Method for calculating apparent diffusion parameters based on iterative analysis method in diffusion test

Abstract

The invention discloses a method for calculating apparent diffusion parameters based on an iterative analysis method in a diffusion test, wherein the method comprises the following steps: firstly, according to a basic reaction principle and a law of conservation of mass of diffusion, based on a Friedel-Crafts first law, a Friedel-Crafts second law, diffusion behavior characteristics of solutes ina porous medium, experimental initial conditions and experimental boundary conditions, integrating to obtain a diffusion reaction equation; secondly, obtaining an approach line parameter by using a graphic processing approach method, and further obtaining an initial apparent diffusion coefficient and an initial effective diffusion coefficient; and finally, repeatedly iterating and analyzing by using a parameter identification method based on an iteration and analysis method, and continuously reducing a normalized root-mean-square error to finally obtain an apparent diffusion coefficient with asmaller error. The method is simple, high in accuracy and wide in application range.

Description

technical field [0001] The invention relates to a method for calculating an apparent diffusion parameter based on an iterative analysis method in a diffusion test, and belongs to the technical field of civil engineering and environmental engineering. Background technique [0002] In response to the increasingly prominent environmental problems, our country has proposed a set of systemic contaminated site technologies, which are mainly divided into two systems: one is the repair system. For the repair system, solidification / stabilization, rinsing, and heat treatment have gradually formed. Desorption, chemical oxidation / reduction, aeration / meteorological extraction, and biodegradation are comprehensive technical systems for physical, chemical, and biological remediation of polluted soil and groundwater. These remediation technologies can be divided into ex-situ remediation and in-situ remediation; II. It is an isolation system. The so-called isolation system refers to the isol...

AI Technical Summary

Problems solved by technology

The most important thing in the isolation system is to control the diffusion of pollution. The diffusion test of pollutants is the most intuitive test to judge whether the isolation effect is good or bad. At present, the methods for calculating the diffusion coefficient mainly include: Fick's first law formula in the one-dimensional case; The Fick's second law formula for porous media with high quality and isotropy; the Crank formula for data processing using the image method, etc., in these existing methods for calculating the diffusion coefficient, the number of calculations and the formula are single, and there are certain errors in the data. The error generated in the operation is not eliminated, resulting in the accumulation of data errors, which in turn makes the final prediction results and actual test results have large errors

This low accuracy will affect the research and development and calculation of isolation system materials, so it is necessary to improve the accuracy of diffusion test results

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