Adsorptive capacity of ethylenediamine treated oxidised rice straw for sulfur dioxide

The introduction of sulfur dioxide (SO2) into the atmosphere is of major concern causing acid rain. Thus, the modified rice straw was prepared via sequential reactions of the active groups on rice straw with potassium permanganate (KMnO4) followed by the alkaline molecule, ethylenediamine, to adsorb SO2. The experimental parameters were optimized as the concentration of potassium permanganate of 5%, the concentration of ethylenediamine of 10%, the moisture content of 200%, as well as the reaction temperature of room temperature. Experiments show that the modified rice (Straw–KMnO4–NH2) has better adsorption capacity for SO2 and its saturated sulfur capacity could reach ∼340 mg/g, which was much better than that of the raw straw and other reported modified samples. The performance of the Straw–KMnO4–NH2 was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron micrographs (SEM), and elemental analysis.