Adsorption of Zn (II) from aqueous solution by using chitin extracted from shrimp shells

Background: Chitin and its derivatives (chitosan) are natural biopolymer produced from crustacean shell, which due to their active functional groups such as amine and hydroxyl have high ability to absorb heavy metals from water and wastewater. The aim of this study was to investigate zinc removal from aqueous solutions by using chitin extracted from shrimp shells. Material and methods: To study the removal of zinc, chitin extracted from shrimp shells was used as biosorption in a batch system. In addition, the influence of pH, initial metal concentration, amount of adsorbent and contact time on adsorption process was investigated. Results: The results of this research showed that the absorption capacity of zinc closely depended on the pH of solution, as zinc absorption concentration increased in terms of mg/g with increasing pH. The results of equilibrium studies revealed that zinc absorption process on the extracted chitin was desirable and followed the Freundlich isotherm model and pseudo second kinetic model. Moreover, Fourier Transform Infrared Spectroscopy (FTIR) results indicated that functional groups such as amine (-NH2 (and hydroxyl (-OH) had the highest effect on adsorption of zinc. Conclusion: According to the obtained results, the chitin extracted from shrimp shells appeared to be a suitable adsorbent for removing zinc from aqueous solutions.