We all create it, even if we usually don’t like to think about it: waste. And the journal Science devotes its new issue to the subject. It delves into the problems – home garbage, plastics, metal, water, even everyone’s favorite, sludge – and discusses research into policy and scientific solutions.
Take biosolids. They encompass industrial waste from food production, to agricultural waste to the stuff that gets flushed. Researchers say organics-filled wastewater takes about 15 gigawatts per year in the U.S., but we could be generating electricity with that stuff. They point to one promising technology, a microbial fuel cell: bacteria use the waste as food and release electrons that are captured by an electrode.
The waste could also be used to produce compounds such as biofuels or other industrial chemicals. For instance, microbes can turn waste into hydrogen peroxide – useful for industrial bleaching. [Bruce E. Logan and Korneel Rabaey, Conversion of Wastes into Bioelectricity and Chemicals by Using Microbial Electrochemical Technologies]
More research is needed to scale up these systems – finding the best microbes, and lowering the cost of the electrodes. But the authors say the promise of both energy and chemical production is a strong incentive to move from bio-waste to bio-use. Because waste is a terrible thing to waste.
—Cynthia Graber
