Synthesis of micro-particles using Hydrocotyle Ranunculoides (Floating Water Pennywort) and their use in Cadmium adsorption.

Microparticles were prepared using Hydrocotyle ranunculoides (Floating Water Pennywort) and subsequently used as adsorbent for Cd(II) from aqueous solution in batch systems. The optimum conditions for Cd (II) adsorption were investigated by varying the parameters: initial Cd (II) concentration, pH value, contact time, and adsorbent dose. It was shown that the optimum parameters for Cd(II) adsorption were pH 5.0, dosage 2 g/L, initial Cd (II) concentration 50 mg/L and contact time 240 minutes. The results showed a Langmuir maximum adsorption value of 20.41 mg/g and a separation factor between 0.72 and 0.91, suggesting a feasible adsorption process. An E value of 5.59 kJ/mol which was obtained using the Dubinin Radushkevich model indicated that the adsorption process was physical in nature. The structure of micro-particles was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Thermo Gravimetric Analysis (TGA), and Energy-Dispersive X-ray spectroscopy (EDX). The EDX profile shows that most inorganic impurities present were totally removed during the steam explosion process. The functional groups present in micro-particles, which have the potential to take part in adsorption are hydroxyl groups as confirmed by the FT-IR spectra. The study showed that the material is a good adsorbent.