The Potential of Plasma-Activated Water as a Liquid Nitrogen Fertilizer for Microalgae Cultivation

• Published in: IEEE transactions on plasma science 2024-07, Vol.52 (7), p.2392-2402
• Main Authors: Theepharaksapan, Suthida, Matra, Khanit, Thana, Phuthidhorn, Traiporm, Thawichai, Aryuwong, Wanattapong, Tanakaran, Yottana, Lerkmahalikhit, Yanika, Malun, Laksana, Ittisupornrat, Suda
• Format: Article
• Language: English
• Subjects: Agriculture; air plasma; Biomass; Copper; Electrodes; Fertilizers; gliding arc (GA); microalgae; Neon; Nitrogen; Plasmas; water treatment
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2024.3362629

The influence of plasma-activated water (PAW) as a liquid nitrate-nitrogen (NO3-N) fertilizer on microalgae cultivation has been studied in this research. A helical-electrode gliding arc plasma generator (HGPG) has been proposed for practical use in a circulating PAW generation system. The arcing gap ( A_{\text {G}} ) between HGPG electrodes and treatment time has played a significant role in increasing electrical conductivity (EC), hydrogen peroxide, NO3-N concentration, and oxidation-reduction potential (ORP) of PAW contrasting to the pH, which has the opposite trend. At the 0.25-cm A_{\text {G}} and 45-min treatment time with a 15-kV, 125-W commercial neon power supply, EC, ORP, and NO3-N concentrations of PAW are 3.40, 2.0, and 12.30 times higher than that of the control group, respectively. The pH has dropped from 7.45 ± 0.04 to 3.74 ± 0.02. Regarding the experimental result of applying PAW in microalgae farming, it could be confirmed that the PAW generated by HGPG could be used as a potential nitrogen compound fertilizer for microalgae cultivation. The highest specific growth rates ( \mu ) of microalgae from the setup mentioned earlier conditions are 1.117 times higher than that of the control group.