A Method for Characterizing Spatiotemporal Scale Correlations of Solute Transport in Porous Media

Abstract

The invention discloses a method for representing time-space scale association of solute transport in a porous medium. The method comprises the steps of selecting a solute transport process in the specific porous medium as a research object, determining a test condition, and obtaining test data of a solute breakthrough curve; building a time-space fractal derivative convection dispersion model, and deriving an analytic solution of the time-space fractal derivative convection dispersion model; in combination with the test data of the solute breakthrough curve, calculating parameters of the time-space fractal derivative convection dispersion model, quantizing the solute breakthrough curve by adopting the analytic solution of the model, and analyzing early arrival and trailing features of thebreakthrough curve; and according to values of the model parameters, analyzing an association degree between the model parameters and a time or space scale, and giving a quantitative relationship between the model parameters and the time or space scale. The smaller the orders of a time fractal derivative and a space fractal derivative are, the higher the time-space association degree is, and themore remarkable the early arrival and trailing features of the breakthrough curve is. The method can be used for groundwater and soil pollution prediction, assessment, remediation and the like, and isconvenient for use in engineering.

Description

technical field

[0001] The invention relates to an environmental fluid technology method, in particular to a method for characterizing the time-space scale correlation of solute migration in a porous medium. Background technique

[0002] The collection and transportation of oil and gas, the solidification and storage of carbon dioxide, the deep burial storage of nuclear waste, the site selection of landfills, and seawater intrusion and other engineering problems all involve the common problem of solute migration in porous media. A large number of indoor and field experiments have shown that the solute transport process in porous media usually exhibits time-scale correlation characteristics, that is, its diffusion coefficient or flow rate is no longer a constant, but a linear or nonlinear function of time or space. This type of process is called is a non-Fick, anomalous or non-Gaussian transport process. Therefore, exploring and quantifying the laws of the time-space scale c...

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