Multifunctional Cross-Linked Shrimp Waste-Derived Chitosan/MgAl-LDH Composite for Removal of As(V) from Wastewater and Antibacterial Activity

Abstract

This work synthesized a novel chitosan-loaded MgAl-LDH (LDH = layered double hyroxide) nanocomposite, which was physicochemically characterized, and its performance in As(V) removal and antimicrobial activity was evaluated. Chitosan-loaded MgAl-LDH nanocomposite (CsC@MgAl-LDH) was prepared using cross-linked natural chitosan from shrimp waste and modified by Mg−Al. The main mechanisms predominating the separation of As(V) were elucidated. The characteristic changes confirming MgAl-LDH modification with chitosan were analyzed through Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis-differential thermal analysis, and Brunauer-Emmett-Teller measurements. Porosity and the increased surface area play an important role in arsenic adsorption and microbial activity. Adsorption kinetics follows the general order statistically confirmed by Bayesian Information Criterion differences. To understand the adsorption process, Langmuir, Freundlich, and Liu isotherms were studied at three different temperatures. It was found that Liu's isotherm model was the best-fitted model. CsC@ MgAl-LDH showed the maximum adsorption capacity of 69.29 mg g −1 toward arsenic at 60 °C. It was observed that the adsorption capacity of the material rose with the increase in temperature. The spontaneous behavior and endothermic nature of adsorption was confirmed by the thermodynamic parameters study. Minimal change in percentage removal was observed with coexisting ions. The regeneration of material and adsorption−desorption cycles revealed that the adsorbent is economically efficient. The nanocomposite was very effective against Staphylococcus aureus and Bacillus subtilus.

Recent Advancements in the Field of Chitosan/Cellulose-Based Nanocomposites for Maximizing Arsenic Removal from Aqueous Environment

“…215 In fact, the eluting solution of 0.01 M NaOH even shows only a marginal decrease in adsorption from 87% to 85% from the first to fourth adsorption−desorption cycles in chitosan−LDH composites. 216 A practical adsorbent should exhibit both high removal efficiency and reusability potential, even in the presence of competing metal ions. Under weak acidic or neutral conditions, competitive anions such as phosphate and silicate species may interfere with arsenic adsorption.…”

“…Biopolymeric composites containing silica or clay components can also be effectively eluted using basic solutions with a pH of ≥11 . In fact, the eluting solution of 0.01 M NaOH even shows only a marginal decrease in adsorption from 87% to 85% from the first to fourth adsorption–desorption cycles in chitosan–LDH composites …”

“… 215 In fact, the eluting solution of 0.01 M NaOH even shows only a marginal decrease in adsorption from 87% to 85% from the first to fourth adsorption–desorption cycles in chitosan–LDH composites. 216 …”

Synthesis of Magnesium hydroxide Whisker‐encapsulated Carbonized Chitosan and Basic Magnesium Carbonate Composite for Efficient Pb(II) Removal

“…Zhao [20] prepared a cellulose@Mg(OH) 2 composite film with excellent heavy metal removal. Rachid [21] synthesized a novel chitosanloaded MgAl-LDH nanocomposite, and its performance in As(V) removal and antimicrobial activity was evaluated. Palacio [22] studied the adsorption behavior of water-soluble functionalized chitosan for chromate ions.…”

A pyridinium-modified chitosan-based adsorbent for arsenic removal via a coagulation-like methodology

“…One such example for removal at pH 7 can be found in chitosan-loaded MgAl layered double hydroxides. 28 The amine groups of chitosan are amenable to chemical modification to yield cationic functional groups. One such example was reported by Chen et al , where a pyridinium-moiety was grafted onto the amine-group of chitosan via a linker unit.…”