Efficient adsorption of erythrosine and sunset yellow onto modified palladium nanoparticles with a 2-diamine compound: Application of multivariate technique

Multiwalled carbon nanotubes (MWCNTs) functionalized with (N-3-phenylallaylidene)-N'-trimethox-ysilylpropyl-ethane-1,2-diamine (PATMSPEDA) were prepared and subsequently the MWCNTs-PATMSPEDA-Pd-NPs nanohybrids with high shape selectivity and high specific surface area have been prepared by single step synthesis of Pd nanoparticles (Pd-NPs) loaded on MWCNTs-PATMSPEDA. These materials were characterized by different techniques such as XRD, SEM, FT-IR and TGA-DTA and subsequently were used for the simultaneous ultrasound-assisted removal of erythrosine (ER) and sunset yellow (SY) dyes from aqueous solution. The influences of important variables such as initial dyes concentration, adsorbent dosage, pH and sonication time on the efficiency of ultrasound-assisted removal process were investigated by central composite design (CCD) and the optimization conditions were obtained 4.39 and 4.33 mg L-1 of ER concentration, 11.76 and 11.90 mg L-1 of SY concentration, 0.02 and 0.019 g adsorbent mass, 7.0 and 7.0 for pH value and 3.88 and 3.75 min sonication time for MWCNTs-PATMSPEDA and MWCNTs-PATMSPEDA-Pd-NPs, respectively. The artificial neural network (ANN) model was used for constructing an empirical model to predict the understudy dyes removal behavior onto these adsorbents and the obtained results have good agreement with experimental data. The absolute average deviations (AADs) of ER and SY dyes adsorption by MWCNTs-PATMSPEDA are 0.62% and 0.58%, and the determination coefficient (R-2) values are 0.971 and 0.978, respectively. Also, the AADs of ER and SY dyes adsorption by MWCNTs-PATMSPEDA-Pd-NPs are 0.48% and 0.34%, and the R-2 values are 0.971 and 0.972, respectively. Finally, it was found that the equilibrium isotherm of adsorption process follows the Langmuir isotherm. From the Langmuir isotherm, maximum monolayer capacity (q(max)) were obtained to 30.58 and 38.76 mg g(-1) and 55.25 and 59.17 mg g(-1) at optimum conditions for ER and SY removal onto MWCNTs-PATMSPEDA and MWCNTs-PATMSPEDA-Pd-NPs, respectively. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.