SYNTHESIS OF NEW ADSORBENTS VIA FUNCTIONALIZED MCM-41 FOR THE REMOVAL OF SOME IONS FROM AQUEOUS SOLUTION

Abstract

Background: Mesoporous materials like MCM-41 silica are highly regarded for their structural features and applications in adsorption and catalysis. This study enhances MCM-41's ability to adsorb cobalt and copper ions by introducing amine and Schiff-base groups, boosting its affinity for these pollutants and aiding in their removal from water solutions. Aims: To prepare MCM-41@NTPE and MCM-41@NTPE-BSAL and use them to adsorb heavy pollutants like cobalt and copper divalent ions from aqueous solutions. Methods: Mesoporous materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) derived from rice husk were used as low-cost adsorbents for the adsorption of Co(II) and Cu(II) ions from aqueous solutions. Uptake experiments were performed to determine adsorption parameters like ion concentration, pH, exposure time, and adsorbent mass. Results: MCM-41@NTPE and MCM-41@NTPE-BSAL were characterized by FT-IR, FESEM-EDX, TEM, N2-adsorption–desorption, XRD,AFM and TGA/DTA. FT-IR confirmed the presence of silanol and siloxane groups. XRD and TEM indicated highly ordered hexagonal arrangements. N2–adsorption–desorption analysis revealed average pore diameters of 42.468 nm and 40.417 nm, total pore volumes of 0.094 cm3g?1 and 0.3384 cm3g?1, and specific surface areas of 8.873 m2g?1 and 37.802 m2g?1 for MCM-41@NTPE and MCM-41@NTPE-BSAL, respectively. TGA showed three mass reduction steps. Adsorption assessment showed pH 6 and 5 were optimal for Co(II) and Cu(II) uptake, respectively, and uptake increased with initial concentration and exposure time. Discussion: XRD confirmed the hexagonal mesoporous structure, while BET analysis displayed amorphous natures. TGA suggested MCM-41@NTPE and MCM-41@NTPE-BSAL have potential for stability, although decomposing between 15-900°C. Electron microscopy revealed ordered hexagonal arrangements. The materials demonstrated high efficacy in extracting copper and cobalt ions from aqueous solutions. Conclusions: Two mesoporous silica materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) were prepared from rice husk by functionalizing MCM-41. Adsorption assessment showed uptake depended on exposure time, pH, initial concentration, and adsorbent mass. MCM-41@NTPE-BSAL exhibited better ion uptake than MCM-41@NTPE.