Removal of C.I.Basic yellow 2 from aqueous solution by adsorption onto granular activated carbon using an on-line spectrophotometric analysis system: Kinetic and equilibrium study

The adsorption of Basic yellow 2 (BY2), from aqueous solutions onto Granular activated carbon
(GAC) and its adsorption kinetics at different concentrations, GAC masses, initial pH values and
temperatures were studied. The adsorption process was followed by an on-line spectrophotometric
analysis system, which consisted of UV-spectrophotometer, a designed spectrophotometric cell,
peristaltic pump and a glassy reactor. The effect of initial dye concentration, mass of GAC, initial pH
and temperature on adsorption was studied over 60 min adsorption period. The results showed that
at first the removal percent of BY2 increases with the increase in initial concentration, then the trend
is reversed. The results also showed that removal percent of BY2 at pHi around 7 is more than
acidic pHi. Also the removal percent of BY2 increases with the increase in mass of GAC and
temperature. For kinetic study, the obtained data were treated according to various kinetic models.
The results showed that first order kinetic model is fitted to experimental data better than second
order and intraparticle diffusion models. The Freundlich, Langmuir, Redlich-Peterson and BET
adsorption models were applied to describe the equilibrium isotherms. Type 1 Langmuir isotherm
and non-linear Redlich-Peterson isotherm seemed to be the best-fitting models for the experimental
results with similar values of coefficient of determination.