Insights into the Synergistic Removal of Copper(II), Cadmium(II), and Chromium(III) Ions Using Modified Chitosan Based on Schiff Bases-g-poly(acrylonitrile)

Abstract

Chitosan has received broad consideration as an adsorbent for all pollutants because of its low cost and great adsorption potential. However, its shortcomings, including sensitivity to pH, poor thermal stability, and poor mechanical strength, limit its use. The functional groups of chitosan can be modified to enhance its performance by the grafting technique and Schiff base modification. The grafting process used acrylonitrile (Ch-g-PAN) as a monomer and potassium persulfate as an initiator. After that, the modification via preparation of the Schiff base reaction using salicylaldehyde (Ch-g-Sch I) and P-anisaldehyde (Ch-g-Sch II) was carried out. The synthesized copolymers were detailed and characterized through several spectroscopic and microscopic techniques including infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. In addition, Ch-g-Sch I and Chg-Sch II were applied in the removal of different metal ions such as Cu 2+ , Cd 2+ , and Cr 3+ . The maximum adsorption capacity of Ch-g-Sch I for Cd 2+ was 183.7 mg g −1 in 24 h, while in the case of Ch-g-Sch II, the maximum adsorption capacity for Cd 2+ was improved to 322.9 mg g −1 for the same time. Moreover, adsorption thermodynamic analysis displays that the all ion adsorption process was not random and the pseudo-second-order model fitted with experimental results. Finally, Ch-g-Sch I and Ch-g-Sch II were applied as designs for industrial wastewater treatment with significant efficiency.

Evaluation of Cell Proliferation and Wound Healing Effects of Vitamin A Palmitate-Loaded PLGA/Chitosan-Coated PLGA Nanoparticles: Preparation, Characterization, Release, and Release Kinetics

“…The reason for using acetic acid in the study is the ability of chitosan to dissolve in acidic solutions. 45 All remaining procedures are the same as above, and the formulation ingredients are presented in Table 1 .…”

“…The above procedure was applied with minor modifications when preparing CS-coated formulations. − In the CS-coated formulations, the aqueous phase consisted of CS solution and Pluronic F-68, both prepared in 2% acetic acid (v/v). The reason for using acetic acid in the study is the ability of chitosan to dissolve in acidic solutions . All remaining procedures are the same as above, and the formulation ingredients are presented in Table .…”

Metal Complexes with Schiff Bases as Antimicrobials and Catalysts

“…Chitosan SBs have shown interesting biological activities [83] as being anticancer [84,85], antioxidant [86][87][88], antibacterial [89][90][91][92], and antidiabetic [93]. Some chitosan-based SBs are used for the removal of toxic metal ions from the aqueous medium, including Fe(III) [94], Pb(II) [95], Cu(II), Cd(II) [96], Cr(III) [97], and Cr(VI) [98,99]. Some authors also describe chitosan SBs complexes with metals and their biological activities as antitumoral and antimicrobial.…”

Synthesis, Characterization and Biological Activity of New Oleander Complexes against Bacteria Found in Polluted Water

“…Chitosan is the second most abundant non-synthetic biopolymer. Most chitosan studies have been used to remediate wastewater [5]. On the other hand, chitosan has been extensively used in synthesis research studies as a functional polymer or a supporting matrix [6].…”