Evaluation of photocatalytic process using GO/ZnO nanocomposites under LED irradiation for removal of Endocrine Disrupting Chemicals (EDCs) from aqueous solutions

Endocrine Disrupting Chemicals (EDCs), and potential EDCs are mostly man-made, found in various materials such as pesticides, metals, additives or contaminants in food, and personal care products. Phthalates are a group of these compounds that are carcinogenic to animals and can cause fetal death and congenital anomalies. The aim of this study was to investigate the photocatalytic process using GO/ZnO nanocomposites under LED irradiation for removal of Endocrine Disrupting Chemicals (EDCs) from aqueous solutions.

In this study, GO/ZnO nanorods were characterized by, Field emission scanning electron microscopy, transmission electron microscope, and Brunauer–Emmett–Teller surface area analysis. A Central Composite Design was used to optimize the reaction parameters for the removal of DEP by GO/ZnO. The four main reaction parameters optimized in this study were the following: the LED radiation time, pH, and the initial concentration of phthalates and the concentration of ZnO and graphene-oxide. The interaction between the four parameters was studied and modeled using the Design Expert 10 software. Phthalate detected by HPLC apparatus equipped with a UV detector at 225 nm wavelength with methanol (90%) and Acetonitrile (10%) phases.

The results of FE-SEM and TEM showed that the ZnO is composed of a bar and separate face. Based on the peak obtained, the diameter and length of the nanorods are 20-60 and 200 nm respectively. A maximum reduction of 90% of DEP was achieved at pH 5 and 120 minutes. The results represent the prediction of a model fitted from the Quadratic model (p-value<00001).

The interaction of variables showed that the maximum effect was belonged to the pH and the time in the process reactions. Also, the results showed that the GO/ZnO low power LED irradiation can be used as an effective method for the removal of EDCs from environmental.