Adsorption of purpurin dye from industrial wastewater using Mn-doped Fe2O4 nanoparticles loaded on activated carbon

Mn–Fe2O4 nanoparticles loaded on activated carbon were applied for removal of purpurin dye of solution. The effects of the amount of nanoparticles, pH of the solution, concentration of purpurin, and contact time were studied. The experiments have been designed by response surface methodology. The optimality conditions in the present study were 24 mg L–1 of purpurin concentration, 0.027 g adsorbent mass, pH value of 4.0, and 3.0 min of contact time. The artificial neural network model was employed for data prediction with Levenberg–Marquardt algorithm, purelin or a linear transfer function at output layer, and tansig or a tangent sigmoid transfer function in the hidden layer with 15 neurons. Remarkably, the experimental data and the pseudo-second-order kinetics fitted well. The isotherm analysis revealed that the equilibrium data were well fitted to the Langmuir isotherm model with the highest adsorption capacity of 60 mg g–1 of the adsorbent for removal of purpurin.