Evaluation of Basic Violet 16 Adsorption from Aqueous Solution by Magnetic Zero Valent Iron-activated Carbon Nanocomposite using Response Surface Method: Isotherm and Kinetic Studies

Abstract

Background and purpose: Increasing industrial activities and the subsequent discharge of untreated wastewater containing dye to aqueous environment can cause problems such as reducing the sun light penetration, creating anaerobic conditions, allergy and cancer. Adsorption is considered as one of the most efficient and effective methods for dye removal. The aim of this study was to magnetize the activated carbon with zero-valent iron and using it as an adsorbent for dye removal from aqueous solution. Materials and methods: In this study, co-precipitation method was used for synthesizing magnetic zero valent iron-activated carbon nanocomposite. Characteristics of absorbent were analyzed by SEM, TEM, EDX, XRD, and VSM techniques. We evaluated the effect of independent variables including contact time, solution pH, temperature, adsorbent dosage and the concentration of dyes on response performance (removal efficiency of Basic Violet dye) with response to surface methodology based on box-behnken design. ANOVA was applied to analyze the responses. Results: The optimum conditions for basic violet 16 dyes removal were obtained at pH= 3, contact time= 65 min, absorbent dose= 2 g/L and temperature= 45 C°. Investigating the isotherm and kinetic models showed that the experimental data were correlated with Langmuir adsorption isotherm model (R 2 >0.995) and pseudo-second order kinetic (R 2 >0.931). Conclusion: In optimal conditions, magnetic zero valent iron-activated carbon nanocomposite has the potential to remove violet 16 dyes. Also, its separation from the solution is more simple and faster due to its magnetism property.