Aeration-assisted sulfite activation with ferrous for enhanced chloramphenicol degradation. (January 2020)

• Record Type: Journal Article
• Authors: Chen, Xiaoyan; Miao, Wei; Yang, Yulin; Hao, Sibei; Mao, Shun
• Is Part Of: Chemosphere. Volume 238(2020)
• Publication Date: 2020-01
• Subjects: Chloramphenicol -- Sulfite -- Ferrous -- Advanced oxidation process -- Aeration; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.124599
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this study, an Fe(Ⅱ)/S(IV) system was designed for the degradation of chloramphenicol (CAP). The pseudo-first-order rate constants for CAP degradation under typical conditions with and without air purging were investigated. The greatly enhanced rate of 0.0099 min −1 with air purging compared with 0.0006 min −1 with no air purging indicated that aeration was significant to the degradation of CAP in Fe(Ⅱ)/S(Ⅳ) system. Radical scavenging experiments revealed that SO4 - was the primary oxidant generated from the activation of S(IV) with Fe(II), accounting for around 70% of degradation under weak acidic and neutral conditions. Increasing Fe(II) and S(IV) doses promoted the degradation of CAP, whereas the overdose of them led to a decreased degradation rate by scavenging radicals. Owing to the participation of oxygen in the formation of ferric sulfite complex and SO5 -, the increase of dissolved oxygen improved the removal efficiency of CAP. The removal efficiency of CAP was also found to be pH dependent, decreasing from acid condition (initial pH = 4) to basic condition (initial pH = 8). The presence of coexisting anions and water matrix was found inhibiting CAP degradation in Fe(Ⅱ)/S(Ⅳ) system. This work provides an understanding on the working mechanism and possible applications of Fe(Ⅱ)/S(Ⅳ) system in organic compound degradation in wastewater. Graphical abstract: Image 1 Highlights: Degradation kinetics of chloramphenicol (CAP) are studied for the first time in Fe(II)/S(IV) system. . With air purging, the Fe(II)/S(IV) system shows a high efficiency in CAP degradation. SO4 - is found to be the dominant radical species in CAP degradation. Roles of pH condition and dissolved oxygen are investigated. Inhibitions from coexisting anions and water matrix are identified in CAP degradation.