A composting toilet is a dry toilet that using a predominantly aerobic processing system that treats excreta, typically with no water or small volumes of flush water, via composting or managed aerobic decomposition.Composting toilets may be used as an alternative to flush toilets in situations where there is no suitable water supply or waste treatment facility available or to capture nutrients in human excreta as humanure. They are in use in many of the roadside facilities in Sweden, in National Parks both in the United States and the United Kingdom
he human excrement is normally mixed with sawdust, coconut coir, peat moss to support aerobic processing, absorb liquids, and to reduce the odor. The decomposition process is generally faster than the anaerobic decomposition used in wet sewage treatment systems such as septic tanks.
SUN-MAR composting toilets recycle waste on-site by evaporating the liquids, and converting the solids to a fertilizing soil which is perfect for uptake by plants. SUN-MAR composting toilets use naturally occurring aerobic bacteria to convert the carbon atoms in the waste to carbon dioxide, and the hydrogen atoms to water. In this way the waste is oxidized and reduced to its essential minerals. Since waste is some 95% moisture, after the liquid has been evaporated and the solid waste composted, the residual is only about 3% of the starting volume.
Operating process
A urine-diverting-dehydration toilet. 1:Humus compartment, 2:Ventilation pipe, 3:Toilet seat, 4:Urinal, 5:Urine collection and dehydration
Although there are many designs, the process factors at work are the same. Rapid aerobic composting will be thermophilic decomposition in which bacteria that thrive at high temperatures (40-60 °C / 104-140 °F) oxidize (break down) the waste into its components, some of which are consumed in the process, reducing volume, and eliminating potential pathogens.
Drainage of excess liquid or leachate via a separate drain at the bottom of the composter is featured in some manufactured units, as the aerobic composting process requires moisture levels to be controlled (ideally 50% +/- 10): too dry, and the mass decomposes slowly or not at all; too wet and anaerobic organisms thrive, creating undesirable odors (cf. Anaerobic digestion). This separated liquid may be diverted to a blackwater system or collected for other uses. Some units include a urine-separator or urine-diverting system.
"Self-contained" composting toilets complete or begin the composting in a container within the receiving fixture. They are slightly larger than a flush toilet, but use roughly the same floor space. Some units use fans for aeration, and optionally, heating elements to maintain optimum temperatures to hasten the composting process and to evaporate urine and other moisture.Remote," "central," or "underfloor" units collect excreta via a toilet stool, either waterless or micro-flush, from which it drains to a composter. "Vacuum-flush systems" can flush horizontally or upward with a small amount of water to the composter; "micro-flush toilets" use about 0.5 litres (0.88 imp pt) per useDesiccating toilets" dry the excreta to destroy pathogens, though one study suggested that drying can result in rehydration of pathogens when in contact with moisture later
he human excrement is normally mixed with sawdust, coconut coir, peat moss to support aerobic processing, absorb liquids, and to reduce the odor. The decomposition process is generally faster than the anaerobic decomposition used in wet sewage treatment systems such as septic tanks.
SUN-MAR composting toilets recycle waste on-site by evaporating the liquids, and converting the solids to a fertilizing soil which is perfect for uptake by plants. SUN-MAR composting toilets use naturally occurring aerobic bacteria to convert the carbon atoms in the waste to carbon dioxide, and the hydrogen atoms to water. In this way the waste is oxidized and reduced to its essential minerals. Since waste is some 95% moisture, after the liquid has been evaporated and the solid waste composted, the residual is only about 3% of the starting volume.
Operating process
A urine-diverting-dehydration toilet. 1:Humus compartment, 2:Ventilation pipe, 3:Toilet seat, 4:Urinal, 5:Urine collection and dehydration
Although there are many designs, the process factors at work are the same. Rapid aerobic composting will be thermophilic decomposition in which bacteria that thrive at high temperatures (40-60 °C / 104-140 °F) oxidize (break down) the waste into its components, some of which are consumed in the process, reducing volume, and eliminating potential pathogens.
Drainage of excess liquid or leachate via a separate drain at the bottom of the composter is featured in some manufactured units, as the aerobic composting process requires moisture levels to be controlled (ideally 50% +/- 10): too dry, and the mass decomposes slowly or not at all; too wet and anaerobic organisms thrive, creating undesirable odors (cf. Anaerobic digestion). This separated liquid may be diverted to a blackwater system or collected for other uses. Some units include a urine-separator or urine-diverting system.
"Self-contained" composting toilets complete or begin the composting in a container within the receiving fixture. They are slightly larger than a flush toilet, but use roughly the same floor space. Some units use fans for aeration, and optionally, heating elements to maintain optimum temperatures to hasten the composting process and to evaporate urine and other moisture.Remote," "central," or "underfloor" units collect excreta via a toilet stool, either waterless or micro-flush, from which it drains to a composter. "Vacuum-flush systems" can flush horizontally or upward with a small amount of water to the composter; "micro-flush toilets" use about 0.5 litres (0.88 imp pt) per useDesiccating toilets" dry the excreta to destroy pathogens, though one study suggested that drying can result in rehydration of pathogens when in contact with moisture later
