Zero Waste, Perpetual Food

It's beginning to seem like breweries are making the running in waste reduction: "In Namibia, the the process is used for a brewery. The spent grain from the brewing process (once fed to cattle, which can't properly digest it) is used to fertilize mushroom growth and to cultivate earthworms, which are in turn used as chicken feed. The waste water, once heavily chemically treated to make it pH neutral, is instead used to grow Spirulina algae; the remainder is channeled to a fish farm. The waste from the mushrooms, earthworms and chickens provide food for the fish. The chicken manure is also put through a digester to produce methane as fuel, reducing demand for wood."

WorldChanging: Another World Is Here: Zero Waste, Perpetual Food: