Nanobubble technology: An environmentally sustainable approach for gas dissolution and water chemistry modulation

This study investigates the dissolution behaviour of different gases (O₂, O 3 , CO₂, H₂, N₂, and air) in nanobubble (NB) form in pure water. The experiment was conducted in a pure water-filled tank equipped with sensors to monitor pH, dissolved CO 2 (DCO 2 ), dissolved O 2 (DO), dissolved H 2 (DH), dissolved O 3 (DO₃), oxidation-reduction potential (ORP), and electrical conductivity. The influence of the NBs in pure water was continuously monitored by measuring the parameters throughout the experiment. The findings highlight that NBs play a crucial role in rapid gas dissolution in water and change the water chemistry. For instance, CO 2 NBs reduced the pH of water from 6.8 ± 0.2 to 4.2 ± 0.2 within 20 min of CO 2 -NBs generation, and DCO 2 concentration reached >1500 mg/L in 30 min. DO concentration was noted as 31.6 ± 3.0 mg/L and 51.8 ± 5.0 mg/L, with O 2 and O 3 NBs infusion, respectively. H₂ and N₂ gases were easily able to replace the inherent DO saturated with air and reduced the DO concentration to 2.3 ± 0.1 and 1.8 ± 0.1 mg/L. The study suggests the potential industrial applications of NB technology in processes like wastewater treatment, enhanced gas solubility, and disinfection because of the unique physicochemical properties of NBs. This report might provide valuable insights for further investigations about physicochemical properties and performances of various gas NBs on water chemistry and their potential usage in environmental sustainability. • Nanobubble (NB) technology (NBT) is great for enhancing the gas dissolution processes. • Carbon ceramic nozzle generates CO₂, O₂, H₂, N₂, and air NBs for rapid alteration of water chemistry. • Significant reduction in pH from 6.8 to 4.2 can achieved by CO₂-NBs within 20 min. • Dissolved oxygen level reaches to 31.6 mg/L and 51.8 mg/L by O₂-NB and O₂-NB respectively. • The findings underscore the transformative potential of NBT in chemical engineering and environmental sustainability.