Published on June 13th, 2010 | by Tina Casey1
Researchers Mine Microbes for New Wastewater-to-Energy Process
The energy pipeline of the future will draw from many sources other than fossil fuels, and one of the most intriguing new alternatives is the use of wastewater to generate electricity and hydrogen. The process works by harnessing the biochemical reactions in microbes as they feed on human or farm wastewater, or even plain seawater. Now researchers at Arizona State University have discovered a key to making a microbial fuel cell that can function far more efficiently than earlier versions.
The new process focuses on using wastewater as a feedstock to produce hydrogen, which otherwise relies on natural gas and other fossil fuels for production. Since hydrogen fuel cells are emerging as a low-emission alternative to internal combustion engines, the recycling of wastewater to manufacture hydrogen is, sustainably speaking, icing on the cake.
Microbial Fuel Cells and Sustainability
The field of microbial fuel cells is still relatively new, but it has been developing rapidly thanks in part to interest by the U.S. military’s move away from fossil fuels. The U.S. Navy’s work with microbial fuel cells is one example. At Arizona State, a research team headed by Dr. Prathap Parameswaran has developed a way to reconfigure the cells, using the biochemical process to release hydrogen gas instead of generating an electric current. They also found that the efficiency of the process can be boosted by increasing the presence of certain bacteria. To top it off, they were able to tweak the process to reduce the effect of other microbes that would otherwise weaken the current.
Wastewater and Sustainability
Microbial fuel cells are just one means of recycling wastewater for energy. New Zealand researchers have been exploring a process for reclaiming high pressure steam from wastewater, which can be used to generate electricity. Here in the U.S., Infospi is one of a number of companies that are converting wastewater to biofuel. The EPA and the Department of Agriculture have also just launched an ambitious new program to introduce biogas production from farm waste to the U.S. dairy industry.
Fossil Fuels, Wastewater, and Sustainability
Fossil fuel harvesting is rapidly becoming a dead weight on the U.S. economy that destroys jobs to say nothing of its effect on the environment and public health. In less than two months BP’soil spill has accomplished in the Gulf of Mexico what mountaintop coal mining has been doing to the Appalachian region for years. In BP’s case the connection to the international fossil fuel market is transparent but Appalachian coal has also been sent overseas to power factories; in other words, the U.S. has allowed itself to be recolonized through fossil fuels. Instead of a $2.7 billion subsidy for fossil fuel companies in the federal budget, President Obama has called for more investment in clean energy, and in that regard sewage is looking fine: an endless supply is close at hand (so to speak), and massive quantities are collected each day through existing infrastructure with no harm to fish or fowl.
Image: Sewer pipes by Marc from Borft on flickr.com.