Forums | HES 健康与环境科学

15 November 2024, 5:02 PM

Speaker: Dr. Thomas Lawrence Goût

报告人： 顾·托马斯博士

Title: From dissolution to precipitation: Quantitatively deconvoluting concurrent processes using isotope geochemistry

报告题目： 从溶解到沉淀： 利用同位素地球化学定量分解同时发生的过程

Date: 2024-11-18

Time: 14:30-15:30 

Room: ES354

Host: Dr. Zheng Chen

主持人： 陈正

Tencent Meeting ID: 748-5683-7998

Abstract: 

The dissolution of natural minerals and synthetic materials in natural environments is typically coupled with aqueous species transport and secondary phase precipitation. Quantitatively separating these simultaneous processes is crucial for elucidating weathering mechanisms and creating accurate models describing the release, transport and immobilization of contaminants, such as in predicting radionuclide release during the weathering of nuclear waste. However, elemental kinetic datasets, frequently gathered to study dissolution processes, struggle to resolve dissolution mechanisms concurrent with precipitation, and ex-situ analyses provide limited insights into these processes. Here, this presentation discusses the application of lithium isotope fingerprinting techniques to study the dissolution mechanisms of a synthetic glass. This technique afforded in-situ quantitative resolution of the contributions of diffusive release, congruent dissolution, and clay phase precipitation to aqueous lithium concentrations. For the glass studied, these results demonstrate a transition from diffusion-dominant dissolution to a rate controlled by congruent dissolution coupled with smectite clay precipitation.

摘要：

自然环境中天然矿物和合成材料的溶解通常与水体物种迁移和次生相沉淀同时进行。定量分离这些同时发生的过程对于阐明风化机理和建立描述污染物释放、迁移和固定的精确模型（例如预测核废料风化过程中放射性核素的释放）至关重要。然而，为研究溶解过程而经常收集的元素动力学数据集难以解决与沉淀同时发生的溶解机制，而原位分析对这些过程的了解也很有限。本报告将讨论锂同位素指纹技术在合成玻璃溶解机制研究中的应用。该技术可现场定量分析扩散释放、同向溶解和粘土相沉淀对水体锂浓度的影响。就所研究的玻璃而言，这些结果表明其溶解速率已从以扩散为主过渡到由同向溶解和直闪石粘土沉淀控制。

Biography：

Dr. Thomas Goût is a Boya Research Fellow at the College of Environmental Sciences and Engineering, Peking University, having previously worked as a Research Associate in the Department of Earth Sciences, University of Cambridge, UK. Prior to this, he graduated with a PhD in earth sciences from the University of Cambridge in 2020. His research interests broadly encompass the application of isotope geochemistry to mechanistically study mineral dissolution and precipitation processes. Whilst at Cambridge, he investigated the dissolution mechanisms of glasses and ceramics in natural environments using isotope geochemistry. His current research focusses on using isotope geochemical methods to study the precipitation of sulphate solid solutions and iron mineral-organic matter interactions. Dr Goût has 12 peer-reviewed journal publications to date with seven first-author publications, including first-author publications in GCA and npj Materials Degradation. He was recently awarded NSFC’s Research Fund for International Young Scientists.

嘉宾介绍：

Thomas Goût (顾·托马斯) 博士是北京大学环境科学与工程学院的博雅博士后，此前曾在英国剑桥大学地球科学系担任博士后。在此之前，他于 2020 年从剑桥大学获得地球科学博士学位。他的研究兴趣广泛，包括应用同位素地球化学对矿物溶解和沉淀过程进行机理研究。在剑桥大学期间，他利用同位素地球化学研究了自然环境中玻璃和陶瓷的溶解机制。他目前的研究重点是利用同位素地球化学方法研究硫酸盐固溶体的沉淀以及铁矿物与有机物之间的相互作用。迄今为止，Goût 博士在同行评审期刊上发表了 12 篇论文，其中 7 篇为第一作者发表，包括在GCA和 npj Materials Degradation 上发表的第一作者论文。他最近还获得了国家自然科学基金委的国际青年科学家研究基金。

Look forward to seeing you!

Liwen Wu