Comparative Analysis of Volumetric Mass Transfer Coefficients for Oxygen Uptake and Desorption with Nanobubbles

Water, Journal Year: 2025, Volume and Issue: 17(1), P. 130 - 130

Published: Jan. 6, 2025

The volumetric mass transfer coefficients (kLa) of oxygen during sorption and desorption were analyzed using nanobubbles (NBs) air pure under various experimental conditions. results showed that NBs achieved an increase in dissolved (DO) levels absorption, reaching peaks 30–34 mg∙L−1 stabilizing at 31.3 ± 0.2 mg∙L−1, with a coefficient 0.105 0.002 min−1. In comparison, lower efficiency, peak DOs 8∙10 kLa 0.048 0.001 studies, had higher DO retention, reducing from 30.0 to 15.0 300 min, 0.042 0.003 min−1, while decreased more rapidly, 0.028 When was used, outperformed both absorption desorption, stability. addition, the show residence time has important impact on performance NBs, showing direct influence flow dynamics surface/to/volume ratio influences value kLa. highlight superior versus terms efficiency stability effect NB composition applications requiring efficient transfer, given promising prospects for development advanced aeration technologies industrial environmental contexts.

Language: Английский

Vortex–Swirl Flow Results in Microbubble-Enhanced Transient Water Properties: A Time-Resolved Analysis from Fine-Bubble Engineering

Water, Journal Year: 2024, Volume and Issue: 16(24), P. 3565 - 3565

Published: Dec. 11, 2024

The inward vortex–swirl-type motion of convective, rectilinear water flow has been studied vis-à-vis its propensity for bubble formation, with a particular focus on the microbubble region. It found that large population smaller microbubbles, around 1 μm in diameter, is created process these types motions, and time-dependent behaviour this “micro-bubbly” analysed as Stokes’ law dissipation occurs, such population, dissolved oxygen, pH, etc. Exponential decay analysis DLS-measured populations gave relaxation times τ ~2.4 h 3.6 exp(−t/τ) fits DI filtered tap water, respectively. downward shift pH was about 0.08 ± 0.016 0.11 0.018 For level oxygen (DO) at room temperature 19 °C ~102% “t = 0”, it declined to ~87% within 3 (with unprocessed background sample being 84 1.1%). respective DO results case (at °C) were ~105% declining 91% (background 86 1.2%). This allows dynamic properties be understood context how microbubbles determine observed post-flow including rationalising observations time-transient properties. Naturally, may well interest gas transfer optimisation growing field “fine-bubble engineering”.

Language: Английский