A new study from the University of Kentucky shows that the nanoscale composition of coal ash plays a key role in determining how well toxic elements leach out of the ash. The study, published in the journal Environmental Science & Technology, has implications for the management of coal ash, which is a byproduct of coal-fired power plants.

Coal ash is a complex mixture of minerals, metals, and other elements. When coal ash is exposed to water, some of these elements can leach out and contaminate groundwater and surface water. The extent to which elements leach out of coal ash depends on a number of factors, including the composition of the ash, the pH of the water, and the temperature.

The new study focused on the role of nanoscale composition in leaching. The researchers used a variety of techniques to characterize the nanoscale composition of coal ash samples. They then conducted leaching experiments to measure how well toxic elements leached out of the ash.

The results of the study showed that the nanoscale composition of coal ash had a significant impact on leaching. Ash samples with a higher concentration of nano-sized particles leached out more toxic elements than ash samples with a lower concentration of nano-sized particles.

The researchers believe that the nanoscale composition of coal ash affects leaching because nano-sized particles have a higher surface area than larger particles. This means that nano-sized particles have more contact with water, which allows more toxic elements to leach out.

The study's findings have implications for the management of coal ash. By understanding the role of nanoscale composition in leaching, it may be possible to develop strategies to reduce the leaching of toxic elements from coal ash. This could help to protect groundwater and surface water from contamination.

"Our study shows that the nanoscale composition of coal ash is a key factor in determining how well toxic elements leach out of the ash," said Dr. Gang Chen, professor of civil engineering at the University of Kentucky and lead author of the study. "This information could be used to develop strategies to reduce the leaching of toxic elements from coal ash and protect human health and the environment."