Chlorination, ozonation and non-thermal plasma water purification technologies were compared in terms of their effectiveness, efficiency, capital and operating costs, energy yield and chemical demand. Retrofitting plasma technology to chlorination plants offered the lowest capital cost (ZAR 14,000 or USD 253,376 based on the current South African Reserve Bank rate of ZAR/USD of 18.0983) and the most effective contaminant removal (of the three possible combinations). How- ever, this combination yielded the highest operating costs (ZAR 586,000 per annum or USD 10.6 million) and the lowest energy efficiency. It was concluded that retrofitting chlorination plants with plasma technology is feasible. However, plasma generators should be redesigned to consume less energy or to operate using renewable energy. Furthermore, research should be performed on contaminants of emerging concern to establish a deadline after which their concentration must not exceed a specified limit. This will accelerate the implementation of plasma technology and secure the health of our posterity.

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.