Adsorption of Direct Blue 53 dye from aqueous solutions by multi-walled carbon nanotubes and activated carbon.
Multi-walled carbon nanotubes (MWCNT) and powder activated carbon (PAC) were used as adsorbents for adsorption of Direct Blue 53 dye (DB-53) from aqueous solutions. The adsorbents were characterised using Raman spectroscopy, N2 adsorption/desorption isotherms, and scanning and transmission electron microscopy. The effects of initial pH, contact time and temperature on adsorption capacity of the adsorbents were investigated. At pH 2.0, optimum adsorption of the dye was achieved by both adsorbents. Equilibrium contact times of 3 and 4 h were achieved by MWCNT and PAC adsorbents, respectively. The general order kinetic model provided the best fit of the experimental data compared to pseudo-first order and pseudo-second order kinetic adsorption models. For DB-53 dye, the equilibrium data (298-323 K) were best fitted to the Sips isotherm model. The maximum sorption capacity for adsorption of the dye occurred at 323 K, with the values of 409.4 and 135.2 mg g(-1) for MWCNT and PAC, respectively. Studies of adsorption/desorption were conducted and the results showed that DB-53 loaded MWCNT could be regenerated (97.85%) using a mixture 50% acetone + 50% of 3 mol L(-1) NaOH. Simulated dye house effluents were used to evaluate the application of the adsorbents for effluent treatment (removal of 99.87% and 97.00% for MWCNT and PAC, respectively, were recorded).
Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS, Brazil.
Lizie D T
LD
Prola
Fernando M
FM
Machado
Carlos P
CP
Bergmann
Felipe E
FE
de Souza
Caline R
CR
Gally
Eder C
EC
Lima
Matthew A
MA
Adebayo
Silvio L P
SL
Dias
Tatiana
T
Calvete
D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D001391:Azo Compounds; D004396:Coloring Agents; D037742:Nanotubes, Carbon; D002606:Charcoal
Adsorption; Carbon nanotubes; Direct Blue 53; Nonlinear isotherm fitting