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Jiang YY, Chen ZW, Li MM, Xiang QH, Wang XX, Miao HF, Ruan WQ. Degradation of diclofenac sodium using Fenton-like technology based on nano-calcium peroxide. Sci Total Environ 2021; 773:144801. [PMID: 33582322 DOI: 10.1016/j.scitotenv.2020.144801] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/05/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
A nano-calcium peroxide (nCaO2) powder with a purity of 89.1% was prepared using an improved traditional method. Then, the as-prepared nCaO2 was used as the source of hydrogen peroxide (H2O2) for the Fenton-like degradation of diclofenac sodium (DCF). The results showed that nCaO2 performed better for DCF removal when compared to nCaO2 prepared by a conventional method and commercial calcium peroxide (CaO2). Further experimental results indicated that 97.5% of DCF could be removed in 180 min at a nCaO2/Fe2+-EDTA/DCF molar ratio of 16/8-8/1, which was more efficient than in the H2O2/EDTA-Fe2+/DCF and nCaO2/Fe2+/DCF systems. The best removal rate of DCF was at pH 6.0, unlike previous claims that stated that the lower the pH in the buffer system, the better the degradation of DCF. In addition, the influence of water quality parameters, such as Cl-, NO3-, SO42-, HCO3-, and humic acid (HA), on DCF removal were evaluated. A free radical masking experiment revealed the existence of hydroxyl radical (OH), superoxide radical (O2-) and singlet oxygen (1O2), and indicated that the degradation of DCF was mainly due to oxidation caused by OH. Electron paramagnetic resonance (EPR) studies for different systems and different active oxygen species were carried out, and it was further confirmed that OH radicals have high intensity in the Fenton-like system based on nCaO2. EPR results also showed that the addition of EDTA can promote the production of OH. According to the identification of the dominant reactive species and GC-MS, the possible theoretical DCF degradation pathways were proposed.
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Affiliation(s)
- Ying-Ying Jiang
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Zi-Wen Chen
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Man-Man Li
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Qiu-Hong Xiang
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Xi-Xi Wang
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Heng-Feng Miao
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, PR China; Water Treatment Technology and Material Innovation Center, Suzhou University of Science and Technology, Suzhou 215009, PR China; Jiangsu Engineering Laboratory of Biomass Energy and Carbon Reduction Technology, Jiangnan University, Wuxi 214122, PR China.
| | - Wen-Quan Ruan
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, PR China; Water Treatment Technology and Material Innovation Center, Suzhou University of Science and Technology, Suzhou 215009, PR China; Jiangsu Engineering Laboratory of Biomass Energy and Carbon Reduction Technology, Jiangnan University, Wuxi 214122, PR China
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