An Investigation of Black Carbon Degradation Potential in a Forest Soil Environment

An Investigation of Black Carbon Degradation Potential in a Forest Soil Environment
William, H. C.; Lee, E.; Grannas, A.; Hatcher, P. G.
American Geophysical Union, Fall Meeting 2003, abstract #B21B-0711, 12/2003

Abstract
Except for emission processes, there is currently little understanding of the mechanisms driving the degradation and biogeochemical cycling of black carbon (BC). Considering current estimates of the global BC pool (>2,500x1015gC), and its annual emission rates (55-205x1012 gC/year), BC represents roughly 16% of Earth's actively cycling organic carbon. Without significant chemical and biological degradation pathways, all of the actively cycling carbon on earth would have accumulated as charcoal in <100,000 years. This investigation show that charcoals recovered from experimental forest fires are altered significantly by microbial colonization, and mineral complexation during exposure to soil processes. Charcoal surface morphology and elemental composition were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and BET surface area measurements. The influence of 90 years aging upon carbon functionality was probed by solid-state 13C NMR spectroscopy. The prevalence of fungal mycorhizae in these forest soil charcoals also motivated an investigation of black carbon degradation via extracellular enzymes and acids known be exuded by mycelia. Degradation is quantified by carbon loss, and soluble products are examined by mass spectrometry.

AA(The Ohio State University Department of Chemistry, 100 W. 18th Ave., Columbus, OH 43210 United States; whockada@chemistry.ohio-state.edu), AB(The Ohio State University Department of Chemistry, 100 W. 18th Ave., Columbus, OH 43210 United States; elee@chemistry.ohio-state.edu), AC(The Ohio State University Department of Chemistry, 100 W. 18th Ave., Columbus, OH 43210 United States; agrannas@chemistry.ohio-state.edu), AD(The Ohio State University Department of Chemistry, 100 W. 18th Ave., Columbus, OH 43210 United States; hatcher@chemistry.ohio-state.edu)