CN-122020968-A - Non-equilibrium process contribution rate decoupling calculation method for solute non-feik abnormal migration

CN122020968ACN 122020968 ACN122020968 ACN 122020968ACN-122020968-A

Abstract

The invention discloses a non-equilibrium process contribution rate decoupling calculation method for solute non-fick abnormal migration, which comprises the steps of constructing an abnormal migration effect index for quantifying and characterizing non-fick abnormal migration behaviors of solutes based on a mathematical mapping relation between a solute experiment penetration curve and a equilibrium adsorption model calculation penetration curve, defining a solute experiment penetration curve concentration function conforming to a double-pore medium model as C a (v), obtaining a concentration function C b (v) of a equilibrium adsorption model calculation penetration curve, obtaining a concentration function C c (v) of a single-point adsorption model calculation penetration curve, obtaining a concentration function C d (v) of a two-point adsorption model calculation penetration curve, and calculating contribution rates of various physical and chemical non-equilibrium processes to abnormal migration effects according to C a （v）、C b （v）、C c （v）、C d (v) decoupling.

Inventors

ZHU JUN
CHEN CHAO
YANG SONG
WANG RUIQING
HAO YING
Liang Pengliang
XIE TIAN
LIU TUANTUAN
ZHANG AIMING

Assignees

中国辐射防护研究院

Dates

Publication Date: 20260512
Application Date: 20251229

Claims (8)

1. A method for calculating the non-equilibrium process contribution rate decoupling of abnormal migration of a solute non-fick, comprising: calculating a mathematical mapping relation between a penetrating curve based on a solute experiment penetrating curve and a balance adsorption model, and constructing a total abnormal migration effect index for quantifying and characterizing non-feik abnormal migration behaviors of solutes, wherein the total abnormal migration effect index is a sum of abnormal migration effect indexes caused by a convection-diffusion transport process between communicating pores, a water quantity and solute exchange process between dead-end pores and communicating pores, a dynamic adsorption process between communicating pores, an instantaneous adsorption process between communicating pores and an instantaneous adsorption process between dead-end pores; Fitting an actual penetration curve of the solute by using a double-pore medium model to obtain parameters of a physical and chemical unbalance process of the solute in the double-pore structure, wherein the parameters of the physical and chemical unbalance process comprise dispersity, water exchange rate and solute exchange rate between dead-end pores and connected pores, and the parameters of the chemical unbalance process comprise instantaneous adsorption site proportion among the connected pores, chemical adsorption rate among the connected pores, adsorption site proportion contacted with the dead-end pores and distribution coefficient; defining a concentration function conforming to the dual pore medium model as C a (v); Substituting the distribution coefficient and the dispersion into a balance adsorption model to obtain a concentration function C b (v) of a calculated penetration curve of the balance adsorption model; Substituting the chemical adsorption rate, the dispersity and the distribution coefficient among the communicated pores into a single-point adsorption model to obtain a concentration function C c (v) of a single-point adsorption model calculation penetration curve; Substituting the chemical adsorption rate, the dispersity, the distribution coefficient and the instantaneous adsorption site proportion among the communicated pores into a two-point adsorption model to obtain a concentration function C d (v) of a calculated penetration curve of the two-point adsorption model; And respectively solving abnormal migration effect indexes caused by a convection-dispersion transportation process between the communicating pores, a water quantity and solute exchange process between the dead-end pores and the communicating pores, a dynamic adsorption process between the communicating pores, an instantaneous adsorption process between the communicating pores and an instantaneous adsorption process between the dead-end pores according to C a （v）、C b （v）、C c （v）、C d (v).
2. The method of claim 1, wherein constructing a total anomalous migration effect index comprises: ; Where ATI T is the total anomalous migration effect index, v a is the pore volume corresponding to the peak of the early breakthrough portion breakthrough curve, v b is the pore volume corresponding to the peak of the trailing portion breakthrough curve, and M 0 is the total injection mass.
3. The method of claim 2, wherein the convection-diffusion transport process between communicating pores does not cause abnormal migration of solute penetration curves, and is free of components in ATI T .
4. The method of claim 1, wherein solving for the index of anomalous migration effects caused by the exchange of water and solutes between the dead-end pores and the connected pores, the kinetic adsorption process between the connected pores, the transient adsorption process between the connected pores, and the transient adsorption process between the dead-end pores, respectively, based on C a （v）、C b （v）、C c （v）、C d (v) comprises: calculating the abnormal migration effect index caused by the process according to the following calculation formula: ; ; ; ; ; ; The method comprises the steps of obtaining an abnormal migration effect index caused by water volume and solute exchange process between a dead end pore and a connected pore, wherein the ATI E is positive, the ATI M-D is an abnormal migration effect index caused by dynamic adsorption process between the connected pores, the ATI M-S is negative, the ATI I-S is an abnormal migration effect index caused by transient adsorption process between the dead end pores, the ATI I-S-1 is an abnormal migration effect index of a part with the same proportion as the transient adsorption position between the connected pores, the ATI I-S-2 is an abnormal migration effect index of a part with the same proportion as the dynamic adsorption position between the connected pores, the v G is a pore volume corresponding to the peak of the early part of the two-point model penetrating curve, the v H is a pore volume corresponding to the peak of the trailing part of the two-point model penetrating curve, the v C is a pore volume corresponding to the peak of the early breakthrough part of the two-point model penetrating curve, the v D is a pore volume corresponding to the peak of the early breakthrough part of the two-point model penetrating curve, the v E is a pore volume corresponding to the peak of the two-point model penetrating curve, and the total mass of the two-point model penetrating curve is a pore volume corresponding to the peak of the two-point model penetrating curve, and the average pore volume of the two-point model penetrating the peak is a total pore volume of the equilibrium pore is a volume of the equilibrium pore model corresponding to the two-point model, and the average pore mass of the two-end-permeable model penetrating a positive end is a pore model, and a positive average ratio of a pore is obtained.
5. The method according to claim 4, wherein the method further comprises: The method for verifying the rationality and the correctness of the decoupling calculation method by utilizing two parameters of the instantaneous adsorption bit proportion between the communicated pores and the adsorption bit proportion contacted with the dead end pores, which are obtained by fitting a double-pore medium model, comprises the following steps: Judging the consistency of f em and |ATI M-S |/（|ATI M-S |+ATI M-D ); and judging the consistency of f mi and |ATI I-S |/（ATI M-D +|ATI M-S |+|ATI I-S |).
6. The method of claim 1, wherein the rate of water exchange and the rate of solute exchange between the dead-end pores and the connected pores is obtained by performing a breakthrough experiment with the non-reactive tracer and fitting the actual breakthrough curve of the non-reactive tracer with a dual pore medium model.
7. The method of claim 1, wherein the instantaneous adsorption site ratio between the interconnected pores, the chemisorption rate between the interconnected pores, the adsorption site ratio in contact with the dead end pores, and the partition coefficient are obtained by performing a breakthrough experiment with the target solute and fitting the actual breakthrough curve of the solute with a dual pore medium model.
8. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the method of one of claims 1-7.

Description

Non-equilibrium process contribution rate decoupling calculation method for solute non-feik abnormal migration Technical Field The invention relates to the field of environmental hydrogeology, in particular to a decoupling calculation method for a contribution rate of a non-equilibrium process of non-fick abnormal migration of a solute. Background In an ideal state, the migration behavior and rule of the solute in the equivalent continuous porous medium can be described by introducing an adsorption distribution coefficient (K d) into a convection-dispersion model (ADE) based on the Fick's law of diffusion, and the penetration curve of the solute under the condition of pulse injection shows a unimodal form of symmetrical normal distribution. A large number of tracing experiments show that the penetration curve actually observed by the solute can deviate from the theoretical prediction of a convection-dispersion model obviously, so that early breakthrough and tailing occur, and the migration behavior of the solute which does not conform to the Phake law is defined as abnormal migration, which is the most common mode of solute migration in groundwater. The abnormal migration characteristics of solutes and their mechanism studies have become an important scientific problem in the field of environmental hydrogeology. The anomalous migration effect of the solute penetration curve is a result of coupling by a physical-chemical coupling imbalance mechanism. The physical unbalance process is caused by existence of dead-end pores, solute enters the dead-end pores under the drive of concentration gradient and then needs to undergo long-time diffusion action to be exchanged again into the communication pores, so that the diffusion among the pores and the retarding action of molecular diffusion are reflected, and the chemical unbalance process is caused by instantaneous adsorption/dynamic adsorption between the dead-end pores and the communication pores. By introducing mass exchange coefficients and transient/kinetic adsorption parameters between the pores, a synergistic characterization of both types of unbalanced processes is achieved. The 5 physical and chemical non-equilibrium processes of solutes in the dead-end-connected double pore structure are summarized as follows: ① A water quantity and solute exchange process between the dead end pore and the communicating pore; ② Instantaneous adsorption process between dead end pores; ③ A convection-dispersion transport process between the communicating pores; ④ A kinetic adsorption process between the interconnected pores; ⑤ And (5) connecting transient adsorption processes among the pores. Pore structure and fluid dynamics are the main factors of the driving solute imbalance anomalous migration behavior. The number of dead-end pores may reflect the intensity of the solute abnormal migration effect to some extent, and thus the number of dead-end pores as determined by the X-ray μct imaging technique may reflect the intensity of the solute abnormal migration effect to some extent. At a fixed scale, the number of dead-end voids, as measured by X-ray μct imaging techniques, is an upper limit and an inherent attribute. In the dynamic solute transport process, the number of dead-end pores participating in the reaction is a dynamic value along with the change of environmental conditions such as fluid dynamics. Therefore, it is necessary to establish a unified index that dynamically reflects the number of dead-end pores participating in the reaction under different hydrodynamic conditions and is used to quantitatively characterize the contribution of various physical and chemical non-equilibrium processes to the anomalous migration effect. Disclosure of Invention To achieve the above and other related objects, the present invention discloses a method for calculating a non-equilibrium process contribution rate decoupling of abnormal migration of a solute other than feik, comprising: Calculating a mathematical mapping relation between a penetrating curve based on a solute experiment penetrating curve and a balance adsorption model, and constructing an abnormal migration effect index for quantifying and characterizing non-feik abnormal migration behavior of solutes, wherein the abnormal migration effect index is the sum of abnormal migration effect indexes caused by a convection-diffusion transport process between communicating pores, a water quantity and solute exchange process between dead-end pores and communicating pores, a dynamic adsorption process between communicating pores, an instantaneous adsorption process between communicating pores and an instantaneous adsorption process between dead-end pores; Fitting an actual penetration curve of the solute by using a double-pore medium model to obtain parameters of a physical and chemical unbalance process of the solute in the double-pore structure, wherein the parameters of the physical and chemical unbalance process comprise dis