Adsorption of Acid Orange 7 in Aqueous Solution by Biochar from Peanut Shell Supported with Clay Mineral Kaolinite

Biochar was prepared from the peanut shell.Then, it was mixed with the clay mineral kaolinite and stirred under the magnetic stirrer.The biochar derived from peanut shell supported with clay mineral kaolinite (B@K) was obtained.Adsorption experiments of dye Acid Orange 7 by B@K were conducted.The characteristics of B@K were determined by the elemental analyzer, specific surface area meter, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectrometer and the model axis-HS.The experimental results showed that a large number of oxygen-containing functional groups appear on the surface of B@K, which is beneficial for binding dye ions.The adsorption process fits well with the pseudo-second-order kinetic model.It indicated that the adsorption process was both physical adsorption and chemical adsorption.Chemical adsorption is the main adsorption process.Langmuir isotherm model can better describe the adsorption isothermal process of B@K on dye Acid Orange 7. The adsorption process is monolayer adsorption process.