题目：Diffusive gradients in thin films (DGT): An emerging technology for measurements of bioavailable phosphorus and metals in sediments and soils

主讲人：Dr. Chaosheng Zhang（张朝生）

讲座时间： 2013年5月7日（星期二） 下午 4：00—5：00

讲座地点：大学城校区四号大教室

讲座主要内容：

This talk provides an overview of the principle and latest development of the diffusive gradients in thin films (DGT) technology and its applications in environmental studies with a focus on bioavailability assessment of phosphorus and metals. Compared with conventional methods, the DGT technology has significant advantages: “in situ” measurement, time averaged concentrations and high spatial resolution. The “in situ” feature avoids the artificial influences including contamination of sample collection and treatment which may change the forms of chemicals, thus providing “true” information of the bioavailable or labile forms in the environment. Due to the strong temporal variations of the dissolved forms of chemicals in waters, the time-averaged (normally in 24 hours) concentrations provide reliable and robust results. As the labile chemicals are absorbed on the binding gel, the micro-scale spatial distribution of their concentrations in the environment can be obtained at a resolution of sub-millimetres and at the two-dimensional level in combination with the analyses by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), computer-imaging densitometry techniques (CID) or a routine procedure consisting of 2D slicing, elution, and detection. The feature of high-resolution measurement with the DGT provides novel information for the understanding of the micro-scale environmental processes and mechanisms. The DGT technology provides promising potential for novel applications in agriculture, environmental monitoring and mining industry for the measurement of bioavailable forms of P and metals. However, further studies are needed to properly interpret the DGT measured results in relation to bioavailability under different environmental conditions and standard procedures are required to make the DGT results comparable. 

 

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主讲人简介：
Dr. Chaosheng Zhang received his bachelor’s and master’s degrees from Peking University, and PhD degree from Institute of Geography, Chinese Academy of Sciences.
Dr. Chaosheng Zhang is head of GIS Centre, Ryan Institute at National University of Ireland, Galway. He teaches Geographic Information System (GIS) and statistics courses at School of Geography and Archaeology of the University. Dr. Zhang’s academic background covers both GIS and environmental geochemistry. His research interest focuses on spatial analyses of environmental variables, especially metals in soils and soil organic carbon, using GIS, geostatistics and other spatial statistical techniques. One of the current research directions of Dr. Zhang is spatial analyses of environment and health. Dr. Zhang has published more than 80 papers in peer-reviewed journals. He is a reviewer for more than 30 international journals.
Dr. Zhang has research experience in China, Sweden, the USA, Australia, Jamaica, the UK, and Ireland. Dr. Zhang is chair and organizer of two internationally leading conferences in environment and health (SEGH 2010 International Conference and Workshops on Environmental Quality and Human Health; SESEH 2012 Sino-European Symposium on Environment and Health).
Dr. Zhang holds the following international professional positions:

• Councilor of SEGH (Society for Environmental Geochemistry and Health)
• Councilor of IMGA (International Medical Geology Association)
• Member of Editorial Board of Science of the Total Environment
• Member of Editorial Board of Environmental Geochemistry and Health