• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.31-36
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• 2008

In hydrogen production for fuel cell by reforming ADG, sulfur compounds, odorant in ADG, are detrimental to reforming catalyst and fuel cell electrodes. We prepared alkali metal impregnated activated carbon to remove sulfur compounds in ADG by adsorption. The sulfur breakthrough adsorption capacity was changed depending on the oxygen concentration and relative humidity. Oxygen 0.2 vol% and RH 90% showed the highest sulfur breakthrough capacity. Adsorption characteristics of $H_2S$ on KI impregnated activated carbon were evaluated using dynamic adsorption method in a fixed bed. Based on the results, adsorption tower was designed and field-tested.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.131-139
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• 2020

The current study focused on the preparation of low-cost PVC-based adsorbing membrane. Metakaolin, as available adsorbent, was embedded into the PVC matrix via solution blending method. The as-prepared PVC/metakaolin mixed matrix membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM), pure water permeability and contact angle measurements. The results confirmed the improvement of PWP and hydrophilicity due to the presence of metakaolin in the PVC matrix. Additionally the structure of PVC membrane was changed due to the incorporation of metakaolin in the polymer matrix. The static adsorption capacity of all samples was determined through dye removal. The effect of metakaolin dosage (0-7%) and pH (4, 8, 12) on dye adsorption capacity was investigated. The results depicted that the highest adsorption capacity was achieved at pH of 4 for all samples. Additionally, adsorption data were fitted on Langmuir, Freundlich, and Temkin models to determine the appropriate governing isotherm model. Finally, the dynamic adsorption capacity of the optimum PVC/metakaolin membrane was studied using dead-end filtration cell. The dye removal efficiency was determined for pure PVC and PVC/metakaolin membrane. The results demonstrated that PVC/metakaolin mixed matrix membrane had a high adsorption capacity for dye removal from aqueous solution.

• Journal of Environmental Science International
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• v.21 no.6
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• pp.687-694
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• 2012

Zeolite 4A was synthesized by fusion method from coal fly ash discharged at the thermal power plants. The synthesized zeolite(FAZ) was characterized through particle size analyzer, XRD, XRF and SEM. $N_2$ adsorption-desorption measurement was used to examine surface and pore structures. The adsorption experiments were carried out under dynamic conditions of trace $SO_2$ in $N_2$ to investigate $SO_2$ adsorption capacity of FAZ. The experiments were conducted to characterize the breakthrough characteristics of $SO_2$ in a fixed bed under different operating conditions including temperature(50-$125^{\circ}C$), concentration of $SO_2$(3000-10000 ppm) and FAZ with 4 kinds of commercial zeolite. The adsorption capacity of FAZ was 53.84 $mgSO_2/g$ adsorbent, larger than that of the same type commercial zeolite(WK4A).

• Carbon letters
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• v.7 no.4
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• pp.249-258
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• 2006

Treatment of water hyacinth with sulphuric acid produces carbonaceous materials that have been used to remove Cu(II) and Cd (II) ions from aqueous solutions. Untreated water hyacinth was also used for the subject of comparison. The textural properties of the carbonaceous materials were determined from nitrogen adsorption at 77 K. The optimum pH for the sorption of Cu (II) and Cd (II) ions on the investigated sorbents was determined. Dynamic adsorption measurements have been taken at 298 K whereas equilibrium measurements were carried out at 298, 313 and 323 K. The adsorption of nitrogen at 77 K on the untreated sample was too low and the surface areas of the treated samples 2, 3 and 4 were found between $70-208\;m^2/g$. The total pore volumes of these samples which were determined for the carbonaceous materials investigated were found to be 0.076-0.140 ml/g. The kinetic adsorption data of Cu (II) and Cd(II) were applicable to both pseudo - first and pseudo-second order but fit more the latter order. The equilibrium adsorption data were found to fit Freundlich and Langmiur equations. The values of DG, DH and DS are all negative indicating the feasibility and the spontaneous nature of the sorption of Cu (II) and Cd (II) ions by the sorbents investigated.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.149-154
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• 2012

The adsorption and desorption behavior of biofilter-medium was investigated on the performance of an adsorption column. Continuous flow-isothermal adsorption experiments were performed to treat waste air containing such a VOC as ethanol under the same condition of > 90% relative humidity as the condition of the feed to a biofilter process. In case of feeding waste air containing ethanol of 1,000 ppmv (or 2,050 mg ethanol/$m^3$) to the adsorption system at the rate of 2 L/min, the onsets of its breakthrough and reaching the state of dynamic equilibrium at the exit had been delayed 10 and 3 times, respectively, later than those at the 1st stage sampling port. Moreover, in case of 2,000 ppmv (or 4,100 mg ethanol/$m^3$), they had been delayed 9 and 3 times, respectively. Thus, regardless of feeding concentration, the ratios of delaying period were observed to be quite consistent each other at the exit of the adsorption column. With regard to the period of desorption, the ratios of delaying period were consistent each other to be 1.5 for both cases. In addition, the effect of microbial activity and sterilization-process was studied on adsorption equilibrium. The ethanol concentration in the vapor phase of vials packed with sterilized granular activated carbon (GAC) was quite consistent to that with unsterilized GAC. However, the ethanol concentrations in the vapor phase of vials packed with unsterilized compost and the unsterilized mixture of GAC and compost were higher than those with sterilized compost and the sterilized mixture of GAC and compost, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.265-274
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• 1992

A mathematical model was proposed to predict the fate of a priority organic pollutant, anthracene, accidently spilled into a stream. The model consists of 6 differential equations with 5 input variables and 9 rate constants. Volatilization, biodegradation, adsorption/desorption, photodegradation as well as the convective inputs and outputs are included in the model. As a result of a series of dynamic simulations and sensitivity analyses under the given conditions, the concentrations of the organic chemical could be predicted within a detection limit in the stream. It was also suggested that the rate constant for diffusion/transport and adsorption rate constant are the most influential ones for predicting the chemical conentrations in dissolved and particulate phase. The model proposed appears to be a useful tool for assessing chemical spills.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.8-18
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• 2005

Adsorption capacity for the charcoal were tasted in this study to verify the performance of them for the use of the sampling media in industrial hygiene field. Two set of experiments were conducted. The first experiment was to test performance of the tested charcoal tube that were assembled in the laboratory with the use of the GR grade charcoal. The other tests were investigate the adsorption capacity of the charcoal tested in this study and charcoals embedded in the commercial charcoal tubes. Known air concentration samples for benzene, toluene, and o-xylene were prepared by the dynamic chamber. 1. At low air concentration levels (0.1${\times}$TLV), there was no significant differences between the tested charcoal tubes and the SKC charcoal tubes. This implies that there is no defect with the adsorption capacity of the charcoal. 2. At high concentration with 60 minutes sampling, the breakthrough were found only in the tested charcoal while no breakthrough were shown in the SKC charcoal. 3. From the breakthrough tests for the charcoal, the micropore volume(Wo) were calculated by the curve fitting with the use of Dubinin/Radushkevich(D/R) adsorption isotherm equation. The calculated values were 0.687cc/g for SKC, 0.504cc/g for Sensidyne, and 0.419cc/g for the tested charcoal(Aldrich). 4. Adsorption capacities were obtained from the isotherm curves shown adsorption capacities at several levels of the challenge concentration. All range of the air concentration concerned in industrial hygiene, the SKC charcoal showed approximately two times of adsorption capacity compared to the tested charcoal.

• Environmental Engineering Research
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• v.8 no.2
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• pp.98-106
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• 2003

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.620-625
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• 2005

This study is to investigate the correlation between pore structures of activated carbons and adsorption characteristics of acetone vapor using the dynamic adsorption method. The experimental results showed that the breakthrough time of ACT activated carbon made by Takeda was the longest, because ACT has more micropores below pore diametr $10{\AA}$ than the compared activated carbons. The equilibrium adsorption capacity had direct correlation to the breakthrough time. The relation between BET specific surface area and the equilibrium adsorption capacity was hard to say linear. Therefore, it was difficult to estimate the adsorption ability of activated carbons only by BET specific surface area. The correlation factor between the cumulative surface area and the equilibrium adsorption capacity decreased with enlarging the range of pore size, and there was the highest correlation factor in the range of below $10{\AA}$.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2384-2393
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• 2018

Porous alginate-based hydrogel beads (porous ABH) have been prepared through a facile and sustainable template-assisted method using nano-calcium carbonate and nano-$CaCO_3$ as pore-directing agent for the efficient capture of methylene blue (MB). The materials were characterized by various techniques. The sorption capacities of ABH towards MB were compared with pure sodium alginate (ABH-1:0) in batch and fixed-bed column adsorption studies. The obtained adsorbent (ABH-1:3) has a higher BET surface area and a smaller average pore diameter. The maximum adsorption capacity of ABH-1:3 obtained from Langmuir model was as high as $1,426.0mg\;g^{-1}$. The kinetics strictly followed pseudo-second order rate equation and the adsorption reaction was effectively facilitated, approximately 50 minutes to achieve adsorption equilibrium, which was significantly shorter than that of ABH-1:0. The thermodynamic parameters revealed that the adsorption was spontaneous and exothermic. Thomas model fitted well with the breakthrough curves and could describe the dynamic behavior of the column. More significantly, the uptake capacity of ABH-1:3 was still higher than 75% of the maximum adsorption capacity even after ten cycles, indicating that this novel adsorbent can be a promising adsorptive material for removal of MB from aqueous solution under batch and continuous systems.