Synthesis of a coordination polymer based on Zn(DMF)(Tp) as a novel adsorbent for the simultaneous removal of quinoline yellow and azure B

Abstract

In this study, a Zn(DMF)(Tp) coordination polymer was synthesized by solvothermal method using dimethylformamide (DMF) and terephthalic acid (TP). It was then characterized by single crystal X-ray diffraction (SCXRD), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier-transform infrared spectrometer (FT-IR). The polymer was used as an adsorbent for the simultaneous removal of quinoline yellow (QY) and azure B (AZB) dyes. Accordingly, the effects of four parameters, including pH, amount of adsorbent, contact time, and initial dye concentration, on removal efficiency were studied and optimized by response surface methodology based on the central composite design (RSM-CCD). The optimal conditions for maximum adsorption theoretically determined by RSM-CCD were as follows: 6 min contact time, 15 mg Zn(DMF)(Tp), pH of 3, 10 mg/L AZB, and 13 mg/L QY, with percentage removal values of 94.70 and 90.79 for QY and AZB, respectively. The monolayer adsorption capacity was 46.57 and 40.983 mg/g for QY and AZB, respectively. A kinetic study was performed under optimal conditions. In addition, all data corresponding to the process were fitted with pseudo-second-order model. The adsorbent provides fast adsorption due to its porous structure and high removal efficiency due to its high specific surface area.