Turning your toilet water into energy

Posted: Feb 22, 2013 1:23 PM by Cameron Polom, KSBY News
Updated: Feb 22, 2013 2:19 PM

Cal Poly research team turns wastewater into energy

Attention all toilet flushers: a Cal Poly research team is turning your wastewater into energy.

Last month the group received a more than $1 million grant from the Department of Energy to expand the project.

"So we initially started with these small ponds right here eventually led up to the bigger ones," said Cal Poly research student Matt Rodrigues.

Thanks to a $250,000 grant early on, these Cal Poly students have hit a royal flush with their research.

"It's extremely cost effective compared to typical wastewater treatment," said Elliott Ripley.

Powered by sunlight, oil-rich algae feed on polluting nutrients in wastewater.
After the process is complete, it gives you the initial stages of purified water and a thick buildup of algae.
That buildup can be converted to liquid biofuel or fertilizer.

"So we just start here with our distribution system which takes some of the city's wastewater, and pumps it into these foot depth race way ponds," said Rodrigues.

From there, paddle wheels circulate the water, allowing the sun to penetrate the pond equally giving them large and sustainable algae growth.

The algae are then harvested into what they call tube settlers.

"What we can do from there is just open these valves and get a thick algae biomass," said Rodrigues.

That allows them to turn that green sludge into greenbacks for the city.

"We're hoping it's going to be an actual energy gain, so not only are we treating wastewater with this process, it's actually a source of energy now," said Ripley.

The biofuel from the algae can run all sorts of things from your stove to your car to fertilizing crops.

If successful, algae ponds similar to these could replace conventional wastewater plants. But they would need a sun rich climate and adequate land because the ponds would cover many acres.
According to the researchers millions are spent on wastewater treatment every year and the new technique could cut that by 30 to 40 percent.