In-situ synthesised hydroxyapatite-loaded films based on cellulose nanofibrils for phenol removal from wastewater

Abstract

Phenol removal from aqueous medium was studied by the batch method using novel and fully biobased solvent-cast films prepared from cellulose nanofibrils (CNFs) and in situ synthesised hydroxyapatite (HAp) by the wet-chemical precipitation method and different concentrations of HAp precursors and weight mass of CNFs. The chemical and morphological structures of as-prepared films were investigated by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, while their physical properties were determined by water contact angle and swelling kinetic measurements. The HAp precursor leads to a surface modification of CNFs, which increases its activity by forming differently structured, sized and distributed HAp particles, influencing the phenol adsorption kinetic and capacity. The phenol adsorption was faster and higher (*64 mg g -1 ) in an acidic solution (pH 2) compared to the original phenol solution pH (pH 7.4, *30 mg g -1 ) using films with unevenly-distributed and positively-charged calcium-richer HAp particles synthesised on the CNFs' surface, being reflected also in its higher water swelling properties, compared to their hybrid counterparts. The phenol adsorption is identified to follow pseudo-second order kinetic and intra-particle diffusion models. A highly-efficient reusing ability of the selected film with 86% adsorption capacity of the initial value at the third sequential regeneration cycle, is also confirmed. A super-hydrophilic nature of the films with high water-diffusing and transport properties, as well as low swelling, indicates their potential in the development of highlyeffective adsorbents and, potentially, filter membranes for water purification.

Preparation and characterization of multifunctional sponge-gourd fibers (Luffa cylindrica)/ hydroxyapatite composites for removal of lead and methylene blue

“…It can be seen that the peak intensity of O-H and C-H groups were decreased as shown in Fig. 3 (S4, S5, and S6), probably due to the interaction of these groups with HAp, which helped in attaching HAp on the surface of CNCs (Narwade et al 2017).…”

“…The FTIR spectra of Luffa bers (S1) and oxidized-nanocellulose (S3) samples exhibited a new absorption peak at 1733 cm -1 , resulted from the introduction of C=O group after H 2 O 2 treatment (Oun and Rhim 2018).The characteristic peaks of HAp which loaded on the surface of Luffa samples were detected at 1026 cm -1 due to PO4 3-group stretching mode ( 3, 1) and at 871 cm -1 correspond to 1 CO 3 2-(Yu et al 2013). It can be seen that the peak intensity of O-H and C-H groups were decreased as shown in Fig.3(S4, S5, and S6), probably due to the interaction of these groups with HAp, which helped in attaching HAp on the surface of CNCs(Narwade et al 2017).…”

Recent Advances in the Fabrication and Environmental Science Applications of Cellulose Nanofibril-Based Functional Materials

“…In industrial production, typical dyes, such as methyl orange and phenol red, have been applied widely. Cellulose and CNF-based materials have been synthesized to adsorb and remove these dyes [ 92 , 93 , 94 , 95 ]. For instance, Hasanpour et al reported the synthesis of cellulose/ZnO hybrid aerogels for the efficient removal of methyl orange, and the removal efficiency could reach 99.02% after 90 min of treatment [ 93 ].…”

“…For instance, Hasanpour et al reported the synthesis of cellulose/ZnO hybrid aerogels for the efficient removal of methyl orange, and the removal efficiency could reach 99.02% after 90 min of treatment [ 93 ]. Narwade and co-workers demonstrated the in situ synthesis of CNF/hydroxyapatite hybrid films for the removal of phenol from wastewater [ 95 ]. The removal amount of phenol from acidic and neutral solutions was about 64 and 30 mg/g, respectively.…”

Enhanced catalytic activity of Bacillus aryabhattai P1 protease by modulation with nanoactivator

“…The precipitation was carried out by the drop-wise addition of 0.6 M di-ammonium hydrogen phosphate into 1 M calcium nitrate tetrahydrate solution, under constant stirring of 150 rpm at 80 C for 4 h, followed by aging for about 24 h. The white precipitates were then washed 3-4 times with milliQ water to remove the rest of the precursors, and dried in a hot air oven at 100 C. The dried sample was further annealed at 1000 C for phase formation. AFM and XRD analyses of the preparation phase were performed for checking crystalline nature and finding grain size [52,53,54,55,56,57].…”