Synthesis of Bentonite-Carbon Nanotube Nanocomposite and Its Adsorption of Rhodamine Dye From Water

In this work, cheap and effective nanocomposite material has been synthesized by mixing natural bentonite (B) with 5 % multiwall carbon nanotubes followed by heat treatment to 650C in the inert atmosphere. It makes a potentially attractive adsorbent of rhodamine dye (RhB) from wastewater. The nanocomposite adsorbent (BCA) was characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of contact time, adsorbent dosage, initial dye concentration and pH on dye removal were investigated. The isotherm of dye adsorption was studied. The adsorption isotherm of dye onto B and BCA showed good fitting to Langmuir and Freundlich isotherm models. The maximum adsorption capacity of B and BCA samples is 8.6 and 142.8 mg/g, respectively. Both bentonite and modified bentonite are capable of removing the RhB dye from water. In general, the nanocomposite sample BCA significantly enhances the removal of RhB dye from aqueous solution. In addition, the BCA could be used as an eco-friendly adsorbent to remove the dye from colored wastewater.