Preparation and characterization of FeMoCoS nanocomposites for efficiently adsorbing dye from wastewater

In this study, FeMoCoS (FMCS) nanocomposites were designed and fabricated through a hydrothermal method as a new efficient adsorbent to remove organic dyes in wastewater. The morphology and microstructure of the adsorbent were characterized by using scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller surface area and Fourier-transform infrared spectroscopy. The effects of adsorption isotherm, kinetics, initial concentration and pH value of Rhodamine B (RhB) solution on the experiment were also studied. The results show that FMCS has good adsorption capacity for RhB solution, and the maximum adsorption capacity is 280.89 mg/g calculated by using a Langmuir isotherm model. Column study was made to achieve bulk removal of the dye. Column adsorption capacity has been found to be greater than the batch adsorption capacity. Moreover, the maximum removal rate of RhB reaches 99.64% at pH = 7 and pH(pzc) = 9.57 according to zeta potential. The adsorption kinetics match the pseudo-second-order model, indicating that the adsorption process is dominated by chemisorption. After 5-cycles of consecutive adsorption, the adsorbent can still maintain a high adsorption capacity, indicating a good potential for RhB removal from wastewater.