Chemical reactivity of natural peat towards U and Ra
Chemical reactivity of natural peat towards U and Ra
复制标题
DOI：
10.1016/j.chemosphere.2018.03.140
复制
发表时间：
2018-07-01
期刊：
影响因子：
8.8
通讯作者：
Descostes, M.
中科院分区：
文献类型：
--
作者：
Bordelet, G.;Beaucaire, C.;Descostes, M.
泥炭是一种含有几种有机成分的复杂材料，这有助于它具有很高的保留金属的能力。在铀矿开采的背景下，泥炭可以积累高浓度的铀及其衰变产物，如镭。因此，与泥炭的相互作用似乎是了解控制这些产品命运的地球化学机制的关键因素。研究了U(VI)和Ra-226两种微量元素对泥炭中天然有机质的吸附性能。该方法适用于来自采矿环境的不同有机质含量(从40%到70%)和碎屑负荷的天然泥炭样品，以及有机质含量超过98%的湿地泥炭样品。在本研究中，将泥炭材料作为吸附剂，其对金属和其他污染物的反应性可以描述为离子交换剂的反应性。一种基于羧基位置吸附性质的相对简单的离子交换模型已成功地应用于描述铀和镭的吸附。在铀矿开采中能够控制这些放射性核素迁移率的不同机制的概述中，即使在有氧条件下，有机物也可能是清除放射性核素的主要贡献者之一。(C)2018爱思唯尔有限公司。保留所有权利。
Peat is a complex material with several organic constituents that contribute to its high capacity to retain metals. In the context of uranium mining, peat can accumulate high concentrations of uranium and its decay products such as radium. Hence, interaction with peat appears to be a key factor in the understanding of the geochemical mechanisms controlling the fate of these products. This study aims to determine the sorption properties of two trace elements, U(VI) and Ra-226, on natural organic matter from peat. The presented method was applied to both natural peat samples originating from a mining context, with various contents of organic matter (from 40 to 70%) and detrital loads, and wetland peat with a more than 98% composition of organic matter. In the present study, considering peat material as a sorbent, its reactivity towards metals and other contaminants can be described as that of an ion exchanger. A relatively simple model of ion-exchange based on the sorption properties of carboxylic sites has been applied with success to describe the sorption of uranium and radium. In the general overview of the different mechanisms able to control the mobility of these radionuclides in a uranium mining context, organic matter is likely one of the main contributors to radionuclide scavenging even under oxic conditions. (C) 2018 Elsevier Ltd. All rights reserved.