Article
Geochemistry & Geophysics
Jiacheng Wu, Binglin Guo, Mingliang Kang, Yixiao Kang, Wujian Jin, Hanyu Wu, Shijun Wu
Summary: This study compares the interaction of Se(IV) with different host rocks and reveals that the mechanisms of Se(IV) reduction are different for Beishan granite and Tamusu claystone. The findings provide important data for the safety assessment of China's future high-level radioactive waste repository and improve our understanding of the geochemical behavior of selenium in anoxic environments with Fe(II)- and sulfide-bearing minerals.
APPLIED GEOCHEMISTRY
(2022)
Article
Chemistry, Physical
Tao Wu, Zhengye Feng, Zilong Geng, Minhong Xu, Qiang Shen
Summary: The diffusion of Re(VII) and Se(IV) in bentonite can be restricted by the formation of barite precipitates. The effective diffusion coefficient of these radionuclides decreases with the increase of barite precipitates. The formation of high amounts of barite precipitates can completely stop the diffusive flux.
APPLIED CLAY SCIENCE
(2023)
Article
Engineering, Environmental
Z. H. Wang, T. Su, Heinz Konietzky, Y. L. Tan, G. L. Zhou
Summary: The study focused on the hydraulic properties of Beishan granite, with the findings showing that treatment temperatures below 400 degrees Celsius lead to a gradual decrease in peak strength and crack damage threshold, while treatment at 500 degrees Celsius results in an increase. Additionally, the peak strength and crack damage threshold reached their maximum under a fluid pressure of 4 MPa for each treatment temperature.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Environmental Sciences
Jinlong Peng, Fenglian Fu, Chujia Ye, Bing Tang
Summary: The study found that fulvic acid had different effects on Fh-Se transformation at different pH values. Fulvic acid promoted Fh-Se transformation at initial pH 5.0, inhibited it at initial pH 10.0, and had varying effects at initial pH 7.5 depending on the C/Fe ratio. Fulvic acid induced the generation of more extractable Se(IV) at pH 5.0, more coprecipitated Se(IV) at pH 7.5, and blocked the release of Se(IV) at pH 10.0.
ENVIRONMENTAL POLLUTION
(2022)
Article
Chemistry, Analytical
Tao Wu, Zilong Geng, Zhengye Feng, Guoxiang Pan, Qiang Shen
Summary: The diffusion behavior of Re(VII), Se(IV), and Cr(VI) in compacted Gaomiaozi bentonite was investigated. Re(VII) and Cr(VI) were excluded from the surface of bentonite particles, while Cr(IV) showed stronger exclusion effect due to its lower tortuosity and larger diffusion pore diameter.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2022)
Article
Metallurgy & Metallurgical Engineering
Wang Zi-hui, Zhou Hong-wei, Konietzky Heinz, Li Shu-min, Wang Ting-zheng
Summary: This research investigates the effects of heating treatment on the mechanical properties of Beishan granite. The results show that heating treatment leads to an increase in sample diameter, a slightly higher peak strength, and a lower dilatancy threshold. Moreover, increasing temperature has negative influence on elastic modulus and Poisson ratio, while micro cracks are closed during heating and contribute to the increase of peak strength.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2022)
Article
Engineering, Geological
Jian-Feng Liu, Xing Luo, Gan Feng, Lu-Lin Zhou, Xing-Guo Yang, Gong-Da Lu
Summary: The study examines the influence of thermal exposure on rock response over the long term, focusing on the enhanced geothermal system and geological disposal of radioactive waste. Triaxial creep experiments on thermally-stressed Beishan granite reveal that thermal cracking and hydro-static compaction reshape the crystalline fabric and significantly affect creep deformation. This research provides insights into time-dependent rock deformation and its implications for decarbonized electricity production and sustainable energy transition.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Chemistry, Analytical
Yuzhen Sun, Hui Zhang, Chuan-Pin Lee, Mingbiao Luo, Rong Hua, Weigang Liu, Jie Kong, Yanqin Hu
Summary: The diffusion behavior of Se(IV) in Tamusu clayrock core was studied for the first time in laboratory, and the effects of pH, ionic strength, and humic acid were investigated. The study obtained values for the effective diffusion coefficient, distribution coefficient, and rock capacity factor. Discussion on the diffusion mechanism of radionuclide in Tamusu clayrock provides experimental data support and theoretical references for the pre-selection of clayrock sites and safety assessment in China's high-level radioactive waste deep geological repository.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2021)
Article
Engineering, Geological
Yao Song, Zhongwen Yue
Summary: This study investigated the impact of loading rate on the dynamic fracture behavior of Beishan granite, revealing a positive correlation between fracture toughness and loading rate, with CCNSCB specimens showing higher toughness values than NSCB specimens. The evolution of DSIFs and dynamic fracture energy of Beishan NSCB and CCNSCB specimens were similar, showing a positive relationship with loading rate, while the fracture energy absorption rate gradually decreased with increasing loading rate.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Engineering, Environmental
C. S. Wang, J. F. Liu, Y. W. Zhao, S. J. Han
Summary: This study investigated the tensile properties and crack modes of Beishan granite using different testing methods. It was found that the failure during the Brazilian splitting test was more severe and cracks expanded more rapidly compared to the direct tensile test. Additionally, a damage constitutive model for the rock was established and the change process of the damage variable was divided into three stages.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Environmental
Zidan Yuan, Rui Su, Xu Ma, Le Yu, Yuanming Pan, Ning Chen, Roman Chernikov, Leo Ka Long Cheung, Reza Deevsalar, Ayetullah Tunc, Liang Wang, Xiangfeng Zeng, Jinru Lin, Yongfeng Jia
Summary: The attenuation of acidic Se(IV)-rich wastewater is a significant environmental challenge. This study investigates the effects of various factors on the direct co-precipitation of ferric selenites. The results show that pH values, Se(IV)/Fe(III) molar ratios, initial Se(IV) concentrations, and alkali neutralization agents all play important roles in immobilizing Se(IV).
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Multidisciplinary Sciences
Noriaki Watanabe, Kaori Takahashi, Ryota Takahashi, Kengo Nakamura, Yusuke Kumano, Kohei Akaku, Tetsuya Tamagawa, Takeshi Komai
Summary: The novel chemical stimulation method using chelating agents significantly enhances the permeability of rock fractures, creating voids under confining stress and avoiding the challenges associated with traditional methods. Research results demonstrate a new approach for chemical stimulation.
SCIENTIFIC REPORTS
(2021)
Article
Thermodynamics
Qi He, Shiwan Chen, Guibin Wang, Shuangying Zuo, Fubo Yang
Summary: This study investigated the thermo-mechanical properties of Beishan granite during heating and cooling processes. The temperature difference between different mineral grains was evident, with feldspar expanding and quartz and mica being compressed during heating. The thermal cracking emerged within a certain temperature range and was active during temperature changes. It was found that the mild high temperature caused by decay heat of high-level radioactive waste could enhance the tightness and strength of the repository, contributing to its long-term safety.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Geological
X. G. Zhao, J. Wang, M. Cai, G. S. Su
Summary: Experimental study showed that under different σ(2) loading conditions, the strainburst characteristics of the specimens depend on the magnitude of σ(2). The lubricated specimens exhibited significantly different crack initiation, peak strength, failure mode, and energy release characteristics compared to the non-lubricated specimens. Additionally, with increasing σ(2), the differences in weight and kinetic energy of ejected rock fragments between the two groups also increased.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Energy & Fuels
Yun Wu, Xiao-Zhao Li, Zhen Huang, Ying-Chao Wang, Long-Chuan Deng
Summary: The study found that the P-wave velocity of granite decreases with temperature, the porosity of granite increases rapidly above 500 degrees C, and the tensile strength of granite linearly decreases with temperature. Acoustic emission tests and thin section observations showed that temperature leads to an increase in the closure and unstable extension of cracks. The research findings can provide guidance for the construction safety of rock masses exposed to high temperatures.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2021)
