Hierarchical Porous Chitosan Sponges as Robust and Recyclable Adsorbents for Anionic Dye Adsorption

Abstract

Biomass waste treatment and detrimental dye adsorption are two of the crucial environmental issues nowadays. In this study, we investigate to simultaneously resolve the aforementioned issues by synthesizing chitosan sponges as adsorbents toward rose bengal (RB) dye adsorption. Through a temperature-controlled freeze-casting process, robust and recyclable chitosan sponges are fabricated with hierarchical porosities resulted from the control of concentrations of chitosan solutions. Tested as the adsorbents for RB, to the best of our knowledge, the as-prepared chitosan sponge in this work reports the highest adsorption capacity of RB (601.5 mg/g) ever. The adsorption mechanism, isotherm, kinetics, and thermodynamics are comprehensively studied by employing statistical analysis. Importantly and desirably, the sponge type of chitosan adsorbents exceedingly facilitates the retrieving and elution of chitosan sponges for recyclable uses. Therefore, the chitosan sponge adsorbent is demonstrated to possess dramatically squeezable capability with durability for 10,000 cycles and recyclable adsorption for at least 10 cycles, which provides an efficient and economical way for both biomass treatment and water purification.

Chitosan supported CoFe2O4 for the removal of anthraquinone dyes: kinetics, equilibrium and thermodynamics studies

“…The R L values 0.91 and 0.74 obtained for MG and RB4 dyes respectively is a proof of favourable adsorption of the dyes onto the adsorbent. Similarly, the empirical parameter, n of the Freundlich isotherm indicates surface heterogeneity of the adsorbent, while its value confirms the favourability of adsorption process [27]. The parameters obtained for Tempkin isotherm fit is also in support of surface heterogeneity and the interaction between the adsorbent and the dye molecules, the adsorption heat obtained for MG is higher than that of RB4 whereas the binding constant is higher in the latter than the former, justifying the lower adsorption capacity obtained for RB4.…”

Facile Preparation of Nanofibrillar Networks of “Ureido‐Chitin” Containing Ureido and Amine as Chelating Functional Groups

“…This difference in the amount of water uptake was only because of the properties of aerogels: chemical functional groups on the nanofibers, high specific surface area and open porosity of the material. This insoluble behavior of the material in acidic and alkaline medium can provide opportunities to utilize the aerogel in reusable systems in applications like those reported …”

“…Highly porous chitosan‐based materials can offer potential chelating functional properties. Recently, Wang et al . demonstrated that highly porous chitosan foams with chelating amine functional groups can be a promising adsorbent material for anionic dyes from which the elution of dyes have been accomplished with alkaline treatment of the foams.…”

“…In this case the dye molecules were desorbed by treating the hybrid foams in 0.1 m HCl, followed by washing with 0.1 m NaOH solution. Both of these studies, proved the excellent functional properties of foams for many cycles.…”

Catalisadores ácidos baseados na simples modificação da quitosana para a esterificação do ácido oleico

“…Além dessas características a quitosana ainda apresenta excelentes propriedades como: não toxicidade, biocompatibilidade, biodegradação, reatividade e capacidade de adsorção. Estudos envolvendo a modificação estrutural da quitosana e seus derivados têm sido amplamente realizados com o intuito de empregar esses materiais em uma gama de aplicações [10][11][12][13], com destaque na área de catálise [8,[14][15][16].…”