Effects of Organic Acids and Atmospheric CO2 On Surface Properties of Serpentine Minerals.

Abstract for Oral Presentation

 

Effects of Organic Acids and Atmospheric CO2 on Surface Properties of Serpentine Minerals

 

Emma Holmes¹ (emmapholmes@gmail.com), Les Lavkulich¹ (lml@interchange.ubc.ca) and Greg Dipple² (gdipple@eos.ubc.ca)

 

¹Faculty of Land and Food Systems

²Department of Earth and Ocean Sciences

University of British Columbia, Vancouver, BC, Canada

Chrysotile, a magnesium silicate, is a form of fibrous asbestos. The term 'asbestos' encompasses several different fibrous silicates that are acknowledged potential carcinogens. Their health hazard is attributed to their structure which can readily pierce soft tissues, and their inherent content of oxidizing, and potentially carcinogenic, trace metals such as Cr and Mn present in the octahedral layers in chrysotile. Chrysotile asbestos is also recognized for its atmospheric carbon dioxide sequestration activity. Surface chemistry of these fibers is a necessary prerequisite to assess both the potential negative health effects and the mineral carbonation potential of chrysotile asbestos. The objective of this study is to assess the effect of environmental conditions, such as organic acids and atmospheric CO₂ on fiber surface characteristics. This study compared fresh chrysotile, taken from the landslide in Whatcom county, USA, naturally exposed chrysotile found in sediments and mine tailings, and chrysotile that had been experimentally exposed to organic acids, bicarbonate, and high pCO₂ environments. A combination of techniques was used to determine the surface and internal composition of the fibers including: X-Ray Diffraction, Electron Microscopy, Field Emission Scanning Electron Microscopy, X-ray Photoelectric Spectroscopy, and Secondary Ion Mass Spectroscopy. Results provide an understanding of the chemical, mineralogical and crystallographic dynamics of the surface properties of chrysotile asbestos and its reaction products. The results provide information for development of remediation strategies important for understanding the carcinogenic effects of asbestos and provide much needed information on the kinetics of CO₂ sequestration by asbestos.