Doped Cu0 and sulfidation induced transition from R-O⢠to â¢OH in peracetic acid activation by sulfidated nano zero-valent iron-copper.
Water Res
; 256: 121621, 2024 Jun 01.
Article
en En
| MEDLINE
| ID: mdl-38642536
ABSTRACT
Peracetic acid (PAA) has emerged as a new effective oxidant for various contaminants degradation through advanced oxidation process (AOP). In this study, sulfidated nano zero-valent iron-copper (S-nZVIC) with low Cu doping and sulfidation was synthesized for PAA activation, resulting in more efficient degradation of sulfamethoxazole (SMX, 20 µM) and other contaminants using a low dose of catalyst (0.05 g/L) and oxidant (100 µM). The characterization results suggested that S-nZVIC presented a more uniform size and distribution with fewer metal oxides, as the agglomeration and oxidation were inhibited. More significantly, doped Cu0 and sulfidation significantly enhanced the generation and contribution of â¢OH but decreased that of R-O⢠in S-nZVIC/PAA/SMX system compared with that of nZVIC and S-nZVI, accounting for the relatively high degradation efficiency of 97.7% in S-nZVIC/PAA/SMX system compared with 85.7% and 78.9% in nZVIC/PAA/SMX and S-nZVI/PAA/SMX system, respectively. The mechanisms underlying these changes were that (i) doped Cu° could promote the regeneration of Fe(â
¡) for strengthened PAA activation through mediating Fe(â
¡)/Fe(â
¢) cycle by Cu(â
)/Cu(â
¡) cycle; (ii) S species might consume part of R-Oâ¢, resulting in a decreased contribution of R-O⢠in SMX degradation; (iii) sulfidation increased the electrical conductivity, thus facilitating the electron transfer from S-nZVIC to PAA. Consequently, the dominant reactive oxygen species transited from R-O⢠to â¢OH to degrade SMX more efficiently. The degradation pathways, intermediate products and toxicity were further analyzed through density functional theory (DFT) calculations, liquid chromatography-mass spectrometry (LC-MS) and T.E.S.T software analysis, which proved the environmental friendliness of this process. In addition, S-nZVIC exhibited high stability, recyclability and degradation efficiency over a wide pH range (3.0â¼9.0). This work provides a new insight into the rational design and modification of nano zero-valent metals for efficient wastewater treatment through adjusting the dominant reactive oxygen species (ROS) into the more active free radicals.
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Colección:
01-internacional
Base de datos:
MEDLINE
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Cobre
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Idioma:
En
Revista:
Water Res
Año:
2024
Tipo del documento:
Article
Pais de publicación:
Reino Unido