Hydroxyl radicals(·OH) generated on anode play a vital role in electrochemical oxidation(EO) of organic pollutants for water treatment. Inspired by the four-electron oxygen evolution reaction(OER), we supposed an...Hydroxyl radicals(·OH) generated on anode play a vital role in electrochemical oxidation(EO) of organic pollutants for water treatment. Inspired by the four-electron oxygen evolution reaction(OER), we supposed an anode-selection strategy to stabilize deeply oxidized states(*O and*OOH) which are beneficial to generating·OH. To verify the hypothesis, a candidate anode component(MIL-101(Cr), a well-known metal-organic framework with active variable-valence transition metal centers) was used to coat Ti/TiO_(2)plate to fabricate anodes. Compared to TiO_(2)(101) plane on undecorated anode surface, fast and complete removal of aniline and phenol, and improved energy utilization were achieved on MIL-101(Cr)-coatedTi/TiO_(2)anode. Mechanism investigation, including pollutant degradation pathways, showed the predominate contribution(69.60%–75.13%) of·OH in pollutant mineralization. Density functional theory(DFT)computations indicated Cr site in MIL-101(Cr) was more conducive to stabilizing*O and*OOH, leading to thermodynamical spontaneous generation of·OH. This work opens up an exciting avenue to explore·OH production, and supplies a useful guidance to the development of anode materials for EO process.展开更多
The existence of many anions in wastewater reduces the removal efficiency of phosphate by adsorbents under realistic conditions.Facing this challenge,the study reports on an insistent and stable composite adsorbent of...The existence of many anions in wastewater reduces the removal efficiency of phosphate by adsorbents under realistic conditions.Facing this challenge,the study reports on an insistent and stable composite adsorbent of molybdate complexes Fe-(MoO_(x))embedded in a macroporous anion exchange resin(D-201).[Fe(MoO_(x))]-D-201 shows 93.7%adsorption capacity(28.3 mg/g)for phosphate even when the molar concentration of coexisting ions is 5 times higher than phosphate.The capacity of adsorbent is maintained more than 84.2%after five regeneration cycles to remove phosphate in the wastewater containing coexisting ions.The ability of highly selective removal of phosphate is maintained during the regeneration cycles explained by the change of the binding of molybdate clusters with phosphate,which is due to the different structures of molybdate clusters depending on various pH.In general,this work puts forward a new idea for the development of phosphorus removal adsorbents for the treatment of wastewater containing coexisting ions.展开更多
基金supported by the National Natrual Science of China (NSFC, Nos. 51978341, 52070100 and 52011530433)the Natural Science Foundation of Jiangsu Province of China (No. BK20190087)Jiangsu Key Laboratory of New Power Batteries, and a project funded by the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions。
文摘Hydroxyl radicals(·OH) generated on anode play a vital role in electrochemical oxidation(EO) of organic pollutants for water treatment. Inspired by the four-electron oxygen evolution reaction(OER), we supposed an anode-selection strategy to stabilize deeply oxidized states(*O and*OOH) which are beneficial to generating·OH. To verify the hypothesis, a candidate anode component(MIL-101(Cr), a well-known metal-organic framework with active variable-valence transition metal centers) was used to coat Ti/TiO_(2)plate to fabricate anodes. Compared to TiO_(2)(101) plane on undecorated anode surface, fast and complete removal of aniline and phenol, and improved energy utilization were achieved on MIL-101(Cr)-coatedTi/TiO_(2)anode. Mechanism investigation, including pollutant degradation pathways, showed the predominate contribution(69.60%–75.13%) of·OH in pollutant mineralization. Density functional theory(DFT)computations indicated Cr site in MIL-101(Cr) was more conducive to stabilizing*O and*OOH, leading to thermodynamical spontaneous generation of·OH. This work opens up an exciting avenue to explore·OH production, and supplies a useful guidance to the development of anode materials for EO process.
基金supported by the National Natural Science Foundation of China(Nos.52070100,51978341)the Natural Science Foundation of Jiangsu Province of China(No.BK20190087).
文摘The existence of many anions in wastewater reduces the removal efficiency of phosphate by adsorbents under realistic conditions.Facing this challenge,the study reports on an insistent and stable composite adsorbent of molybdate complexes Fe-(MoO_(x))embedded in a macroporous anion exchange resin(D-201).[Fe(MoO_(x))]-D-201 shows 93.7%adsorption capacity(28.3 mg/g)for phosphate even when the molar concentration of coexisting ions is 5 times higher than phosphate.The capacity of adsorbent is maintained more than 84.2%after five regeneration cycles to remove phosphate in the wastewater containing coexisting ions.The ability of highly selective removal of phosphate is maintained during the regeneration cycles explained by the change of the binding of molybdate clusters with phosphate,which is due to the different structures of molybdate clusters depending on various pH.In general,this work puts forward a new idea for the development of phosphorus removal adsorbents for the treatment of wastewater containing coexisting ions.
