A cement-like substance could help the environment

Science Daily: A Temple University researcher has developed a cement-like substance that could help with stormwater management while potentially keeping millions of plastic bottles out of landfills. Naji Khoury, an assistant professor of civil and environmental engineering at Temple, uses a mixture of recyclable plastic bottles and soil to create "Plastisoil," a trademarked product he describes as an impervious cementing agent. When mixed with course aggregate and heated, it produces what Khoury calls "porous Plastisoil," which functions like pervious concrete and porous asphalt.

Khoury said that Plastisoil could help alleviate environmental problems created by stormwater run-off because stormwater can filter through it into the ground below. The material could be used to form sidewalks, bike/jogging paths, driveways and parking lots. "We are currently testing the porous Plastisoil to see if could also remove or reduce pollutants like motor oil from the water as it filters through," he said.

The product has an additional environmental benefit. Since it is made with polyethylene terephthalate (PET) plastic bottles, it will help reduce the 200 billion plastic bottles that are sent to landfills each year. Khoury said that it takes 30,000 of the no. 1 recyclable bottles to make one ton of porous Plastisoil. He hopes to be able to use different types of recyclable plastic bottles in the future.

In addition, Khoury said that an energy analysis shows that it uses less energy to produce one ton of Plastisoil than one ton of cement or asphalt. He added that preliminary results also show porous Plastisoil to be cheaper to manufacture than existing technologies/products….

A cement mixer in Clausnitz, 1962, from the Bundesarchiv

Pelletized manure reduces toxic runoff

Seed Daily: There is considerable amount of uncertainty concerning the environmental impacts that animal hormones have on surface water. Higher concentrations of hormones in waterways have been found to cause physiological and sexual impairment in fish and other aquatic species. However, a study from the University of Delaware that examined estrogen concentrations runoff from agricultural fields fertilized with chicken manure found that it is as much about the application of the manure as it is about the measurement of the types of estrogen.

The study was conducted on the experimental plots on the Coastal Plain agricultural soils in Middletown, DE. It measured and compared the amounts of both toxic, free forms of estrogen hormones and less toxic species found in runoff. Corn was planted as a cover crop and chicken manure was applied in either a pelletized form or a raw litter form. Reduced tillage and no tillage treatments were also employed. Samples of surface runoff were collected after 10 rain storms during the 2008 summer growing season from April through July.

Sudarshan Dutta, the author of the study, found that the amounts of estrogen were lower in plots fertilized with pelletized manure and plots that received no-tillage treatments. Additionally, Dutta discovered the entire range of estrogen concentrations in the samples was significantly lower than those observed in other previous agricultural studies. Nevertheless, concentrations of the less toxic conjugate forms of estrogen were higher than the toxic, free forms….

Manure, a field in Randers in Denmark, shot by Malene Thyssen, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.5 Generic license