Biodegradable wasteBiodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane, compost, humus, and simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. It mainly includes kitchen waste (spoiled food, trimmings, inedible parts), ash, soil, dung and other plant matter. In waste management, it also includes some inorganic materials which can be decomposed by bacteria.
Night soilNight soil is a historically used euphemism for human excreta collected from cesspools, privies, pail closets, pit latrines, privy middens, septic tanks, etc. This material was removed from the immediate area, usually at night, by workers employed in this trade. Sometimes it could be transported out of towns and sold on as a fertilizer. Another definition is "untreated excreta transported without water (e.g. via containers or buckets)". Night soil was produced as a result of a sanitation system in areas without sewer systems or septic tanks.