JP2007330931A - Organic waste-treating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic waste-treating method which makes the effective use of a waste liquid, which is obtained by hydrothermally treating organic waste, and eliminates the use of diluent water to realize the saving of resources and a reduced load on a sewage treatment plant. <P>SOLUTION: A solid-liquid mixture treated material 4, which contains a solid carbide, is obtained by hydrothermally treating organic waste 1, 2 such as tofu lees and waste paper, and the solid-liquid mixture treated material 4 is filtrated through a filtration part 5 having a tar-catching function to take out a liquid part 6 which contains no tar, and then the obtained liquid 6 is subjected to methane fermentation. The filtration part 5 is preferably provided with a cellulose-based membrane as the tar-catching means, and, preferably, the used cellulose-based membrane, which has been used to catch tar, is hydrothermally treated together with the organic wastes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for treating organic waste.

As shown in FIG. 2, by processing organic waste such as okara 56 and waste paper 57 with a hydrothermal treatment device 51, a solid-liquid mixed processed product 52 containing solid carbide is obtained. Research is being conducted in which the solid carbide 54 is taken out through a metal filter provided in the solid-liquid separation unit 53 and the solid carbide 54 is used in various ways.
JP 2003-300909 A

  By the way, about the waste liquid 55 which passed the metal filter of the solid-liquid separation part 53, even if methane fermentation is carried out, the yield of methane is low. Therefore, the waste liquid 55 may be diluted below the drainage standard and discharged into the sewer. It is considered as the first choice for waste liquid treatment.

  However, there is a problem that a large amount of diluted water is required for draining into the sewer, and the load on the sewage treatment plant is increased.

  In view of the above problems, the present invention can effectively use waste liquid obtained by hydrothermal treatment of organic waste, and at the same time, saves resources by eliminating the use of diluted water and reduces the load on the sewage treatment plant. It is an object of the present invention to provide a method for treating organic waste that can realize the above.

  In the present invention, the cause of the low methane yield by methane fermentation is that the methane fermentation bacteria dislikes the tar content mixed in the waste liquid (the one that has been subjected to hydrothermal treatment of okara etc. to form a tar). A solid-liquid mixed treatment product containing solid carbide is obtained by subjecting organic waste to hydrothermal treatment, and the solid-liquid mixture treatment product is passed through a filtration unit with a tar content capturing function. The content of the organic waste treatment method is characterized in that a liquid portion not containing a portion is taken out and methane fermentation is performed using the obtained liquid (first invention).

  In this method, the liquid part not containing the tar content is taken out from the solid carbide-containing solid-liquid mixed product obtained by hydrothermal treatment, and methane fermentation is performed using the liquid, so the methane yield is high. Moreover, the waste liquid obtained by methane fermentation can be used as liquid fertilizer, and the waste liquid can be effectively utilized.

  And since what was used as waste liquid in this way can be used effectively, the resource saving by the use exclusion of dilution water and the load reduction of a sewage treatment plant are realizable.

  In the first invention, the filtration section may be provided with a cellulose membrane as a tar content capturing means, and the used cellulose membrane used for capturing the tar content may be hydrothermally treated with the organic waste (second invention).

  In this case, the cellulose film can be used as a tar content capturing means, so that the tar content can be effectively captured, and the used cellulose film can be used as a raw material for hydrothermal treatment as an organic waste. As a result, it is possible to effectively utilize this without being troubled by the processing of the used tar content capturing means.

  Since the present invention is as described above, the waste liquid obtained by hydrothermal treatment of organic waste can be used effectively, and at the same time, resources can be saved by eliminating the use of diluted water, and the load on the sewage treatment plant can be reduced. Can be realized.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  The method of the embodiment shown in FIG. 1 is a case where okara 1 and waste paper 2 are used as the organic waste, and when the organic waste 1 and 2 are treated with the hydrothermal treatment apparatus 3, A solid-liquid mixed processed product 4 containing solid carbide is obtained, and when the solid-liquid mixed processed product 4 is passed through a filtration unit 5 using a cellulose film as a tar content capturing means, a liquid portion 6 containing no tar content is taken out. It is. Methane fermentation is performed in the methane fermentation apparatus 7 using this liquid 6. From the liquid subjected to methane fermentation, the tar content disliked by the methane fermentation bacteria is removed by the cellulose membrane, so that methane 8 is obtained in a high yield. Moreover, the waste liquid 9 obtained by methane fermentation consists of what can be used as liquid fertilizer. Then, the used cellulose film having a tar content attached thereto in the filtration unit 5 is treated with the hydrothermal treatment apparatus 3 together with the other organic wastes 1 and 2 as used paper 2 as indicated by arrows.

  As described above, in the above method, the liquid portion 6 not including the tar content is taken out from the solid carbide-containing solid / liquid mixed processed product 4 obtained by hydrothermal treatment, and methane fermentation is performed using the liquid 6. In addition, the yield of methane 8 can be increased, the waste liquid 9 obtained by methane fermentation can be made into liquid fertilizer, the waste liquid generated by hydrothermal treatment can be used effectively, resource saving, sewage treatment plant It is possible to reduce the load of the used tar, and it is possible to effectively use this without being troubled by the processing of the used tar content capturing means.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the case where okara and waste paper are used as the organic waste is shown, but various organic substances such as raw garbage, cow dung and bran may be used. Moreover, there is no restriction | limiting in the use of the obtained solid carbide 10. Further, the solid-liquid separation obtained by the hydrothermal treatment may be such that the tar content of the waste liquid containing the tar content that has passed through the metal filter is captured by a tar content capturing means such as a cellulose membrane.

It is explanatory drawing which shows the processing method of embodiment. It is explanatory drawing which shows the processing method concerning background art.

Explanation of symbols

1 ... Okara (organic waste)
2 ... used paper (organic waste)
DESCRIPTION OF SYMBOLS 3 ... Hydrothermal treatment apparatus 4 ... Solid-liquid mixed processing product containing solid carbide 5 ... Filtration part with tar content capture function 6 ... Liquid not containing tar content 7 ... Methane fermentation equipment 8 ... Methane 9 ... Waste liquid (liquid fertilizer)

Claims (2)

  The organic waste is hydrothermally treated to obtain a solid-carbide-containing solid-liquid mixed treated product, and the solid-liquid mixed treated product is passed through a filtration unit with a tar content capturing function to extract a liquid portion not containing the tar content. A method for treating organic waste, wherein methane fermentation is performed using the obtained liquid.   The organic waste treatment method according to claim 1, wherein the filtration unit includes a cellulose film as a tar content capturing unit, and the used cellulose film used for capturing the tar content is hydrothermally treated together with the organic waste.

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