Technically, a “composting toilet” is a toilet in which composting takes place. Usually, the composting chamber is located under the toilet. The most basic way to compost humanure is simply to collect it in a toilet receptacle and add it to a compost pile. The toilet acts only as a collection device, while the composting takes place at a separate location. Such a toilet requires little, if any, expense and can be constructed and operated by people of simple means in a wide range of cultures around the world.
Composting toilets are recycling devices that should create no pollution and should recover the soil nutrients in human manure and urine.
Anaerobic composting is done through fermentation using no or limited oxygen. It relies on anaerobic microbes to decompose the materials. Pathogens are killed slowly in the unfavourable environment.