Study of reactive Yellow 145 removal by Ag/GO nanocomposite using response surface methodology

Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl. They are a commercially important family of azo compounds, i.e. compounds containing the linkage C-N=N-C. Azo dyes are widely used to treat textiles, leather articles, and some foods. Chemically related to azo dyes are azo pigments, which are insoluble in water and other solvents. Azo dyes should be removed from water resources since they are highly resistant under aerobic conditions and their anaerobic reduction gives aromatic amines, which are intrinsically carcinogenic and mutagenic.1 Azo dyes are highly carcinogenic, mutagenic and resistance against biodegradation.2 Therefore, they must be to remove from water and wastewater. Different physical and chemical processes have been employed to remove of azo dyes.3-4 Adsorption is a efficiency method to removal of pollutants. In recent years, interest in composite based on graphene oxide (GO) with silver species has increased. Response surface methodology (RSM) is a useful technique for evaluation of several input variables that affect the efficiency or the qualitative properties of interest. Also, this method is a beneficial tool for optimization studies.5 RSM proposes a second- or higher-order function to relate the response to the experimental parameters. This study aims to investigate removal of the Reactive Yellow 145 azo (RY 145) dye by the Ag NPs /GO nanocomposite and evaluate the effect of pH, RY 145 concentration, contact time and catalyst dosage on RY 145 removal. Structure of RY 145 is shown in Fig. 1. Performance of the process is predicted and optimized using a second-order equation by RSM.As shown, RY145 removal was increased by increasing the dosage of catalyst. Increasing the dosage of the catalyst increases the active surface area and enhancement of RY145 adsorption. consequently, removal of a of RY 145 was increased.