Contaminant Dispersion with Axial Input Sources in Soil Media under Non-linear Sorption

2021 ◽  
pp. 1-20
Author(s):  
Rakesh Kumar Singh ◽  
Tapan Paul ◽  
Nav Kumar Mahato ◽  
Mritunjay Kumar Singh
Keyword(s):  
Contaminant Dispersion ◽  
Linear Sorption ◽  
Non Linear ◽  
Soil Media

Mathematical Modeling of Sorption on Novel Sorbent Materials 

2021 ◽  
Author(s):  
Adna Koš ◽  
Michal Kuráž
Keyword(s):  
Metal Ions ◽  
Programming Language ◽  
Great Influence ◽  
Langmuir Model ◽  
Parameters Estimation ◽  
Freundlich Model ◽  
Error Functions ◽  
Linear Sorption ◽  
Non Linear ◽  
Sorbent Materials

<p>The emission of metal ions in the environment has increased in recent times and since metal ions are not biodegradable, they belong to the cumulative toxins. Contamination of the environment with metal ions poses a serious danger to the entire ecosystem, agricultural production, quality of food and water, as well as to the health of humans and animals. This study investigates sorption as one of the processes which can be used for pollutants removal and efficiency of certain sorbent materials. Specifically, we focus on development and validation of non-linear Langmuir model and non-linear Freundlich model. Their application in sorption experiments is examined by applying different error functions and statistical methods which are employed to calculate the error divergence between observed data and predicted data of sorbate-sorbent system. Presented non-linear sorption models are developed by using programming language Fortran, and the data analysis is obtained by using different tools and packages in programming language R. Many authors are using linear sorption models in the way that they would linearize non-linear sorption models. It is evident that linear sorption models are used due to their simplicity in parameters estimation. We use approach of trying different algorithms and tools in programming language R in order to find the best objective function. This study shows that both non-linear Langmuir model and non-linear Freundlich model can be used for experimental data representation. The results also denote that better estimation and the better fit is given by Langmuir model due to divergence in error functions and graphical representation itself. The choice of sorption model has a great influence on the prediction of solute transfer and great care should be taken in selection of convenient approach.</p>

scholarly journals Determination of 137Cs and 85Sr transport parameters in fucoidic sand columns and groundwater system

2011 ◽  
Vol 9 (5) ◽  
pp. 798-807 ◽  
Author(s):  
Štefan Palágyi ◽  
Karel Štamberg
Keyword(s):  
Solid Phase ◽  
Breakthrough Curves ◽  
Desorption Isotherm ◽  
Hydrodynamic Dispersion ◽  
Transport Parameters ◽  
Constant Flow Rate ◽  
Linear Sorption ◽  
Non Linear ◽  
Constant Distribution

AbstractThe determination is based on the evaluation of experimentally obtained breakthrough curves using the erfc-function. The first method is founded on the assumption of a reversible linear sorption/desorption isotherm of radionuclides on solid phase with constant distribution and retardation coefficients, whereas the second one is based on the assumption of a reversible non-linear sorption/desorption isotherm described with the Freundlich equation, i.e., with non-constant distribution and retardation coefficients. Undisturbed cores of 5 cm in diameter and 10 cm long were embedded in the Eprosin-type cured epoxide resin column. In this study the so-called Cenomanian background groundwater was used as transport medium. The groundwater containing radionuclides was introduced at the bottom of the columns at about 4 mL h−1 constant flow-rate. The results have shown that in the investigated fucoidic sands: (i) the sorption was in principle characterized by linear isotherms and the corresponding retardation coefficients of 137Cs and 85Sr, depending on the type of sample, were approximately 13 or 44 and 5 or 15, respectively; (ii) the desorption was characterized by non-linear isotherms, and the retardation coefficients of the same radionuclides ranged between 23–50 and 5–25, respectively. The values of the hydrodynamic dispersion coefficients of these radionuclides varied between 0.43–1.2 cm2 h−1.

The Influence of Non-Linear Sorption on Colloid Facilitated Radionuclide Transport Through Fractured Media

1992 ◽  
Vol 294 ◽  
Author(s):  
Paul A. Smith
Keyword(s):  
Safety Assessment ◽  
Transport Model ◽  
Fractured Media ◽  
Radionuclide Transport ◽  
Simple Criterion ◽  
Sorption Data ◽  
Linear Sorption ◽  
Non Linear ◽  
Transport Behaviour ◽  
Waste Repositories

ABSTRACTIn the safety assessment of nuclear waste repositories, sorption of radionuclides on the surfaces of colloids may significantly modify transport behaviour where colloid concentration is sufficiently high. In the case of fractured geological media, colloids may be excluded from matrix pores, in which case radionuclides bound to them are not subject to the retarding effects of matrix diffusion and sorption onto matrix pore surfaces.A model is presented describing colloid facilitated transport through fractured media with non-linear sorption. A simple criterion is developed to predict when the presence of colloids will have a significant influence on transport and effects resulting from non-linearity of sorption are described. However, lack of comprehensive sorption data, as well as computational efficiency, mean that the use of a simplified transport model, with linear sorption both on pore surfaces and colloids, is desirable if it can be demonstrated to be conservative. A further criterion is developed to predict where such a model, with linear sorption calculated for the highest concentration encountered along the flow path, would be expected to yield conservative results.

scholarly journals Application of linear and non-linear P-sorption models for describing phosphate transport.

1989 ◽  
Vol 37 (4) ◽  
pp. 387-390
Author(s):  
S.E.A.T.M. van der Zee ◽  
F. Leus ◽  
M.J.P.F. Louer
Keyword(s):  
Linear Model ◽  
Phosphate Transport ◽  
Breakthrough Curves ◽  
Sorption Model ◽  
P Sorption ◽  
Simple Linear Model ◽  
Precipitation Model ◽  
Linear Sorption ◽  
Non Linear ◽  
Good Agreement

Phosphate transport in small columns was described using a two-site linear sorption model and a non-linear adsorption-precipitation model. Both approaches gave reasonable to good agreement with experimental breakthrough curves. This indicates the applicability of the simple linear model for engineering purposes, besides the general use of the more complex non-linear model. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Modeling of transport of radionuclides in beds of crushed crystalline rocks under equilibrium non-linear sorption isotherm conditions

2010 ◽  
Vol 98 (6) ◽  
Author(s):  
S. Palágyi ◽  
Karel Stamberg
Keyword(s):  
Sorption Isotherm ◽  
Regression Function ◽  
Breakthrough Curves ◽  
Simple Method ◽  
Pulse Input ◽  
Advection Dispersion ◽  
Freundlich Equation ◽  
Linear Sorption ◽  
Retardation Coefficient ◽  
Non Linear

AbstractA simple method for fitting the values of the experimental breakthrough curves in the form of pulse response obtained in dynamic flow column experiments is presented. It is based on the equation obtained by the analytical solution of a 1-D advection-dispersion equation (ADE) under defined conditions (equilibrium dynamics, linear sorption isotherm, constant bed height, pulse input), where the concentration (or activity) dependence on the number of pore volumes is expressed explicitly. It is shown that the method can be used in the case of validity of a non-linear Freundlich sorption isotherm if the experimental data are fitted by means of a Newton-Raphson multidimensional non-linear regression procedure in which the regression function consists of the above mentioned ADE equation and of the equation for a retardation coefficient including the first derivative of the Freundlich equation. Values of four parameters, namely, Freundlich equation parameters (

Solute transport under non-linear sorption and decay

2001 ◽  
Vol 35 (6) ◽  
pp. 1525-1533 ◽  
Author(s):  
Sergio E. Serrano
Keyword(s):  
Solute Transport ◽  
Linear Sorption ◽  
Non Linear
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