Using human waste for electricity and fertilizers… Ok, I get the fertilizer part – after all, our ancestors did use animal waste to make their cultivated soils more productive – but electricity? Yes, scientists have been working at it for some time now and it appears it’s not only feasible, but also incredibly profitable for water saving!
To be more specific, researchers from the Nanyang Technological University (NTU) put together a toilet system called “the No-Mix Vacuum Toilet” that separates the two types of waste and uses only 10% of the regular amount of flushing water. Considering that we use 4 to 6 liters of water for each flush, that makes up for a 160,000-liter per year (42,267 gallons) save. Not too bad, huh?
So what happens to the waste after it goes down the drain? Well, the liquid waste goes to a processing facility where nitrogen, phosphorus and potassium are extracted for fertilizing purposes. The remaining grey water follows its course, but ends up being treated as well.
On the other hand, processing the solid waste is a little more complicated: this time we have a bioreactor in charge of processing. The resulting biogas (with methane in it) is turned into electricity and shipped to power plants as fuel. The leftover food, if any, will most probably be transformed into compost and added to the soil.
The idea of such an efficient system seems to have sprung from the “resource-scarce Singapore” and the people responsible are proud of it not only because it can save a great deal of water, but it also reintegrates the resources taken into the natural cycle.
Associate Professor Wang Jing-Yuan, Director of the Residues and Resource Reclamation Centre (R3C) at NTU is convinced the system also saves money, since the methods of obtaining energy are on-site, more simple and less pricey. Like this, researchers hope to some day see the communities which aren’t linked to the main sewerage system somehow use their waste. Since our natural resources are finite, we welcome this new “device”, although we it is with some skepticism…