Water-submerged nanosecond-pulsed spark system for hydroponic water disinfection and nutrient reuse

Overview

AAPlasma LLC has developed a submerged, nanosecond-pulsed spark plasma system designed to disinfect water used in hydroponic agriculture. The technology achieves greater than 6 log reduction in E. coli O157:H7 at an energy cost of approximately 60 J per liter per 1-log reduction, compared with roughly 300 J per liter per 1-log reduction for conventional 254 nm UV treatment. Applied to hydroponic runoff, the system is intended to eliminate pathogenic bacteria and fungi so that nutrient-rich water can be safely reused, reducing fresh water demand and fertilizer loss while protecting crop quality and consumer safety.

The current offering centers on adapting a proven, validated plasma disinfection platform to the specific conditions of hydroponic farming. The proposed next phase involves side-by-side comparison of two identical vertical hydroponic growth systems, one equipped with the plasma unit and one operating as a control, with and without microbial spiking. Outcomes will inform scale-up and optimization for commercial greenhouse and indoor farm environments.

Technical specifications

• Plasma source: Submerged nanosecond-pulsed spark discharge operating directly in the water stream.
• Disinfection performance: Greater than 6 log reduction of E. coli O157:H7 demonstrated in potable water matrices.
• Energy efficiency: Approximately 60 J per liter per 1-log reduction, about 6 times lower energy consumption than 254 nm UV at comparable inactivation.
• Mode of action: Non-equilibrium atmospheric pressure plasma generates reactive chemical species that inactivate bacteria, fungi, and other pathogens in solution.
• Integration: Designed for inline treatment of hydroponic runoff prior to recirculation, preserving dissolved nutrients while removing microbial contaminants.
• Core competencies: High-voltage pulse electronics, plasma diagnostics, microbiology and virology testing, and end-to-end product development from concept through prototyping and scale-up.

Technology readiness level

The plasma disinfection platform has been validated on potable water with demonstrated pathogen reduction and energy benchmarking against UV. It has not yet been validated in a hydroponic growth system. The proposed project will establish proof of concept in hydroponics by comparing plasma-equipped and control vertical hydroponic systems under both clean and pathogen-spiked conditions, providing the data needed to guide scale-up, optimization, and commercial deployment in subsequent phases.