• Korean Chemical Engineering Research
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• 제53권1호
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• pp.64-70
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• 2015

본 연구는 활성탄에 의한 congo red의 흡착 거동에 대해 회분식 실험을 통해 알아보았다. 흡착변수로 흡착제의 양, pH, 초기농도와 접촉시간과 온도를 사용하였다. 흡착평형자료는 Langmuir, Freundlich, Temkin 및 Dubin-Radushkevich 식에 적용하여 보았다. 평가된 Freundlich 분리계수(1/n)로부터 활성탄에 의한 congo red의 흡착공정이 적절한 처리방법이 될 수 있음을 알았고, Temkin 상수(B)와 Dubinin-Radushkevich 상수(E)로부터 물리흡착공정임을 알았다. 동력학적 실험을 통해 흡착공정이 유사이차반응속도식에 잘 일치함을 알았다. 입상활성탄에 대한 congo red의 흡착공정은 발열반응(${\Delta}H$=42.036 kJ/mol)이었고, Gibbs 자유에너지값(${\Delta}G$=-2.414~-4.596 kJ/mol)은 온도가 증가할수록 감소하였다.

• Advances in environmental research
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• 제6권2호
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• pp.113-125
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• 2017

Santa Barbara Amorphous-15(SBA-15) nanoparticles were utilized as the inexpensive and effective adsorbents to remove methylene blue dye from the aqueous solution.SBA-15 was created by Zhao et al method. Infrared spectroscopy, X-ray diffraction and scanning electron microscopy (SEM) were used for the evaluated physical properties of SBA-15. The results of diffraction X-ray indicated that was the crystalline structure for it. Also IR spectroscopy indicated was a silica the whole structure of the groups and SEM image verify the structure of relatively identical particles size of SBA-15. Factors affecting adsorption including the amounts of adsorbent, pH and contact time were investigated by a SBA-15 nanomaterial design. The extent of dye removal enhanced with increasing initial dye concentration and pH from 4 to 10. The higher percentage adsorption were obtained under optimum conditions of variables (sorbent dose of 200 mg/liter, initial MB concentration 10 mg/liter, initial pH of 10 and temperature of $25^{\circ}C$). Maximum adsorption happened after the 2 hour and the kinetic processes of the dyes adsorption were described by applying the pseudo-first-order and the pseudo-second-order and the relatively High correlation with the kinetic Ellovich models. It was found that the pseudo-second-order models kinetic equation described the data of dye adsorption with a good correlation (R2>0.999) which indicated chemisorption mechanism. Freundlich and Langmuir adsorption models were investigated in conditions of variables (adsorbent dose 0.01 gr/liter, MB concentration 10, 20, 30 mg/liter, pH of 4, 7, 10, contact time 90 min and temperature of $27^{\circ}C$). The adsorption data were represented by Langmuir isotherm model. These values are higher than the adsorption capacities of some other adsorbents that have recently been published in the literature.

• 상하수도학회지
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• 제29권3호
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• pp.407-414
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• 2015

The effect of activated carbon particle diameter (i.e. US sieve No. $8{\times}10$ ($d_p{\approx}2.19mm$), $18{\times}20$ ($d_p{\approx}0.92mm$), $50{\times}60$ ($d_p{\approx}0.27mm$) and $170{\times}200$ ($d_p{\approx}0.081mm$) on caffeine adsorption is investigated. BET surface area was increased with decreasing particle diameter ($d_p$), and caffeine adsorption rates increased with decreasing $d_p$. Moreover, pseudo-second order model is predicted the experimental data more accurately than pseudo-first order model, and the fastest rate constant ($k_2$) was $1.7g\;mg^{-1}min^{-1}$ when $d_p$ was 0.081 mm. Surface diffusion coefficient (Ds) was decreased with decreasing $d_p$ based on the minimum sum of square error (SSE). Practically, certain ranges of Ds are acceptable with high reliability ($R^2$) and it is determined that the effect of $d_p$ on Ds is unclear. The effect of pH on caffeine adsorption indicated the dependency of m/L ratio (mass liquid ratio) and $pH_{pzc}$. The $pH_{pzc}$ (i.e. $7.9{\pm}0.2$) was not affected by $d_p$. The higher caffeine adsorption at pH 4 and pH 7 than at pH 10 is due to $pH_{pzc}$, not $pk_a$ of caffeine.

• Korean Chemical Engineering Research
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• 제53권3호
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• pp.309-314
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• 2015

야자계 활성탄을 사용하여 수용액으로부터 brilliant blue FCF 염료의 흡착에 대해 조사하였다. 회분식 실험은 흡착제의 양, 초기농도와 접촉시간과 온도를 흡착변수로 사용하여 수행하였다. 흡착평형자료는 Langmuir와 Freundlich 식을 사용하여 해석하였으며, Freundlich 식이 더 좋은 일치도를 나타냈다. 평가된 Freundlich 상수(1/n=0.129~0.212)로부터 활성탄에 의한 brilliant blue FCF의 흡착조작이 적절한 처리방법이 될 수 있음을 알았다. 흡착속도실험자료를 유사일차반응속도식과 유사이차반응속도식에 적용해 본 결과, 흡착동력학은 유사이차반응속도식에 잘 맞는 것으로 나타났다. 음수값의 Gibbs 자유에너지(-4.81~-10.33 kJ/mol)와 양수값의 엔탈피(+78.59 kJ/mol)는 흡착이 자발적이고 흡열공정으로 진행된다는 것을 나타낸다.

• Korean Chemical Engineering Research
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• 제54권2호
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• pp.255-261
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• 2016

활성탄을 사용한 Acid Yellow 14 염료의 흡착 실험은 흡착제의 양, pH, 초기농도, 접촉시간과 온도를 흡착변수로 사용하여 수행하였다. 흡착평형자료는 Langmuir, Freundlich 및 Temkin 등온식을 사용하여 해석하였는데, Freundlich 식이 가장 좋은 일치도를 나타냈다. 평가된 Freundlich 상수(1/n=0.129~0.212)와 Langmuir 분리계수($R_L=0.202{\sim}0.243$)로부터 활성탄에 의한 Acid Yellow 14의 흡착조작은 적절한 처리방법이 될 수 있음을 알았다. Temkin의 흡착열관련상수(B)는 5.101~9.164 J/mol로 평가되어, 흡착공정이 물리흡착임을 알았다. 흡착속도실험자료를 유사일차반응속도식과 유사이차반응속도식에 적용해 본 결과, 흡착동력학은 유사이차반응속도식에 잘 맞는 것으로 나타났다. Gibbs 자유에너지(-4.81~-10.33 kJ/mol)와 엔탈피(+78.59 kJ/mol)는 흡착이 자발적이고 흡열공정으로 진행된다는 것을 나타낸다.

• 한국환경과학회지
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• 제14권9호
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• pp.881-888
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• 2005

The biosorption of dye, Rhodamine B(Rh-B), onto waste activated sludge was investigated. The biosorption capacity and contact time were shown as a simulation of dye adsorption equilibrium and kinetics models. We observed that biosorption of Rh-B occurred rapidly less than 4 hr. These experimental data could be better fitted by a pseudo-second-order rate equation than a pseudo-first-order rate equation. The equilibrium dependence between biosorption capacity and initial concentration of Rh-B was estimated and it was found that the equilibrium data of biosorption were fitted by four kinds of model such as Langmuir, Freundlich, Redlich-Peterson, and Koble-Corrigan model. The average percentage errors, $\varepsilon(\%)$, observed between experimental and predicted values by above each model were $21.19\%,\;9.97\%,\;10.10\%\;and\;11.76\%$, respectively, indicating that Freundlich and Redlich-Peterson model could be fitted more accrately than other models.

• 공업화학
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• 제34권1호
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• pp.86-93
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• 2023

In this study, we investigated the various adsorption factors influencing the adsorption of heavy metal ions based on the study of the composition and physicochemical properties of scoria dispersed throughout Jeju Island. Analysis of the distribution characteristics of scoria samples collected from five areas of Jeju showed that reddish-brown-colored scoria were predominant. Analysis of scoria collected from Jeju Island showed that its mineral components are ordered as follows: SiO₂ > Al₂O₃ > Fe₂O₃ > CaO and MgO. The experimental data did not show a linear relationship in the pseudo-first-order adsorption kinetics. In contrast, a pseudo-second-order model yielded a positive linear relationship, and this model was subsequently used. It could be concluded based on an intraparticle diffusion model indicating linear relationships that the capture of metal ions on scoria is dominated by the primary adsorption step.

• Membrane and Water Treatment
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• 제7권5호
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• pp.403-416
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• 2016

The possibility of using carica papaya leaf powder for removal of copper from wastewater as a low cost adsorbent was explored. Different parameters that affect the adsorption process like initial concentration of metal ion, time of contact, adsorbent quantity and pH were evaluated and the outcome of the study was tested using adsorption isotherm models. A maximum of 90%-94.1% copper removal was possible from wastewater having low concentration of the metal using papaya leaf powder under optimum conditions by conducting experimental studies. The biosorption of copper ion was influenced by pH and outcome of experimental results indicate the optimum pH as 7.0 for maximum copper removal. Copper distribution between the solid and liquid phases in batch studies was described by isotherms like Langmuir adsorption and Freundlich models. The adsorption process was better represented by the Freundlich isotherm model. The maximum adsorption capacity of copper was measured to be 24.51 mg/g through the Langmuir model. Pseudo-second order rate equation was better suited for the adsorption process. A dynamic mode study was also conducted to analyse the ability of papaya leaf powder to remove copper (II) ions from aqueous solution and the breakthrough curve was described by an S profile. Present study revealed that papaya leaf powder can be used for the removal of copper from the wastewater and low cost water treatment techniques can be developed using this adsorbent.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1006-1011
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• 2010

This study was focused on the reactivity of furnace slag against cadmium to design the vertical drain method with reactive column for improving contaminated sea shore sediment. The removal capacity of furnace slag was analyzed using pseudo-second-order model. And the effective parameters of removal test were initial concentration and initial pH. According to equilibrium removal amount and reactive constant calculated by pseudo-second-order model, the removal capacity was analyzed. Equilibrium removal amount of furnace slag was linearly increased as increasing intial cadmium concentration. Because the pH was around 11, the removal mechanism of furnace slag could be both sorption and precipitation. Therefore the removal amount was increased due to initial concentration. pH was increased to around 11 in the case of "No treat", but the pH were 3.8 in the case of "HAc added" and 0.7 in the case of "HCl added". The removal amount was different 4.8, 1.19 and 0.27 mg/g. This results show the pH was major factor to remove cadmium using furnace slag.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.301-306
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• 2020

We investigated the individual biosorption removal of lead, copper, and nickel ions from aqueous solutions using Chara sp. algae powder in a batch mode. The impact of several parameters, such as initial concentration of the metal ions, contacting time, sorbent dose, and pH on the removal efficiency, was investigated. The maximum removal efficiency at optimum conditions was found to be 98% for Pb(II) at pH = 4, 90% for Cu(II) at pH = 5, and 80% for Ni(II) at pH = 5. The isotherm study was done under the optimum conditions for each metal by applying the experimental results onto the well-known Freundlich and Langmuir models. The results show that the Langmuir is better in describing the isotherm adsorption of Pb(II) and Ni(II), while the Freundlich is a better fit in the case of Cu(II). Similarly, a kinetic study was performed by using the pseudo-first and second-order equations. Our results show that the pseudo-second-order is better in representing the kinetic adsorption of the three metal ions.