Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto M5S 35E, Canada.
Environmental NMR Centre, Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4, Canada.
Water Res. 2018 Apr 15;133:27-36. doi: 10.1016/j.watres.2018.01.026. Epub 2018 Jan 11.
Strontium (Sr) is a chemical element that is often used as a tracer in hydrogeochemical studies, and is ubiquitously distributed as a radioactive contaminant in nuclear sites in the form of strontium-90 (Sr-90). At the interface between groundwater and surface water, wetlands possess unique hydrogeochemical properties whose impact on Sr transport has not been investigated thoroughly. In this study, the adsorption and desorption of Sr was investigated on six natural wetland substrates and two mixes of exogenous media and wetland sediment: winter and summer wetland sediments, decayed cattails, wood, leaf litter, moss, bone charcoal, and clinoptilolite. The composition of the organic matter was characterized using carbon-13, solid phase Nuclear Magnetic Resonance analysis. The range of the substrates' adsorption coefficients obtained could be explained by factors indicative of proteins in the organic matter, which were shown to support strong and poorly reversible Sr adsorption. In contrast, the proportion of carbohydrates and lignin were found to be indicative of lower adsorption coefficients and higher desorption. The implications of these results for Sr pollution remediation in wetlands are discussed.
锶（Sr）是一种常用于水文地球化学研究的示踪元素，以锶-90（Sr-90）的形式作为放射性污染物广泛分布在核设施中。在地下水和地表水的交界处，湿地具有独特的水文地球化学性质，但其对锶迁移的影响尚未得到充分研究。在这项研究中，我们研究了 Sr 在六种天然湿地基质和两种外源介质与湿地沉积物混合物上的吸附和解吸作用：冬季和夏季湿地沉积物、腐烂的香蒲、木材、落叶、苔藓、骨炭和斜发沸石。使用碳-13、固相核磁共振分析对有机物的组成进行了表征。获得的基质吸附系数范围可以用有机物中蛋白质的指示因子来解释，这些指示因子支持 Sr 的强且不可逆的吸附。相比之下，碳水化合物和木质素的比例表明吸附系数较低，解吸率较高。讨论了这些结果对湿地中 Sr 污染修复的意义。
