Notes on natural recycling vs human generated waste
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Recycling Human Waste
Recycling human wasteOn a yearly basis a human produces roughly 500 liters of urine and 50 liters of feces. These two products contain enough nutrients to grow most of the plants that this person needs as food. But instead of utilizing these 550 liters as a resource, we mix it with roughly 15,000 liters of water, and all goes down the drain. Before it reaches the sewage plant, if there is one, this slurry gets mixed with hundreds of pollutants along the way.
Modern agriculture gets the phosphorous it needs from phosphorous-bearing rocks. But these reserves are rapidly dwindling and increasingly contaminated with pollutants such as cadmium. In as little as 25 years apatite reserves may no longer be economically exploitable and massive world-wide starvation is predicted to follow.
The feces receptacle, except for the lid, is exactly the same device used for the mesophilic storage of household biowaste, and if carefully utilized and cleaned out, the one bin could receive all bio-waste from the household, including human feces.
This toilet can be manufactured as a pedestal toilet or a squatting toilet. Since, in the case of a squatting toilet, the feces receptacle has to bear the entire weight of a person, it is best constructed out of brick.
Biochar can also be added to the storage bin from time to time to further eliminate odor. Since biochar captures ammonia in gaseous form, biochar can also be added to the urine receptacle of this toilet. There is also the concept of a biochar urinal, a concept that will be explained more fully in the conclusion.
Urine could be collected from urine-diverting toilets, diluted and directly applied to certain crops as a source of NPK. Simple soil insertion techniques prevent the volatilization of ammonia. Urine, or a mixture of biochar and urine, can be used as an important source of nitrogen in thermophilic composting operations.
duckweedHowever, if the transport of urine is not feasible, there is another approach, and it allows for the complete processing of urine on site. This approach involves a tiny aquatic plant that is one of the fastest growing plants on earth. As it floats on the surface of the water, it extracts NPK and other nutrients from water through all surfaces of its leaf. Given sufficient sunlight, it can reduce quantities of NPK in water down to almost undetectable levels. This amazing plant, found throughout the world, is called duckweed.
Under optimal conditions, certain duckweed can double in mass within a period of only 16 hours. Its protein content is one of the highest in the plant kingdom (sometimes as high as 45%). It is also rich in beta carotene, xanthophylls, as well as vitamins A and B. It contains very little fiber and indigestible matter.
pondIn this approach, urine would be flushed from the urine-diverting toilet into a small duckweed pond located near the toilet. Since duckweed covers the entire surface of the pond, very little ammonia would volatilize and give rise to unpleasant smells. The duckweed harvested each day makes a wonderful feed for chickens, pigs, fish and, of course, ducks. Duckweed can be dried, ensiled, blanched or fed fresh.
The logic of the sustainable processing of human waste has certain parallels with the logic of the sustainable processing of residential bio-waste. Both demand separation at source. Both employ mesophilic bins, BSF and red worms. Both refuse to define themselves as independent large-scale waste disposal activities, and both are intimately connected to the sustainable production of food, feed and fertilizer. Human waste, like pig waste, is far too nutrient-rich for the production of fuel by means of methanogens.
Human waste
Human waste (or human excreta) refers to the waste products of the human digestive system and the human metabolism, namely feces and urine. As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method or another, depending on the type of toilet being used, ability by the users to pay for services and other factors.
The sanitation systems in place differ vastly across the world, with many people in developing countries having to resort to open defecation where human waste is deposited in the environment, for lack of other options. People in developed countries tend to use flush toilets where the human waste is mixed with water and transported to sewage treatment plants
Natural recycling is helpful for the environment and human generated waste is harmful