# Applications of Plasma Produced with Electrical Discharges in Gases for Agriculture and Biomedicine
## 3 Review of Plasma Applications in Agriculture and Medicine
### Plasma Applications in Agriculture
#### 3.1.1 Water and Sewage Purification with Ozone and AOPs  
In the processes of water and wastewater treatment, it uses non-thermal plasma technologies, mainly ozone generated during electrical discharges in air or oxygen or directly in water [16; 21; 38; 67; 81; 82; 123; 128; 129]. The treatment of drinking water and wastewater requires the production of large amounts of ozone; its advantage of which over commonly used chemical oxidants (chlorine and fluorine) is due to the fact of its high efficiency in removing a wide range of organic water impurities; improving its taste and colour; and the lack of by-products from the ozonation process. Water treatment with ozone and AOTs is the most technologically advanced and used in practice. From the beginning of the 20 th century, water treatment stations were established in Europe (e.g., Nice in 1907) and around the world (e.g., Los Angeles in 1987) in which chlorine, which is harmful to the environment, was replaced with ozone produced in barrier discharges. As an example of a water treatment installation, a mobile ozone rinse and disinfection system is presented; this was constructed by the Polish company WOFIL Ozone Technology, and it was designed to reduce the chlorine used in pools and the processes of water infrastructure facility disinfection such as fittings, pumps, technological installations, tanks, walls, and floors [16; 67; 123]. This autonomous device can prepare a disinfectant solution based on ozonated water, which will require only water and electricity supplied directly from the mains or from a power generator. A three-phase power supply of 400 V and 7 kW is required. The nominal capacity of the system was 4 m\({}^{3}\)/h of highly ozonated water, at a pressure of 12 bars. The _SPID_ system received the Grand Prix main award at the 2017 fair in Bydgoszcz, Poland, for the most innovative solution. Figure 2 depicts the _SPID_ system. This mobile device producing highly ozonated water was tested on various pollutants and under varying atmospheric conditions [16; 123]. Applications of the _SPID_ system also include sterilisation of agriculture product packaging, food product storage preservation, and fruit and vegetable disinfection. Its technological effectiveness in the removal of selected pharmaceuticals (i.e., diclofenac, carbamazepine, and sulfamethoxazole) from sewage was also analysed [11]. The task of the research installation was to reduce the concentration of pharmaceuticals in wastewater in such a way as to reduce the formation of ozone by-products (e.g., bromates) and the toxicity of wastewater after the process, and to optimise the process in terms of economy and energy. The system consisted of three stages for the removal of pharmaceuticals: (1) with ionised air and prefiltration; (2) with highly ozonated water in multi-stage contact columns, and (3) removing residual contaminants on gravel-sand and coal filters. The technological efficiency of the removal of selected pharmaceuticals from wastewater allows for the recommendation for practical use of this innovative technology for the removal of pharmaceuticals from wastewater: the obtained effects were at the level of 80% to over 90%; the reduction in the BOD\({}_{5}\) and COD ratios by 42% and 20%, respectively; and the determined electricity consumption at the level of 0.96 kWh/m\({}^{3}\) in a pilot-scale facility [11]. The authors emphasised that the benefits of improving the quality of treated wastewater discharged into the environment without the need to dose chemicals into them should be considered in the aspect of improving the technological efficiency of the treatment plant. It is a waste-free technology which, compared with other methods of  
Figure 2: Mobile ozone rinse and disinfection system, where H = 1.7 m, L = 2 m, W = 0.6 m and maximal ozone production = 80 g/h: (1) pulse power supply; (2) oxygen and ozone generator; (3) contact columns for the production of highly ozonated water; (4) vent system with residual ozone destructor [16].