Insight into plasma degradation of paracetamol in water using a reactive molecular dynamics approach

Plasma-produced reactive oxygen and nitrogen species are expected to promote micropollutant degradation in water and more generally in liquids. Among these species, the hydroxyl radical (HO•) is recognized as being the most efficient. Molecular dynamics simulations were carried out to determine the reaction steps of HO• interaction with the paracetamol molecule in water, a pharmaceutical residue that is frequently detected in surface and tap water and is well documented. Calculations were performed at various temperatures to determine the oxidation pathways, and the intermediate and final products were identified. Assuming a ratio of 10% HO• in water, it was found that a local temperature of 2500 K is required to decompose paracetamol to CO, H2O, NH3, and C2H2.