Method for determining coal carbon in the reclaimed minesoils contaminated with coal

TitleMethod for determining coal carbon in the reclaimed minesoils contaminated with coal
Publication TypeJournal Article
Year of Publication2008
AuthorsUssiri D.AN, Lai R.
JournalSoil Science Society of America Journal
Volume72
Issue1
Pagination231-237
Date PublishedJan-Feb
ISBN Number0361-5995
KeywordsBLACK CARBON, C-14, FOREST, GENESIS, MATTER, MINING DISTRICT, RICH MINE SOILS, sediments, SITES, SOIL ORGANIC-CARBON
Abstract

Minesoils are anthropic soils developed on land disturbed by mining activities. Minesoils developed on the reclaimed surface-mined sites for coal are contaminated with coal particles resulting from mining and reclamation activities. Therefore, the total organic carbon (TOC) pool in these sites is a mixture of coal and plant-derived recent soil organic carbon (SOC). Accurate estimates of SOC pools and C sequestration rates in the reclaimed minesoils (RMS) is limited by the lack of a standard and cost-effective method for determination of coal C concentrations in the RMS. The chemi-thermal method, based on the oxidative resistance of coal, was developed and validated with radiocarbon analysis using selected artificial soil-coal mixtures and minesoil samples. Radiocarbon analysis of RMS samples indicated that minesoils from the top 10-cm depth developing from topsoil applied during reclamation was coal C free. The contribution of coal C and the radiocarbon age of TOC increased with increasing soil depth. The coal C fraction accounted for 0 to 92% of TOC in the RMS samples. The coal C fraction was highly correlated with delta C-13 (r(2) = 0.84), suggesting that stable isotope composition could estimate the coal C concentration in RMS samples. Analysis of coal and artificial soil and coal mixtures indicated that chemi-thermal treatment was effective in removing recent SOC with minimum effect on coal. Analysis of RMS samples indicated that both radiocarbon activity and the chemi-thermal method were effective in estimating coal C concentration in RMS of southeast Ohio. The coal C concentrations for both methods were highly correlated (r(2) = 0.95), suggesting that the chemi-thermal method was as effective as radiocarbon activity measurement in estimating coal C concentration in these soils.

DOI10.1016/j.dsr2.2008.07.005