A Study of Isotherms and Adsorption Kinetic of Di (2-Ethylhexyl) Phthalate by Nano Cellulose from Aqueous Solutions

Introduction: Di (2-ethylhexyl) phthalate is one of the most abundant phthalate esters and it is widely used as softeners in plastic products. Malformation, carcinogenicity, the poisoning of the reproductive system, and also the disruption of the human endocrine system are the harmful effects of these substances. Materials and Methods: In this research, the removal of di (2-ethylhexyl) phthalate from aqueous solutions by cellulose nanofiber non-continuous was studied. The effects of some variables such as the initial concentration of the di (2-ethylhexyl) phthalate, the adsorbent dosage, the contact time, and the pH at room temperature were tested. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. furthermore, the Freundlich and Langmuir adsorption models were tested based on the optimum conditions. Results: The results indicated that the adsorption of di (2-ethylhexyl) phthalate follows the pseudo-second-order kinetic model (R2  =  0.9674) and the Langmuir isotherm (R2 = 0.9573). Conclusion: Due to the high adsorption capacity of the cellulose nano fiber (312.5 mg/gr), it can be concluded that it is an appropriate adsorbent for removal of di (2-ethylhexyl) phthalate from aqueous solutions.