Radon exhalation from temperature treated loess

• Published in: The Science of the total environment Vol. 832; p. 154925
• Main Authors: Li, Pengfei, Sun, Qiang, Geng, Jishi, Yan, Xusheng, Tang, Liyun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2022
• Subjects: High temperature; Loess; Nitrogen adsorption; Pore structure; Radon exhalation; SEM; Loess; SEM; High temperature; Nitrogen adsorption; Pore structure; Radon exhalation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.154925

Radon gas is a cancer risk and exists naturally in certain soils, such as loess, which is an important raw earth construction material in arid regions such as northwestern China and southern USA. Accordingly, the radon exhalationed from building materials is of increasing concern; however, there is little research on radon exhalation from loess. In this study, the pore structure and radon exhalation characteristics of heat-treated loess were investigated by nitrogen adsorption tests, swept surface electron microscopy, and radon measurements. The rate of radon exhalation increases linearly with temperature until 400 °C and then decreases exponentially. Changes in the internal pore structure (pore type, surface morphology, and specific surface area) of loess are strongly correlated with the radon exhalation rate. The volume of micropores (<2 nm diameter) is an important influence on radon exhalation ability, which is closely related to the fractal dimension of the micropore structure after heating. The results provide guidance for predicting the radiation risk posed by radon diffusing from loess. [Display omitted] •The radon diffusion rate of high temperature loess was studied in detail.•High temperature seriously affects the diffusion rate of radon in loess.•Micro-pore volume is positively correlated with the radon diffusion rate.•The diffusion rate of radon in loess is the fastest at 400 °C.