文章基本信息

标题：The Effect of Dissolved Humic Acids on Aluminosilicate Formation and Associated Carbon Sequestration
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作者：Ashaki A. Rouff ; Brian L. Phillips ; Stacey G. Cochiara 等
期刊名称：Applied and Environmental Soil Science
印刷版ISSN：1687-7667
电子版ISSN：1687-7675
出版年度：2012
卷号：2012
DOI：10.1155/2012/430354
出版社：Hindawi Publishing Corporation
摘要：Allophane and imogolite neogenesis in soils may occur in the presence of organic matter. To understand this process under conditions relevant to soils, the influence of dissolved organic carbon (DOC) as humic acid (HA), on aluminosilicate formation was studied at 25∘C, pH 6, and low-DOC concentrations. For solutions with initial Al/Si ratios of 1–2.1, and 0–6 mg/L DOC, precipitates recovered after 20 h had Al/Si ratios of 2.2–2.7. The formation of allophane, imogolite-like material, and aluminosilicate gel was confirmed by XRD, FTIR, and NMR. The effect of DOC was to produce a small, but systematic increase in imogolite-like Si in the precipitate, and a decrease in the formation of aluminosilicate gel. Results suggest that the presence of DOC as HA slows the otherwise rapid polymerization of Al and Si at low temperature, and may also promote the formation of imogolite. The high C content of these precipitates indicates that this process may facilitate the sequestration of organic matter, slowing C cycling in soils.