Magnetic FeO nanoparticles loaded guava leaves powder impregnated into calcium alginate hydrogel beads (FeO-GLP@CAB) for efficient removal of methylene blue dye from aqueous environment: Synthesis, characterization, and its adsorption performance.

In the present work, a novel FeO-GLP@CAB was successfully synthesized via a co-precipitation procedure and applied for the removal of methylene blue (MB) from aqueous environment. The structural and physicochemical characteristics of the as-prepared materials were explored using a variety of characterization methods, including pH, XRD, VSM, FE-SEM/EDX, BJH/BET, and FTIR. The effects of several experimental factors on the uptake of MB using FeO-GLP@CAB were examined through batch experiments. The highest MB dye removal efficiency of FeO-GLP@CAB was obtained to be 95.2 % at pH 10.0. Adsorption equilibrium isotherm data at different temperatures showed an excellent agreement with the Langmuir model. The adsorption uptake of MB onto FeO-GLP@CAB was determined as 136.7 mg/g at 298 K. The kinetic data were well-fitted by the pseudo-first-order model, indicating that physisorption mainly controlled it. Several thermodynamic variables derived from adsorption data, like as ΔG, ΔS, ΔH, and E, accounted for a favourable, spontaneous, exothermic, and physisorption process. Without seeing a substantial decline in adsorptive performance, the FeO-GLP@CAB was employed for five regeneration cycles. Because they can be readily separated from wastewater after treatment, the synthesized FeO-GLP@CAB was thus regarded as a highly recyclable and effective adsorbent for MB dye.