Basic Dye Adsorption onto Clay/MnFe2O4 Composite: A Mechanistic Study.

  Native, HCl pretreated clay and MnFe2O4/clay composite were investigated as an adsorbent for crystal violet (CV) removal. The adsorption behavior of dye was studied in batch experiments as a function of contact time, adsorbent dose, pH, dye initial concentration and temperature. The medium pH 8, contact time 30 min, MnFe2O4/clay composite dose 0.05 mg/L, temperature 35 °C and 100 mg/L dye initial concentration furnished maximum CV adsorption. Adsorption data fitted well to the Langmuir isotherm model and maximum CV dye adsorption capacity of composite was 49.74 mg/g. The thermodynamic parameters revealed that the adsorption process of CV was exothermic and spontaneous in nature. CV adsorption followed the pseudo second order kinetic model. MnFe2O4/clay composite exhibited good CV adsorption capacity and can be used as an alternative adsorbent for the removal of basic dyes from effluents.