Determination of diffusion coefficients in sandy sediments using resistivity techniques
Diffusion coefficients at the sediment-water interface are essential for prediction of flux rates across the interface. For calculating bulk sediments diffusion coefficients from free solution diffusion coefficients, Formation factor, F, can be estimated from Φ, porosity of sediments. To determine formation factor, resistivity of pore water and sandy sediments with different diameter, originated from Qingdaos seashore, were measured by using a modified Miller Soil Box, then the exponent, m, of Archie formula was obtained through curve fit. The results indicate that using the empirical m (for Φ≤0.7, m=2) given by Ullman and Aller to calculate bulk diffusion coefficient may introduce 40％～50％ error; the relationship between F and Φ can be expressed as F=Φ-1.52 for nearshore sandy sediments; substitution of m=1.52 into Ds=D0·φm-1 is verified to be suited for calculating bulk diffusion coefficient in sandy sediments.
sandy sediment diffusion coefficient resistivity formation factor
Wang Dongsheng Gao Zengwen Du Pengfei
Department of Environmental Science and Engineering Tsinghua University Beijing,China College of chemical and environmental engineering Qingdao University Qingdao,China
国际会议
北京
英文
1-3
2009-06-11（万方平台首次上网日期，不代表论文的发表时间）