Electrolysis: processes – compositions used therein – and methods – Electrolytic material treatment – Organic
Reexamination Certificate
1999-06-30
2001-08-28
Phasge, Arun S. (Department: 1741)
Electrolysis: processes, compositions used therein, and methods
Electrolytic material treatment
Organic
C205S746000, C205S466000
Reexamination Certificate
active
06280600
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of decomposing composing an organic chemical such as a phenol contained in water.
2. Description of the Related Art
It has been reported in recent years that certain organic chemicals, e.g., p-tertiary butyl phenol, bisphenol A, etc. act as endocrine-disrupting chemicals. These endocrine disrupters are known as being related to serious human and animal health problems and as having special undesirable effects on the environment.
There have heretofore been available various processes of decomposing or removing organic chemicals contained in water. These processes include an adsorption process using activated carbon or the like, an ultrafiltration process, and a distillation process. Another process which has recently attracted attention in the art employs a photocatalyst of titanium oxide.
The adsorption process is disadvantageous in that it can remove only a limited range of organic chemicals. The ultrafiltration process fails to separate low-molecular-weight compounds from water because they pass together with water through the ultrafiltration membrane, though the process is capable of removing high-molecular-weight compounds from water. The distillation process is effective to remove organic substances from water to a certain extent because it relies upon different boiling points thereof. However, the distillation process cannot remove those organic substances completely from water, and requires a great amount of energy as it heats water that contains organic substances. Although the recent process which employs the titanium oxide photocatalyst is able to decompose almost all organic substances with the strong oxidizing power of the photocatalyst, the process fails to process a large quantity of organic substances because it requires irradiation with ultraviolet light.
Consequently, it has been desired in the art to develop a process of easily decomposing organic substances such as endocrine disrupters.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method of easily decomposing organic substances contained in water.
Generally, it is known that hydroxyl radicals (.OH) have a strong oxidizing ability and a strong sterilizing ability. For example, it has been reported that many organic substances are oxidized by hydroxyl radicals which are formed on the surface of a titanium oxide photocatalyst upon exposure to light. The hydroxyl radicals have a very short lifetime, generally in microseconds.
The inventor has proposed a method of producing electrolyzed water containing hydrogen peroxide by supplying a first electrolytic chamber which houses an anode plate and a cathode plate with an ion-permeable membrane interposed therebetween, with raw water containing an electrolyte as chloride ions, electrolyzing the raw water, and electrolyzing only electrolyzed water obtained at the cathode side in the first electrolytic chamber, at an anode side in a second electrolytic chamber which houses an anode plate and a cathode plate with an ion-permeable membrane interposed therebetween. For details, reference should be made to Japanese patent application No. 9-271245. The inventor has studied the electrolyzed water produced by the above method, and found that the electrolyzed water produces hydroxyl radicals successively, so that the hydroxyl radicals have an apparent long lifetime. The inventor has completed the present invention based on the above finding.
According to a first aspect of the present invention, there is provided a method of decomposing an organic substance, comprising the steps of supplying a first electrolytic chamber which houses an anode plate and a cathode plate with an ion-permeable membrane interposed therebetween, with raw water containing an electrolyte as chloride ions, electrolyzing the raw water, electrolyzing only electrolyzed water obtained at a cathode side in the first electrolytic chamber, at an anode side in a second electrolytic chamber which houses an anode plate and a cathode plate with an ion-permeable membrane interposed therebetween, for thereby generating hydroxyl radicals in the electrolyzed water, adding the electrolyzed water containing the hydroxyl radicals to water containing an organic substance to cause the hydroxyl radicals to attack to the organic substance for thereby decomposing the organic substance.
According to the first aspect, the raw water containing the electrolyte is supplied to the first electrolytic chamber and then electrolyzed. Thereafter, only the electrolyzed water obtained from the cathode side in the first electrolytic chamber is electrolyzed at the anode side in the second electrolytic chamber which is identical in structure to the first electrolytic chamber, for thereby obtaining electrolyzed water containing hydroxyl radicals. Though hydroxyl radicals have a short lifetime as microseconds, since hydroxyl radicals are produced successively by the method according to the first aspect, the hydroxyl radicals have an apparent long lifetime of several hours after the electrolyzed water is produced.
The electrolyzed water containing the hydroxyl radicals is then added to water containing an organic substance. The hydroxyl radicals attack to the organic substance for thereby decomposing the organic substance with a strong oxidizing capability of the hydroxyl radicals.
According to a second aspect of the present invention, there is provided a method of decomposing an organic substance, comprising the steps of preparing raw water by adding an electrolyte as chloride ions to water containing an organic substance, supplying the raw water to a first electrolytic chamber which houses an anode plate and a cathode plate with an ion-permeable membrane interposed therebetween, electrolyzing the raw water, electrolyzing only electrolyzed water obtained at a cathode side in said first electrolytic chamber, at an anode side in a second electrolytic chamber which houses an anode plate and a cathode plate with an ion-permeable membrane interposed therebetween, for thereby generating hydroxyl radicals in the electrolyzed water, and causing the hydroxyl radicals to attack to the organic substance contained in the raw water for thereby decomposing the organic substance.
According to the second aspect, raw water is prepared by adding the electrolyte to water containing an organic substance, rather than adding electrolyzed water containing the hydroxyl radicals to water containing an organic substance. The raw water is supplied to the first electrolytic chamber and then electrolyzed. Thereafter, only the electrolyzed water obtained from the cathode side in the first electrolytic chamber is electrolyzed at the anode side in the second electrolytic chamber which is identical in structure to the first electrolytic chamber. Hydroxyl radicals are produced in the second electrolytic chamber, these radicals attack to the organic substance contained in the raw water, at the same time, an electro-chemical reaction of the organic substance occurs in an electrode surface, various of reaction carried out in the system. As a result, the organic substance is decomposed.
In each of the above aspects of the present invention, since the chloride is used as the electrolyte, when the raw water containing the electrolyte is electrolyzed, oxygen, hydrogen peroxide, hydroxyl radicals, chlorine, and hypochlorous acid are generated at the anode side in the second electrolytic chamber. It is presumed that of these substances, hydrogen peroxide and chlorine, or hypochlorous acid is involved in the successive production of the hydroxyl radicals.
The chloride may be sodium chloride (NaCl) or potassium chloride (KCl), for example.
The methods according to the above aspects of the present invention are effective to decompose an aromatic compound, which is generally known as not being easily decomposable. For example, the methods are capable of decomposing a phenol shown by the following formula (1):
In the formula (1), R may be a group which
Miyashita Kohichi
Muto Go
Nagano Keiji
Arent Fox Kintner & Plotkin & Kahn, PLLC
Honda Giken Kogyo Kabushiki Kaisha
Phasge Arun S,.
LandOfFree
Method of decomposing organic compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of decomposing organic compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of decomposing organic compounds will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2509679