Lignocellulose-Based Superabsorbent Polymer Gel Crosslinked with Magnesium Aluminum Silicate for Highly Removal of Zn (II) from Aqueous Solution

Abstract

Lignocellulose (LCE) was ultrasonically treated and intercalated into magnesium aluminum silicate (MOT) clay to prepare a nano-lignocellulose magnesium aluminum silicate polymer gel (nano-LCE-MOT) for the removal of Zn (II) from aqueous solution. The product was characterised using nitrogen adsorption/desorption isotherm measurements, Fourier-transform infrared spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The conditions for the adsorption of Zn (II) on nano-LCE-MOT were screened, and adsorption kinetics and isotherm model analysis were carried out to explore the adsorption mechanism and achieve the optimal adsorption of Zn (II). Optimal adsorption was achieved at an initial Zn (II) concentration of 800 mg/L at 60 °C in 160 min at a pH of 4.52. The adsorption kinetics were explored using a pseudo-second-order model, with the isotherm adsorption equilibrium found to conform to the Langmuir model. The maximum adsorption capacity of the nano-LCE-MOT polymer gel toward Zn (II) is 513.48 mg/g. The materials with adsorbed Zn (II) were desorbed using different media, with HCl found to be the most ideal medium to desorb Zn (II). The optimal desorption of Zn (II) was achieved in 0.08 mol/L HCl solution at 65 °C in 60 min. Under these conditions, Zn (II) was almost completely desorbed from the adsorbents, with the adsorption effect after cycling being slightly different from that of the initial adsorption.

Nitrate adsorption characteristics of synthesized allophanes with various chemical compositions

“…In a report on the removal of Zn(II) by nano-lignocellulose Mg–Al silicate polymer gels, adsorption mechanisms were investigated and adsorption kinetics and isothermal modelling analysis were performed to achieve the optimal adsorption of Zn(II) (An et al , 2021). The presence of hydroxyl and carboxyl groups at the activated sites on the surface of the polymer gel revealed that they formed new chemical bonds with Zn(II).…”

“…The presence of hydroxyl and carboxyl groups at the activated sites on the surface of the polymer gel revealed that they formed new chemical bonds with Zn(II). The main adsorption process was chemisorption, although ion exchange and electrostatic attraction could also occur during the adsorption (An et al , 2021). Regarding the superior nitrate adsorption characteristics and the mechanism of the synthesized allophane, it is considered that the cation- and anion-exchange capacities of soil allophane depend on the pH of the solution, which is interpreted as the development of negative and positive charges resulting from the dissociation and uptake of H + through the edge OH groups bonded to Si and Al (Wada, 1967).…”

“…Adsorption is an environmentally friendly method of water treatment that is more advantageous and used more widely than other methods due to its simplicity of design and application (Donia et al , 2009; An et al , 2021; Mahi et al, 2021). Among the several methods that have been employed for the purification of contaminated water, adsorption is a straightforward and inexpensive technique (Garcia-Montano et al , 2008; Nezamzadeh-Ejhieh & Shahriari, 2011).…”

Advancements in Cellulose-Based Superabsorbent Hydrogels: Sustainable Solutions across Industries

“…The adsorption kinetics followed a pseudo-second-order model, and the Langmuir isotherm model was applied. The gel demonstrated a maximum adsorption capacity of 513.48 mg/g, and optimal adsorption conditions and desorption methods were identified [ 55 ].…”

“…The efficiency of SAPs in removing pollutants varies depending on the type of contaminant, pointing to the necessity for optimization across a wide range of applications. The use of cellulose additives in cement composites and the environmental effects of materials like kaolin require specific approaches and additional research [ 54 , 55 ]. Finally, developing nanocellulose-based composites and other specialized SAPs often involves complex synthesis processes, high production costs, and safety concerns, particularly related to microbial interactions and the use of toxic crosslinkers.…”