Method for treating uranium-containing wastewater by using electricity-generating microorganism supported Fe/C nano composite material

Abstract

The invention provides a method for reducing and adsorbing uranium in wastewater by using nano-synthetic material combined with self electricity-generating microorganisms under illumination conditions. The method uses nano-zero valent iron (nZVI), a high-electroconductivity nano carbon material (C), and electricity-generating microorganisms as raw materials, uses the high reduction activity of thenZVI, the photocatalytic effect of an nZVI oxidation product combined with the C, and the characteristics of producing bioelectronics of the electricity-generating microorganisms for efficient reduction and adsorption treatment of the uranium-containing wastewater. The method comprises the following specific steps: (1) synthesizing a nano material (nZVI-CNT); (2) loading the nZVI-CNT on the surfaces of the microorganisms to obtain bio-nZVI-CNT; (3) placing the bio-nZVI-CNT into the uranium-containing wastewater with a concentration of <=50 mg / L under illumination, adjusting the pH to 4-6, andperforming uniform mixing under stirring; (4) performing solid-liquid separation after 2 hours; and (5) performing desorption to recover the uranium, and recycling the bio-nZVI-CNT. The method can reduce the uranium content in the uranium-containing wastewater with the concentration of <=50 mg / L by 96% or more, and the adsorption capacity is as high as 436.4 mg / g; and the method is simple and convenient to operate, has high removal efficiency and short removal time, and has good environmental, social and economic benefits.

Description

technical field [0001] The invention relates to the field of uranium-containing radioactive wastewater treatment, and is a complete set of technologies for rapidly removing hexavalent uranyl in uranium wastewater by comprehensively utilizing the bioelectronics of electricity-producing microorganisms, the high reactivity of nanomaterials and the photocatalytic properties of oxides. Background technique [0002] Uranium is currently the most important nuclear fuel in the utilization of nuclear energy. With the rapid development of nuclear energy, the demand for uranium resources increases, and the scale of uranium mining and smelting expands, more waste water polluted by low-concentration uranium will be produced. There are more and more, and the potential threats to human health and the natural ecological environment are becoming more and more serious, and people have put forward higher requirements for the treatment of radioactive wastewater. In the treatment of radioactive ...

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Problems solved by technology

[0004] According to relevant research reports [Ding, C., et al., Effects of Bacillus subtilis on the reduction of U(VI) by nano-Fe0. Geochimica et Cosmochimica Acta, 2015. 165:p. 86-107], nano-sized zero-valent iron It has high activity and can quickly reduce hexavalent uranyl, but because the nano-zero-valent iron is too active and easy to aggregate, the pure nano-zero-valent iron is rapidly oxidized to form an oxidation state during the process of removing uranyl. The membrane blocks the internal electron transport, resulting in a low reduction rate of uranyl by nanometer zero-valent iron per unit mass

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