Toxic waste, a combination of harmful toxins and pollutants, is the heritage of the Cold War, the hostile yet nonviolent relations between the former Soviet Union and the United States, and their respective allies, from around 1946 to 1989. During this time, they manufactured weapons with no disregard to how its waste products may affect the future generations. This article sheds some light on how some scientists never gave up pursuing the cleanup of toxic waste and how they are still conducting studies that will hopefully lessen the toxic contamination of our soil and water systems.
Uranium, a heavy radioactive metallic chemical which was used as fuel in nuclear reactors and weapons, is causing some concern in this generation. Humans afflicted with uranium toxicity exhibit kidney damage and cancer. This toxic chemical is found in groundwater where factories for making such weapons once stood. A professor of civil and environmental engineering at Stanford, Craig Criddle explains that once the toxic uranium contaminates the surface water, this can do a lot of serious damage to living organisms and existing water supplies. Previous decontamination methods involved excavation of the polluted soil or pumping and treating the water system. This has proven costly and lead to further problems concerning where and how the contaminated soil will be allocated.
This prompted Criddle and his team of scientists and researchers at Stanford to study alternative ways to cleanup uranium. They wanted to work with microorganisms initially natural to the soil and stimulate them to turn the uranium into a compound that could be transported via the water. Together with the research team of Phil Jardine at the Oak Ridge National Laboratory (ORNL), they set out to discover a possible solution to the grave dilemma.
They started with groundwater that was contaminated more than 1,000 times the water regulatory limit for uranium and were able to bring the concentration of uranium down. This article states that the detailed methods and early results were published in the journal of Environmental Science and Technology.
The project, six years in the making and costing about $4.5 million, was supported by the US Department of Energy (DOE), which encourages research on bioremediation, the use of biological means to restore or clean up contaminated land, for example, by adding bacteria and other organisms that consume or neutralize contaminants in the soil.
The problem with uranium is that the mineral sticks to soil, so pumping contaminated water to the surface for treatment is next to impossible to do. Uranium dissolves into the water over time and can be transported to surface water systems, where it can do a lot of damage to wildlife, water supplies and humans.
However, the researchers found that they were not only dealing with uranium. The researchers found a combination of sulfuric and nitric acids, toxic heavy metals and solvents. These posed some challenge for the team.
Bioremediation with the use of several species of bacteria mainly works by the bacterium utilizing the fuels as a food source, rendering the fuel non-toxic or immobilizing the compound. Link to the article