Breakthrough curves, on a semi-log scale, from tests in porous media with block-input of viruses, bacteria, protozoa and colloidal particles often exhibit a typical skewness: a rather slowly rising limb and a smooth transition of a declining limb to a very long tail. One-site kinetic models fail to fit the rising and declining limbs together with the tail satisfactorily. Inclusion of an equilib...

in this study, bimodal meso-porous silica (uvm-7) synthesized and fabricated amino silane modified supports were characterized by powder x-ray diffraction (xrd), n2 adsorption/desorption, transmission electron microscope (tem), elemental analysis and titration. capacity of co2 capture on modified bimodal pore structure silica at 70°c was calculated using breakthrough curves; and it was found th...

Contaminants in surface water entering karst aquifers in focused recharge can be transported rapidly through the system to discharge at springs. Such contaminants act as anthropogenic tracers of ground-water transport; analysis of their breakthrough curves as they discharge from springs allows identification and apportionment of contaminant sources, and can provide insight into aquifer structur...

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...

The emerging contaminants are commonly derived from municipal, agricultural, and industrial wastewater sources and pathways. These compounds are polar and poorly biodegradable. The dynamic removal of atenolol from aqueous solutions by activated carbon in fixed bed column systems was investigated. As far as we know, this is the first study reporting the decontamination by adsorption in fixed bed...

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...

This study examined the applicability of the mathematical empirical models by Bohart-Adams, Wolborska, Thomas and Yoon-Nelson on lead removal from aqueous solutions on a fixed bed of natural zeolite. Applicability of these models has been evaluated by fitting the experimental breakthrough curves with the curves obtained from the applied model. Experimental results have shown that the values of ...

Calibration of ground water transport models is often performed using results of field tracer experiments. However, little attention is usually paid to the influence, on resulting breakthrough curves, of injection conditions and well-aquifer interactions, more particularly of the influence of the possible trapping of the tracer in the injection wellbore. Recently, a new mathematical and numeric...

abstract microbial contaminants transport to groundwater is a serious environmental problem that can result in large outbreaks of waterborne diseases. some of bacteria can travel from vadose zone and cause contamination of groundwater resources. thus, an accurate prediction of transport and fate of pathogenic microorganisms in unsaturated soil is needed to protect groundwater resources. the mai...