Fabrication of Bi1.81MnNbO6.72/sulfite system for efficient degradation of chlortetracycline. (April 2021)

• Record Type: Journal Article
• Authors: Zhao, Jie; Song, Qiang; He, Qiang; Dionysiou, Dionysios D.; Wu, Fei; Feng, Yawei; Zhang, Xinying
• Is Part Of: Chemosphere. Volume 268(2021)
• Publication Date: 2021-04
• Subjects: Bi1.81MnNbO6.72 -- Hydrothermal -- Sulfite -- Advanced oxidation technology -- Chlortetracycline -- Degradation; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.129269
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The design of eco-friendly Bi1.81 MnNbO6.72 /sulfite system for efficient degradation of chlortetracycline was achieved. The feasibility of synthesizing Bi1.81 MnNbO6.72 by hydrothermal method was determined by X-ray diffraction. The magnetic test suggested that Bi1.81 MnNbO6.72 possessed paramagnetic properties, indicating unpaired electrons were present. Scanning electron microscope and transmission electron microscopy images revealed that Bi1.81 MnNbO6.72 octahedra exhibited exposed [1, 1, 1] crystal plane containing high density of Bi, Mn and Nb metal atoms. Large numbers of metal atoms will facilitate heterogeneous catalytic process. In a batch system with aeration, Bi1.81 MnNbO6.72 could be used as sulfite activator for the disposal of chlortetracycline. The reaction kinetics of the degradation process conformed to the pseudo-second-order kinetic model. In Bi1.81 MnNbO6.72 /sulfite process, initial pH, Bi1.81 MnNbO6.72 dosage, sulfite and chlortetracycline concentrations, as well as inorganic salt ions had great effect on chlortetracycline degradation. Under optimal conditions, the efficiency of Bi1.81 MnNbO6.72 /sulfite system for degradation of chlortetracycline could reach 76.2%. Moreover, Mn (II) plays a key role in the initiation of the catalytic reaction in Bi1.81 MnNbO6.72 /sulfite process. Generated SO3 ●‒ could act as main reactive species in Bi1.81 MnNbO6.72 /sulfite process, while HO ● was also involved. Three new degradation products were detected by UHPLC/MS/MS and the possible degradation pathways in this system were proposed. Based on this, we believe that Bi1.81 MnNbO6.72 /sulfite is a type of process for degradation of organic contaminants with research significance and application prospects. Graphical abstract: Image 1 Highlights: A hydrothermal method for preparing Bi1.81 MnNbO6.72 was developed. An efficient Bi1.81 MnNbO6.72 /sulfite system with aeration was established for the removal of chlortetracycline. Three new transformation products of chlortetracycline were elucidated. The key role of SO3 . ●‒ during heterogeneous catalytic process was confirmed.