Patent ID: 8349192

Claim:
A method for collapsing microbubbles, the microbubbles having a diameter of 50 μm or less and floating in a solution and decreasing gradually in size by natural dissolution of a gas contained in the microbubbles, the method comprising: circulating the solution between a container and a microbubble generator along a first path; injecting the gas into the solution in the microbubble generator to form the microbubbles in the solution; circulating a portion of the solution containing the microbubbles between the container and one of an orifice plate and a porous plate along a second path; and accelerating a speed of microbubble size decrease and disappearance by passing the solution containing the microbubbles through the one of the orifice plate and the porous plate, wherein a great amount of free radical species are released from a gas-liquid interface by increasing a charge density at the gas-liquid interface of the microbubbles.