校友之家

首页

【学术报告】Applications of Mercury Stable Isotopes

2020-11-10

报告时间:2020.11.12(星期四)上午10:00-12:00AM

 

线上会议:1. zoom (会议号:623 5221 9512)  建议优先通过该方式观看报告,以便交流提问

                  2.Bilibili直播链接:https://live.bilibili.com/22606419

线下观看:221

嘉宾:Bridget Bergquist 教授

嘉宾简介:

Bridget Bergquist 是加拿大多伦多大学地球科学学院副教授。博士毕业于麻省理工学院和伍兹霍尔海洋研究所。她主要利用金属稳定同位素研究金属元素的生物地球化学循环以及相关的环境过程,例如碳循环、大洋环流、环境演化,和人类活动对环境的影响等。她是最早发现汞同位素非质量分馏的研究者,她对汞同位素非质量分馏的研究于2007年发表在Science(引用已达500多次),开启了汞同位素研究的黄金时代,是金属同位素地球化学领域的里程碑事件。目前的研究主要关注汞的生物地球化学循环、汞铅等重金属污染和海洋微量元素循环。

 

报告摘要:

Applications of Mercury Stable Isotopes

 

Mercury is a globally distributed metal that bioaccumulates in aquatic food webs leading to dangerous exposure to humans and wildlife. Despite decades of research, many knowledge gaps hinder our understanding of both the modern and past Hg cycle. These gaps make it challenging to predict how changes in emissions and climate will affect the Hg cycle. A rapidly growing tool to study Hg is Hg stable isotope geochemistry. Mercury is unique in that it exhibits many types of isotopic fractionation including conventional mass dependent fractionation (MDF) and at least three types of mass independent fractionation (MIF). Hg isotope geochemistry is already being used to successfully trace sources of Hg, quantify certain transformations of Hg in the environment, and challenge our understanding of Hg in the environment. Much like the traditional stable isotope systems (i.e. C, O), Hg MDF is ubiquitous in nature and occurs during redox, biological, speciation and phase changes. Unlike Hg MDF, large Hg MIF is thought only to occur in photochemical reactions, with different photochemical reactions displaying unique patterns of MIF for different isotopes of Hg, six of which are routinely measured. Because MIF signatures are only affected by a limited number of reactions, the extent and ratio of MIF from different isotopes is preserved and can be used as a reliable tracer of different sources if the sources have different MIF signatures. In this talk, applications of Hg isotopes to soils, biota and the atmosphere will be discussed.

 

 


相关链接 天津大学 天津大学办公网 天津大学教务处 天津大学研究生院 天津大学图书馆