|Composting Toilets - Self made systems|
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Self made systems
Far simpler DIY systems can be constructed and maintained cheaply. Lately, through the internet, good practical information and plans have become available. Especially Practical Action and EcoSanRes are now providing good approaches to recycling human waste to regain the nutrients and provide good DIY-toilet schematics. Other plans and schematics can be obtained from the Humanure Composting System Handbook (see below), Ecowaters, Composting Toilet World , VillageEarth Weblife , and to some extent National Parks Board Vela creations , Freecycle.org , and Jouneytoforever . Finally DIY UDD toilets can be found at Susana UDD DIY toilets. Odors are controlled by ensuring adequate ventilation, sometimes simply by leaving a small gap between the top of the wall and the roof, or using a low-voltage extractor fan. Odor can also be controlled by separating urine and feces, or by adding sufficient high-carbon content ''soak'' material (see below) to absorb excess liquid. The material should remain aerated to prevent the compost from becoming anaerobic, which causes unpleasant odor. It must also either heat the feces to the point that pathogens are destroyed (a thermophilic process), or allow time (up to a year) for such pathogens to break down and disappear naturally (a mesophilic process). The advantages are that they use little water and may produce fertilizer safe for small scale agricultural use.
Another variant is the tree bog—a type of compost toilet that never needs emptying. Nutrient-hungry trees, such as fast growing willows, are planted around the tree bog, and they take up the nutrients and convert them to biomass, which may then be harvested.