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Method for removing Se(IV)/Se(VI) from water by magnetic field enhanced zero-valent iron

A magnetic field strengthening, zero-valent iron technology, applied in the fields of magnetic field/electric field water/sewage treatment, chemical instruments and methods, water/sewage treatment, etc. Achieve the effect of low price, improved reaction rate and long service life

Active Publication Date: 2012-12-05
TONGJI UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Studies have found that iron-based bimetals are usually more effective in removing pollutants than pure zero-valent iron, but noble metals are usually too expensive to be used in actual production, and people are concerned about the release of noble metals used to synthesize iron-based bimetals and its ecotoxicity are doubtful
In addition, the reactivity of iron-based bimetals is greatly affected by the synthesis process, which also limits its application.

Method used

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  • Method for removing Se(IV)/Se(VI) from water by magnetic field enhanced zero-valent iron
  • Method for removing Se(IV)/Se(VI) from water by magnetic field enhanced zero-valent iron
  • Method for removing Se(IV)/Se(VI) from water by magnetic field enhanced zero-valent iron

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specific Embodiment approach 1

[0025] Specific embodiment one: a kind of magnetic field strengthening zero-valent iron in this embodiment removes the method for Se(IV) / Se(VI) in water is in complete mixing reactor, to containing 38.76 mg L -1 Add 1 g L of Se(IV) to the water -1 The zero-valent iron (particle size is 3 microns), the mass ratio of zero-valent iron to Se is about 25:1, pH=4.0, the magnetic field used is an alternating magnetic field, and the magnetic field strength is about 0.2~10 mT. In the presence of a magnetic field, zero-valent iron can remove more than 99% of Se(IV) within 0.25 h. In the absence of a magnetic field, when the initial Se(IV) concentration was reduced to 10.77 mg L -1 , even if the reaction is 2 h, only about 94% of Se(IV) can be removed. see details figure 1 .

specific Embodiment approach 2

[0026] Specific embodiment two: a kind of magnetic field strengthening zero-valent iron in this embodiment removes the method for Se(IV) / Se(VI) in water is in complete mixing reactor, to containing 35.68 mg L -1 Add 1 g L of Se(IV) to the water -1 The zero-valent iron (particle size is 3 microns), the mass ratio of zero-valent iron to Se is about 25:1, pH=5.0, the magnetic field used is an alternating magnetic field, and the magnetic field strength is about 0.2~10 mT. In the presence of a magnetic field, zero-valent iron can remove more than 99% of Se(IV) within 0.25 h. In the absence of a magnetic field, when the initial Se(IV) concentration was reduced to 9.55 mg L -1 , even if the reaction is 2 h, only about 25% of Se(IV) can be removed. see details figure 2 .

specific Embodiment approach 3

[0027] Specific embodiment three: a kind of magnetic field strengthening zero-valent iron in this embodiment removes the method for Se(IV) / Se(VI) in water is in complete mixing reactor, to containing 39.58 mg L -1 Add 1 g L of Se(IV) to the water -1 The zero-valent iron (particle size is 3 microns), the mass ratio of zero-valent iron to Se is about 25:1, pH=6.0, the magnetic field used is an alternating magnetic field, and the magnetic field strength is about 0.2~10 mT. In the presence of a magnetic field, zero-valent iron can remove more than 98% of Se(IV) within 1 h. In the absence of a magnetic field, when the initial Se(IV) concentration was reduced to 9.99 mg L -1 , even if the reaction is 2 h, only about 26% of Se(IV) can be removed. see details image 3 .

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Abstract

The invention relates to a method for removing Se(IV) / Se(VI) from water by magnetic field enhanced zero-valent iron and relates to a water and waste water treatment method. The method solves the problems of low reaction speed of the conventional micron-sized zero-valent iron / iron scrap and the Se(IV) / Se(VI), low removal efficiency, narrow pH application range and short life of the zero-valent iron. The method adopts the following modes: (1) a stationary bed mode: applying magnetic field at the periphery of the zero-valent iron stationary bed and allowing the Se(IV) / Se(VI)-containing water to pass through the zero-valent iron stationary bed to be purified; and 2) a completely mixed reactor mode: adding a certain amount of zero-valent iron in the Se(IV) / Se(VI)-containing water, magneticallystirring or externally applying the magnetic field to realize quick reaction of the micron-sized zero-valent iron / iron scrap and the Se(IV) / Se(VI) so as to purify the water. According to the method, the magnetic field can inhibit generation of a zero-valent iron passivation film, the mass transfer speed of the Se(IV) / Se(VI) and the micron-sized zero-valent iron / iron scrap is increased and the removal efficiency of the micron-sized zero-valent iron / iron scrap on the Se(IV) / Se(VI) is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of water treatment, relates to a method for treating water and waste water, in particular to a method for removing Se(IV) / Se(VI) from water by strengthening zero-valent iron with a magnetic field. Background technique [0002] In water bodies, there are two sources of selenium: First, individual water bodies flow through formations with high selenium content, resulting in excess selenium in groundwater or spring water. In general natural water, there are hexavalent and tetravalent selenium, most of which are in Below, but due to the pollution of water rich in selenium, the selenium content can seriously exceed the standard (national drinking water quality standard ). Second, selenium in water comes from industrial pollution, which is also the main source of selenium in water. According to the survey, selenium-containing wastewater mainly comes from smelting selenium-containing metal ores, oil refining, ...

Claims

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Application Information

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IPC IPC(8): C02F1/48C02F1/70C02F1/58
Inventor 关小红梁丽萍
Owner TONGJI UNIV
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