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As the demand for potable water increases, direct potable reuse of wastewater is an attractive alternative method to produce potable water. However, implementation of such a process will require the removal of emerging contaminants which could accumulate in the drinking water supply. Here, the removal of atrazine, a commonly used herbicide, has been investigated. Using real and synthetic wastewater, as well as sludge from two wastewater treatment facilities in the United States in Norman, Oklahoma and Fayetteville, Arkansas, atrazine removal has been investigated. Our results indicate that about 20% of the atrazine is removed by adsorption onto the particulate matter present. Significant biodegradation of atrazine was only observed under aerobic conditions for sludge from Norman, Oklahoma. Next-generation sequencing of the activated sludge revealed the abundance of Noncardiac with known atrazine degradation pathways in the Norman aerobic sludge, which is believed to be responsible for atrazine biodegradation in our study. The detection of these bacteria could also be used to determine the likelihood of biodegradation of atrazine for a given wastewater treatment facility.
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This content will become publicly available on June 1, 2026
A novel MnFe2O4@CDs material of dual behavior: photothermal conversion performance and fluorescent probe. Capture, detection, and degradation of Atrazine
The detection and removal of Atrazine (ATZN), a pesticide of environmental concern, requires more efficient methods to facilitate its degradation. The adequate structural morphology, high specific surface area, great photothermal conversion performance, higher amount of oxygenated functional groups, and intense and stable fluorescence signals are considered as favorable properties of the materials used in the in the proposal of physicochemical methods for detection, capture and degradation of nitrogenous herbicides. Herein, the design, preparation, and characterization of MnFe2O4@CDs as a dual-functional material is reported. Due to its optical, photothermal, textural and surface chemistry properties, the material is able to capture, detect, and degrade the herbicide "Atrazine" in synthetic samples. The preparation of the proposed composites, formed by particles of bimetallic oxides (Mn-Fe2O4) and a covering of carbon dots (CDs), was confirmed using various characterization techniques including SEM, TEMHR, RAMAN, FTIR, UV-Visible, Photoluminescence, DRX, N2 adsorption-desorption isotherms, superficial chemistry, and photothermal. The study revealed that the ATZN capture occurs through hydrogen bonding interaction between −COOH and −COH functional groups exposed on CDs surface and amine groups −NH− of the herbicide. Furthermore, the CDs behave as fluorescent markers of single-channel employed to detect ATZN and to monitor the capture-degradation process. The MnFe2O4@CDs composite was integrated as the main thermoactive material into a photothermal reactor on which was incident a NIR laser. The high near-infrared absorption of the Mn-Fe2O4 particles resulting in an efficient photothermal conversion; which in turn, increase the temperature of the surrounding medium. The increase in temperature promotes the activation of persulfate (PS) at the interface of the MnFe2O4@CDs−PS system producing SO4• − radicals as oxidizing agents of atrazine. Our results demonstrate that the process may effectively degrade 99 % of atrazine for a concentration of CATZN [20 mM], when NIR light irradiated by 45 min and the system reaches a temperature of ca. 53 ºC. Additionally, the degradation of ATZN was confirmed by analysis of total organic carbon (TOC). The fluorometric analytical assay by CDs-base fluorescence probes allowed following the FL signal at 520 nm(λexit = 375 nm) for the capture “turn on” and degradation “turn off” of atrazine. Finally, as a comparison, we highlight the significant efficiency shown by the process studied here, compared to other similar atrazine degradation processes previously reported.
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- Award ID(s):
- 2108462
- PAR ID:
- 10621440
- Editor(s):
- Lim, Teik-Thye; Vilar, Vítor
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Journal of Environmental Chemical Engineering
- Volume:
- 13
- Issue:
- 3
- ISSN:
- 2213-3437
- Page Range / eLocation ID:
- 116226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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