The Lenard effect is where the water collides intensely with the surface (waterfall, fountain) to project electrons from water molecules and attaches them to oxygen or carbon dioxide to produce negative ion, or anion.

 

To produce anion, one can use the Lenard effect of water-falls or the corona discharge method produced by artificial electricity.

 

The Micro Bubble Shower produces anion through the Lenard effect, producing negative ions (anion) that are identical to the natures of forests and waterfalls.