Abstract:
In this work, 4-carboxybenzaldehyde (4-CBA) removal from aqueous solution onto low cost
adsorbent- bagasse fly ash (BFA) was carried out. A 4-factor 5-level Central composite design
under response surface methodology was used to optimize the 4-CBA removal and adsorption
uptake. Variable considered for the study were pH, adsorbent dose, initial concentration and
time. The optimum value of these parameters were found as pH=4, adsorbent dose=9 g/l, initial
concentration=100 mg/l and time 7.5 h. At optimized condition the removal efficiency and
adsorption uptake of 4-CBA onto BFA were found to be 79% and 9.9 mg/g, respectively.
Quadratic regression model was developed to evaluate impact of linear and quadratic interaction
and R2 (=0.873) value suggest that the model was significant. Adsorption capacity of BFA and
GAC was compared. BET surface area of BFA and GAC was found to be 284 m2/g and 591
m2/g, respectively. Both the adsorbents were predominately mesoporous in nature. Kinetic study
was carried out by employing pseudo first and pseudo second order model and possibility of
intra particle diffusion controlling the adsorption mechanism was also investigated. Adsorption
equilibrium data were fitted for Langmuir, Freundlich, Redlich- Peterson, Sips, Hills, Temkin
model. Positive value of DH 0 suggest that the adsorption process was endothermic. Change in
the entropy was found to be positive. Negative values of 0
ads DG indicates that the adsorption
process is feasible and spontaneous...
