PhD students Anna Kolganova and Brittany Multer joined dozens of their peers at the Ohio State University Union on Friday, March 1st, for the 38th Edward F. Hayes Advanced Research forum.
By Brittany Multer
Brittany Multer’s project is investigating the carbon capture potential and environmental impact of concrete weathering in soil under field conditions. Enhanced weathering is being explored widely as a carbon capture technique; crushed up rocks and minerals are being land applied to speed up the natural weathering process and form inorganic carbonates. Soil is being explored as a medium because the physical, biological, and chemical processes occurring increase weathering rates. Most of the materials investigated thus far have been natural materials that require mining and transportation which can offset the benefits from the carbon captured. Concrete is the second most used material on Earth and existing literature has already explored the carbonation of concrete during its service life. There is immense potential for concrete as an enhanced weathering material after service life because of its chemical composition as well as its high availability. Quantification of carbon capture potential will be completed by analyzing the chemical composition of the soil leachate for evidence of weathering products like Ca2+, H4SiO4, and SO42. Modeling will then be completed with the measured water chemistry and used to determine if carbonates have been formed. Other more direct measurements are still being explored. In addition to the carbon capture potential, the environmental impacts of concrete weathering to surrounding soil and water are also being studied. Concrete is a highly alkaline material and has been shown to increase leachate and soil pH. The greater soil pH can lead to increased organic nitrogen mineralization which leads to nitrogen leaching that can initiate eutrophication as well as cause a potential danger to drinking water. Soil microbes can be sensitive to changes in their environment and can also be negatively affected. A suite of soil tests will be completed to fully understand the environmental implications of concrete weathering in soil.