List of Articles breakthrough curve

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  1 - The effect of particle shape of porous media on the longitudinal dispersivity: contaminant transport
  ghasem mirzaei
  One of the most challenging quantities in analyzing the transfer of contaminant in the porous medium is the determination of longitudinal dispersivity. In this research, the effects of the porous media particle shape on the longitudinal dispersivity were investigated by More

  One of the most challenging quantities in analyzing the transfer of contaminant in the porous medium is the determination of longitudinal dispersivity. In this research, the effects of the porous media particle shape on the longitudinal dispersivity were investigated by experiments on three column of soil (broken texture, river sand, spherical texture). Flow and contaminant (NaCl) were injected at five levels of velocities and the Breakthrough curve was extracted at five points along the column by Self-Potential Method, Then, by simulating the results with FEFLOW software and the inverse analysis with CXTFIT2 software, longitudinal dispersivity was determined. The results indicate that, for constant velocity, the medium with spherical texture has a longitudinal dispersivity greater than the other two medium and in the sandy medium it is more than the broken texture. This can be due to the increase in the contact surface as well as the path’s tortuosity, with the particle coming out of the spherical shape. With increasing velocity, the longitudinal dispersivity decreases in all three medium. Also, as the particles are closer to the spherical shape, the scale effect will be greater, and with increasing velocity, the decrease in the longitudinal dispersivity in these medium will be less. Manuscript profile
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  2 - Experimental Investigation and Evaluation Results of Numerical Simulation and Analytical Solution of classical ADE for conservative solutes
  alireza emadi yaghoub azhdan jafar chabokpour Rasoul daneshfaraz
  The longitudinal dispersion coefficient from the perspective of public safety and human health, is one of the important parameters for predicting and characterizing the transport of pollution in rivers and shallow waters. This paper aimed at investigating the efficiency More

  The longitudinal dispersion coefficient from the perspective of public safety and human health, is one of the important parameters for predicting and characterizing the transport of pollution in rivers and shallow waters. This paper aimed at investigating the efficiency of the classical advection- dispersion Equation for predicting transport of pollution in a gravel bed rivers. Some tracer experiments were done in a flume with longitudinal slopes of (S= 0.001, 0.007) and five discharges include of (7.5, 11.5, 15.5, 20.5, 25.5) lit/sec. Simulated (OTIS) and analytical breakthrough curves were compared with observed data. The results of this study indicated that advection- dispersion equation in prediction of tailing edge of breakthrough curve has less accuracy. So it not be used in rivers with storage area but it is very helpful to estimate initial value of longitudinal dispersion coefficient. The calculated dispersion coefficient increased with augmentation distance from the injection site. The domain of estimated dispersion coefficient for the tracer test of this research is between (0.0073- 0.18) m2/sec. the results of calculating travel time parameters from experimental BT curves showed an exponential relationship between them and the distance from the injection site. Finally, using a geometric, hydraulic, and tracer test data and applying a Buckinghamۥ π theorem a new equation was developed to predict the longitudinal dispersion coefficient. The relative error and normalized root mean square error for the proposed equation were calculated respectively 24% and 1.37. Manuscript profile
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  3 - Evaluating Equilibrium and Non-Equilibrium Bromide Transport in Forest and Rangeland Soils on a Laboratory-Scale
  Nima Golabizadeh MOHAMMADREZA DALAIAN Shahram Shahmohammadi Kalalagh Maryam Hajrasouli Siamak Saedi
  10.30495/wsrcj.2022.19228
  Background and Aim: to better management of solute transport in porous media, it is essential to recognize their transport behavior using appropriate models. In this research, convection-dispersion equation (CDE) and mobile-immobile model (MIM), as physical equilibrium More

  Background and Aim: to better management of solute transport in porous media, it is essential to recognize their transport behavior using appropriate models. In this research, convection-dispersion equation (CDE) and mobile-immobile model (MIM), as physical equilibrium and non-equilibrium models, respectively, were used to simulate the bromide transport through saturated and unsaturated forest soil, with clay loam texture, and rangeland soil, with sandy loam texture, columns (diameter of 6 and height of 10 cm).Method: to obtain the BTCs, the PVC soil columns with a height of 10 and a diameter of 6 cm were prepared. The breakthrough experiment was carried out in near saturation and saturated condition under a water head of -1 and 3 cm, respectively. The soil columns were saturated from the bottom with a Ca(NO3)2 solution of 0.01 molar as the background solution. At near saturation, the CaBr2 solution with a concentration of 0.01 M equal to a pore volume was injected into the saturated columns of the background solution through the infiltration disk. A Mariotte bottle was used to establish a constant water head. After CaBr2 injection started, the effluents with a volume of 0.1 pore volume were collected at different times, and their bromide concentrations were determined using a pH-meter equipped with a bromide selector electrode. After the complete injection of CaBr2, the steady-state saturated flow of the background solution was re-established. The experiment continued until the bromide concentration in the effluent were almost zero. The measured concentrations, by dividing by the initial concentration, were converted to relative concentrations (C/Co). Then the BTCs was plotted as C/Co versus time or the number of pore volumes.Results: The values of mass transfer coefficient (ω<100) and mobile water fraction (β<1) as an indicator for determining the equilibrium and non-equilibrium indicated that bromide transport behavior within these columns was anomalous or non-Fickian transport. Hence, the non-equilibrium or the mobile-immobile model (MIM) is suitable and more efficient than the Fickian-based CDE model. The fitted breakthrough curves (BTCs) and the higher determination coefficient (R2) and the lower root mean square error (RMSE) values of the MIM model compared to those of the CDE confirmed the effectiveness of the MIM model in simulating bromide transport in the forest and rangeland soil columns.Conclusion: Better fit of measured and estimated breakthrough curves of bromide with non-equilibrium model compared to CDE equilibrium model, especially in the tail of breakthrough curves indicates more accuracy and the should be added efficiency of the non-equilibrium model. Given that the samples were replaced in the columns as disturbed, it can be said that heterogeneity conditions were established in the columns experiments. According to Huang et al. (2005) and Berkowitz et al. (2008), heterogeneity could be one of the reasons to justify the better performance of non-equilibrium models in the present study. The high efficiency of the non-equilibrium model compared to the equilibrium model in this controlled laboratory research cannot be a reliable judgment in evaluating these models. Accurate judgment will depend on conducting research and experiments in real and field conditions, taking into account more effective parameters. Manuscript profile
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  4 - Monitoring of the Transfer of Kerosene and Water through the Light Soil Contains Montmorillonite Nanoclay
  Shokufe Fazlali Soheila Ebrahimi Mehdi Zakerinia Sayyed Alireza Movahedi Naeini
  Water and organic contaminant transport in soil porous media, particularly in light textured soils due to high transmission capacity and create a secondary sources of pollution is  very important. The aim of this study was kerosene and water transport in a light te More

  Water and organic contaminant transport in soil porous media, particularly in light textured soils due to high transmission capacity and create a secondary sources of pollution is  very important. The aim of this study was kerosene and water transport in a light texture soil system containing different treatments of montmorillonite nanoclay. For this purpose, treatments including 0, 2, 4 and 6 wt% of nano clay- sandy soil in a funnel containing filter paper based system was applied. Then kerosene and water (4 pore volumes alternatively) were passed into soils. The breakthrough curves showed that the water passes through soils was slower and gentler slope, so the volume output was lower compared to kerosene. It seems that water molecules with a diameter of less than 3.0 nm fitted well in the small spaces between the layer of nanoclay, which are held with strong hydrogen bonds. Kerosene, with a density equals 0.78, only attract surface places, therefore, pass from porous soil surface well due to having molecules with 11 to 15 carbon atoms, which are larger than the density of water. In both fluids, the more percentage of nanoclay there is, the more retention of kerosene and water would be expected. The results of X-ray showed that the distance of nanoclay increased from 14.4 to 24.77 Å with addition of water. Manuscript profile
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  5 - An investigation on the adsorption behavior of Sb (III) on a cationic ion exchange resin in Fixed-bed column: experimental design and breakthrough curves modeling
  fereshteh moghimi nejad abdolhamid jafari Hossein Yoozbashi zadeh masood askari
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