Anion adsorbing carbon material, as well as manufacturing method and manufacturing facilities for same

Abstract

This invention provides an anion adsorbing carbon material which is inexpensive, environmentally friendly and excellent in the anion adsorption, as well as a manufacturing method and a manufacturing facilities for the same. This invention is characterized in that a raw material which comprises plant(s) is contacted with a solution including calcium ions, and after that, carbonized, and subsequently, contacted with an acid solution.

Description

TECHNICAL FIELD [0001] This invention relates to an anion adsorption carbon material for adsorbing anions such as nitrate ions and fluoride ions, as well as a manufacturing method and a manufacturing facilities for the same. BACKGROUND ART [0002] Contamination of a water quality and soil by heavy metals, agricultural chemicals and an organochlorine compounds has become a problem in that it destroys the environment. Though these harmful substances can be adsorbed and removed with adsorbents such as activated carbon and a zeolite, it is presently difficult to treat nitrate nitrogen, nitrite nitrogen, fluorine, arsenic and cyan which exist in the form of anions with adsorbents. [0003] That is to say, nitrate nitrogen and nitrite nitrogen are included in fertilizers used in tea fields, turfs for golfing and the like, and have become a factor in ground water contamination, which is presently a large problem. This is because nitrate ions and nitrite ions have negative charge and do not be...

AI Technical Summary

Benefits of technology

[0061] In the invention according to any of claims 1 to 3, a raw material which comprises plant(s) is contacted with a solution including calcium ions, and after, that, carbonized, and subsequently, was contacted with an acid solution, a raw material which comprises plant(s) which has contacted with a solution including calcium ions is carbonized, and this carbonized material is contacted with an acid solution, or a carbonized material gained by carbonizing a raw material which comprises plant(s) which has contacted with a solution including calcium ions is contacted with an acid solution, and therefore, an anion adsorbing carbon material having anion adsorbing properties equal or superior to those of an anion exchange resin can be gained by setting an appropriate temperature for carbonization. In addition, an anion adsorbing carbon material manufactured in accordance with the above described manufacturing method for an anion adsorbing carbon material has a material originating from plant(s) as a main body and is environmentally friendly.

[0062] In the invention according to any of claims 4 to 8, an anion adsorbing carbon material having anion adsorbing properties which are equal or superior to those of an anion exchange resin can be gained. Furthermore, this anion adsorbing carbon material has a raw material which comprises plant(s) as a main body and is environmentally friendly.

[0063] In addition, in the invention according to claim 9, an anion adsorbing carbon material which can be repeatedly restored for use can be gained.

[0064] In addition as described in claim 10, the adsorbed anions are removed from the above described anion adsorbing carbon material, and anions which can be ion exchanged with anions that are the next object of adsorption are combined with the above described anion adsorbing carbon material in place of the above described removed anions, and thereby, the above described anion adsorbing carbon material can be repeatedly restored for use.

[0065] In the invention according to claim 11, a carbonization apparatus for carbonizing a raw material which comprises plant(s) and an apparatus for contacting a carbonized material which has been created in this carbonization apparatus with an acid solution are provided, and therefore, an acid solution can contact with the walls of the micro pores in the carbonized material, and thus, anions which can be ion exchanged with anions that are the object of adsorption can be combined with the functional groups which have formed on the walls of the above described micro pores.

[0066] In addition, in the invention according to claim 12, an apparatus for contacting a raw material which comprises plant(s) with a solution including calcium ions, a carbonization apparatus for carbonizing the above described material after it has been contacted with the solution, and an apparatus for contacting a carbonized material which has been created by this carbonization apparatus with an acid solution are provided, and therefore, an acid solution can contact with the walls of the micro pores of a carbonized material, and anions which can be ion exchanged with anions that are the object of adsorption can be combined with the functional groups which have been drawn out from and formed on the walls of the above described micro pores directly or via calcium ions.

Problems solved by technology

Contamination of a water quality and soil by heavy metals, agricultural chemicals and an organochlorine compounds has become a problem in that it destroys the environment.

Though these harmful substances can be adsorbed and removed with adsorbents such as activated carbon and a zeolite, it is presently difficult to treat nitrate nitrogen, nitrite nitrogen, fluorine, arsenic and cyan which exist in the form of anions with adsorbents.

That is to say, nitrate nitrogen and nitrite nitrogen are included in fertilizers used in tea fields, turfs for golfing and the like, and have become a factor in ground water contamination, which is presently a large problem.

Thus, though measures against the above described problem are r there are limitations, such that anaerobic conditions are required in biological treatment where, for example, denitrifying bacteria are used to remove nitrate ions and nitrite ions, and in addition, there are similar limitations with other methods, and no effective measures have been found.

In addition, fluorine is included in wastewater from semiconductor factories, glass factories, plating factories and the like, and though a method for adding calcium compounds to fluorine in industrial wastewater so that the fluorine can be removed in the form of calcium fluorine is used, further installation of adsorption towers having an anion exchange resin for active alumina and fluorine is required, raising the cost.

In addition, expensive dedicated anion exchange resins are required in order to meet the Japanese environmental standard of 0.8 mg / L.

Furthermore, expensive anion exchange resins are separately required for treating arsenic, cyan and the like, which are included in industrial wastewater and ground water.

As described above, no inexpensive material for adsorbing anions including nitrate ions as that described above have been found at present, and therefore, contamination by these anions tends to sped, and once the environment is contaminated by anions as described above, high cost becomes necessary to restore it.

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