Cleaning

Cleaning is the process of removing unwanted substances, such as dirt, dust, and other impurities, from an object or environment.  Cleaning is often performed for aesthetic,  hygienic, functional, safety, or environmental protection purposes. Cleaning occurs in many different contexts, and uses many different methods. Several occupations are devoted to cleaning.

Contexts
Cleaning occurs in various commercial, domestic, personal, and environmental contexts, which differ in scale and requirements.

Commercial cleaning, in business or other commercial settings
Terminal cleaning, in healthcare settings
Housekeeping, including spring cleaning
Hygiene, including personal grooming
Environmental remediation, the removal of pollution or contaminants from the natural environment

Methods

Cleaning is broadly achieved through mechanical action and/or chemical processes (usually solvation); many methods rely on a combination of mechanical and chemical action. Methods include:

• Washing, usually done with water and often some kind of soap or detergent
  • Mopping, usually using a mop
  • Wiping, usually using a dry or moist piece of cloth (such as toilet paper, paper towel and wet wipe)
  • Pressure washing, using a high-pressure stream of water
  • Wet cleaning, methods of professional laundering that avoid the use of chemical solvents
• Abrasive blasting, typically used to remove bulk material from a surface, may be used to remove contaminants as well
• Acoustic cleaning, the use of sound waves to shake particulates loose from surfaces
  • Ultrasonic cleaning, using ultrasound, usually from 20 to 400 kHz
  • Megasonic cleaning, a gentler mechanism than ultrasonic cleaning, used in wafer, medical implant, and industrial part cleaning
• Carbon dioxide cleaning, a family of methods for parts cleaning and sterilization using carbon dioxide in its various phases
• Dry cleaning of clothing and textiles, using a chemical solvent other than water
• Flame cleaning of structural steel, with an oxyacetylene flame
• Green cleaning, using environmentally friendly methods and products
• Plasma cleaning, using energetic plasma or dielectric barrier discharge plasma created from various gases
• Sputter cleaning, performed in a vacuum by using physical sputtering of the surface
• Steam cleaning, in both domestic and industrial contexts
• Sweeping, mechanical removal usually using a brush
• Thermal cleaning, in industrial settings, involving pyrolysis and oxidation
• Ultraviolet germicidal irradiation, which destroys microorganisms; used extensively in the medical and food industries
• Vacuum cleaning, using a vacuum cleaner