Can Human Waste be Used as a Fertiliser to Grow Plants?
Processed human waste is a by-product of the water recycling process and can be used safely and environmentally friendly as an organic fertiliser on food crops.
Composting toilet and using it in agriculture was very popular in Asia before chemical fertilisers appeared. Every rural home in Asia was an organic ecosystem where no resource was wasted, e.g. kitchen scraps and left over food were used for feeding pigs, human waste was composted and became an ideal organic fertiliser.
In rural areas of China, toilets are connected to a separate, relatively large composting unit located near the toilet. A scoop is used to scoop decomposed dung into a pail which is then carried to the field for fertilising. The scoops is usually made of wood rather than metal due to the erosion of metals when contact poop.
Human waste (humanure) has been promoted in western countries recently. Human orgaic dung was pushed through machines to create a cake, it was then baked at 2000 degrees which dried in to pellets.
The humanure compost bins shown in the following youtube video is like the composting toilets in rural China and in old times.
Why animal dung is used more often than human dung?
Human waste has to be treated to kill parasites and pathogens which can easily be transmitted, whereas horse or cow manure from field grazing animals, is relatively safe to use just as it comes.
It is important that human waste is treated by proper composting methods before using as fertiliser. Composting naturally heats the compostable materials to a fairly high temperature so that would kill parasites and pathogens. In history there were many diseases like cholera transmitted via open sewers. Cholera wiped out whole populations in India, Europe, and Northen America.