Synthesis and application of AuNi@AC nano adsorbents for the removal of Maxilon Blue 5G azo dye from aquatic mediums

Abstract

In this research, gold-nicel supported on activated carbon (AC) nanoadsorbent (AuNi@AC) synthesized by following a series of physicochemical procedures was prepared for the removal of Maxilon Blue 5G (MB) which is a cationic textile dye. Experimental studies based on parameters specifically pH, contact time, nano catalytic adsorbent particle, initial MB dye concentration and temperature effect were conducted in aqueous solutions in a batch system. AuNi@AC nanoadsorbents (NAs) reached the equilibrium in 30 min under optimum conditions in adsorption of the dye. The pseudo-first, second-order, and intra-particle diffusion models were tested to evaluate a the experimental results. Adsorption kinetics were found to be represented by the pseudo-second-order model, and the maximum adsorption capacity (qmax.) was calculated to be 542.90 mg/g (or 2.041 mmol/g). The synthesized magnetic AuNi@AC nanoadsorbent showed a high-efficiency reusability effect of about 64% after five reuse runs. Also, thermodynamic function parameters such as activation energy (Ea), Gibbs free energy (ΔG *), and entropy (ΔS *) were investigated in the sorption study. After all evaluation of data, it was concluded that the novel AuNi@AC nanoadsorbent could be considered as an effective support material for the removal of various organic pollutants in aquation solution especially for the removal of MB.