Efficient removal of MB dye from wastewater via cadmium ferrite nanocomposites

The current study reports the dye adsorption of methylene blue (MB) on PANi, PANi-treated cadmium ferrite, and the composite (50% PANi/50% cadmium ferrite) adsorbents. The adsorbents were characterized using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The semicrystalline and spinel structure of the prepared samples was confirmed via X-ray diffraction of the PANi and cadmium ferrite nanoparticles, respectively. The FT-IR spectra results confirm the vibration bands of PANi at the surface of cadmium ferrite nanoparticles. Two isotherm models were used to fit the adsorption data at equilibrium, and two kinetic models were used to fit the kinetic data. The kinetics of MB adsorption were evaluated at different contact times (5, 15, 25, 35, and 40) min. Both ferrite and the composite adsorbent fit well with the pseudo-second-order kinetic model, with R² values of 0.998 and 0.9871, respectively. In contrast, the samples of PANi and treated PANi fit well with the pseudo-first-order model. The MB adsorption process fitting the Langmuir model (R² = 0.9851, 0.9655, 0.9783, 0.9729, PANi, PANi treated, cadmium ferrite, and the composite (50% cadmium ferrite: 50%PANi), respectively and the maximum adsorption capacity (17.921 mg g⁻¹) for the adsorbent treated PANi. The highest removal yield was found to be 85% when the adsorbed condition was 0.05 g of treated PANi in 50 mL of a 10 ppm MB dye solution, at a pH of 3, and an adsorption time of 40 min.