Duckweed could be a faster and cheaper resource than corn for the production of ethanol. Researchers at North Carolina State University say the tiny aquatic plant can be used to clean up animal waste at hog farms, as well as municipal wastewater. According to researcher Dr. Jay Cheng, growing duckweed on hog wastewater can produce five to six times more starch per acre than corn. That starch can then be readily converted into ethanol using the same facilities currently used for corn.
Cheng points out that large-scale hog farms manage their animal waste by storing it in large "lagoons" for biological treatment. Duckweed utilizes the nutrients in the wastewater for growth, thus capturing these nutrients and preventing their release into the environment. In other words, Cheng says duckweed could be an environmentally friendly, economically viable feedstock for ethanol.
The duckweed system consists of shallow ponds that can be built on land unsuitable for conventional crops, and is so efficient it generates water clean enough for re-use. Researchers are currently establishing a pilot-scale project to further investigate the best way to establish a large-scale system for growing, harvesting and drying duckweed.