Degradation of Pollutants Using Advanced Ecomaterials

Abstract

Chitin, available from waste products of the shellfish industry (shells of the crab, shrimp, etc.), is one of the most abundant natural polymers in the world, and it is used for the production of chitosan by deacetylation. Chitosan, a cationic poly- saccharide, natural, nontoxic, biodegradable, biocompatible, bioadhesive, and available commercially, has been employed in a variety of applications ranging from membrane separation, tissue engineering, wound healing, and dressing to hydro gels formation and biodegradable films for food packaging. It is also a well-known biopolymer for its broad antimicrobial activity against bacteria and fungi. Chitosan possesses high positive charge on NH3 + groups when dissolved in aqueous acidic solution, and therefore it is able to adhere to or aggregate with negatively charged molecules forming three-dimensional networks. Moreover, chitosan acts as stabilizer of hydrocolloids, lipids, and mixtures, promoting emulsion formation and interfacial stabilization, so it is frequently used as emulsifier in film-forming solutions. Due to all these advantageous characteristics added to its excellent film-forming properties and low cost, chitosan has gener- ated enormous interests, and thus the quantity and quality of research using this polymer in the area of packaging have increased steadily in the last few years. Chitosan-based food packaging can be classified as “active” because they include systems capable of inhibiting microorganism action and avoiding loss of food quality. In particular, the antimicrobial packaging is one of the most innovative M.R.