1. US20170072408 - ULTRAFINE BUBBLE CLEANING METHOD USING ULTRAFINE BUBBLE-CONTAINING LIQUID, APPARATUS THEREFOR, AND DISSOLVED AIR FLOATATION APPARATUS

An ultrafine bubble cleaning apparatus uses a liquid containing ultrafine bubbles having a size of less than 30 nm to rinse fine particles adhered to soil, sand, etc. to separate and collect the fine particles. The ultrafine bubble cleaning apparatus includes a water tank-shaped reservoir, a stirring device, a supernatant discharge device including a pump for discharging a supernatant of the liquid in the reservoir, and a sedimentation extraction device. Substances are loaded into the ultrafine bubble-containing liquid stored in the reservoir, and the ultrafine bubble-containing liquid is repeatedly brought into contact with the surface of the substance using the stirring device. When ultrafine bubbles get into a space between fine metal particles adhered to the surfaces, cracks, and pits of the substances to be cleaned (including metal ions) and fine particles of organic substances including a solvent, a chemical, and oil, the fine particles are separated and floated.