In this research paper, an experimental breakthrough curve for citric acid in an adsorption recovery process was determined by an ion-exchange resin in 20, 35, 55 °C. Also, a mathematical model for breakthrough curve was presented. Among ion exchange resins that have been experienced, many weak and strong basic anionic resins are available such as, IRA-92, IRA-93, IRA-420 and IRA-458 and all of...

The transport of solutes and colloids in porous media is influenced by a variety of physical and chemical nonequilibrium processes. A combined physical-chemical nonequilibrium (PCNE) model was therefore used to describe general mass transport. The model partitions the pore space into "mobile" and "immobile" flow regions with first-order mass transfer between these two regions (i.e, "physical" n...

dispersivity (?) and effective transport porosity (?eff) are input parameters in equilibrium convection dispersion equation (cde). normally these parameters are obtained from breakthrough curves by inverse method. however, obtaining breakthrough curves in the field is not often possible in practice. the objective of this study was to estimate ? and feff from soil hydraulic data. for this purpos...

Mixing-transport of solute entering at sinkholes or from within the limestone matrix in cavernous conduits is an important process for contaminant migration in karst aquifers. This process may be described with a one-dimensional advection-dispersion equation incorporating the fluxes of solute and water across the conduit wall. For the dilution-dispersion equation, which does not include solute ...

The development of a reliable and accurate method to predict thermal breakthrough time is a significant open problem in geothermal reservoir engineering. Such a method would enable more informed decisions to be made regarding reservoir management. Methods developed at present include analytical models and solute tracers, both of which have limitations. The use of particles as temperaturesensiti...

Accurate assessment of the fate of salts, nutrients, and pollutants in natural, heterogeneous soils requires a proper quantification of both spatial and temporal solute spreading during solute movement. The number of experiments with multisampler devices that measure solute leaching as a function of space and time is increasing. The breakthrough curve (BTC) can characterize the temporal aspect ...

[1] Temporary storage of solutes in streams is often controlled by flow-induced uptake in hyporheic zones. This phenomenon accounts for the tails that are generally observed following the passage of a solute pulse, and such exchange is particularly important for the transport of reactive substances that can be subject to various biogeochemical processes in the subsurface. Advective pumping, ind...

Rapid movement of agricultural chemicals through soil to groundwater via preferential flow pathways is one cause of water contamination. Previous studies have shown that time domain reflectometry (TDR) could be used to characterize solute transport in soil. However, previous studies have only scarcely addressed preferential flow. This study presents an extended application of TDR for determinin...

Modeling the contaminant transport process in soils requires the solute transport parameters. Displacement experiments were carried out on soil columns (Sand – Silt – Clay) by injecting a solution of 0.8 M KCl in a steady state. Breakthrough curves are symmetrical, characteristics of an equilibrium solute transport. The hydrodynamic dispersion coefficients were estimated by optimizing the measu...