Characteristics of Biochar: Microchemical Properties
Characteristics of Biochar: Microchemical Properties
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DOI：
10.4324/9781849770552-10
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发表时间：
2012-05
期刊：
影响因子：
--
通讯作者：
J. Amonette;S. Joseph
中科院分区：
文献类型：
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作者：
J. Amonette;S. Joseph
生物炭来源于各种生物原料，这些原料在一系列条件下被热降解，因此在组成和化学性质上表现出相应的大范围。部分由于热过程本身的混乱性质，这种化学异质性甚至在单个生物炭中扩展到微观尺度。因此，从最严格的意义上说，在特定原料/工艺组合下制成的每种生物炭都呈现出独特的相和微环境混合物，从而产生一套独特的化学性质。在某些方面，生物炭的化学复杂性可以与早期土壤相媲美。在本章中，我们主要关注生物炭在微观和分子尺度上的化学复杂性。我们首先描述生物炭的形成过程，以及这如何影响固相的组成和性质，夹带油，以及它们在微观水平上的组织。然后，我们继续讨论生物炭在官能团和电化学性质方面表现出的表面化学范围。最后，我们讨论了这些性质对生物炭表面水相吸附的影响。
Biochars, being derived from a variety of biological feedstocks that have been thermally degraded under a range of conditions, exhibit a correspondingly large range in composition and chemistry. Due in part to the somewhat chaotic nature of the thermal process itself, this chemical heterogeneity extends to the microscopic scale even within a single biochar. Thus, in the strictest sense, each biochar made under a particular feedstock/process combination presents a unique mixture of phases and microenvironments that gives rise to a unique set of chemical properties. In some respects, the chemical complexity of biochars rivals that of incipient soils. In this chapter we focus on the chemical complexity of biochar as manifested primarily at a microscopic and molecular scale. We start by describing the biochar-formation process and how this influences the composition and nature of the solid phases, entrained oils, and their organization at the microscopic level. We then proceed to discuss the range of surface chemistries exhibited by biochars in terms of functional groups and electrochemical properties. We conclude with a discussion of the influence of these properties on the sorption of aqueous species at biochar surfaces.