Sludge Eaters.

first_img Photo:UGA CAES Earthworms eat and convert sludge into a more environmentally safe product. Earthworms have a healthy appetite. If you get enough of themtogether and don’t disturb them, scientists say they can safely,quietly dispose of many forms of waste.Vermiculture is a composting system that uses worms to processorganic waste, said Sid Thompson, a professor of engineering withthe University of Georgia College of Agricultural and EnvironmentalSciences.The process could be a viable alternative, he said, for currentwaste-management practices that continue to grow more expensiveand impractical as the world’s population expands.Goes in Bad, Comes Out Good The earthworms don’t have to be trained for vermiculture or doanything unusual. They just do what comes naturally: eat. As theworms eat organic materials, such as sludge from wastewater treatmentplants, they excrete it as castings. Worm castings, which look much like freeze-dried coffee crystals,make good fertilizer for plants. They also improve the waterand nutrient-holding capacity of the soil. “Castings are more microbially active,” Thompson said.”The nutrients are more available to plants.”The worms get rid of the harmful waste and in return provide amuch nicer product that’s not as smelly. Not only are the castingseasy on the environment, they can catch a good price as well.Castings are advertised on the Internet for as much as $4.25 perpound.Cities around the world are looking to vermiculture to combatwaste problems, Thompson said. Vermiculture in India, one of themost heavily populated places in the world, gets rid of as muchas 30 tons of waste a day.Thompson said vermiculture could work for Georgia, too. To beviable on a large scale, though, it must be proven economicallyfeasible.Worms take to sludge like mice to cheese. In fact, one worm caneat its weight in sludge every day. One pound of worms can eatand process one pound of sludge.However, a large land area would be needed for the worms to processlarge amounts of sludge, said Jason Governo, a graduate studentworking closely with Thompson’s research.A Pound of Worms Can Tell You More Most vermiculture research uses only one or two worms in smalllaboratory settings. Thompson and Governo are using pounds ofworms in their research.Their studies show that only 3 to 4 inches of sludge can be placedonto the worms at any one time, Governo said. With such a thinlayer, it would take too much land and wouldn’t be economicallyfeasible for Georgia.But Thompson said the land problem could be solved simply. Heproposes placing the sludge and the worms in trays and then stackingthose trays in a tall structure. “There are ways this canbe done for waste in the state,” he said.Thompson said worms can convert a range of organic material, aslong as the material is presented in an acceptable form.Georgia is one of the leading poultry producers in the world.It’s also one of the leading producers of manure from layer hens,the birds that lay eggs. Large quantities of this manure can strainthe environment.Worms, Thompson said, could convert layer manure into a more environmentallyacceptable product. However, the natural high salt and ammoniacontent found in layer manure dries up and kills the worms.Vermiculture could be the answer to the large volume of chickenlitter produced in Georgia, he said. Scientists just have to findthe right way to present it to the worms.last_img

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