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PerspectivePure2169 t1_irpz2z0 wrote

Reply to comment by bernpfenn in How fast do bubbles rise in water? by crazunggoy47

Oh this is fascinating, please expand on these! It's crazy to think they can survive that long, what's the predominant force at that scale that keeps them from collapsing or dissolving?

Also, is this a significant source of dissolved oxygen in water for fish etc?

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rdsd1124 t1_irqi06t wrote

At ambient temperature and pressure too high of an energy barrier exists for the dissolution of the bubble's contained gas. This is b/c small bubbles have a large internal pressure (scales w/ 1/r) and a high chemical potential, just like bernpfenn mentioned. Here's a cool paper showing the math behind this (doi.org/10.1021/acsomega.0c05384)

u/bernpfenn would probably know better if a more updated source exists.

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bernpfenn t1_irsg3hi wrote

Immediate benefits of nano-bubble aeration

Saturates water with up to 79,000x more oxygen than traditional aeration

Can remain within the water column for 2-3 months
Sustains the rapid growth of beneficial bacteria and desirable microbes

Prevents accumulation of anaerobic bottom muck and sediments

Helps reduce the impact of nutrients responsible for fueling weeds and algae

Provides cyanotoxin control as demonstrated in laboratory settings

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bernpfenn t1_irsorug wrote

>oi.org/10.1021/acsomega.0c05384

That was a nice dive into the theory.
In essence, to dissolve gas into liquids, smaller bubbles have a longer time in contact with the liquid due to the mentioned stability and surface in contact with the liquid multiplied with the time.

Size, there are nanobubble generators with 1000 GPM water flow. These generators require 100 psi gas pressure and 3.3 m3 gas per hour.

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bernpfenn t1_irsgti5 wrote

Gas bubbles having such a small diameter shrink in water due to ions existing at the interface between gas and liquid, which in turn increases the ion concentration at the interface and raises the inner pressure and temperature of the bubbles, causing various phenomena to occur.
We think that taking advantage of these phenomena will provide many different possibilities.

In recent years, it was revealed that the micro-nano bubbles have a lot of useful properties. These include the following capabilities:

Sterilization capability:The agglomeration and collapse process of the micro-nano bubbles converts oxygen in the air into active oxygen, creating bactericidal molecules including OH and O3.

Cleaning capability: Ions existing at the gas-liquid interface of the micro-nano bubbles decompose and adsorb oil and fat contamination, which allows removal of the contamination without the need for cleaning agents.

Bio-activation capability: It has been proven that the micro-nano bubbles penetrate deep into biological cells and enhance the immunity of the cells. This has allowed elimination of the need for antibiotics or reduction of the amount of antibiotic usage.

Growth promotion capability: It has been verified that using the micro-nano bubbles allows fish, crustacea and plants to be grown 20 to 30 percent larger than those grown in an ordinary manner.

Cell protection capability: It has been found that oysters grown with the micro-nano bubbles remain alive even if they are frozen to minus 20°C. This is likely because the micro-nano bubbles protect oysters’ cells against damage due to freezing.

Heat transfer capability: The micro-nano bubbles can be used to raise or lower the temperature of a liquid rapidly and effectively.

Vaporization promotion capability: It has been proven that the micro-nano bubbles contained in a liquid promote vaporization of the liquid. Applications based on this effect include highly efficient water-cooled cooling towers and evaporation based desalination systems.

Environmental purification capability: The micro-nano bubbles help restore the biological balance in lakes, rivers or seas and remove odors and toxic substances produced by anaerobic bacteria. This effect stays for a long time even in a large water body such as oceans and seas.

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