An Index-Based Approach to Assessing Recalcitrance and Soil Carbon Sequestration Potential of Engineered Black Carbons (Biochars)

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• 作者：Omar R. Harvey ; Li-Jung Kuo ; Andrew R. Zimmerman ; Patrick Louchouarn ; James E. Amonette ; Bruce E. Herbert
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：February 7, 2012
• 年：2012
• 卷：46
• 期：3
• 页码：1415-1421
• 全文大小：299K
• 年卷期：v.46,no.3(February 7, 2012)
• ISSN：1520-5851

文摘

The ability of engineered black carbons (or biochars) to resist abiotic and, or biotic degradation (herein referred to as recalcitrance) is crucial to their successful deployment as a soil carbon sequestration strategy. A new recalcitrance index, the R₅₀, for assessing biochar quality for carbon sequestration is proposed. The R₅₀ is based on the relative thermal stability of a given biochar to that of graphite and was developed and evaluated with a variety of biochars (n = 59), and soot-like black carbons. Comparison of R₅₀, with biochar physicochemical properties and biochar-C mineralization revealed the existence of a quantifiable relationship between R₅₀ and biochar recalcitrance. As presented here, the R₅₀ is immediately applicable to pre-land application screening of biochars into Class A (R₅₀ 鈮?0.70), Class B (0.50 鈮?R₅₀ < 0.70) or Class C (R₅₀ < 0.50) recalcitrance/carbon sequestration classes. Class A and Class C biochars would have carbon sequestration potential comparable to soot/graphite and uncharred plant biomass, respectively, whereas Class B biochars would have intermediate carbon sequestration potential. We believe that the coupling of the R₅₀, to an index-based degradation, and an economic model could provide a suitable framework in which to comprehensively assess soil carbon sequestration in biochars.