Dual action of plasma discharge: E. faecalis inactivation and tetracycline degradation with eco-safe effluents

• Plasma discharge provokes a rapid removal of E. faecalis and tetracycline . • Hydroxyl radicals and singlet oxygen are the main reactive species in the matrix. • Low energy efficiency per order rates, order of 1.9–9.6 kWh/m 3 . • Treated samples increase germination and growth rates of some seeds. • Plasma discharge does not produce toxic by-products for lettuce, tomato or radish . Plasma treatments are innovative methods for wastewater regeneration, generating reactive oxygen and nitrogen species (RONS) in plasma-activated water (PAW). PAW has a low pH, enhances oxidative capacity, eliminates organic and biological contaminants, and promotes plant germination and growth. The plasma discharge was produced using an experimental setup with a voltage of 1–8 kV and an average current of 4 mA and frequency of 40 Hz. The energy consumption was 23 Wh, and the discharge was produced at the centre of the vortex created to isolate the high-voltage electrode from the water. This study targeted the effective simultaneous removal of Enterococcus faecalis and tetracycline from diverse water sources. E.faecalis was reduced by 4–5 logs in 15 min under optimal conditions for all water matrices. Tetracycline removal ranged from 85–99 %, with singlet oxygen and hydroxyl radical the most influent RONS in the degradation. Lettuce, tomato, and radish seeds were treated with fresh PAW and PAW storage 3 and 6 days to evaluate its fertilizing effects and potential phytotoxicity. PAW was non-phytotoxic for most of the seeds and enhanced radicle growth, 85 %–150 % for radish and 2 %–64 % for tomato. The results highlight a sustainable treatment method, enabling wastewater reuse with agricultural purposes.