Flocculants based on Ocimum Basilicum L. starch grafted polyacrylamide in jar test, settling test, dye removal, heavy metal ion removal, and in-vitro drug delivery
摘要
Ocimum basilicum L. starch (OBS) is an abundant and eco-friendly natural polysaccharide that can serve as a backbone in grafting with synthetic polymers. This combination enhances their structural and functional properties, making them highly suitable for industrial applications, particularly in wastewater treatment. In the present work, five different grades of graft copolymers (OBS-g-PAM-1 to OBS-g-PAM-5) have been fabricated by grafting polyacrylamide onto the backbone of OBS, extracted from Ocimum basilicum L. seeds, through free radical solution polymerization. Partial hydrolysis of these products has yielded five grades of hydrolysed graft copolymers (Hyd-OBS-g-PAM-1 to Hyd-OBS-g-PAM-5). The synthesized polymers were characterized for their structural determination through FTIR and 1H-NMR spectroscopic studies. Molecular weights of the unhydrolysed graft copolymers have been determined through GPC and intrinsic viscosity measurements. Flocculation efficiency of the unhydrolysed and the partially hydrolysed graft copolymers has been checked in kaolin suspension through jar and settling tests. A comparative study of methylene blue dye removal was conducted using the best grades from each series, namely OBS-g-PAM-4 and Hyd-OBS-g-PAM-3. A separate study of removal of heavy metal ions namely Cu(II), Cd(II), Ni(II), Hg(II), and As(III) has been performed using OBS-g-PAM-4. Additionally, in-vitro drug delivery of diclofenac sodium was evaluated using Hyd-OBS-g-PAM-3. This study introduces Ocimum basilicum L. starch as a novel backbone for grafting polyacrylamide, yielding eco-friendly copolymers with dual functionality. Unlike conventional flocculants, the synthesized materials simultaneously achieve efficient dye and heavy metal removal while enabling controlled drug delivery, bridging environmental and biomedical applications.