Washington, June 1 (IANS) Field-sized algal turf scrubbers could clean up streams, canals, and lakes polluted by agricultural, domestic and some industrial runoff.
These devices work by pulsing contaminated water across algae that are allowed to grow on screens. Algae, a seaweed, uses sunlight as their principal source of energy and simultaneously restore oxygen levels.
Algal scrubbers produce waste suitable for use as a nitrogen and phosphorus-rich fertilizer and for conversion to biofuel or high-value nutraceuticals. Some of them can even operate in open water, thus minimizing loss of agricultural land to the systems, reports the journal BioScience.
Walter H. Adey, Smithsonian Institution, Patrick C. Kangas, University of Maryland, and Walter Mulbry, US Department of Agriculture, note that the need to clean wastewater contaminated with nitrogen and phosphorus is immediate in many places where natural waters are polluted.
Although more productive than terrestrial crops, algae, like other potential sources of biofuel, are expensive to cultivate, harvest, process, and convert into useful amounts of energy, according to a Smithsonian statement.
But algal turf scrubbing could become common if the economic value of nutrient removal can be applied to the cost of building and running the units.
That might depend on public policy that imposes a predictable cost on pollution of natural waters. But the fuel, fertilizer, and nutraceutical byproducts from algal turf scrubbing can only help.
