The Use of a Novel Graphitic Carbon Nitride/Cobalt Molybdate (G-C3 n4 /ComoO4 ) Nanocomposites for the Doxycycline Removal by Photocatalytic Degradation in Pharmaceutical Industry Wastewaters and the Evaluation of Microtox (Aliivibrio Fischeri) and Daphnia Magna Acute Toxicity Assays

Abstract

In this study, a novel graphitic carbon nitride/cobalt molybdate (g-C3 N4 /CoMoO4 ) nanocomposites (NCs) as a photocatalys was examined during photocatalytic degradation process in the efficient removal of Doxycycline (DOX) from pharmaceutical industry wastewater plant, İzmir, Turkey. Different pH values (3.0, 4.0, 6.0, 7.0, 9.0 and 11.0), increasing DOX concentrations (5 mg/l, 15 mg/l, 30 mg/l and 45 mg/l), increasing g-C3 N4 /CoMoO4 NCs concentrations (1 mg/l, 2 mg/l, 3 mg/l, 4 mg/l, 6 mg/l, 8 mg/l and 10 mg/l), different g-C3 N4 /CoMoO4 NCs mass ratios (5/5, 6/4, 7/3, 8/2, 9/1, 1/9, 2/8, 3/7 and 4/6), increasing recycle times (1., 2., 3., 4., 5., 6. and 7.) was operated during photocatalytic degradation process in the efficient removal of DOX in pharmaceutical industry wastewater. The characteristics of the synthesized nanoparticles (NPs) were assessed using X-Ray Difraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-Ray (EDX), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and Diffuse reflectance UV-Vis spectra (DRS) analyses, respectively. The acute toxicity assays were operated with Microtox (Aliivibrio fischeri also called Vibrio fischeri) and Daphnia magna acute toxicity tests. ANOVA statistical analysis was used for all experimental samples. The maximum 99% DOX removal efficiency was obtained during photocatalytic degradation process in pharmaceutical industry wastewater, at 150 W UV-vis light irradiation power, after 180 min photocatalytic degradation time, at pH=9.0 and at 25°C, respectively