PHOTOCATALYTIC DEGRADATION OF METRONIDAZOLE USING BIOI–MWCNT COMPOSITES: SYNTHESIS, CHARACTERIZATION, AND OPERATIONAL PARAMETERS

Authors : Davoud BALARAK, Chinenye Adaobi IGWEGBE, Pius Chukwukelue ONYECHI

Pages : 1235-1249

View : 34 | Download : 10

Publication Date : 2019-12-01

Article Type : Research Paper

Abstract :This study centers on the application of photocatalytic process using supported bismuth insert ignore into journalissuearticles values(III); oxyiodide–multi-walled carbon nanotube insert ignore into journalissuearticles values(BiOI–MWCNT); composites for the elimination of Metronidazole insert ignore into journalissuearticles values(MNZ); from its solution. The characteristics of BiOI and synthesized BiOI–MWCNTs composites were analyzed via the scanning electronic microscopy insert ignore into journalissuearticles values(SEM);, X-ray diffraction insert ignore into journalissuearticles values(XRD);, and transmission electron microscopy insert ignore into journalissuearticles values(TEM);. The photocatalytic study was performed to evaluate the effect of UV insert ignore into journalissuearticles values(8, 15, 30, and 125 W);, irradiation time insert ignore into journalissuearticles values(10–90 min);, pH insert ignore into journalissuearticles values(5-9);, initial MNZ concentration insert ignore into journalissuearticles values(10-100 mg/L); and BiOI–MWCNTs dosage insert ignore into journalissuearticles values(0.3–1.2 g/L); on MNZ removal at fixed neutral pH of 7. MNZ concentration was examined via the HPLC by measuring at 348 nm. Higher MNZ degradation was achieved using both BiOI–MWCNTs and UV light than using each separately. Maximum MNZ degradation efficiency of 99.95 % was obtained at pH 7, BiOI–MWCNTs dosage of 0.6g/L, MNZ concentration of 10mg/L, and irradiation time of 90min. MNZ removal was increased by increasing irradiation time and decreasing initial MNZ concentration. Pseudo-first-order rate of reaction insert ignore into journalissuearticles values(K); based on the Langmuir-Hinshelwood insert ignore into journalissuearticles values(L-H); model and adsorption equilibrium constant of 1.629 mg/L.min and 0.044 L/mg, respectively were obtained. Also, the adsorption kinetic study fitted the pseudo-first-order reaction. The electrical energy consumption per order of magnitude insert ignore into journalissuearticles values(E); for MNZ degradation was lower for the UV/BiOI–MWCNTs process than the BiOI–MWCNTs- alone and UV- alone processes. The photocatalytic degradation process using BiOI–MWCNTs can be applied efficiently for the removal of MNZ from aqueous solutions.
Keywords : Metronidazole, BiOIMWCNTs, nanocomposites, photocatalytic oxidation, Langmuir Hinshelwood model

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