Psi-chitosan copolymer crosslinked with edta for heavy metals adsorption

Environmental protection became an important element of modern European societies. Old chemical industry technologies are being replaced by modern ones. Waste become a rich source of precious metals, plastics, natural biopolymers and biomass. To decrease the extraction of valuable minerals, metals and oil, a new technologies allowing to convert waste into useful products are extensively studied. Chitin is one of the most abundant carbohydrate that may be converted during basic hydrolysis into chitosan, which is a long chain polymer consisting of N-acetylglucosamine units found in exoskeletons of arthropods and in cell walls of fungi. Free amine and hydroxyl groups are reactive under microwave radiation that makes chitosan a good raw material susceptible to chemical modification. Chitosan may be used as a natural sorbent. Heavy metals ions occurring in drinking water are a big threat to the health of humans and animals. In this paper a chitosan based hydrogels synthesis under microwave radiation as a heavy metal sorbent, is presented. Chitosan was modified by EDTA, aspartic acid and 1,2-propanodiol. The obtained hydrogels, after drying and rehydration, were examined as a heavy metal ions sorbents. Sorption of Hg2+, Cr3+ and Al3+ ions was examined during six days.