Sorption of copper onto low molecular weight chitosan derivative from aqueous solution.

In this study, sorption of copper onto low molecular weight chitosan derivative was studied. Experimental parameters such as pH of the solution (A), temperature (B), dose of the sorbent (C), and concentration of solution (D) were considered. The statistical results indicated that the dose of sorbent (C) and Cu (II) concentration (D) influenced removal efficiency at 5% significance level. Also, some interactions such as ABCD, ACD, ABC and AC affected the removal process. The sorbent was characterized with FTIR, SEM and TG/DSC. Freundlich isotherm model was the best isotherm model. The kinetic study results correlated well with the pseudo-second-order model. The thermodynamic studies revealed that the nature of copper sorption was spontaneous and endothermic. Strong affinity of the sorbent for copper (II) was revealed by the Isothermal Titration Calorimetry (ITC) technique.

Sorption of heavy metal ions onto carboxylate chitosan derivatives--a mini-review.

Chitosan is of importance for the elimination of heavy metals due to their outstanding characteristics such as the presence of NH2 and -OH functional groups, non-toxicity, low cost and, large available quantities. Modifying a chitosan structure with -COOH group improves it in terms of solubility at pH ≤7 without affecting the aforementioned characteristics. Chitosan modified with a carboxylic group possess carboxyl, amino and hydroxyl multifunctional groups which are good for elimination of metal ions. The focal point of this mini-review will be on the preparation and characterization of some carboxylate chitosan derivatives as a sorbent for heavy metal sorption.

Application of depolymerized chitosan in crop production: A review.

Currently, chitosan (CHT) is well known for its uses, particularly in veterinary and agricultural fields. However, chitosan's uses suffer greatly due to its extremely solid crystalline structure, it is insoluble at pH levels above or equal to 7. This has sped up the process of derivatizing and depolymerizing it into low molecular weight chitosan (LMWCHT). As a result of its diverse physicochemical as well as biological features which include antibacterial activity, non-toxicity, and biodegradability, LMWCHT has evolved into new biomaterials with extremely complex functions. The most important physicochemical and biological property is antibacterial, which has some degree of industrialization today. CHT and LMWCHT have potential due to the antibacterial and plant resistance-inducing properties when applied in crop production. This study has highlighted the many advantages of chitosan derivatives as well as the most recent studies on low molecular weight chitosan applications in crop development.

Removal of cadmium from aqueous solution using low molecular weight chitosan derivative.

A 2(3) factorial design was used to examine the sorption of Cd(2+) onto cross-linked low molecular weight chitosan pyruvic acid derivative. Three factors and two levels of solution pH (A) (6.0 or 10.0), temperature (B) (45 or 70 °C) and Cd(II) concentration (C) (1 or 3 mg/L) were considered. Batch mode system was employed with 0.05 g of the sorbent and 25 mL of Cd(II) solution. The efficiency of cadmium removal during an exposition time of 4h was then evaluated. The factors and their interaction effect on the cadmium removal efficiency followed the order: Cd(II) concentration > solution pH > interaction between solution pH and Cd(II) concentration>interaction between solution pH, temperature and Cd(II) concentration. Langmuir isotherm model was the best isotherm model. The Pseudo second order fitted well the kinetic data. The thermodynamic studies revealed the nature of the cadmium sorption.