A composting toilet is a system that evaporates liquids and biodegrades solid human waste into nutrient rich fertilizing soil. Toilet waste is over 90% water. A composting toilet evaporates this liquid and releases it through a vent system. The remaining solid is then recycled back into the environment. They can be self-contained or have a remote composting area.
These toilets are not connected to a sewage system or septic tank. They can be waterless, use very little water, have vacuum flushing or a fully flushing system. They come in two basic types, batch and continual processing systems.
These consist of a series of containers. As one batch becomes full it is sealed and replaced with an empty container. The waste is dehydrated and composted within these sealed containers. These containers can be manually changed or built into a carousel-like system.
By the time the container is ready to be used again the waste has been composted and the container emptied. Batch composting can provide unlimited capacity by adding more containers as needed. It also reduces the risk of living disease organisms in the final product.
Continual Processing Systems
These systems remain in a continual state of composting. After waste enters, it’s volume is decreased and it is moved through the system and composted until it is ready to be harvested. The waste is contained in a single chamber and works it’s way down to the bottom where it can be removed. Because of the continual addition of waste into the matter there is an increased risk of living disease organisms in the final product.
Benefits of Composting Toilets
The use of a composting toilet is beneficial to the individual, the community and the environment.
The reduction of water consumption will reduce the cost of water for your household. The air flow vent acts like a continual fan to reduce odor. The end product can be used as a fertilizer for plants or gardens. Independence is increased.
If there is a problem with the sewage system or a water shortage, composting toilets are much more flexible than conventional toilets. A composting toilet can be used to recycle much of your household waste. Food scraps, glass clippings, paper and grease can all be composted along with the human waste in the composting toilet.
They also reduce the amount of marine pollution and minimize damage to the eco-system. They require little investment and planning when compared to conventional sewage systems. They can be added as needed. Leakage of raw sewage into the environment by deterioration of sewage pipes is eliminated. The need for pipeline installation and the disruption of existing soil beds is eliminated.
The Main Components of a Composting Toilet
A compost reactor (shown at right) which is connected to one or more composting toilets. An exhaust system to remove odors, carbon dioxide, water vapor and other byproducts is another important component. This can be fan-forced and is screened.
A means of ventilation to provide aeration to the organisms responsible for decomposition is also needed. A way of draining excess liquids is another must. There is an access door for removal of the finished product. Other system controls may be used to maximize the efficiency of the system.
Active Versus Passive Systems
Composting toilets can be an active or passive system. Active systems refers to the utilization of automatic mixers, tumblers, level adjusters, heaters and fans. Because of it’s increased efficiency in composting, an active system can be much smaller than a passive one. In a passive system the process is allowed to progress without any mechanical assistance.
Through the use of gravity, time, container shape, and ambient temperature the process is allowed to progress at it’s naturally occurring speed. This type of composting is called moldering. This is because the micro-organisms at work are primarily molds as opposed to the faster acting bacteria in the active system.
The acceptance of composting toilets by health authorities is varied. This depends on their experience with these systems and their knowledge of them. Currently, most health authorities prohibit the use of composting toilets where conventional sewage is available, approving their use only with the absence of available sewage. However, as they begin to understand its benefits and more people are aware of their options, composting toilets will become more commonplace.