Hierarchical approach towards adsorptive removal of Alizarin Red S dye using native chitosan and its successively modified versions

Abstract

In the present work, native chitosan (Ch) along with its chemically and physico-chemically modified versions namely sulphate cross-linked chitosan (SCC) and sulphate cross-linked chitosan-bentonite composite (SCC-B) were employed as potential adsorbents for the removal of an anionic dye, Alizarin red S (ARS) from aqueous solutions. All the three adsorbents were extensively characterized using techniques such as FT-IR, SEM, EDX, XRD, BET, TGA-DTA and pHPZC. Various parameters were optimized including pH of dye solution, contact time, adsorbent dose, initial adsorbate concentration and temperature of adsorption. Four adsorption isotherm models were studied and it was found that Freundlich model was best-fit for all the three systems. Maximum adsorption capacities towards adsorption of ARS were found to be 42.48, 109.12 and 131.58 mg g−1 for chitosan, SCC and SCC-B respectively. Kinetics of adsorption was thoroughly examined by employing three well-known models in order to deduce the mechanism of adsorption. Thermodynamic studies show that the process is spontaneous and exothermic for all adsorbents employed. Further, it was observed that for large sample volumes, column adsorption method was more effective as compared to batch method.

Chitosan entrapped microporous activated carbon composite as a supersorbent for remazol brilliant blue R

“…However, the combination of the two led to a much effective adsorption owing to the enhanced surface area of charcoal and the effective molecular interactions of chitosan. Similar results were reported by Khapre et al (2020) for successively modified materials towards alizarin red S dye.…”

“…25 Several studies have been carried out on the adsorption of water pollutants using chitosan-activated charcoal composites involving the removal of dyes in the recent years. [26][27][28] Recently, we reported a composite of cellulose fabricated by the co-precipitation of Fe and Al in the cellulose material for the detoxification of various reactive dyes with high adsorption capacities. 29 In this study, we used a hybrid approach involving crosslinking chitosan with sodium tripolyphosphate (STTP) for imprioved mechanical strength and for entrapping activated carbon through the enhanced surface area and porosity, leading to a supersorbent with excellent confiscation capability for RBBR dye.…”

Evaluation of adsorptive and photocatalytic degradation properties ofFeWO4/polypyrrole nanocomposite for rose bengal and alizarin red S from liquid phase: Modeling of adsorption isotherms and kinetics data

“…The values of q D are 184. 42 Au-NPs loaded on activated carbon 123.45 [48] Carbon nanotubes 135.2 [49] Activated carbon 20 [39] Iron oxide-modified activated clay 32.70 [50] Activated carbon 0.064 [51] Fe-BTC MOF 79.88 [52] Native chitosan 131.58 [53] FeWO 4 /PPy nanocomposite 142.80 Present study…”

Mesoporous Fe–Al-doped cellulose for the efficient removal of reactive dyes

“…1 Biosorption studies using a natural polymer in its native or modified state are gaining more importance nowadays. A number of naturally occurring polymers that are abundantly available in nature and upon proper treatment have been reported as effective adsorbents are cellulose, 2-4 chitin 5,6 and chitosan, [7][8][9][10][11] alginates, 12,13 clays, 14 magnetic ferrites 15,16 and resins. 17,18 They are applied for the removal of various water pollutants such as heavy metals, 19,20 dyes in single 21,22 and binary systems, 23 pesticides, paints etc.…”

“…Many workers have reported similar kinds of composites for the efficient removal of fluoride ions. 26–28 Our research group has reported various mesoporous composites for the adsorptive removal of fluoride, 5,9 dyes, 10–13 arsenic 8 and Cr( vi ). 14 In the present study, a mesoporous composite of cellulose has been prepared by co-precipitation of iron and aluminium in the cellulose matrix.…”