Insights on the material, adsorptivity, reusability and phytotoxicity of Grewia Optiva amorphous nanocellulose and its magnetite composite for pharmaceuticals removal

Magnetite (MNP) was immobilised onto a novel amorphous nanocellulose isolated from Grewia Optiva fibre (GOF-ANC) with an aim to enhance the material, adsorptive and desorptive features of the composite. XRD, FTIR, TEM, BET and Fe-SEM analysis showed successful fabrication of GOF-ANC@MNP. The composite had enhanced crystallinity, nano-spherical dimensions of size 5.34 nm, higher surface area of 79 m²/g surface, higher mesoporosity of 98% and pore volume of 0.14 cc/g, better surface functionalities when compared to that for GOF-ANC (surface area, 9.95 m²/g; pore volume, 0.08 cc/g; mesoporosity, 95%). VSM showed superparamagnetism favouring the easy recovery of the composite post adsorption studies. Batch adsorptivity of composite was not only high for ciprofloxacin, tetracycline (TTC) and Eriochrome Black-T (91.6, 95.6 and 74.58 mg/g for single component) but also showed high TTC removal under presence of multi-pharmaceuticals including norfloxacin and trinidazole. Binding interactions were monolayer and physical as elucidated by kinetic and isotherm model. Fall in TTC after five cycles of operation was 6% by the composite against 32% by GOF-ANC. pH range for achieving highest adsorptivity was enhanced from 1.5–5 in the GOF-ANC to 1.5–7.5 in the composite. Phytotoxicity tests revealed non-toxicity of the composite vis-a-vis that of MNP, but also effective immobilisation of TTC onto GOF-ANC@MNP facilitated germination of mung bean seeds. MNP immobilisation onto GOF-ANC is a promising strategy for advanced material and adsorptive characteristics, enabling better reusability and environmental friendliness in the composite.