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CN-121990653-A - Application of filter electrode in reduction recovery of complex copper in wastewater

CN121990653ACN 121990653 ACN121990653 ACN 121990653ACN-121990653-A

Abstract

The invention relates to an application of a filter electrode in reducing and recycling complex copper in wastewater, and relates to the technical field of water treatment. The application of the filter electrode in recycling metal copper in organic complex state copper-containing wastewater is characterized in that the filter electrode takes a carbon felt as a substrate, an active layer containing polybenzimidazole is wrapped on the surface of the substrate, the active layer further comprises a binder and a conductive agent, the filter electrode performs an electroreduction reaction when filtering a feed liquid containing complex state copper, and copper is deposited on the surface of the electrode in a metal simple substance form, so that recycling of copper resources in the organic complex state copper-containing wastewater is realized. The filter electrode has the advantages of low energy consumption, high stability and the like, can directly capture copper ions in wastewater without breaking collaterals, and realizes high-efficiency electroreduction of organic complex copper.

Inventors

  • WANG XUEYE
  • LEI ZHENDONG
  • LIAN JINCHUAN
  • WANG ZHIWEI
  • SHI WEI

Assignees

  • 同济大学

Dates

Publication Date
20260508
Application Date
20260410

Claims (10)

  1. 1. The application of the filter electrode in reducing and recycling complex copper in wastewater is characterized in that the filter electrode takes carbon felt as a substrate, and an active layer containing polybenzimidazole is wrapped on the surface of the substrate; the active layer further includes a binder and a conductive agent; the filtering electrode carries out electroreduction reaction when filtering the feed liquid containing complex state copper, and copper is deposited on the surface of the electrode in the form of metal simple substance, thereby realizing the recovery of copper resources in the wastewater containing organic complex state copper.
  2. 2. The use according to claim 1, wherein the filter electrode is prepared by the following method: mixing polybenzimidazole, a binder and a conductive agent in a solvent, and performing ultrasonic mixing to obtain conductive ink; and (3) dripping the obtained conductive ink on the surface of a substrate, and drying to obtain the filter electrode.
  3. 3. The use according to claim 2, wherein the molecular weight of the polybenzimidazole is 50000-100000 and the purity is 95% -100%.
  4. 4. Use according to claim 2, wherein the binder comprises PVDF and/or perfluorosulfonic acid resin; The conductive agent is selected from one or more of conductive carbon black, carbon nano tubes and graphene; the solvent includes one or more of N-methylpyrrolidone, N-dimethylformamide, and N, N-dimethylacetamide.
  5. 5. The use according to claim 2, wherein the mass ratio of polybenzimidazole, conductive agent to binder is (6-8): (1-3): 1.
  6. 6. The use according to claim 2, wherein the concentration of polybenzimidazole in the conductive ink is 0.0625 wt% -0.25 wt%.
  7. 7. The use according to claim 2, wherein the time of the ultrasound is 10-30 min and the reaction temperature is 25-30 ℃.
  8. 8. The use according to claim 1, characterized in that the concentration of copper in complex form in the wastewater is 4.5-32 mg/L.
  9. 9. The use according to claim 1, wherein the copper in complex form in the wastewater comprises one or more of Cu-EDTA, cu-HEDTA, cu-EDDA, cu-IDA, cu-NTA, cu-Gly and Cu-citric acid.
  10. 10. The use according to claim 1, wherein the flux of water filtered during the filtration process of the filter electrode is 150-2400L/(m 2 h), and the operating voltage of the electro-reduction reaction is 1.5-2.5V.

Description

Application of filter electrode in reduction recovery of complex copper in wastewater Technical Field The invention relates to the technical field of water treatment, in particular to an application of a filter electrode in reducing and recycling complex copper in wastewater, and specifically relates to a preparation method and an application of a filter cathode which are free of oxidation and vein breaking and can directly recycle complex copper in wastewater, and the method and the application are suitable for recycling heavy metal copper in industrial wastewater containing organic complex copper. Background The total amount of copper-containing industrial wastewater discharged annually worldwide is over 200 ten thousand tons, counted by the united nations environmental planning agency (United Nations Environment Programme, UNEP). Heavy metals have strong biotoxicity, can be enriched through food chains, and can seriously threaten the safety of regional water environment and resident water if discharged into natural water along with wastewater without proper treatment. Copper-containing wastewater has pollution characteristics and resource attributes, and the economic potential of copper resource enrichment and recovery in wastewater is huge (copper recovery value exceeds 6 ten thousand Yuan people's notes/ton). Copper in industrial wastewater often forms stable complexes (HMCs) with organic ligands (EDTA, citric acid, etc.), which account for up to 60-80%. In the prior art, complex copper recovery efficiency is limited due to low complex breaking efficiency (< 30%), such as that a non-redox separation method (adsorption and membrane separation) is interfered by coexisting ions and cannot dissociate complex bonds, and an oxidative decomposition-recovery method (Fenton reaction and ozone oxidation) has the problems of high oxidant consumption, secondary pollution generated by mineralized ligand, high energy consumption (0.5-1.5 kWh/g) and the like, so that development of an efficient recovery technology is needed to achieve the dual aims of pollution control and resource regeneration. The electrochemical reduction technology has the advantages of synchronous broken-channel recovery, no secondary pollution and the like, and becomes one of the emerging technologies for recovering complex heavy metals in recent years. However, the electroreduction technology is limited by the blocking and orbit occupation of the ligand to the electron transfer path of the heavy metal center, and a high cathode potential needs to be continuously applied to overcome the limitation of the electron transfer reduction process, so that the key problem of the bottleneck of the recovery efficiency of the broken channel still exists. Disclosure of Invention In order to solve the technical problems, the invention provides an application of a filter electrode in reducing and recycling complex copper in wastewater. The method comprises the steps of constructing a functional ligand with strong coordination activity at an electrode interface, utilizing the lone pair electrons of the functional ligand to generate specific strong coordination with the empty orbits of target heavy metal ions, so that the functional ligand can competitively replace weak binding ligands in original complexes, realizing spontaneous decomplexing of complex heavy metals, establishing a direct and efficient electron transfer channel between the heavy metal ions and the electrode surface, reducing the activation energy barrier and overpotential required by the reduction reaction of the heavy metal ions, simultaneously catalyzing water molecules (or protons) to generate active hydrogen atoms (H *, -2.3V vs. SHE) by the heavy metal simple substance generated by in-situ electroreduction at the cathode surface, and simultaneously, constructing a filtration type electroreduction system aiming at the key problems of insufficient mass transfer rate of the traditional electrochemical system under the interface of an overcurrent electrode, low utilization rate of active sites and the like, and greatly improving the removal efficiency and recycling energy efficiency of complex heavy metals by strengthening the coupling system of self-catalytic electroreduction and overcurrent type reinforcement through the convection effect of the reinforced interface. The invention aims to provide an application of a filtering electrode in reducing and recycling complex copper in wastewater, wherein the filtering electrode takes carbon felt as a substrate, and an active layer containing polybenzimidazole is wrapped on the surface of the substrate; the active layer further includes a binder and a conductive agent; the filtering electrode carries out electroreduction reaction when filtering the feed liquid containing complex state copper, and copper is deposited on the surface of the electrode in the form of metal simple substance, thereby realizing the recovery of copper resources in the wast