In this work, we used cathodic microarc plasma electrolysis (CMPE) to degrade 2,4-dichlorophenol (2,4-DCP) in simulated wastewater. By investigating and comparing the removal efficiencies and chemical oxygen demand (COD) during the degradation process, higher bath voltage and alkaline condition were considered as more suitable for the 2,4-DCP decomposition. Higher initial 2,4-DCP concentration was attributed to the increase in the utilisation of the energy input. The plasma characteristics during CMPE were studied by optical emission spectroscopy (OES). It was found that the 2,4-DCP directly participated in the plasma discharge process. Furthermore, by studying the evolution of intermediate products at different experimental parameters, it was found that the existence of Cl played an important role in the opening of benzene ring, which activated the ortho-substitutions of hydroxyl, meanwhile accelerated the p-substitutions. The instantaneous high temperature and high pressure and the Cl that were generated and driven by cathodic plasma made the decomposition of 2,4-DCP much quicker.
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http://dx.doi.org/10.1080/09593330.2020.1797896 | DOI Listing |
Materials (Basel)
May 2024
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
The correlation between negative pulse and the black electrolyte properties of magnesium alloy micro-arc oxidation and the treated area was investigated by introducing a negative pulse electric field. The physical phase composition, microstructure, elemental distribution, and content of the coating were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results showed that the introduction of negative pulses favored the generation of MgO and MgSiO contents in the coatings, and an increase in the MgO phase was found in the coatings formed in the failed electrolytes; the microporous size and microcracks of the coatings were gradually and significantly reduced; the average consumption of Cu ions was 0.
View Article and Find Full Text PDFNanomaterials (Basel)
May 2024
State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
Micro-arc oxidation (MAO) is a promising technology for enhancing the wear resistance of engine cylinders by growing a high hardness alumina ceramic film on the surface of light aluminum engine cylinders. However, the positive and negative pulse coordination, voltage characteristic signal, hardness distribution characteristics of the ceramic film, and their internal mechanism during the growth process are still unclear. This paper investigates the synergistic effect mechanism of cathodic and anodic current on the growth behaviour of alumina, dynamic voltage signal, and hardness distribution of micro-arc oxidation film.
View Article and Find Full Text PDFJ Environ Manage
April 2024
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, No. 1 Qinggongyuan, Ganjinzi District, Dalian, 116034, PR China. Electronic address:
The main challenge facing the anodic electro-Fenton through the 2e water oxidation reaction (WOR) for toxics degradation lies in the electrode's stability, because the anodic oxygen evolution (OER) generated O will inevitably exfoliate the electro-active components loaded on the electrode substrate. To address this point, two aspects need attention: 1) Identifying a catalyst that exhibits both excellent electrocatalytic activity and selectivity can improve the faradaic efficiency of hydrogen peroxide (HO); 2) Employing novel methods for fabricating highly stable electrodes, where active sites can be firmly coated. Consequently, this study utilized microarc oxidation (MAO) to prepare a ceramic film electrode ZnSnO@Ti at 300 V.
View Article and Find Full Text PDFACS Appl Bio Mater
December 2023
Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
Ti surfaces must exhibit antibacterial activity without cytotoxicity to promote bone reconstruction and prevent infection simultaneously. In this study, we employed a two-step electrochemical treatment process, namely, microarc oxidation (MAO) and cathodic electrochemical deposition (CED), to modify Ti surfaces. During the MAO step, a porous TiO (pTiO) layer with a surface roughness of approximately 2.
View Article and Find Full Text PDFMaterials (Basel)
July 2023
School of Mechanical Engineering, Dalian University, Dalian 116000, China.
Currently, research on the edge effect issue in the micro-arc oxidation process primarily focuses on investigating process conditions and enhancing additives. However, some scholars have utilized finite element analysis software to simulate the edge effect during the simulation process, overlooking the investigation of the morphology of the auxiliary cathode. This study analyzes the growth characteristics of the oxide film on aluminum alloy 2A12 during micro-arc oxidation.
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