Non-Thermal Plasma-Ozonation in Water Treatment—Synergistic Effect and Reactor Systems for Organic Micropollutant Removal (Phenolics, Pesticides and Dyes): A Review

Many sectors that sustain humanity’s daily life and wellbeing contribute to the occurrence and accumulation of organic micropollutants (OMPs) in the environment, making them a global concern. This manuscript presents an appraisal of existing scientific literature on removal of OMPs from water by non-thermal plasma-ozonation (NTPO) synergy with specific attention on phenolics, pesticides and herbicides and organic dyes. An overview of non-thermal plasma (NTP) degrading agents in gas and aqueous phases has been given, complemented with diagnostic systems and reactive species detection methods. A scrutiny of reactor systems and their influencing operating parameters has also been discussed. For the analysed types of OMPs, the kinetics, reaction mechanisms and the synergistic degradation effects have been explored. Several studies showed NTPO and NTP/other process synergy resulting in higher degradation efficiency than the individual processes. Most removal reactions followed pseudo-first-order and second-order kinetics while the mechanistic breakdown mainly involved the action of the nonselective OH radical. This scientific critique brings to light utilisable data, provides novel insights on NTPO of OMPs, unveils science gaps for further investigation and presents a wide spectrum of points to consider in plasma water research on OMPs.