• Journal of Korean Society of Environmental Engineers
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• v.39 no.1
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• pp.26-33
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• 2017

The objective of this study was to evaluate the characteristic of adsorption by using a meso-porous adsorbent (MPA), and investigate the removal efficiency of geosmin which taste and odor causing compounds in drinking water supplies through batch test. The results for the adsorption isotherm was analyzed by using the Langmuir equation and Freundlich equation, generally being applied. And the study showed that the both Langmuir and Freundlich equation explains the results better. Both of pseudo-first-order model and pseudo-second-order model were respectively applied for evaluation of kinetic sorption property of geosmin onto MPA. The adsorption experiment results using MPA showed that maximum adsorption capacity of MPA was lower 7 times than that of GAC, and adsorption rate of MPA was faster 11 times than that of GAC, on the basis of pseudo-first-order model. Therefore, it was determined that MPA was effectively able to remove geosmin in drinking water supplies in short EBCT condition, but regeneration cycle in MAP process was shorter than that in conventional process.

• Journal of Pharmaceutical Investigation
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• v.4 no.1_2
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• pp.25-30
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• 1974

The adsorption of nalidixic acid on human erythrocytes was found to expressed by Freundlich's isotherm. The amount of adsorption of nalidixic acid on erythrocytes increased with an increase of pH. The adsorption of nalidixic acid on human plasma was found to expressed at Scatchard's equation by the equilibrium dialysis method. An influence of pH on adsorption of nalidixic acid to human plasma proteins was studies at pH 4-10. It was found that the degree of adsorption increase with the increase of pH from 4-6, but descreased above pH 9.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.146-154
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• 2017

Recently, self-healing concrete has been researched as maintenance and repair of concrete structures are important challenges we face. This paper focused on possibility of ion exchange resin as a novelty material directly and actively controlling harmful ions of concrete, whereas most self-healing concrete researches have been focused on methods to automatically filling and repairing internal crack of concrete. Because equilibrium properties between ion exchange resin and harmful ion is important before design of cement mixing proportion, it was conducted to remove chloride or sulfate in saturated $Ca(OH)_2$ solutions containing NaCl or $Na_2SO_4$. The removal performance was analyzed using kinetic equation and isothermal equation. Consequently, the removal properties of anion exchange resin were relatively more dependent on pseudo second reaction equation and Langmuir equation than pseudo first reaction equation and Freundlich equation. And it was concluded that each chloride and sulfate can be removed to the maximum 1068 ppm and 1314 ppm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.3
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• pp.11-18
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• 1991

Volatile organic compounds(VOC) present in or generated by many sources, can be toxic, mutagenic or even carcinogenic, so that control of such emissions is significant. The 6 chlorinated organic chemicals as VOC were examined in this study. Prediction of the behavior of VOC on activated carbon beds is an important part of control system design. The objective of this study was to predict gas phase sorption isotherms from physical properties and liquid phase isotherms obtained with the same adsorbent and adsorbate. One of the techniques that was investigated was quantitative structure-activity relationships(QSAR) for the predicition procedures. It was possible to estimate sorption isotherms in the gas phase($a_g$) using either connectivity index, $^2{\chi}$, and the Henry's law coefficient ($H_a$) or the solubility and the equilibrium concentration in the gas phase. As a result of study, the predictive equation based on Freundlich model for $a_g$ was ${\log}\;a_g=0.238\;^2{\chi}+0.573\;{\log}\;H_a+4.330(r^2=0.94)$. Finally, this would provide a potentially useful tool to describe and predict sorption capacity without time-consuming tests.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.499-504
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• 2009

Erythrosine is used a food coloring, ink and dye, etc. but erithrosine is rarely used in United States due to its known hazards. The adsorption characteristics of erythrosine by granular activated carbon were investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for erythrosine were largely improved by pH control. When the pH was 11 in the sample, the erythrosine could be removed 98% of initial concentration. It was estabilished that the adsorption equilibrium of erythrosine on granular activated carbon was successfully fitted by Freundlich isotherm equation in the concentration range from 10mg/L to 1,000mg/L. The characteristics of breakthrough curve of activated carbon packed column depend on the design variables such as initial concentration, bed height, and flow rate.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.17-23
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• 2001

The adsorption and movement characteristics of herbicide pendimethalin was studied in three kinds of soil, sandy loam, silty clay and loam. The results of the batch test and columnexperimentweresummarizedasfollows. The shaking time reached to the adsorption equilibrium of pendimethalin in soils was 6 hours. The adsorption rates of pendimethalin for sandy loam, silty clay and loam were 59.6%, 77.3% and 64.0%, respectively. The adsorption isotherms with the Freundlich equation showed better consistency than that with the Langmuir one. The adsorption coefficients of pendimethalin for soils were 8.0. 16.1 and 9.5. respectively. When breakthrough point was 0.05Co, the breakthrough times reached for soils were 256 minutes, 810 minutes and 420 minutes. respectively.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.63-68
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• 2001

A laboratory experiment was performed to invstigate the nitrate removal using FeCl$_3$ -treated activated carbon. Iron chloride(III) was coated onto the surface of activated carbon. The removal efficiency of nitrate was increased with increasing of FeCl$_3$ was used for coating material. About 22~26mg of Fe per unit g of activated carbon was adsorbed. The nitrate removal was not affected by the pH under the experiment range of pH, but the pH value in solution decrease to 3.5~4.0 after reaction. The removal efficiency of nitrate was increased with increasing of dosage of adsorbents. Ammonia was not detected and the Fe concentration as low as 0.22mg/$\ell$ was desorbed from the adsorbents. The adsorbents was regenerated using KCl solution, and recovery was 76.6% at 1 M of KCl. The adsorption of nitrate by FeCl$_3$-treated activated carbon followed the Freundlich isotherm equation and the Freundlich constant, 1/n, was 0.346. These results showed that the FeCl$_3$-treated activated carbon could serve as the basis of a useful nitrate removal.

• Journal of environmental and Sanitary engineering
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• v.17 no.3
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• pp.7-13
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• 2002

The removal efficiency of heavy metals by chitosan complex isolated from biological industrial waste was investigated through laboratory experiments. The results of the study are as follows. The adsorption kinetics of heavy metals were reached the equilibrium adsorption in approximately 30 minutes and the removal efficiency were showed 70.7～97.4%. The effect of temperature on heavy metals adsorption by chitosan complex shows that as the temperature increased, the amount of heavy metals adsorption per unit weight of chitosan complex increased. The correlation between amount of heavy metals adsorption per unit weight of chitosan complex and temperature were obtained through the coefficient of determination($R^2$). $R^2$ values were 0.75(p<0.05), 0.99(p<0.05) and 0.98(p<0.05) in Hg, Mn, and Zn, respectively. The injected chitosan complex in which 0.1 g was adsorpted highly and the removal of heavy metals was found to have the best removal efficiency A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the adsorption intensity(I/n) was 0.5564, 0.4074, 0.5244 on the Hg, Mn, Zn, respectively And the measure of adsorption(k) was 2.2144, 1.6963, 2.0792 on the Hg, Mn, Zn, respectively. So, it was concluded that adsorption of heavy metals by chitosan complex is effective.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.19-31
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• 1999

Most breakthrough tests are conducted at higher concentration levels compared to those in the field of air-purifying respirator applications. For example, typical challenge concentrations for breakthrough tests agains tcarbon tetrachloride are ranged between 250-1000 ppm although applicable concentrations range for air-purifying cartridge is 5-50 ppm for carbon tetrachloride. However, no guarantee has been made that isotherms derived from the experiment at high challenge concentrations could estimate adsorption capacity at the lower concentration range where workers wear usually air-purifying respirators. Three models of adsorption isotherms (Freundlich, Langmuir and Dubinin/Radushkevich(D/R) isotherms) that have been commonly applied for respirator cartridge testing were evaluated. Adsorption capacity at each challenge concentration was calculated from the Reaction Kinetic equation fitted for the breakthrough data. These data were used for derivation of three isotherms. In general, the D/R isotherm has given the best agreement between estimated adsorption capacities and experimentally measured. If the challenge concentration of 100 ppm is included for derivation of models, Freundlich and D/R models could succes sfully produced good estimations for adsorption capacities at 50 ppm level. Estimated adsorption capacities by both models ranged in 94 - 109 % of the experimentally measured. However, Langmuir model gives underes timation in all cases.

• Carbon letters
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• v.8 no.3
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• pp.199-206
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• 2007

The activated carbon produced from rubber wood sawdust by chemical activation using phosphoric acid have been utilized as an adsorbent for the removal of Cu(II) from aqueous solution in the concentration range 5-40 mg/l. Adsorption experiments were carried out in a batch process and various experimental parameters such as effect of contact time, initial copper ion concentration, carbon dosage, and pH on percentage removal have been studied. Adsorption results obtained for activated carbon from rubber wood sawdust were compared with the results of commercial activated carbon (CAC). The adsorption on activated carbon samples increased with contact time and attained maximum value at 3 h for CAC and 4 h for PAC. The adsorption results show that the copper uptake increased with increasing pH, the optimum efficiency being attained at pH 6. The precipitation of copper hydroxide occurred when pH of the adsorbate solution was greater than 6. The equilibrium data were fitted using Langmuir and Freundlich adsorption isotherm equation. The kinetics of sorption of the copper ion has been analyzed by two kinetic models, namely, the pseudo first order and pseudo second order kinetic model. The adsorption constants and rate constants for the models have been determined. The process follows pseudo second order kinetics and the results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. It was concluded that activated carbon produced using phosphoric acid has higher adsorption capacity when compared to CAC.