Chitosan Adsorbent Derivatives for Pharmaceuticals Removal from Effluents: A Review

Abstract

Chitin is mentioned as the second most abundant and important natural biopolymer in worldwide scale. The main sources for the extraction and exploitation of this natural polysaccharide polymer are crabs and shrimps. Chitosan (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) is the most important derivative of chitin and can be used in a wide variety of applications including cosmetics, pharmaceutical and biomedical applications, food, etc., giving this substance high value-added applications. Moreover, chitosan has applications in adsorption because it contains amino and hydroxyl groups in its molecules, and can thus contribute to many possible adsorption interactions between chitosan and pollutants (pharmaceuticals/drugs, metals, phenols, pesticides, etc.). However, it must be noted that one of the most important techniques of decontamination is considered to be adsorption because it is simple, low-cost, and fast. This review emphasizes on recently published research papers (2013–2021) and briefly describes the chemical modifications of chitosan (grafting, cross-linking, etc.), for the adsorption of a variety of emerging contaminants from aqueous solutions, and characterization results. Finally, tables are depicted from selected chitosan synthetic routes and the pH effects are discussed, along with the best-fitting isotherm and kinetic models.

Review on Agrobiowaste‐mediated Nanohybrids for Removal of Toxic Heavy Metals from Wastewater

“…[90][91] The chitosan is considered as an effective cationic adsorbent for removing number of pollutants including HMs. [92][93][94][95][96][97] Major advantages of chitosan possess are its biocompatibility, biodegradability, hydrophilicity, high reactivity, and non-toxicity. [92] It has a linear polyamine structure with several free amine groups.…”

Uranium Removal from Aqueous Solutions by Aerogel-Based Adsorbents—A Critical Review

“…The effect of the initial concentration on the sorption efficiency at a constant temperature is of particular interest because it enables the fitting of the experimental data and the evaluation of the maximum adsorption values by applying simple empirical models (usually, Langmuir and Freundlich adsorption isotherm models). Adsorption isotherms are essential for expressions of the theoretical maximum adsorption capacities and surface characteristics of the adsorbents, adsorption mechanism pathway optimization, and the productive design of the adsorption systems since they explain how model pollutants are interrelated with the materials of the adsorption process (adsorbents) [ 151 ]. Although in some cases, these models are used to evaluate the adsorption mechanism (e.g., chemisorption) [ 72 ], this approach is very vague and should be used only as an indication.…”

Antimicrobial Activity of Composites-Based on Biopolymers

“…Therefore, it is necessary to modify natural polymers such as chitosan to become partially water solubility and enhance their antimicrobial activity [150]. The presence of amino and hydroxyl groups on the structure makes the chemical modification of chitosan possible to improve its solubility and electric change [151,152].…”