Scientists from MIT: one brewery is able to clean the water of an entire city from heavy metals.

Inactive yeast can be an effective and inexpensive way to remove lead from drinking water sources. One gram of this yeast can remove up to 12 milligrams of lead in less than five minutes. The research team calculated that there was enough waste yeast thrown away from one brewery in Boston to clean up the city's entire water supply. Such a completely sustainable system would not only purify water, but also solve the problem of waste disposal from production.