Composting Toilet and the Eloo Solar and Wind Evaporation Toilet
A composting toilet is an aerobic human waste processing system. It uses flush water or no water via composting managed aerobic decomposition. This is usually a faster process than the anaerobic decomposition at work in most wastewater systems, such as septic systems. Composting toilets are often used as an alternative to central wastewater plants or septic systems. The Eloo Solar and wind evaporation toilet uses no water therefore provides a more environmentally friendly toilet.
The Eloo Solar Toilet nor a composting toilet should be confused with pit latrines, all of which are forms of less controlled decomposition, and may not protect ground water from nutrient or pathogen contamination or provide optimal nutrient recycling. "Self-contained" composting toilets complete or begin the composting in a container within the receiving fixture. "Remote," "central," or "under floor" units collect excreta via a toilet stool, either waterless or micro-flush, from which it drains to a composting container.
Although there are many designs, the process factors at work are the same. Rapid aerobic composting will be thermal decomposition in which bacteria that thrive at high temperatures breaks down the waste into its components, some of which are consumed in the process, reducing volume, and eliminating potential pathogens.
Drainage of excess liquid via a separate drain at the bottom of the compost container is featured in some units, as the aerobic composting process requires moisture levels to be controlled: too dry, and the mass decomposes slowly or not at all; too wet and anaerobic thrive, creating undesirable odors This separated liquid may be diverted to gray water system or collected for other uses.
An approach that is becoming more common is the "dry" toilet, or urine-separating toilet. Where solar heat is used, this might be called a "solar" toilet. These systems depend on desiccation to achieve sanitation safety goal features systems that make use of the separated liquid fraction for immediate area fertilization.
The other requirement critical for microbial action (as well as drying) is oxygen. Commercial systems provide methods of ventilation that move air from the room, through the waste container, and out a vertical pipe, venting above the enclosure roof. This air movement will vent carbon dioxide and odors.
Most units require manual methods for periodic aeration of the solid mass such as rotating a drum inside the unit or working an "aerator rake" through the mass. Composting toilet brands have different provisions for emptying the "finished product," and supply a range of capacities based on volume of use. Frequency of emptying will depend on the speed of the decomposition process and capacity, from a few months (active hot composting) to years (passive, cold composting). With a properly sized and managed unit, a very small volume (about 10% of inputs) of humus-like material results, which can be suitable as soil amendment for agriculture, depending on local public health regulations.
