Academic Reports at the 2020 SEG International Symposium on Rock Physics and Groundwater Fluid Detection

发布时间: 2020-12-30

On December 19, 2020, from 14:00 to 17:30, seven foreign professors and senior scientists, Ekkehard Holzbecher, Ralf Brauchler, Peter Bayer, Hans Ruppert, Arnaud Igor Ndé Tchoupé, Chicgoua Noubactep, Willis Gwenzi made academic reports at the 2020 SEG International Symposium on Rock Physics and Groundwater Fluid Detection, held by the School of Earth Sciences and Engineering. These reports were invited and presided over by Professor Dr. Rui Hu. A total of more than 80 people participated online and offline. The forum focused on porous and fractured aquifer characterization,  precise aquifer detection, groundwater and soil pollution remediation and other topics. Foreign experts and participants conducted in-depth discussions and interacted with the audience with shared experience.

1、Ekkehard Holzbecher's report is titled “Hydraulic conductivity in fracture matrix networks”. Professor Holzbecher conducted a study on discrete fracture matrix model with Comsol Multiphysics® to simulate groundwater flow with different densities, connectivity, aperture, and fracture distributions with different lengths, resulting in a secondary relationship between hydraulic conductivity and maximum fracture lengths. The effective conductivity increases with the ratio of fracture conductivity and matrix conductivity.

2、Ralf Brauchler’s report is titled “High-resolution characterization of the induced fracture network around galleries in the Callovo-Oxfordian Clay using Pneumati Tomography”. Dr. Brauchler introduced the principle of hydraulic tomography and its applications in the highly resolved aquifer characterization. With an engineering case study, he demonstrated how to utilize the pneumatic tomography to characterize the distribution of tunnel fractures with high spatial resolution.

 

3、Peter Bayer’s report is titled “Climate change in shallow groundwater: long-term temperature trends in Central European aquifers”. Professor Bayer focuses on the long-term temperature change trend of shallow groundwater in Europe, and focuses on the overlay effects of global climate change on passive heating of shallow groundwater and active heating of shallow groundwater in urban areas, which provides a basis for further research on the sustainable use of groundwater and geothermal energy.

  

 

 

4、Hans Ruppert’s report is titled “Is phytoremediation a possible strategy to clean contaminated sites?” Professor Ruppert discussed the feasibility of plant remediation of contaminated areas and introduced the bioavailability process in soil–plant system. He studied the abundance of heavy metals in different plants and pointed out that ordinary plants are not able to treat contaminated areas within a limited time because of their growth rate, even high-yielding crops can only absorb limited harmful elements, wood burning in high-polluting areas needs to be properly handled to avoid secondary pollution. He recommended ferment crops and return the residue to crop harvest areas for multiple cycles. The study provides a new scheme for the restoration and treatment of soil pollution using biological energy.

 

5、Arnaud Igor Ndé Tchoupé’s reports is titled “Methods for metallic iron materials selection for groundwater remediation: developing the H2 evolution test”. Dr. Ndé Tchoupé mainly introduced the application of zero-valent iron (ZVI) material in groundwater remediation. He pointed out that reasonable choice should be made according to the 3+ valent reaction of iron material in groundwater remediation. At present, there is a lack of a simple and reliable method to characterization of the intrinsic reactivity of ZVI materials. The objectives of this study are to test some selected ZVI materials in acidic solution to produce hydrogen, and to compare the ability of ZVI in aqueous solutions to remove uranium (VI.), and to explore the long-term efficiency trend of ZVI materials for groundwater remediation. Dr. Ndé Tchoupé concludes that some waste iron can be used instead of industrial raw materials for groundwater remediation; the surface state of ZVI (roughness, porosity, corrosion) determines the efficiency of their removal ability of contaminants (uranium) for groundwater. It is shown that testing the effects of individual material parameters on the removal ability of a given pollutant appears to be the only way to make iron materials suitable for specific conditions in various field conditions.

6、Chicgoua Noubactep’s report is titled “Designing the next generation permeable reactive barriers for groundwater remediation”. Professor Noubactep mainly focuses on how to design a new generation of permeable reaction walls for groundwater remediation. He introduced the reaction process in Fe0/H2O system, including adsorption, co-precipitation and volume expansion, indicating that Fe0 is oxidized by H+ or H2O, O2 is reduced by Fe2+, Fe3+’s hydrolysis and polymerization, nFe (OH)3 is crystallization etc. In his report, Professor Noubactep confirms the effectiveness and long-term performance of ZVI as a permeable reaction wall medium.

 

7、Willis Gwenzi’s report is titled “African groundwater systems as reservoirs of toxic geogenic contaminants: Occurrence, health risks, mitigation and research needs”. Using Africa as an example, Professor Gwenzi described the groundwater systems as the reservoirs of toxic geological pollutants. In Africa, the Millennium Development Goal of safe water supply has largely been achieved, yet more than 600 million people still lack access to safe drinking water. The problem of drinking water in Africa is not just a water supply problem, and the continent's natural geological conditions pose a significant risk to human health and cannot be addressed through water supply (drilling) because of the widespread presence of highly toxic geological pollutants in African groundwater systems. Professor Gwenzi discusses medical hydrogeology in Africa and focuses on toxic geological pollutants in underground systems.