((PKG)) ALGAE SCRUBBER
((Banner: Algae Scrubber))
((Reporter/Camera: Steve Baragona))
((Adapted by: Martin Secrest))
((Map: Baltimore, Maryland))
((Banner: University of Maryland researchers are testing an algae-based system that can remove excess nutrients contained in runoff wastewater headed for the Chesapeake Bay))
((Peter May, University of Maryland))
This is an algal turf scrubber, a trade name. We’re calling it an algal flow way technology, and it is a technology that is ecologically engineered to use algae to strip nutrients and sediment out of the water body. This technology allows you to use the forces of nature, if you will, sunlight, photosynthesis, gravity flow. We’re pumping water from the river. And so that water, as it pulses down the flow way, stimulates algal attachment on the flow way, essentially creating a controlled algal bloom on land, which put the algae to work, pulling nutrients out of the water body and then creating algal biomass, which then needs to be harvested. In order to remove those nutrients and the sediment and carbon, you would need to harvest it. So, algae grows very fast. It’s the fastest growing organism on the planet. So, we harvest this about every week. That algae is collected on the flow way, and at the end, we have a large mass of algae that we’re producing every week. What do we do with that algae? You have to have an end use, otherwise you’re going to pile that algae up very quickly.
((NATS))
((Stephanie Lansing, University of Maryland))
So, this is algae that we took off the turf scrubber. And what we’re doing with this algae, this is biomass, that again, nutrients from the bay, there’s too much nutrients in the bay. The algae love it. The algae take up the nutrients in the biomass. But then, once you’ve harvested this algae, the question is what are you going to do with it. We actually put it into an anaerobic digestion system. In that digestion process, the bacteria break down this carbon material, and they produce methane biogas, methane-enriched biogas.
((NATS))
((Courtesy: Amro Hassanein))
((Stephanie Lansing, University of Maryland))
So, we collect this biogas, and then the biogas is used to run a fuel cell. The fuel cell is actually a very efficient way of using the energy. So, we use the biogas and that fuel cell can be used anywhere you need to put electricity in.
((NATS))
((Stephanie Lansing, University of Maryland))
But as you scale up, we have systems that are two megawatts, three megawatts, very large systems using this anaerobic digestion process. All you have to do is make the vessels bigger and put more materials inside.
((NATS))
((Peter May, University of Maryland))
Over wetlands, treatment wetlands, rain gardens, bio-swales, you name it, this will extract more nutrients per unit area when it’s running than any of those other systems. Very efficient at doing what it does.
((NATS))
