Device and method for extracting uranium from uranium-containing wastewater or seawater and application thereof

Abstract

The invention discloses a device, method and application for extracting uranium from uranium-containing wastewater or seawater, and the device for extracting the uranium comprises a photo-anode, a cathode reaction piece and a photocatalytic light source. The photo-anode comprises an anode reaction piece and a photocatalyst layer arranged on the surface of the anode reaction piece. The cathode reaction piece is connected with the anode reaction piece through a wire. The photocatalytic light source adopts ultraviolet light, visible light or infrared light. When a photocatalytic fuel cell is usedfor extracting the uranium from the uranium-containing wastewater and seawater, an external power source is not needed, a proton exchange membrane and an oxide inhibitor do not need to be added, meanwhile, inert gas atmosphere protection is not needed, and operation can be conducted in the air atmosphere. Hexavalent uranyl ions in the wastewater and seawater can be efficiently reduced into tetravalent uranium which is low in toxicity and almost insoluble in water, the tetravalent uranium is gathered onto a cathode, uranium is desorbed from the surface of a photocatalyst without acid picklingor air purging reoxidation, uranium can be efficiently recycled by regularly replacing a cathode material, uranium reduction products are easy and convenient to collect, and continuous operation of asystem is not influenced.

Description

technical field [0001] The invention belongs to the technical field of water pollution prevention and new energy technology, and particularly relates to a device, method and application for extracting uranium from uranium-containing wastewater and seawater. Background technique [0002] In recent years, with the rapid development of nuclear energy, the demand for uranium resources in the nuclear energy industry is increasing day by day. On the other hand, a large amount of uranium is released into the environment in a series of nuclear industry activities such as uranium mining, uranium processing, and nuclear power plant operation, threatening the ecological environment and human health. Therefore, it is necessary and urgent to extract uranium from uranium-containing wastewater, which can effectively solve the aforementioned contradictions. In addition, seawater is rich in uranium resources, and the global seawater contains thousands of times more uranium resources than la...

AI Technical Summary

Problems solved by technology

However, the currently reported photocatalytic reduction methods for extracting uranium have many deficiencies: First, most of the reported methods use nanoparticle photocatalysts, so membrane filtration is required (Jiang et al., 2018; Li et al., 2017 ; Liang et al., 2020; Zhu et al., 2019), centrifugation (Gao et al., 2020; Gong et al., 2019; Guo et al., 2017; Guo et al., 2016; Wang et al., 2015) and other cumbersome and complicated solid-liquid separation measures to realize the separation and recovery of the catalyst, which increases the difficulty of operation and production cost; Oxidation inhibitors (such as EDTA, methanol and other organic substances) to avoid the reoxidation of the reduction product U(IV) to U(VI) (Le et al., 2020; Liang et al., 2020; Lu et al., 2017; Yu et al., 2020); Third, the reported method of extracting uranium by photocatalytic reduction can deposit U(IV) on the surface of the catalyst. In order to realize the regeneration of the catalyst and the recovery of uranium, pickling ( Chen et al., 2020a; Gong et al., 2019; Jiang et al., 2018; Ke et al., 2017; Li et al., 2019a; Lu et al., 2016), air purging multiple oxidation (Deng et al., 2019; Li et al., 2019c; Li et al., 2017; Liang et al., 2020; Wang et al., 2020a; Wang et al., 2020b) and other means to desorb uranium deposited on the catalyst surface , but the former will cause secondary pollution, and the latter will take a long time

For example, the patent CN108906102 proposed "a method for extracting uranium using photocatalytic technology under visible light", using carbon nitride supported by cadmium sulfide (CdS / C 3 N 4 ) powder as catalyst, extract uranium from aqueous solution under visible light irradiation, but this method still has many deficiencies: the catalyst used is nano-particles, and its separation and recovery needs to be filtered; recovery of uranium requires the separation of the catalyst in the air Add Na after standing for 24h 2 CO 3 The desorption method of the solution is cumbersome and time-consuming; before the operation of photocatalytic reduction and extraction of uranium, N 2 Two hours, increasing the operation process and cost

Another invention CN107572650 proposes a process for photocatalytic reduction of U(VI) using copper hydroxyphosphate powder, which also has the aforementioned problem of difficult catalyst separation and regeneration

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