A three-dimensional macroporous network structured chitosan/cellulose biocomposite sponge for rapid and selective removal of mercury(II) ions from aqueous solution

Removal of Mercury Ions from Aqueous Solutions by Crosslinked Chitosan‐based Adsorbents: A Mini Review

“…[72] A porous sponge has also be prepared by freezedrying, during which the chitosan solution or gel is frozen then lyophilized. [21,44] Chemical modification of chitosan, such as crosslinking and grafting, does not alter the core skeleton of chitosan, but generates new properties allowing higher adsorption capacity and efficiency. [73,74] Many chitosan derivatives have been synthesized by grafting new functional groups on the chitosan backbone to adsorb metal ions.…”

“…After 3 hours of stirring, glutaraldehyde is added dropwise under stirring to yield a yellow sol, which is then frozen and lyophilized. [21] The C and N composition on the surfaces of chitosan and the chitosan/cellulose biocomposite sponge can be analyzed by X-ray photoelectron spectroscopy (XPS, Figures 2a and 2b). The N 1s spectrum of the biocomposite displays two peaks, and the N 1s (399.36)/N 1s (401.71) ratio is weaker than that of chitosan, [87] indicating that some amino groups were involved in a Schiff base reaction with glutaraldehyde.…”

“…[18,19] The main adsorbents for mercury ions removal include activated carbon, clay, polymeric materials, cellulose, starch and chitosan. [20][21][22][23][24][25] As a versatile, low cost and green product, [26,27] chitosan has drawn great attention, and it has been extensively studied and applied in the chemical industry, agriculture, cosmetics, pharmacy, and biomedical engineering. [28][29][30][31] In addition, chitosan derivatives have also been used for the treatment of wastewater, especially for coagulation-flocculation, metal extraction and recovery and dye removal.…”

Adsorption Processing for the Removal of Toxic Hg(II) from Liquid Effluents: Advances in the 2019 Year

“…Using nitric acid, the adsorption efficiency decreased from near 99% (1st cycle) to almost 90% (5th cycle); however, the use of 2 M KCl solution was more critical since a mere 12% of mercury(II) was adsorbed in the 5th cycle. A chitosan/cellulose biocomposite sponge (CCS) adsorbent was developed for removing Hg(II) aqueous solution [117]. This adsorbent was generated via a glutaraldehyde cross-linking reaction and lyophilization; experiments showed that maximum adsorption occurred at pH 5.5, and the adsorption process followed the pseudo-second-order kinetic model, being the adsorption capacity of 2.47 mmol/g.…”

Keratin/Hydrotalcites Hybrid Sponges as Promising Adsorbents for Cationic and Anionic Dyes

“…Nevertheless, among them, adsorption by means of the use of biomasses, is considered one of the most efficient method to remove pollutant dyes from water, due to its low-cost-biocompatibility and eco-friendliness (Sulyman et al, 2017). As typical biomasses, agricultural products, especially those of polysaccharidic nature, such as chitosan, cellulose or nanocellulose, starch and its derivatives, showed a high potential pollutants uptake, due to their excellent metal-binding and complexing capacities (Lü et al, 2012;Hu et al, 2019;Zhang et al, 2019). However, among biosorbents, keratin wastes are widely considered in recent years as raw materials from which to derive adsorbents for water treatment.…”