A method for low-temperature treatment of commercial iron powder with liquid nitrogen to enhance its ability to reduce and remove pollutants

A technology for low temperature treatment and pollutants, applied in the field of environmental chemistry, can solve the problems of poor reducing ability and low pollutant removal activity, and achieve the effects of simple method, easy acquisition and easy preparation

Active Publication Date: 2020-08-04
DONGGUAN PUREMATE ENVIRONMENTAL PROTECTION TECH CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a simple, non-polluting liquid nitrogen low-temperature treatment method for commercial iron powder to enhance its ability to reduce and remove pollutants in view of the low activity of reducing and removing pollutants in commercial iron powder in the prior art
The invention solves the problem of poor reducing ability due to the existence of an oxide layer on the surface of the commercial iron powder, and the commercial iron powder after low-temperature treatment with liquid nitrogen has the advantages of high efficiency, environmental friendliness, and no secondary pollution for the removal of water body pollutants

Method used

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  • A method for low-temperature treatment of commercial iron powder with liquid nitrogen to enhance its ability to reduce and remove pollutants
  • A method for low-temperature treatment of commercial iron powder with liquid nitrogen to enhance its ability to reduce and remove pollutants
  • A method for low-temperature treatment of commercial iron powder with liquid nitrogen to enhance its ability to reduce and remove pollutants

Examples

Experimental program
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Effect test

Embodiment 1

[0028] Example 1 Effect diagram of treating hexavalent chromium in polluted water by low-temperature treatment of iron powder with different particle sizes in liquid nitrogen

[0029] Pour 1g of commercial iron powder with a particle size of 100 mesh, 200 mesh, and 400 mesh into a Dewar bottle containing 1.0L liquid nitrogen. The iron powder has been sinking at the bottom of the Dewar bottle under the action of gravity. Nitrogen is poured into a liquid nitrogen bottle for recycling. After the residual liquid nitrogen is volatilized, the iron powder is poured out and dried at 50 degrees under the protection of nitrogen, which is the commercial iron powder (LNFe) treated with liquid nitrogen. Use 20mL of potassium dichromate aqueous solution with a hexavalent chromium concentration of 2mg / L to simulate chromium wastewater, add 0.1g of commercial iron powder (LNFe) treated at low temperature with liquid nitrogen, put it into a shaker with a rotation speed of 200rpm / min, take regul...

Embodiment 2

[0030] Example 2 Effect diagram of liquid nitrogen low temperature treatment of 200 mesh iron powder to treat bromate in water

[0031] Put 2g of commercial iron powder with a particle size of 200 mesh into a Dewar bottle containing 1.0L liquid nitrogen and soak for 20min, then pour out the iron powder and dry it under the protection of nitrogen. Use 20 mL of 2 mg / L bromate aqueous solution to simulate bromate-containing wastewater, add 0.5 g of commercial iron powder (LNFe) treated at low temperature with liquid nitrogen, and put it into a shaker with a rotation speed of 200 rpm / min. Sampling at regular intervals, measuring its concentration with anion chromatography, and using commercial iron powder (CFe) as a control test at the same time, the results are shown in Figure 4 . After 180 minutes of reaction, the bromate removal rate of commercial iron powder LNFe treated at low temperature with liquid nitrogen reached 100%, while the removal rate of commercial iron powder (C...

Embodiment 3

[0032] Example 3 Low-temperature treatment of 100-mesh iron powder with liquid nitrogen to treat uranyl ions in nuclear industry wastewater

[0033] Put 5 g of commercial iron powder with a particle size of 100 mesh into a Dewar bottle containing 1.0 L of liquid nitrogen and soak for 60 minutes, then pour out the iron powder and dry it under the protection of nitrogen. Use 20mL of uranyl aqueous solution of 20mg / L to simulate nuclear industry wastewater, add 0.2g of commercial iron powder (LNFe) treated at low temperature with liquid nitrogen, put it into a shaker with a rotation speed of 200rpm / min, take samples regularly and measure the concentration of uranyl, the results are shown in Figure 5 . After 50 minutes of reaction, the removal rate of commercial iron powder LNFe treated with liquid nitrogen at low temperature reached 100%, while the removal rate of commercial iron powder (CFe) was 35%.

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Abstract

The invention relates to a method for low-temperature treatment of commercial iron powder with liquid nitrogen to enhance its ability to reduce and remove pollutants. Since commercial iron powder is easily oxidized during the preparation and storage process, the surface is covered with a layer of nano-scale iron oxide, which greatly reduces its reducing ability. The purpose of the present invention is to adopt a simple and easy method to solve the problem of poor activity of commercial iron powder. The method comprises: quenching the commercial iron powder to obtain the commercial iron powder with enhanced ability to reduce and remove pollutants. The quenching treatment cracks the oxide layer on the surface of the iron powder, exposing the active zero-valent iron inside (bottom layer). Compared with other chemical or physical methods, the method for low-temperature treatment of commercial iron powder with liquid nitrogen provided by the invention is simple and easy, and has the characteristics of high efficiency, no pollution and environmental friendliness, and solves the problem of low activity of pollutants in the current commercial iron powder treatment. It is expected to be widely used in environmental pollution control.

Description

technical field [0001] The invention belongs to the field of environmental chemistry, specifically relates to the control and repair of high-valence toxic pollutants in water bodies, and is suitable for the treatment of waste water in the fields of printing and dyeing, industry, nuclear industry and the like. Background technique [0002] In today's 21st century, environmental pollution has always been a major problem faced by human beings all over the world. The economic development in the past few decades has been accompanied by the over-exploitation of natural resources and the random disposal of the three wastes, which have led to a series of environmental degradation problems. For example, the emergence of cancer villages, the increase of deformed children, the younger age of major diseases, and the deterioration of the living environment have forced people to pay attention to environmental issues that are closely related to themselves. In particular, the treatment of ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F1/70B22F1/00G21F9/20C02F101/22C02F101/12C02F101/00
CPCG21F9/20C02F1/70C02F2101/006C02F2101/22C02F2101/12B22F1/142
Inventor 张礼知胡月贾法龙
Owner DONGGUAN PUREMATE ENVIRONMENTAL PROTECTION TECH CO LTD
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