in aromatic rings. Ma et al [165] studied the composition of penicillin (PCN) in SCWO, which consists of the linear-chain cleavage and the ring-opening reactions of two heterocycles and one aromatic ring. Because of the unstable structure of the two adjacent heterocycles, the heterocycles were opened first, and then the linear chain was broken.…”

“…The initial reaction of TNT oxidation in SCWO included four pathways: (1) NO2→ONO, (2) R-NO2 bond breaking to produce a NO2 molecule, (3) R-NO2 transforming into R-NOOH by the attack of H radicals, and (4) O2 embedding into the aromatic ring of TNT. In their study [151,163,165], since the C-O bond in the produced ring structure is much Molecular dynamics simulation is also used to investigate the reaction paths of organics in SCW with/without oxidants. The aromatic ring-opening reaction of disperse orange 25 (DO25) happens mainly through three different pathways since DO25 can be attacked by OH•, O 2 , and OH• together with O 2 , respectively [163].…”