Plasma treatment of water and wastewater as a promising approach to promote plant growth

Abstract Plasma agriculture as a novel approach started to gain more attention in the last decade. In this work, the effect of plasma activated water (PAW) prepared with different plasma sources from three types of water on germination and growth of Cucumis melo L. was studied. The best effect of PAW from distilled water on the growth of seedlings was observed when prepared using the surface-wave-sustained microwave discharge. The effect of artificially prepared plasma activated water (ArtPAW) was studied, however, it was found that while ArtPAW may cause similar effects to the plasma PAW, the effect is not as significant and consistent. Further, PAW was prepared from tap and wastewater. It was found that PAW from wastewater has positive effects on both germination of the seeds and the growth of the seedlings. The root elongation of C. melo after application of plasma treated wastewater increased up to 130% compared to the control. Moreover, it was found that plants grown in PAW from wastewater contained significantly higher concentrations of plant nutrients. Therefore, it shows a promising approach for the application of non-thermal plasma in plant fertilization and a method of wastewater reuse after plasma treatment.