Editing Composting toilet (section)

==Types==
[[File:Local de compostage - composting unit (6150163178).jpg|thumb|External composting chamber of a composting toilet at a house in France]]
Commercial units and construct-it-yourself systems are available.<ref>{{Cite web |url=http://www.nesc.wvu.edu/pdf/WW/publications/eti/comp_toil_tech.pdf |title=National Small Flows Clearinghouse, West Virginia University, Composting toilet technology |access-date=2009-03-06 |archive-url=https://web.archive.org/web/20190214235745/http://www.nesc.wvu.edu/pdf/WW/publications/eti/comp_toil_tech.pdf |archive-date=2019-02-14 |url-status=dead }}</ref> Variations include number of composting vaults, removable vault, [[urine diversion]] and active mixing/aeration.<ref name=":1" />

=== Slow composting (or moldering) toilets ===
Most composting toilets use slow composting which is also called "cold composting". The compost heap is built up step by step over time.

The finished end product from "slow" composting toilets ("moldering toilets" or "moldering privies" in the US), is generally not free of pathogens. [[World Health Organization]] Guidelines from 2006 offer a framework for safe [[reuse of excreta|reuse of waste]], using a multiple barrier approach.<ref name=":2">WHO (2006). [http://www.susana.org/en/resources/library/details/1004 WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater - Volume IV: Excreta and greywater use in agriculture]. World Health Organization (WHO), Geneva, Switzerland</ref>

Slow composting toilets employ a passive approach. Common applications involve modest and often seasonal use, such as  remote trail networks. They are typically designed such that the materials deposited can be isolated from the operational part. The toilet can also be closed to allow further mesophilic composting.<ref name="Alppal">Appalachian Trail Conservancy (2014). [http://www.susana.org/en/resources/library/details/2130 Backcountry Sanitation Manual, 2nd Edition]. Appalachian Trail Conservancy, Green Mountain Club, USDA Forest Service, National Park Service, USA</ref> Slow composting toilets rely on long retention times for pathogen reduction and for decomposition of waste or on the combination of time and/or the addition of [[Eisenia fetida|red wiggler worms]] for vermi-composting. Worms can be introduced to accelerate composting. Some jurisdictions of the US consider these worms as [[invasive species]].<ref name=":2" />

=== Active composters (self-contained) ===
"Self-contained" composting toilets compost in a container within the toilet unit. 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. Operators of composting toilets commonly add a small amount of absorbent carbon material (such as untreated [[sawdust]], coconut [[coir]], or [[peat moss]]) after each use to create air pockets to encourage aerobic processing, to absorb liquid and to create an odor barrier. This additive is sometimes referred to as "bulking agent". Some owner-operators use microbial "starter" cultures to ensure composting bacteria are in the process, although this is not critical.

=== Vermifilter toilet ===
A [[vermifilter toilet]] is a composting toilet with flushing water where [[earthworm]]s are used to promote decomposition to compost. It can be connected to a [[Low-flush toilet|low-flush]] or a micro-flush toilet which uses about {{convert|500|ml|USoz}} per use. Solids accumulate on the surface of the filter bed while liquid drains through the filter medium and is discharged from the reactor. The solids (feces and toilet paper) are aerobically digested by aerobic bacteria and [[Vermicompost#Suitable worm species|composting earthworms]] into castings (humus), thereby significantly reducing the volume of organic material.<ref name="Furlong2015">C. Furlong, W. T. Gibson, M. R. Templeton, M. Taillade, F. Kassam, G. Crabb, R. Goodsell, J. McQuilkin, A. Oak, G. Thakar, M. Kodgire, R. Patankar. [http://washdev.iwaponline.com/content/5/4/608 The development of an onsite sanitation system based on vermifiltration: the "Tiger Toilet"], Journal of Water, Sanitation and Hygiene for Development, January 2015</ref>

=== Other ===
Some units employ roll-away containers fitted with aerators, while others use sloped-bottom tanks.