A method for high-efficiency electrochemical reduction, enrichment, and recovery of uranium in uranium-containing wastewater and groundwater

Abstract

The invention discloses a method for recovering uranium-containing wastewater and uranium in underground water through high-efficiency electrochemical reduction enrichment. Metal electrodes are used as a cathode and an anode to construct an electrochemical system, and hexavalent uranyl ions are used to reduce electrons into tetravalent insoluble uranium dioxide, so the electrodes reduce hexavalenturanium into uranium dioxide and make the uranium dioxide enriched on the surfaces of the electrodes without an exogenous additive. A tetravalent uranium coating layer can further catalytically reduce hexavalent uranium in wastewater to form a new tetravalent uranium coating layer. The uranium dioxide enriched electrodes are taken out from the solution after the electrochemical reduction enrichment in order to realize high-efficiency reducing removal of the uranium in the wastewater and underground water. The electrodes are placed in a dilute nitric acid solution, and are oxidized to furtherrealize high-efficiency recovery. The method has the advantages of wide application range, and realization of high-efficiency removal and recovery of uranyl carbonate in low-concentration and high-concentration uranium-containing wastewater and carbonate-containing underground water.

Description

technical field [0001] The invention belongs to the field of waste water treatment and relates to a method for high-efficiency electrochemical reduction, enrichment, and recovery of uranium-containing waste water and ground water. Background technique [0002] With the mining of uranium and the widespread use of nuclear energy, uranium pollution is becoming more and more serious around the world. As a heavy metal toxic and radioactive pollutant, uranium migrates in the water environment and poses a great threat to the ecological environment and human health. The uranium content in surface or groundwater in many countries has greatly exceeded the drinking water standard (30μg / L) set by the World Health Organization. For example, the uranium concentration in wastewater from some uranium mining areas is as high as 50mg / L. The key to solving uranium pollution is to develop cost-effective uranium pollution control technology. At the same time, with the increasing demand for glo...

AI Technical Summary

Problems solved by technology

Due to the limited treatment capacity of the adsorption method, the treatment effect on high-concentration uranium-containing wastewater is not ideal, and the treatment efficiency for complexed uranium in groundwater, such as uranyl carbonate, is very low; in addition, due to the adsorption equilibrium of the adsorbent, for low The treatment efficiency of the concentrated uranium-containing wastewater system is low

The chemical precipitation method is to fix uranium from the water environment in the form of precipitation by adding flocculants and coagulants, but this method is not effective for complexed uranium, such as uranyl carbonate, and a large amount of flocculants and waste residues can also cause secondary pollution

The ion exchange method is similar to the adsorption method, and the uranium is enriched by adding an ion exchanger, but the treatment effect of the ion exchange method is limited by the concentration of competing ions in the water environment

Membrane separation method is a method that uses membranes to selectively permeate uranium. It is difficult to separate complex uranium, and the membrane is easily blocked by organic matter in water, resulting in a decrease in processing capacity, which is not conducive to large-scale application.