Photo-Assisted Removal of Tetracycline Using Bio-Nanocomposite-Immobilized Alginate Beads

Abstract

In the present study, we report an efficient method for tetracycline (TC) removal from contaminated wastewater using alginate beads, immobilized with bio nanocomposite (BNC) consisting of Fe3O4 (iron oxide) and TiO2 (titanium dioxide) nanoparticles along with dead biomass of TC-resistant bacteria Acinetobacter sp. Chemically synthesized Fe3O4 nanoparticles and commercially available TiO2 (P25) nanoparticles were combined to form nanocomposite followed by encapsulation within alginate beads along with heat-killed biomass of Acinetobactersp. for the efficient degradation and adsorption of the target pollutant. The primary characterization of chemically synthesized nanoparticles was carried out with Fourier transform infrared, scanning electron microscopy–energy-dispersive X-ray spectrometry, transmission electron microscopy, and X-ray diffraction techniques. The batch studies for TC removal were performed by varying the reaction parameters such as bead weight, initial TC concentration, and pH in a photoreactor with UV-C irradiation. TC concentration of 10 mg/L, bead weight 10 g, and pH 6 were fixed as the optimum condition where 98 ± 0.5% of TC was removed from the solution. The possible removal mechanism was investigated with the help of UV–visible, total organic carbon, oxidation–reduction potential, Brunauer–Emmett–Teller, and liquid chromatography–mass spectroscopy analyses. The applicability of the process was successfully tested with the natural water systems spiked with TC at 10 mg/L. To assess the ecotoxic effects of the treated effluents, the cell viability assay was performed with the algal strains, Chlorella, and Scenedesmussp. and the bacterial strains, Pseudomonas aeruginosaand Escherichia coli. Finally, the reusability of the BNC bead was successfully established up to the 4th cycle.

A review on tetracycline removal from aqueous systems by advanced treatment techniques

“…used in a photobioreactor for the continuous TC degradation and adsorption, and the results showed 98% TC removal under UV-C irradiation. 140 The novel heterogeneous photocatalyst, Fe@Bacillus subtilis, was used for the Fenton-like oxidation of TC from aqueous system with a 96% removal rate, and this system is environmentally friendly with the complete elimination of TC with negligible iron leaching. 141 Zhuang et al (2019) studied the application of novel Fe 3 O 4 @Fe/graphene aerogel (MGA) for TC removal, and it shows higher TC and TOC removal percentage with lower iron leakage due to its fast electron transfer rate between the catalyst and the pollutant.…”

Photocatalytic Degradation of Tetracycline by ZnO/γ-Fe2O3 Paramagnetic Nanocomposite Material

“…Thus, in the last years, several physical, chemical and biological methods have been developed to remove pollutants and dangerous compounds from water [6,7]. However, traditional biological wastewater treatments are not efficient enough to remove tetracycline due to its low biodegradability [8] and indeed this antibiotic has been found in natural waters [9]. Therefore, the design and development of new technological approaches able to remove tetracyclines from wastewater before their discharge into aquatic environments are required.…”

“…Thus, in the last years, several physical, chemical and biological methods have been developed to remove pollutants and dangerous compounds from water [ 6 , 7 ]. However, traditional biological wastewater treatments are not efficient enough to remove tetracycline due to its low biodegradability [ 8 ] and indeed this antibiotic has been found in natural waters [ 9 ].…”

“…Therefore, the design and development of new technological approaches able to remove tetracyclines from wastewater before their discharge into aquatic environments are required. Among the various wastewater treatments, which include biodegradation, adsorption, electrochemical degradation and ozonation [ 10 , 11 , 12 , 13 ], new methods based on advanced oxidation processes (AOPs) have been recently developed [ 9 ]. AOPs involve the use of photocatalytic systems, such as zinc oxide (ZnO) or titanium dioxide (TiO 2 ) nanoparticles, that produce hydroxyl radicals (∙OH) in situ under electromagnetic radiation [ 14 , 15 ].…”

“…AOPs involve the use of photocatalytic systems, such as zinc oxide (ZnO) or titanium dioxide (TiO 2 ) nanoparticles, that produce hydroxyl radicals (∙OH) in situ under electromagnetic radiation [ 14 , 15 ]. These radicals trigger the oxidation of contaminants and convert them into less harmful byproducts [ 9 , 14 ]. In addition, AOPs allow mineralization of recalcitrant organic pollutants into green products with a rapid degradation rate under ambient temperature and pressure conditions [ 16 ].…”