Investigation On The Adsorption Characteristics Of Basic Magenta And Rhodamine B Onto Fe/Cu Nanocomposites

A large amount of printing and dyeing wastewater is produced and discharged to the receiving environment during the dyes production and use processes,which causes a great threat to ecological environment and human health.Adsorption is one of the effective methods to remove dye in the wastewater.Sweet potato leaf,as agricultural waste,was rich in polyphenols compounds which could serve as reducing for green synthesized metal nanoparticles.In this work,the adsorption characteristics of Basic magenta(BM)and Rrhodamine B(Rh B)were investigated by Fe/Cu nanocomposites which were synthesized using sweet potato leaf extract.Fe/Cu nanocomposites were synthesized by extracts of sweet potato leaves and the characteristics of Fe/Cu nanocomposites were performed by SEM-EDS,FTIR,BET,XRD and XPS.The adsorption capacity was investigated of basic magenta(BM)on Fe/Cu nanocomposites.The effects of various parameters such as adsorption time,adsorbent dosage and p H were optimized by Box-Behnken Design(BBD)of response surface methodology(RSM).The optimal adsorption experiment conditions were adsorption time 443 min,adsorbent dosage 0.4 g/L,p H 5.5.Thermodynamic studies showed that the BM adsorption equilibrium data was fitted well to the Redlich-Peterson and Sips isotherm models,the maximum adsorption capacity of BM on Fe/Cu nanocomposites was 235.92 mg/g at 298 K.The studies of thermodynamic parameters(ΔG,ΔH and ΔS)of BM adsorption onto Fe/Cu nanocomposites indicated that the adsorption process of BM onto Fe/Cu nanocomposites was endothermic and spontaneous,it was favorable for adsorption at high temperature.The results of kinetic fitting data analysis showed that the pseudo-second order kinetic model was suitable to describe the adsorption process of BM onto Fe/Cu nanocomposites.The adsorption rate was not only controlled by the intra-particle diffusion,but also influenced by the boundary layer diffusion.The adsorption performance of Rh B on Fe/Cu nanocomposites was studied.Adsorption conditions including adsorption time,adsorbent dosage and solution p H were optimized using BBD of RSM.The optimal experiment conditions were adsorption time 507 min,adsorbent dosage 0.2 g/L,p H 5.61.The nonlinear fitting analysis of the thermodynamic experimental data of adsorption Rh B showed that Sips model can well describe the adsorption process of Rh B on Fe/Cu nanocomposites,the maximum adsorption capacity was 484.18 mg/g at 298 K.Thermodynamic studies showed that the adsorption process of Rh B onto Fe/Cu nanocomposites was endothermic and spontaneous,high temperature was beneficial to the adsorption process.Kinetic studies showed that the adsorption data followed the pseudo-second order kinetics model.The adsorption process was controlled by the intra-particle diffusion and boundary layer diffusion,and the intra-particle diffusion was the rate-limiting step.The BM and Rh B adsorption process on Fe/Cu nanocomposites was influenced by the hydrogen bonding,π-π,complexation and electrostatic interaction.The results indicated that Fe/Cu nanocomposites synthesized using sweet potato leaf extract had a relatively large BM and Rh B adsorption capacity and can be considered as adsorbent for the removal of BM and Rh B from aqueous solution.