Meifang Hou,Yaofei Chu,Xiang Li,Huijiao Wang,Weikun Yao,Gang Yu,Seiichi Murayama,Yujue Wang
This study compares the degradation of diethyl phthalate (DEP) by the electro-peroxone (E-peroxone) process with three different carbon-based cathodes, namely, carbon-polytetrafluorethylene (carbon-PTFE), carbon felt, and reticulated vitreous carbon (RVC). Results show that the three cathodes had different electrocatalytic activity for converting sparged O 2 to H 2 O 2 , which increased in order of carbon felt, RVC, and carbon-PTFE. The in-situ generated H 2 O 2 then reacts with sparged O 3 to yield OH, which can in turn oxidize ozone-refractory DEP toward complete mineralization. In general, satisfactory total organic carbon removal yields (76.4–91.8%) could be obtained after 60 min of the E-peroxone treatment with the three carbon-based cathodes, and the highest yield was obtained with the carbon-PTFE cathode due to its highest activity for H 2 O 2 generation. In addition, the carbon-PTFE and carbon felt cathodes exhibited excellent stability over six cycles of the E-peroxone treatment of DEP solutions. Based on the intermediates (e.g., monoethyl phthalate, phthalic acid, phenolics, and carboxylic acids) identified by HPLC-UV, plausible reaction pathways were proposed for DEP mineralization by the E-peroxone process. The results of this study indicate that carbon-based cathodes generally have good electrocatalytic activity and stability for application in extended E-peroxone operations to effectively remove phthalates from water.
Synergy between adsorption and photocatalysis provides an ideal green technology to treat antibiotic pollution in water. In this study, single-atom Mn anchored on N-doped graphene oxide (Mn-NGO) was synthesized for enhanced adsorptive-photocatalytic removal of aqueous sulfanilamide (SNM) and the corresponding mechanisms were revealed. The Mn-NGO had better performance of SNM degradation and TOC removal than GO and NGO. Density functional theory (DFT) calculation showed that the electrons of d-orbital (Mn) and p-orbital (N) upgraded the electronic structures of GO of the Mn-NGO to interact with amino and aromatic rings of SNM, increasing the adsorption and polarizing of SNM. Furthermore, more hydroxyl and superoxide radicals were observed on Mn-NGO, leading to the generation of key reaction intermediates of 2-aminohydroquinone and benzenesulfonic and thus subsequently opening loops and mineralizing SNM. In addition, Mn-NGO effectively removed SNM in different types of water systems (e.g., lake water, tap water, and deionized water) through synergistic adsorption-photocatalytic degradation.
A new system of flow electrode capacitive deionization coupled with in situ electro-oxidation (FCDI-EO) was constructed to achieve the degradation of organic pollutants while maintaining high desalination efficiency. The effects of different parameters of potential difference, electrolyte, and pH on the chloride removal performance of FCDI-EO and the removal performance of rhodamine B (RhB) were investigated. Under the optimal conditions of potential difference = 4 V, [Cl − ] = 500 mg/L, and pH = 4, the removal of chloride ions, RhB and total organic carbon (TOC) was as high as 88.74 %, 99.02 %, and 87.82 %, respectively. The quenching experiments showed that hydroxyl radicals ( OH) and reactive chlorine species (RCS) were involved in the FCDI-EO system. The liquid chromatography-mass spectrometry (LC-MS) analysis suggested the possible mineralization pathway of RhB. Furthermore, toxicity assessment analysis showed that the toxicity of the degradation intermediates of RhB decreased during the treatment. Overall, this study provides a promising process that reducing the generation of high-concentration saline water in desalination and in situ utilizing the Cl − gathered from the feed water. The findings of this study could provide useful guidance for the development of flow electrode capacitive deionization technology and organic pollutant control.
危险品化学品经营许可证（带存储）