Synthesis of Nano‐zero‐valent Iron/Chitosan based on Bimetallic Nanoparticles for the Simultaneous Removal of Reactive Violet 5 and Reactive Blue 171 from Aquatic Media: Response Surface Methodology

Abstract

In this study, a nanostructure adsorbent was fabricated from mixed nanosized zero‐valent iron (nZVI), chitosan (CS), and copper (Cu) for the simultaneous removal of Reactive Violet 5 and Reactive Blue 171 from the aqueous media. The prepared adsorbent was characterized by scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Brunauer‐Emmett–Teller, Fourier transform infrared spectroscopy, and X‐ray diffraction. The impact of variables, including pH, adsorbing dosage, contact time, and temperature on the removal percentages of RV5 and RB171 dyes were simultaneously investigated using response surface methodology (RSM) based on a central composite design. The maximum removal efficiency (77.67 %) was obtained at a pH of 3, an adsorbent dosage of 0.3 g, a contact time of 15 min, and a temperature of 10 °C. The adsorption process fitted well with the Langmuir isotherm model with a coefficient of determination (R2) equal to 0.9996 and the pseudo‐second‐order kinetic model (R2=0.9988). Hence, it could be concluded that the process of adsorption mechanism is monolayer and chemical. The maximum adsorption capacity (qmax) was 50.25 mg g−1. In conclusion, nZVI‐CS‐Cu can be considered as an efficient and inexpensive adsorbent for dye removal from aqueous solutions, because its separation is quick and easy, it possesses high efficiency, and there is no secondary pollution.