Various technologies are available meant to reduce, or rather to completely eliminate, the use of water in disposing human wastes.
Apart from trying to eliminate the use of water in flushing toilets, the designers of waterless toilets have also endeavored to incorporate technologies to enable excreta to be of importance, instead of being thrown away.
Here are 6 popular waterless toilet technologies.
The most basic dry toilet technology is referred to as humanure. It involves placing a bucket filled with sawdust for collecting feces and urine. Sawdust is also used for ‘flushing’ the toilet and assists in containing the odor. When full, the bucket is emptied outside in a composting pile or bin.
This dry toilet technology is better than a pit latrine and is cost effective, as well. The human waste deposited in the bucket can be used as fertilizer.
- Composting toilets
A notable improvement from humanure, the composting toilet technology uses aerobic processing to break down wastes, including the tissue papers used for cleaning after the excretion.
A composting waterless toilet normally serves three purposes:
- Evaporate moisture from the excreta
- Decompose the excreta without generating foul odors
- Ensure the final compost is safe from harmful pathogens
- Incinerating toilets
Incinerating toilet technology uses fuel to burn human excreta.
Instead of relying on water to flush waste down the drain, this technology ensures feces or urine are reduced to ashes.
Although the ashes may not be used effectively as fertilizers, incinerating toilets are mainly important in eliminating smells from the toilets.
- Solar-powered, hydrogen-generating toilet
Even though it’s not completely waterless, this technology offers much better use of water than the ordinary flush toilets. Furthermore, a great thing about it is that it produces energy.
The solar-powered toilet uses solar energy to clean the water used for sending excreta down the drain. The water becomes clean as if it were not used for flushing. This technology also generates hydrogen, which can be used as a source of energy.
- Biogas harvesting toilet
This biogas toilet technology is closest to the composting toilet technology. However, unlike the composting toilet technology, it uses anaerobic processing to break down the waste, producing biogas and fertilizer.
The biogas, which is mainly composed of methane, can be used in the same manner as natural gas. And, the fertilizer from this technology is semi-liquid and fiber-rich, something that makes it desirable for plants’ nourishment.
The biogas harvesting toilet technology has a biodegradable film for flushing without using any water. More so, you do not have to worry about odor, as it is catered for by an innovative odor-inhibiting system.
The end product ends up in a cartridge which requires periodic emptying—either daily, weekly, or as you like.
- Nano membrane toilet
This is another example of dry toilet technology. After excretion, you need to close the lid of the nano membrane toilet, enabling the toilet bowl to make a 270-degree turn to deposit the waste into a vat.
A scraper tool is also available to wipe any residue waste left on the bowl.
On the vat, sedimentation enables solid wastes to go down while liquid wastes to move to the top. The solids are propelled into a gasifier to generate gas and electricity.
The liquid waste is further processed to generate clean water, which can be used for irrigation or other purposes.
Here is a video explaining how it works:
The volume of water used in disposing human wastes in the world is enormous and difficult to realize, especially in water-scarce areas.
Therefore, the benefits of waterless toilets has attracted the interest of environmentally conscious organizations and philanthropists, like Bill Gates, who are supporting initiatives to perfect this technology.
As much as most of the present waterless technologies are still under development, increased research into this area will lead to the creation of efficient systems that eliminate the need of water for flushing toilets.