Clean Technology, Vol.26, No.2, 122-130, June, 2020
활성탄에 의한 Reactive Blue 4 염료의 흡착에 대한 등온선, 동력학 및 열역학적 특성
Characteristics of Isotherm, Kinetic, and Thermodynamic Parameters for Reactive Blue 4 Dye Adsorption by Activated Carbon
E-mail:
초록
입상 활성탄에 대한 reactive blue 4 (RB 4) 의 등온흡착과 동력학적, 열역학적 파라미터에 대해 활성탄의 양, pH, 초기농도, 접촉시간, 온도를 흡착변수로 하여 조사하였다. 활성탄에 의한 RB 4 염료의 흡착은 pH 7을 기점으로 양쪽으로 흡착 백분율이 증가하는 concave 모양을 나타내었다. 등온흡착자료는 Langmuir, Freundlich, Temkin 등온흡착식에 적용하였다. Freundlich과 Langmuir 등온흡착식이 모두 잘 맞았다. 계산된 Freundlich 분리계수(1/n = 0.125 ~ 0.232)과 Langmuir 분리계수(RL = 1.53~ 1.59) 으로부터 활성탄이 RB 4를 효과적으로 처리할 수 있다는 것을 알 수 있었다. Temkin의 흡착열관련상수(BT = 17.611~ 29.010 J mol-1)는 이 공정이 물리흡착임을 나타냈다. 동력학적 실험으로부터 흡착공정은 유사 이차 반응속도식에 잘 맞았다. 입자 내 확산식에 대한 결과는 표면확산을 나타내는 두 번째 직선의 기울기보다 입자내 세공확산을 나타내는 첫 번째 직선의 기울기가 작게 나타나서 입자내 세공확산이 속도지배단계인 것을 확인하였다. Gibbs 자유에너지 변화(ΔG = -3.262 ~-7.581 kJ mol-1)와 엔탈피 변화(ΔH = 61.08 kJ mol-1)은 각각 흡착공정이 자발적 공정 및 흡열과정임을 나타내었다.
The isotherm, kinetic, and thermodynamic parameters of reactive blue 4 adsorbed by activated carbon were investigated for activated carbon dose, pH, initial concentration, contact time, and temperature data. The adsorption of the RB 4 dye by activated carbon showed a concave shape in which the percentage of adsorption increased in both directions starting from pH 7. The isothermal adsorption data were applied to Langmuir, Freundlich, and Temkin isotherms. Both Freundlich and Langmuir isothermal adsorption models fit well. From determined Freundlich separation factor (1/n = 0.125 ~ 0.232) and Langmuir separation factor (RL = 1.53 ~ 1.59), adsorption of RB 4 by activated carbon could be employed as an effective treatment method. The constant related to the adsorption heat (BT = 2.147 ~ 2.562 J mol-1) of Temkin showed that this process was physical adsorption. From kinetic experiments, the adsorption process followed the pseudo second order model with good agreement. The results of the intraparticle diffusion model showed that the inclination of the first straight line representing the surface diffusion was smaller than that of the second straight line representing the intraparticle pore diffusion. Therefore, it was confirmed that intraparticle pore diffusion is the rate-controlling step. The negative Gibbs free energy change (ΔG = -3.262 ~ -7.581 kJ mol-1) and the positive enthalpy change (ΔH = 61.08 kJ mol-1) indicated the spontaneous and endothermic nature of the adsorption process, proving this process to be spontaneous and endothermic.
Keywords:Activated carbon;Adsorption kinetics;Dye adsorption;Reactive blue 4;Thermodynamic parameter
- Lee JJ, Clean. Technol., 20(3), 290 (2014)
- Park YS, Lee JY, Sohn MJ, J. Korea Soc. Waste Manag., 36(5), 421 (2019)
- Lee SW, Kim DK, J. Korea Soc. Waste Manag., 36(2), 138 (2019)
- Epolito WJ, Lee YH, Bottomley LA, Pavlostathis SG, Dyes Pigment., 67(1), 35 (2005)
- Ozcan A, Omeroglu C, Erdogan Y, Ozcan AS, J. Hazard. Mater., 140(1-2), 173 (2007)
- Demirbas E, Nas MZ, Desalination, 243(1-3), 8 (2009)
- Isah U, Absulraheem G, Bala S, Muhammad S, Abdullahi M, Int. Biodeterior. Biodegra., 102, 265 (2015)
- Argun ME, Guclu D, Karatas M, J. Ind. Eng. Chem., 20(3), 1079 (2014)
- Lee JJ, Appl. Chem. Eng., 28(2), 206 (2017)
- Lee JJ, Clean Technol., 25(1), 56 (2019)
- Sivakumar P, Palanisamy PN, Intl. J. Chem. Technol. Res., 1(3), 502 (2009)
- Kansal SK, Ali AH, Kapoor S, Desalination, 259(1-3), 147 (2010)
- Ghasemi M, Naushad M, Ghasemi N, Khosravi-fard Y, J. Ind. Eng. Chem., 20(4), 2193 (2014)
- Al-Kadhi NS, Egypt. J. Aquat. Res., 45(3), 231 (2019)
- Gercel O, Ozcan A, Ozcan AS, Gercel HF, Appl. Surf. Sci., 253(11), 4843 (2007)
- Lee EH, Lee KY, Kim KW, Kim HJ, Kim IS, Chung DY, Moon JK, Choi JW, J. Nucl. Fuel Cycle Waste Technol., 14(3), 223 (2016)
- Pan M, Lin X, Vie J, Huang X, Royal Soc. Chem., 7, 4492 (2017)
- de Souza TNV, de Carvalho SML, Vieira MGA, da Silva MGC, Brasil DDB, Appl. Surf. Sci., 448, 662 (2018)