Rapid visible-light degradation of EE2 and its estrogenicity in hospital wastewater by crystalline promoted g-C3N4

Vinod Kumar V; Dror Avisar; Lakshmi Prasanna V; Yifaat Betzalel; Hadas Mamane

doi:10.1016/j.jhazmat.2020.122880

Rapid visible-light degradation of EE2 and its estrogenicity in hospital wastewater by crystalline promoted g-C₃N₄

J Hazard Mater. 2020 Nov 5:398:122880. doi: 10.1016/j.jhazmat.2020.122880. Epub 2020 May 17.

Authors

Vinod Kumar V¹, Dror Avisar², Lakshmi Prasanna V², Yifaat Betzalel³, Hadas Mamane³

Affiliations

¹ School of Mechanical Engineering, Water Research Center, Environmental Engineering Program, Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel. Electronic address: vinodkumarv@mail.tau.ac.il.
² The Water Research Center, The Hydro-Chemistry Laboratory, Porter School for Environment and Earth Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 69978, Israel.
³ School of Mechanical Engineering, Water Research Center, Environmental Engineering Program, Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel.

PMID: 32768817
DOI: 10.1016/j.jhazmat.2020.122880

Abstract

Metal-free, chemically activated crystalline graphitic carbon nitride (g-C₃N₄) nanorods with enhanced visible-light photoactivity demonstrated rapid photodegradation of 17α-ethinylestradiol (EE2) in water and real hospital wastewater. Pure g-C₃N₄ and another three crystalline promoted g-C₃N₄ photocatalysts developed by hydrothermal method were characterized by, High-Resolution Transmission Electron Microscopy (HRTEM), X-ray diffraction (XRD), Fourier-Transform Infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Photoluminescence (PL), Electron spin resonance (ESR), X-ray Photoelectron Spectroscopy (XPS) and Diffuse Reflectance Spectroscopy (DRS). Hydrothermal-based chemical activation did not alter the crystal structure, functional group or surface morphology, but it enhanced the specific surface area of activated g-C₃N₄ due to intralayer delamination and depolymerization of g-C₃N₄. Compared to pure g-C₃N₄, the activated g-C₃N₄-3 demonstrated efficient degradation of EE2 (<30 min, 3 mg/l) by visible wavelengths of the solar spectrum. This work provides advanced insight into the construction of heterojunction visible-light photocatalysts and production of O₂^- via reduction of O₂ with photogenerated electrons. Proposed and derived mechanism for photodegradation of EE2 by g-C₃N₄-3 using gas chromatography-mass spectrometry (GCMS). Yeast Estrogen Screen (YES) was performed to evaluate the estrogenicity of treated water samples. Efficient removal of EE2 estrogenic activity (<45 min, 3 mg/l) was achieved using the visible light-activated g-C₃N₄. Estrogenicity removal rate corresponded well with EE2-degradation rate.

Keywords: 17α-Ethynylestradiol; Crystalline g-C(3)N(4); Estrogenicity; Hospital wastewater; Visible-light photocatalyst; YES assay.

Publication types

Research Support, Non-U.S. Gov't