Scientists at Uppsala University make rocks absorb CO2 by stabilizing them. This is done with the help of worms, bacteria and fungi. The research is being carried out by the Bio-Accelerated Mineral Weathering (BAM) research project. This was reported by Uppsala University in a press release.
Weathering is the process by which rocks are mechanically or chemically broken down into grit, sand, clay and ions. These ions then combine and precipitate as new minerals and rocks. This allows CO2 to be absorbed by limestone, for example, a process that Project BAM researchers want to do on a large scale.
Thomas Corbett, a postdoctoral fellow in the Department of Earth Sciences, said the weathering of silicate minerals has been controlling global temperatures for millions of years. “The idea behind this technology is to speed up processes that happen naturally,” said Corbet.
By combining specially selected microbes with crushed stone in a sealed container, researchers have achieved results. They were able to double the speed of the weather. However, the weather needs to be accelerated many times to really work.
This can be done using specially designed bioreactors. The first prototype of these is nearing completion. The water and CO2 are combined with organic matter, crushed rock and natural food for the organisms, such as hay. The leachate, also known as worm tea, then drips out of the room. This can be used to combat ocean acidification.
Corbett explains that a careful decision was made to start with relatively small reactors, which can hold 400 grams of material. Then the project will be promoted. “We use thousands of these reactors or the best combination of organisms and the best known method,” says Corbett.
Directly at the source of production
This solution can be applied directly to the source of CO2 emissions, such as a factory or industrial site. Turning excess concrete into a steel maker, for example, will be good for the climate and the environment.
However, before we get to that point, the right mix of organisms still needs to be found. “We use different types of fungi and bacteria. There are genetically modified varieties that provide more weather, but they also cause some problems that we don’t like. So we use wild species, which poses less risk to the environment and researchers,” Corbett said.