Evaluation of diffusion parameters of radon in porous material by flow-through diffusion experiment

✍ Scribed by Chun-Nan Hsu; Shih-Chin Tsai; Shih-Ming Liang

• Book ID: 103989645
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 468 KB
• Volume: 45
• Category: Article
• ISSN: 0969-8043
• DOI: 10.1016/0969-8043(94)90215-1

✦ Synopsis

The effectiveness of a material in reducing the fluence rate of Rn from soil was assessed in this study by using a flow-through diffusion experiment to evaluate the diffusion parameters-apparent diffusion coefficient and capacity factor--of radon (Rn) in a porous material. The diffusion process would be required to have already reached a steady state so that an accurate estimate of the diffusion parameters could be obtained. An improved method based on the nonlinear least-squares and Marquardt's method (NLSM method) was proposed to provide more reliable analyses of experimental data than the graphical method. The NLSM method was confirmed by the experimental results to be capable of estimating the diffusion parameters, even if the process was transient. This method was also demonstrated to correlate sufficiently with the results by the conventional method while the process had already reached steady-state. Natural mordenite was employed in this study as a testing material because it has more effective sorption for noble gas than any other earthen material.