ECNU Scientists discover nano particles at coal burning sites


Yang Yi (Right) and her colleague.

Three ECNU professors and some international field-scientists discovered new forms of nano scale particles that can be used to trace and track down coal emissions from industrial power plant sites. The discovery was regarded by the scientific community as an outstanding achievement because it can identify nano particles generated from human activity. It can also have an impact on environmental toxicology research.  

Yang Yi and Liu Min with the School of Geographic Sciences and Ge Jianping with the College of Chemistry and Molecular Engineering at ECNU took part in the research project, which found that emissions from burning coal produce large quantities of rare Magnéli phase titatium oxide (TiO2) that are a likely source of toxic ecological factors; the relationship between coal emissions and human lung cancer can now be analyzed more closely.  

The research paper about the discovery is published in Nature Communications.

The details of the discovery was among the most widely read reports published in the August 8 issue of Nature Communications - an open access journal that publishes high-quality research in many related fields of science.  Readers interested in the discovery can read the research paper"Discovery and ramifications of incidental Magnéli phase generation and release from industrial coal-burning" on line.

Coal is the world’s largest fuel source for electricity and is one of the most abundant and consumed sources of energy production worldwide. Yet, coal production emanates more CO2 compared to other fossil fuels, moreover, it is a major contributor to particulate matter (PM) pollution - a result formed by chemical reactions between two pollutants in the atmosphere - it posits a high potential danger to the environment and to the cardiovascular health of individuals living near high concentration of emissions.  

Coal emissions are a major contributor to PM pollution in the earth’s atmosphere, even an aerodynamic diameter smaller than 2.5μm (PM2.5) has been predicted to cause disastrous effects: estimated 3.3 million premature deaths per year on a global scale.  

Now, there is also a significant amount of research on ultrafine particles - nanoscale particulate matter that have higher degrees of health risk - such nanoscale particles can penetrate into the lung’s alveolar (air-sack) membranes and thereafter undergo translocation into the heart and other blood vessels. Many nanoscale particles can also infiltrate blood circulation to the brain.  

The National Natural Science Foundation of China (NSFC) and its U.S. counterpart at Virginia Tech (VT) have worked together for more than three years in the area of nanoparticles and environmental research. Prof. Yang and a team led by Prof. Hochella at VT have dedicated a large part of their time and resources to observe environmental effects derived from nano particles; combining information from relevant toxicology studies to understand its impact up to now.  

They originally made the discovery of Magnéli phases (TixO2x-1,4  x  9) while investigating a industrial accident where a coal spill impacted the ecology of a riverine area. In that study, the collaborative research team presumed that the effects were associated with coal combustion residuals (CCR’s).  

The research scientists of ECNU and VT were able to locate Magnéli phases through soil arsenic (As) bioavailability assessment, which until recent years could rarely be spotted in a natural environment due to its distinct chemical make up and lack of modern advanced tools.  

The researchers selected 22 coal ash samples from 12 coal-producing power plants, utilizing various coals mine throughout the United States and China. Conclusive evidence verified that Magnéli phase-TiO2 in the atmosphere is caused by burning coal at power plant production sites.  

Next, it was time to test their hypothesis: TiO2 coal-accessory minerals are converted to Magnéli phases in the earth’s atmosphere, which radiates from heat produced by active coal-producing power plants. In doing so, the research team conducted an extensive set of experiments to demonstrate their reasoning: The 900°C temperature regional zone is approximately the minimal temperature that can be used to generate Magnéli phases derived from TiO2-produced coal emissions; an environment that contains nitrogen elements also has potential hazard effects.  

Some members of the research team.

Given the thermal stability of nanoscale Magnéli phase-TiO2, it is possible that these findings could lead to the ultimate source of pollutant emissions derived from burning coal, according to the research team.  

Prof. Yang is the main author of the report in Nature Communications and Prof. Hochell is credited as co-author. ECNU also became the first collective contributor to this particular field of study. Other individual contributors recognized for the project include Ph.D. Chen Bo and Prof. Priya with VT; Prof. Hower with U.S. Applied Energy Research Center; Prof. Schindler with Canada's Laurentian University; Prof. DiGiulio with Duke University; and Prof. Zhang Lijun with Jilin University.  

There are a multitude of Magnéli phases, which vary potentially based on different types of coal, temperatures and various ecological factors, according to Prof. Yang. It is clear that an accurate identification of an individual member of the Magnéli family will effectively curb carbon emissions derived from coal pollutants. Furthermore, the discovery can also benefit other areas of cardiorespiratory research and offer new solutions to treat widespread diseases such as lung cancer and cardiovascular diseases.


East China Normal University