• Journal of Korean Society of Water and Wastewater
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• v.10 no.3
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• pp.64-72
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• 1996

The one of the most important factors we shoud consider in designing the processes using porous media such as activated carbon adsorber is the prediction of the breakthrough curve. In this study, the breakthrough curve of BAC process for the treatment of refractory pollutants was evaluated by simplified engineering analysis. Through the experiments, the slope of the breakthrough curve can be determined by retardation factor, R and apparent dispersion coefficient, $D_{app}$ which is determined by hydrodynamic dispersion, mass transfer effects and isotherm. Estimated concentration of effluent was agreed with the experimental values. Also, it is possible to use this method for predicting the breakthrough curve of the pollutants removal and tranport of pollutants in porous media.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.595-601
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• 2009

The effects of the cation-to-anion resin ratio and bed depth on ion exchange performance of mixed-bed were studied at ultralow solution concentration. Breakthrough curves were experimentally obtained for NaCI solution as functions of resin ratio and bed depth. The bed depth affects the pattern of the sodium breakthrough curve but not the chloride breakthrough curve in beds because of the selectivity difference. Resin selectivity determines the shape of breakthrough curves, Some sodium and chloride breakthrough curves crossed at a point as a function of resin ratio. The lower cation-to-anion resin ratio showed the higher effluent concentration or treated volume of the crossover point regardless of the total resin weight.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.40-54
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• 2005

This dissertation aims to develop adsorption tubes for measuring organic solvents in the working environment, by comparing and analyzing breakthrough condition and adsorption capacity with ACF. 1. In breakthrough characteristics, the raising velocity of breakthrough curve is increasing according to assault concentration, but $50\%$ breakthrough time is decreasing. As breakthrough curve of calculated data using this agrees with the one of experimental data both of them can be used on determining sampling time of adsorption tubes. It is predicted by theoretical that $10\%$ breakthrough time is increasing in the case of increasing filled adsorbent amount. 2. $10\%$ breakthrough time is regularly decreasing as much as assault concentration is increasing. As a result, we can predict the life of adsorbent within the range of the low concentration, and adsorption amount that ACF can sample during $10\%$ breakthrough time is increasing as much as assault concentration is increasing.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.312-316
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• 2004

Single-well tracer tests, especially push pull tracer tests, are more effective to estimate hydraulic parameters and microbial metabolic activities in terms of duration and cost compared to multi-well tracer tests. However, there are some drawbacks in accuracy, complicated data analysis and uniqueness. These shortages are thought to be derived from the applied conditions which affect mass recovery curve and breakthrough curve. Factors such as extraction rate, resting period, hydraulic conductivity and hydraulic gradient are considered as the major factors determining the mass recovery rate and shape of the breakthrough curve. The results of the sensitivity analysis are summarized as follows: 1) the significant change in concentration of breakthrough curve is obtained when the extraction rate increases. This effect would also be much higher if the hydraulic conductivity is lower; 2) the mass recovery rate decreases with the increase of resting time, and the difference of mass recovery rates for different resting times is inversely proportional to the hydraulic conductivity; 3) the sensitivity values decrease with time. The hydraulic conductivity affects not only the early period, but the later period of the breakthrough curves; 4) The influence of the hydraulic gradient on the breakthrough curves is greater at earlier stage than at later stage. The mass recovery rate is inversely proportional to the hydraulic gradient.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.191-199
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• 1999

This study evaluated the availability as an alternative adsorbent which is cheaper and more efficient than CuO/${\gamma}$-$Al_2O_3$ which have been studing vigorously to remove $SO_2$. Five adsorbents (CuO/${\gamma}$-$Al_2O_3$, Iron ore, Slag, LD slag, $Fe_2O_3$) was employed in a fixed bed reactor. $SO_2$ breakthrough curves were obtained as a function of temperature, initial gas velocity and particle size. Saturation capacities calculated by the numerical integration of breakthrough curves of $SO_2$ increased with increasing reaction temperature. $SO_2$ breakthrough curve equation of $Fe_2O_3$ for this system can be expressed as Kr=3,914,000 exp(-37,329.86/RT). By means of the breakthrough curve, the influence of bed height on breakthrough time was also estimated.

• Journal of the Korean Society of Safety
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• v.17 no.1
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• pp.54-60
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• 2002

To obtain the breakthrough characteristics for the design of fixed bed adsorption plant, adsorption experiment on granular activated carbon was performed with tharonil in the fixed bed. The pore diffusivity and surface diffusivity of tharonil estimated by the concentration-time curve and adsorption isotherm were $D_s=2.825{\times}10^{-9}cm^2/s,\;D_p=1.26{\times}10^{-5}cm^2/s$, respectively. From comparison of the pore diffusivity and surface diffusivity, it was found that surface diffusion was controlling step for intrapaticle diffusion. The breakthrough curve predicted by constant pattern-linear driving force model were shown to agree with the experimental results. The surface diffusivity and film mass transfer coefficient had no effect on the theoretical breakthrough curve but the adsorption isotherm had fairly influence on it. Appearance time of breakthrough curve is faster with the increase flow rate and inflow concentration of liquid. The utility of granular activated carbon is enhanced with the increase of bed height and with the decrease of inflow rate.

• Clean Technology
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• v.10 no.3
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• pp.159-168
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• 2004

Benzene adsorption experiment was carried out for activated carbon and zeolite 13X adsorbents. Single column and dual column packed with two adsorbents were used to investigate the dynamic adsorptive characteristics. Effect of feed flow rate on the breakthrough curve was not significant. Specific adsorption amount of benzene for activated carbon was larger than that for zeolite 13X. On the contrary, adsorption amount per column volume was larger for zeolite 13X column because the density of zeolite 13X was larger. In the dynamic experiment using dual adsorbents column, length of mass transfer zone was changed by the feed direction. Breakthrough time was longer and breakthrough curve was sharper when activated carbon was packed in feed inlet and zeolite 13X was packed in column outlet. Also breakthrough time and breakthrough curve slope were affected by the packing ratio of the two adsorbents.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1593-1600
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• 2014

Adsorption and desorption characteristics of the representative 10 kinds components consisting of gasoline vapor on activated carbon were investigated at the temperature range of $-30^{\circ}C{\sim}25^{\circ}C$. The breakthrough curves of each vapors obtained by the Thomas model were well described the breakthrough experimental results of this study. The breakthrough times of each vapors were correlated with the molecular weight, density, and vapor pressure. The breakthrough times had greater correlation with boiling point than molecular weight and density. The slope of the breakthrough curve was a proportional relationship with the rate constant (k) of Thomas model expression. The higher the slope of the breakthrough curve, the rate constant was larger. The biggest slope vapor had the smallest adsorption capacity ($q_e$). Adsorption and desorption characteristics of mixed vapor similar to the gasoline vapor were studied at room temperature ($25^{\circ}C$). The mixed vapor consisting of 9 components; group A (pentane, hexene, hexane), group B (benzene, toluene), group C (octane, ethylbenzene, xylene, nonane) was examined. Group A was not nearly adsorbed because of substitution by group C, and the desorption capacity of group A was smaller than group C. The adsorbed substances were confirmed to be Group C.

• Journal of Environmental Science International
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• v.23 no.1
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• pp.53-60
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• 2014

Adsorption of phenol on activated carbon in a fixed bed was studied. The effects of fixed-bed length, superficial velocity (flow rate) and particle size of adsorbent on fixed-bed performance were investigated. Some characteristic parameters such as the breakthrough time ($t_{0.05}$), saturation time ($t_{0.95}$), length of mass transfer zone ($L_{MTZ}$), adsorptive capacity (W), and adsorption rate constant ($K_a$) were derived from the breakthrough curves. Adsorbent particle sizes significantly affected the shape of the breakthrough curve. Larger particle sizes resulted in an earlier breakthrough, a longer $L_{MTZ}$ and a lower adsorption rate. Superficial velocity was a critical factor for the external mass transfer during fixed-bed adsorption process. The external mass transfer resistance was dominant as increasing superficial velocity.

• Journal of the Korean Society of Safety
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• v.11 no.2
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• pp.89-95
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• 1996

To predict the service life of an organic vapor respirator cartridge, the breakthrough curve of respirator was simulated using a fixed-bed adsorption model and compared with that of sampling tube. And the effects of bed porosity, length to diameter ratio and flow rate of the sampling tube were studied. The life time of respirator cartridge was increased with the decrease of particle size and bed porosity. And the breakthrough time of sampling tube was affected by the flow rate, however not by the length to diameter ratio. The 10% breakthrough time of the sampling tube was corresponded with that of cartridge.