Carboxyl-richness controls organic carbon preservation during coprecipitation with iron (oxyhydr)oxides in the natural environment
Carboxyl-richness controls organic carbon preservation during coprecipitation with iron (oxyhydr)oxides in the natural environment
复制标题
DOI：
10.1038/s43247-021-00301-9
复制
发表时间：
2021-11-04
影响因子：
7.9
通讯作者：
Peacock, Caroline L.
中科院分区：
文献类型：
--
作者：
Curti, Lisa;Moore, Oliver W.;Peacock, Caroline L.
有机碳与铁矿物的共沉淀对于其在土壤和沉积物中的保存是重要的，但是碳-铁相互作用的机制以及因此对有机碳循环的控制还远未被理解。在这里，我们将羧酸与铁（氧氢）氧化物铁铁矿共沉淀，并使用近边X射线吸收精细结构光谱和湿化学处理来确定封存机制与有机碳稳定性对其释放和化学氧化再矿化之间的关系。我们表明，有机碳封存，稳定性和持久性增加的羧基官能团的数量增加。我们认为，羧基丰富提供了一个重要的控制有机碳保存在自然环境中。我们的工作为理解土壤和沉积物中有机碳的稳定性和持久性提供了一个机制基础，这可能用于发展地球系统中有机官能团丰富度、矿物相互作用和有机碳保存之间的总体关系。有机碳通过与铁的相互作用而被封存、稳定和埋藏，有机部分的羧基丰富度增强，根据实验产生的共沉淀物的元素和显微结构分析。
The coprecipitation of organic carbon with iron minerals is important for its preservation in soils and sediments, but the mechanisms for carbon-iron interactions and thus the controls on organic carbon cycling are far from understood. Here we coprecipitate carboxylic acids with iron (oxyhydr)oxide ferrihydrite and use near-edge X-ray absorption fine structure spectroscopy and wet chemical treatments to determine the relationship between sequestration mechanism and organic carbon stability against its release and chemical oxidative remineralisation. We show that organic carbon sequestration, stabilisation and persistence increase with an increasing number of carboxyl functional groups. We suggest that carboxyl-richness provides an important control on organic carbon preservation in the natural environment. Our work offers a mechanistic basis for understanding the stability and persistence of organic carbon in soils and sediments, which might be used to develop an overarching relationship between organic functional group-richness, mineral interactions and organic carbon preservation in the Earth system.Organic carbon sequestration, stabilisation and burial through its interaction with iron is enhanced by carboxyl-richness of the organic moiety, according to elemental and microstructure analysis of experimentally produced co-precipitates.