Uptake of anionic and cationic dyes from water using natural clay and clay/starch/MnFe2O4 magnetic nanocomposite

The present research was designed to explore the adsorption of sunset yellow (SY) and Nile blue (NB) from water using clay and clay/starch/MnFe2O4 magnetic composite. The magnetic composite was synthesized by chemical precipitation and the physical-chemical characteristics of the adsorbents were evaluated. The specific magnetic saturation values for MnFe2O4 nanoparticles and clay/starch/MnFe2O4 were obtained 31.88emu/g and 10.33emu/g, respectively. In the batch mode experiments, the effect of operational factors was studied. The pseudo-second-order had a better correlation coefficient compared to the pseudo-first-order, Elovich, and intraparticle diffusion models. The Langmuir and Freundlich model fitted the equilibrium data for adsorption of both dyes (SY and NB) using clay and clay/starch/MnFe2O4, respectively. The maximum adsorption capacity for the adsorption of SY and NB dyes using clay was 67.82 mg/g and 72.25 mg/g, respectively and these values increased by about 15% after using the clay/starch/MnFe2O4 composite. The negative value of Gibbs free energy and enthalpy parameters proved that the SY and NB adsorption is spontaneous and exothermic. A sample of textile wastewater was properly treated using adsorbents. Finally, clay and clay/starch/MnFe2O4 magnetic composite can be used as viable adsorbents for dyes removal from water and industrial wastewater.