Abstract:
To provide a billing method for use of a water purification system that gives incentives for using the water purification system. Such a water purification system is equipped with water purification apparatus having controller and with monitoring server connected to water purification apparatus via public network and having controller. Filtration filter of water purification apparatus has water quality sensor, which measures water quality data of inflow water, and water quality sensor, which measures water quality data of purified water. Water quality data measured by water quality sensors are transmitted to controller and controller. Usage fees for the water purification system are calculated corresponding to improvement rates of water quality, which are calculated based on water quality data of inflow water and water quality data of purified water.
Abstract:
To provide a method for producing a filtration filter that can simplify the process for providing clean water or freshwater. By etching silicon substrate 1 using masking film formed on a surface of substrate 1 and having numerous openings to expose portions of the surface, numerous circular holes 2 with an approximate diameter of 100 nm are formed in substrate 1. Diameter (D1) at minimum-diameter portions 4 near the openings of circular holes 2 to be reduced by silica film 3 is adjusted to be 1 nm˜100 nm by depositing silica film 3 on the inner surfaces of circular holes 2.