Comparative study of the adsorptive removal of reactive yellow 14 azo dye from an aqueous solution on different synthetic materials

Abstract

The purpose of this study is to investigate the adsorption behavior of the Reactive Yellow 14 (RY14) azo dye from an aqueous solution onto silica gel (SG), alumina (AO) and powdered activated carbon (PAC) via batch adsorption technique at room temperature (25 °C). Physicochemical properties of the adsorbents were characterized by means of scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The factors influencing the adsorption of SG, AO and PAC, such as adsorbent dosage, pH, ionic strength, contact time and initial concentration, were conducted to evaluate the adsorption performance. The kinetic studies indicated that the adsorption of RY14 on SG and PAC can be very well fitted by a pseudo-second-order kinetic model, and onto AO by a pseudo-first-order kinetic model. The equilibrium data were best described by a Langmuir model for all adsorbents. The maximum estimated adsorption capacity was 124.6, 116.2 and 200.7 mg·g−1, for SG, AO and PAC, respectively. HIGHLIGHTS Removal of RY14 azo dye from an aqueous solution onto SG, AO and PAC adsorbents.; The adsorption of RY14 on SG and PAC was well fitted by a pseudo-second-order kinetic model, whereas the adsorption was fittеd by a pseudo-first-order kinetic model on AO.; The maximum adsorption capacity was 124.6, 116.2 and 200.7 mg·g−1, for SG, AO and PAC, respectively.;

Keywords

• adsorption mechanism
• azo dyes
• isotherm
• kinetics
• reactive yellow 14
• water treatment