PDMAEMA grafted microspheres as an efficient adsorbent for the removal of Sunset yellow from pharmaceutical preparations, beverages and waste water

Abstract

Sunset yellow (SY) dye removal in the beverages, waters and pharmaceutical preparations is of great importance due to its negative side effects. In this context, a new and efficient adsorbent, PDMAEMA grafted PS-DVB-VBC microspheres were synthesized and applied for the adsorption of SY dye. The morphology, chemical and physical properties of the proposed adsorbent was fully characterized using scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), elemental and Brunauer–Emmett–Teller (BET) surface area analysis. The adsorption performance of the adsorbent was investigated systematically, including the influence of pH, contact time, adsorbent dose, adsorption isotherms, adsorption kinetics, and reusability. The optimized conditions of the SY towards the sorbent were as follows: pH of 2.0, contact time of 40.0 min, adsorbent dose of 0.4 g L−1 at 25 °C. The equilibrium adsorption process followed the Langmuir isotherm model with a maximum adsorption capacity of 312.5 mg g−1. Pseudo-second-order kinetic model was found to be most appropriate to define the adsorption of SY dye onto the adsorbent. The quantitative results (96.3–103%) obtained for the real samples (beverages, pharmaceutical preparation and synthetic waste water) confirmed the high performance, feasibility and efficacy of the novel method. The uptake of SY dye was high (>90%) even after recycling five times indicating that the adsorbent could be regenerated and reused in practical applications.