Simultaneous remediation of polycyclic aromatic hydrocarbon and heavy metals in wastewater with zerovalent iron-titanium oxide nanoparticles (ZVI-TiO2)

Abstract

Abstract The presence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HM) in wastewater is a major challenge to the environment as various approaches have been used to remediate these contaminants from the environment. Zerovalent iron-titanium oxide nanoparticle (ZVI-TiO2 NPs) was synthesized by wet reflux in an inert environment using nitrogen gas and sodium borohydride as reducing agents. Characterization was carried out using a scanning electron microscope (SEM) coupled with electron diffraction X-ray (EDX) and Fourier transform infrared spectrophotometer (FTIR). Assessments of the wastewater were carried out with atomic absorption spectrophotometer (AAS) for HM and a gas chromatography-mass spectrophotometer (GCMS) for PAHs to determine the initial concentration (C i) compared with permissible limits of surface water and adsorption capacity with ZVI-TiO2 NPs (C f), respectively. The results obtained indicate a percentage yield of 65.51 ± 0.01 of ZVI-TiO2 NPs, with a particle size of 100 nm, weight composition of iron, titanium, and oxygen at 49.69, 5.24, and 35.41 g, respectively. FTIR shows a vibrational change of 3465, 2929, and 1641 cm−1 of OH, CH, and CO group needed for metal binding and adsorption. Remediation of HM after acid digestion gave effective removal of zinc, copper, cadmium, cobalt, and lead at an adsorption capacity of 64.29, 54.83, 53.13, 48.39, and 42.66% respectively. The adsorptions of benzo[a]pyrene, fluoranthene, pyrene, benzo[b]fluoranthene, and perylene were 77.87, 67.85, 52.17, 29.50, and 25.45%, respectively. These results indicate that metal/metal oxide (ZVI-TiO2) nanoparticles have a high potential in the remediation of heavy metals and PAHs from the water ecosystem.