Removal of pharmaceuticals from aquatic environment using modified biomaterials

Abstract

Pharmaceuticals in the environment are of growing interest as a result of continuous occurrence through human into municipal wastewater without adequate treatment. Green methods are needed to overcome this problem without adverse impact on the environment. In this work, modified nanobiopolymers have been dedicated to solve this problem. Accordingly, modified chitosan with nanosilica is proposed to mediate ibuprofen. Spectroscopic analysis was carried outbased on both experimental techniques such as FTIR spectrophotometry and theoretical approach represented in semiemprical calculations. QSAR descriptors were also conducted in order to quantify biological activities of both structures. Results of FTIR ensure that chitosan can be modified using silica through the formation of both chemical and physical bonds. Furthermore, FTIR shows that spectra of chitosansilica after interaction with ibuprofen suffers from a general reduction in all of its peaks and shifting in many bands. Significant reduction in bands of –NH bending and –CH stretching proposed that chitosan may interact with ibuprofen through electrostatic and hydrophobic mechanisms. PM6 calculations illustrate that amine group of modified chitosan is the most probable active site for interaction either in the complex or adsorb forms. The calculated vibrational frequencies ensure that the calculated structures correspond to minimum energy structures.