Effect of extracellular polymer substances on the tetracycline removal during coagulation process. (August 2020)

• Record Type: Journal Article
• Authors: Xu, Qiongying; Han, Bo; Wang, Huidi; Wang, Qiandi; Zhang, Weijun; Wang, Dongsheng
• Is Part Of: Bioresource technology. Volume 309(2020)
• Publication Date: 2020-08
• Subjects: Coagulation/flocculation -- Extracellular polymeric substances -- Tetracycline -- Mediated effect -- Density functional theory; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.123316
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: The interaction between EPS and TC was related to π–π stacking reaction and electrostatic interaction. The presence of EPS could enhance the TC removal efficiency in PACl coagulation. NH2 in EPS and CO in TC were bridged by Al 3+ responsible for TC coagulation. Conjugated system of aromatic proteins and TC was coordinated with Al 3+, which also contributed to TC removal. Abstract: In this study, the effect of extracellular polymer substances on the tetracycline removal under hydroxyl aluminium treatment was investigated, and the molecular mechanisms of extracellular polymeric substances mediated coagulation of tetracycline were also explored. The results show that the presence of extracellular polymeric substances could significantly enhance the removal efficiency of tetracycline in hydroxyl aluminium coagulation. Findings suggest that tyrosine and tryptophan in extracellular proteins acted as binding sites to capture tetracycline. Evidences provided by the density functional theory calculations in combination with spectroscopy analysis indicated that two main mechanisms accounted for tetracycline removal in the presence of extracellular polymeric substances and polyaluminum chloride: (1) amino group in proteins and carbonyl in tetracycline were bridged by Al 3+ ; (2) benzene rings in tryptophan and tyrosine were π–π stacked with tetracycline, and the amino group in complexes were further coordinated with Al 3+ .