Changing a baby’s diaper is one of the least inspiring activities imaginable. However, when Hong Liu changes her 1-year-old son, Joshua, she finds herself imagining a cleaner, brighter future, in which biological waste becomes a source of electricity for houses and hydrogen for cars. Rinsing out a diaper (and flushing gallons of water to a distant treatment plant) or tossing out a disposable (and shipping it to a landfill), Liu thinks about a different kind of waste, about the inefficient use of resources. "I think about all this wastefulness," she says. "It is my hope that we can make use of biological waste, collect energy from it, and not send it to some central place for disposal."
For Liu, extracting energy from wastewater is no pipe dream. She is developing a microbial fuel cell as a way of harnessing electricity from wastewater.
