Water Science and Technology (Sep 2023)
Nanocomposites from spent coffee grounds and iron/zinc oxide: green synthesis, characterization, and application in textile wastewater treatment
Abstract
This study reports on a novel composite of bimetallic FeO/ZnO nanoparticles supported by spent coffee grounds (SCGs). The leaves of eucalyptus (Eucalyptus globulus Labill) and trumpet (Cuphea aequipetala Cav), with their high antioxidant content, serve as bio-reductant agents for the green synthesis of nanoparticles. It was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Stable nanoparticles were produced with different diameters of 5–30 nm, and they were applied as catalysts in Fenton-like processes. Box–Behnken experimental design (BBD) was used to determine the optimal removal efficiency with three factors and was used in the degradation of textile dyes from wastewater. The nanocomposite displayed a high decolorization ratio (88%) of indigo carmine in the presence of H2O2 combined. This resulted in a reduction in chemical oxygen demand (COD) of 56% at 120 min of contact time at an initial pH of 3.0 and a 0.5 g/L of catalyst dose, a H2O2 concentration of 8.8 mM/L, an initial dye concentration of 100 mg/L, and a temperature of 25 °C. HIGHLIGHTS Green synthesis of FeO/ZnO NPs using eucalyptus (Eucalyptus globulus Labill) and trumpet (Cuphea aequipetala Cav) extract was done.; The process was optimized using a Box–Behnken design.; UV–Visible spectroscopy, SEM, XRD, and TEM were done to analyze the structure morphology, size, and shape of nanoparticles.; Nanocomposite of bimetallic FeO/ZnO was used for the removal of indigo carmine supported by spent coffee grounds (SCGs).;
Keywords