Synthesis of S-ligand tethered cellulose nanofibers for efficient removal of Pb(II) and Cd(II) ions from synthetic and industrial wastewater

Abstract

Cellulose nanofibers (CNFs) tethered with sulphur as anionic ligand were synthesized from medical absorbent cotton by dissolution with NaOH, CO(NH)₂ followed by mechanical intrusion of sulphur from SC(NH₂)₂ at an elevated temperature. The solid-phase CNFs embedded with sulphur complexes possessed negative sites which were used to remove cationic metals viz., Pb(II) and Cd(II) from synthetic and industrial wastewater. The physicochemical properties of the CNFs were analyzed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), pH at point of zero charge (pH) and X-ray photoelectron spectroscopy (XPS). Batch adsorption studies were conducted with synthetic wastewater to optimize the conditions for Pb(II) and Cd(II) removal by CNFs. Different adsorption kinetic models were applied to assess and define the adsorption mechanism. The maximum Langmuir adsorption capacity was found to be 1.16 and 0.82 mmol g for Pb(II) and Cd(II) ions, respectively. Regeneration studies showed that the CNFs can be reused using 0.1 M NaOH as eluent. The percentage removal efficiency of different cationic metals by CNFs from untreated industrial wastewater ranged from ca. 90-98%.

A comparative study of magnetic chitosan (Chi@Fe3O4) and graphene oxide modified magnetic chitosan (Chi@Fe3O4GO) nanocomposites for efficient removal of Cr(VI) from water

“…The FT-IR spectra of Fe 3 O 4, chitosan modified ferrites (Chi@Fe 3 O 4 ), chitosan and graphene oxide modified ferrites (Chi@Fe 3 O 4 GO), and chitosan are presented in Fig 1(a). For chitosan, the broad peak stretching from ~3400 to 3280 cm -1 is assigned to polymeric OH [23]. The broad nature of the peak suggests the presence of both OH group and other H-bonded moieties as reported in other study [24].…”

Facile functionalization of cellulose from discarded cigarette butts for the removal of diclofenac from water

“…The adsorption trend also suggests that deprotonation is fast therefore, the decline in adsorption capacity is also fast. This trend of pH dependent pollutant remediation has been reported in adsorption studies (Abu-Danso, et al, 2018), and photocatalytic degradation ( Mousavinia, et al, 2016, Mosleh, et al, 2016b, Mosleh, et al, 2017, Lu, et al, 2019. To assess the performance of unmodified celluloses (CNFs and CNCs) for Dfc removal, adsorption experiments were conducted with all three synthesized celluloses under similar experimental conditions and the results are summarized in Fig.…”

“…DCBs also possess a bulk reserve of cellulose based on the parent material and the extracted cellulose has the potential, as celluloses from other sources, to be transformed into films, membranes, and fibers. Cellulose nanofibers currently have been exploited as reinforcement agents in composites (Kumagai, et al, 2019), and surfacemodified to obtain an effective heavy metals adsorbent (Abu-Danso, et al, 2018). The main barrier in the transformation of DCBs into cellulose is finding an efficient procedure to remove the acetate groups and the myriad of pollutants to obtain celluloses and further A C C E P T E D M A N U S C R I P T purification to achieve the desired cellulosic product without altering the original cellulose structure.…”

“…celluloses due to the metal elution properties of NaOH(Abu-Danso, et al, 2018). The proposed elution phenomenon in this regard is represented in the equation M(X) + NaOH → M(OH) + Na(X) where M represent a metal and X represents a metal complex (NO3, SO4, PO4 etc.…”

Modified biochar from Moringa seed powder for the removal of diclofenac from aqueous solution

“…3c. These results suggest that diffusion was probably not the rate-limiting step but other factors may have control on the rate of adsorption (Yakout and Elsherif 2010;Abu-Danso et al 2018). Pseudo-first-order q e exp (mg g −1 ) 95.383 q e cal (mg g −1 )…”