Human Waste / Toilets

[Iasin the Steward]

At the WI site we are going to use th composting toilet model.

explained by Wikipedia:

"Composting toilets use biological processes to deal with the disposal and processing of human excrement into organic compost material."

[Iasin the Steward]

From Wikipedia, the free encyclopedia.
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Types of toilet

There are two basic types of compost toilet, those that complete the composting process 'in situ' (such as a Clivus Multrum, BioLet, Envirolet or Sun-Mar composting toilet), and those that are emptied to a separate compost pile remote from the toilet itself. The latter arrangement is sometimes referred to colloquially as a ‘bucket and chuck it’ system, like a Humanure Bucket System. This means that faeces is deposited into a plastic container to which soak material such as straw, sawdust, dry grass, etc, is added in order to absorb excess liquid, cover human waste materials, exclude flies, reduce smells and balance Carbon:Nitrogen ratios. When full the bucket is removed and emptied onto a composting pile that is kept separate from other composting materials such as kitchen or garden waste.

Some composting toilets use electricity, while others do not. Some electrical systems use fans to exhaust air and increase microbial activity. Other systems require the user to rotate a composting drum or otherwise stir the composting humanure from time to time.

Some composting toilets are large with a significant space requirement in the room below the toilet. Others are not significantly larger than a traditional toilet. Those small systems generally do not claim to finish the composting on-site, but are preparing the human waste materials for secondary composting in another location (like a compost pile).

All composting toilets need to be emptied, although some manufacturers claim as few as two to three times a year (or less) even with commercial use.

A related device, the incinerating toilet, uses natural gas or propane to reduce the waste material to ash in a process similar to a self cleaning oven.

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'DIY' compost toilet systems

Far more simple and basic DIY systems can also be constructed that require very little cost or maintenance, provided that attention is paid to a number of important factors. The toilet must control odours. This is achieved by ensuring adequate ventilation (sometimes simply by leaving a small gap between the top of the wall and the roof, more sophisticated systems may incorporate some kind of low voltage extractor fan). Odours can also be controlled by either ensuring that urine and faeces are kept separate or by adding sufficient high carbon content 'soak' material (see below) to absorb excess liquid. The design of the composting toilet should allow the material to remain aerated to prevent the compost from becoming anaerobic, which can result in unpleasant odours. It must also either heat the faeces to the point that pathogens are destroyed (a thermophilic process), or else allow sufficient time (up to a year) for such pathogens to break down and disappear naturally (a mesophillic process). The upside however is that they do not use any significant amount of water and they may produce fertilizer safe for small scale agricultural use.

Another variant is the Tree bog- a type of compost toilet which never needs emptying. Nutrient hungry trees such as fast growing willows are planted around the Tree bog which take up the nutrients converting them to biomass which may then be harvested.




Reference:
en.wikipedia.org/wiki/Composting_toilet