Hydroxypropyl-Β-Cyclodextrin Modified Nickel Ferrite Nanocomposites For Removal Of Pharmaceutical Pollutants

Abstract

The growth of the pharmaceutical companies has been a boon to the mankind in myriad ways. However, the consequences due to the excess usage of these pharmaceutical compounds in our day-to-day life have resulted in irreplaceable damage to the ecosystem. Researchers have used nanocomposite-based systems for the removal of a wide range of pharmaceutical pollutants from the aqueous systems. Among them the magnetic based silica system has gained momentum due to its ease of synthesis and wide applicability. Nickel ferrite-based silica nanocomposites attached to cysteine and nickel ferrite-based silica nanocomposites attached to aminosilanes were both optimised for their size and morphology. Cysteine coated and amine coated nanocomposites revealed a particle size of 130-150 nm and 50- 100 nm. The physiochemical properties of the nanocomposites were evaluated using different characterization techniques such as TEM, FESEM, XRD, FTIR and TGA. The adsorption studies were performed on both the nanocomposites which revealed a higher adsorption potential of 97.01%, 94.12% and 70.13% for IBF, ACE and STR respectively for aminosilane coated nanocomposite. The nanocomposites revealed a good removal efficiency of ~90% up to 4 cycles with reduction in removal efficiency during the 5th cycle. Hence, aminosilane coated nanocomposites were further grafted with hydroxypropyl- -cyclodextrin to determine the removal efficiency post grafting. The hydroxypropyl- -cyclodextrin grafted nanocomposites (14 mg /L) revealed a very good removal efficiency of 98.01 %, 98.89 %, 98.3 % for IBF, ACE and STR respectively. The nanocomposites also showed good reusability of ~92% for up to 5 cycles thus exhibiting higher pollutant removal in comparison to aminosilane coated nickel ferrite-based silica nanocomposites. The adsorption kinetics for the adsorption seemed to follow pseudo second order reaction kinetics. Also, the Langmuir model of adsorption seemed to fit well with the experimental data confirmation monolayer adsorption process.