Recycling of Rice Husk for Preparation of Activated Carbon/Magnetite Nanocomposites for Removal of Methylene Blue from Wastewater

This work focuses on recycling of rice husk for production of activated carbon/Fe3O4 nanocomposite. Moreover, the synthesized composites were applied for elimination of methylene blue dye from wastewater. The proposed nanocomposite can replace pure activated carbon which is expensive and has some difficulties during its reusability. First, the activated carbon was extracted by thermal and chemical activations of rice husk ash. On the other hand, the activated carbon/magnetite nanocomposite was prepared by co-precipitation method using the suitable iron salts. The qualitative phase identification of prepared composite was performed by X-ray technique (XRD) and confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). The morphology and particle size of prepared activated carbon and its composite were investigated by transmission electron microscope (TEM). The batch-adsorption method was utilized for studying the elimination of methylene blue dye from wastewater. Various factors like adsorbent dosage, pH of reaction, initial dye concentration, and duration of reaction were examined. The results showed that the prepared nanocomposite was almost amorphous as indicated from XRD patterns. Also, its particle size was very small (5-10 nm) and lower than the activated carbon alone (40-80 nm). Regarding the removal percentage of methylene blue dye from waste water, 98% was the maximum obtained percentage under the condition: pH 7, adsorbent dosage 0.1 g/100 mL, 50 ppm MB and 20 min. contact time at 25 & DEG;C. Furthermore, the maximum adsorption reaction followed the pseudo-second-order type and the Langmuir isotherm model.