Properties of Surface Functional Groups of Black Carbon from Historic Charcoal Blast Furnaces
EMSL Project ID
13303
Abstract
In recent years, geochemical and biological properties of black carbon (BC) have received increasing attention owing to its potential importance in a wide range of biogeochemical processes. Although some research has recently been done on the quantification of BC in marine sediments and soils, information about the quality of BC remains scarce. The surface functional groups of BC are the most important factors that affect the quality of BC and those surface functional groups make BC have different chemical activity and amphoteric characteristics. When BC is exposed in the natural ecosystem, temperature and humidity would further increase or alter the BC surface functional groups into more acidic functional groups, such as carboxylic and phenolic groups. In this study, we propose to study the long-term effects of temperature on BC surface functional groups along a climosequence. The BC samples will be collected from historic charcoal blast furnaces. Based on their similar history and vast geographic distributions, those historical BC deposits can give us an excellent opportunity to understand the change of BC over long periods of time and how different environment factors or temperature affect the BC properties. We hypothesize that the BC will be more oxidized and will have more acidic surface oxides under higher temperature than under lower temperature. We will use potentiometric titration methods, Boehm titration, and Zeta potential to determine the acid-base properties and surface charge. Those methods, as well as the basic soil properties and FTIR spectroscopy, will be done at Cornell University before we measure the XPS analysis. We propose to use the XPS at EMSL for determining surface functional groups of BC in different size fractions. BC particles larger than 2 mm will be collected from soils whereas smaller particles (200 and 63 um) will be separated by sieving and then collected under the microscope or separated by density in a water slurry. Part of the BC fractions will be washed under ultrasonic treatment to detach the adsorbed inorganic or organic matters. Whole energy scans and detailed carbon 1s and oxygen 1s will be used for samples both before and after ultrasonic treatment. The larger BC particles can be directly detected by the X-ray beam, while the smaller BC particles will be spread on a tape and then mounted in the chamber.
Project Details
Project type
Capability Research
Start Date
2005-07-18
End Date
2006-07-31
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Cheng CH, Lehmann J and Engelhard M 2008 Natural oxidation of black carbon in soils: changes in molecular form and surface charge along a climosequence. Geochimica et Cosmochimica Acta 72: 1598-1610.
Cheng CH, Lehmann J, Thies JE and Burton S 2008 Stability of black carbon in soils across a climatic gradient. Journal of Geophysical Research 113, G02027. 10.1029/2007JG000642
Oxidation of black carbon by biotic and abiotic processes Chih-Hsin Cheng a, Johannes Lehmann a,-, Janice E. Thies a, Sarah D. Burton b, Mark H. Engelhard b a Department of Crop and Soil Sciences, Cornell University, 909 Bradfield Hall, Ithaca, NY 14853, USA b Environmental Molecular and Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA Received 27 January 2006; received in revised form 19 May 2006; accepted 28 June 2006 Available online 22 August 2006