JP2013184107A - Method for solubilizing wastewater containing used tea leaf - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently solubilizing, particularly, used tea leaves in biomass waste.SOLUTION: An enzyme treatment liquid mainly composed of pectinase and protease is added to wastewater containing used tea leaves. The enzyme treatment liquid further contains cellulase.

Description

  The present invention relates to a method for solubilizing teacup-containing wastewater discharged from a beverage factory or the like.

  A large amount of biomass waste such as teacups is generated from beverage factories. Conventionally, most of such waste is composted or incinerated.

  In composting, it is difficult to secure a large site and a stable receiving place for composting biomass waste generated in large quantities every day. In incineration treatment, biomass waste contains water, so a large amount of energy for incineration is required, and dioxins may be generated due to incineration with other waste. From the point of view, it is not preferable. For this reason, improvement is required for the treatment of biomass waste.

  Therefore, attention has been paid to the features that these biomasses are discharged in a stable amount from the factory, that they are discharged separately from other general waste, and that the quality is stable with no contamination from foreign matter, and that there is less odor. However, in response to the recent increase in the concept of combined effective treatment of waste such as zero emission, a more efficient treatment method is being sought. For example, research has been conducted on reuse such as a treatment method in which waste is mixed with raw garbage and composted, or a reuse treatment method in which carbonization is used as activated carbon (for example, Patent Document 1).

  In addition, attempts have been made to obtain methane gas by subjecting such waste to methane fermentation (for example, Patent Document 2).

Japanese Patent Laid-Open No. 2003-325044 Japanese Patent Laid-Open No. 2007-326070

  Such waste is characterized by its hard solid components and difficulty in biodegradation, and how to make such waste solubilized and ready for methane fermentation is a major issue. It was.

  Therefore, in view of the above situation, the present invention aims to provide a method for efficiently solubilizing teacups by focusing on teacups among the biomass wastes.

Based on the fact that the main component of the material constituting the teacup is cellulose, when the teacup is solubilized, an enzyme treatment solution containing cellulase as a main component is generally added to the material constituting the teacup. Although it is conceivable to reduce the molecular weight of the components, as a result of studies conducted by the present inventors, it has become clear that this method is not very effective. Therefore, as a result of intensive studies by the present inventors, it was newly clarified that an enzyme treatment solution containing pectinase and protease as main components is effective for solubilization of teacups. The present invention is based on this new finding.
[Configuration 1]
The characteristic configuration of the present invention for achieving the above object is that an enzyme treatment liquid mainly composed of pectinase and protease is added to teacup-containing wastewater.
[Operation effect 1]
The present inventors have found that the constituent material of the tea bowl contains cellulose and lignin in 60% (mass%, the same applies hereinafter) or more, whereas the protein component also contains about 40%. It is predicted that there is a possibility that degradation and molecular weight reduction by protease as well as degradation by molecular weight by protease may be effective, and attention is paid to the fact that about 3.3% of pectin in protein components is included. However, we also examined pectinase and conducted a solubilization test of teacups under various conditions. Surprisingly, it was found that when pectinase was used, it showed significantly higher solubilizing ability than using cellulase. .

  That is, it was clarified that the enzyme that should be used most preferentially in the solubilization of teacups is pectinase and then protease. And it was clarified that the enzyme treatment liquid containing these two components as main components is effective in achieving a very high solubilization rate. In other words, it has been found that the addition of an enzyme treatment solution containing pectinase and protease as main components enables solubilization of the teacup and efficient execution of methane fermentation.

  In addition, in the present invention, when it is referred to as “main component”, it may contain other active ingredients, but means that it is contained as an ingredient that works better for solubilization than other ingredients, It should just be contained as a component which mainly functions irrespective of a content rate.

[Configuration 2]
Moreover, it is preferable that the said enzyme treatment liquid contains a cellulase further.

[Operation effect 2]
Further, according to an additional experiment, according to the enzyme treatment liquid containing cellulase, pectinase, and protease, it can be clarified that most of the components of the tea bowl can be efficiently decomposed. It was found that methane fermentation can be performed while solubilizing tea bowls very efficiently.

  Therefore, it becomes possible to solubilize tea bowls and perform methane fermentation very efficiently, and conventionally, when processing tea bowls, it is necessary to use large-scale solubilization tanks and methane fermentation tanks. As a result, tea can be solubilized in a compact and energy-saving manner, and methane fermentation becomes possible, so it can be said that it is extremely useful from the viewpoint of efficient treatment of waste.

  Below, the solubilization method of the teacup containing waste water of this invention is demonstrated. In addition, although suitable examples are described below, these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

[Method of solubilizing teacup-containing wastewater]
The method for solubilizing teacup-containing wastewater according to the present invention includes a step of adding an enzyme treatment liquid mainly composed of pectinase and protease to a storage tank for temporarily storing teacup-containing wastewater discharged from a beverage factory or the like. It is. The teacup-containing wastewater to which the enzyme treatment liquid has been added is solubilized in the storage tank and then subjected to methane fermentation in a methane fermentation tank.

  The enzyme treatment liquid contains pectinase and protease as main components, and may further contain cellulase or other components.

[Solubilization test with enzyme treatment solution]
The efficiency of the reaction of adding various enzymes to teacup-containing wastewater was investigated.
In the test, the degree of increase in COD was determined by sequentially adding various enzymes to teacup-containing wastewater, and the solubilizing ability of the enzyme was evaluated.

  1.5 g of dried teacup (water content 10%) was added to 50 ml of 50 mM phosphate buffer (pH 7.0) to obtain teacup-containing wastewater. Cellulase, amylase, protease, hemicellulase, lipase, and pectinase were sequentially added to this teacup-containing wastewater.

  The enzyme to be added is a commercially available enzyme solution. The solubilization reaction was carried out overnight by adding 4.5 μl of the enzyme and in a shaking incubator at 50 ° C. and 150 rpm. After the reaction, the COD of the incubator was measured, and an enzyme was added in order to perform a solubilization reaction. The properties of the enzyme solution are shown in Table 1 below, and the test results are shown in Table 2.

  “Cumulative use” in Table 2 is the test result in a state where enzymes are sequentially added in the order described (for example, 1204 in the above table is solubilized by adding cellulase to teacup-containing wastewater. This shows the COD measurement result when the amylase was added and the solubilization test was performed overnight after the test was conducted overnight.) “Additional effect” indicates the amount of COD by the cumulatively used enzyme. The test result obtained for the COD increased by the newly added enzyme. (For example, in the above table, +3310 is a numerical value obtained from 4514-1204, and protease is further added to the COD produced in the solubilization test in which cellulase and amylase are added to the wastewater containing teacup. This corresponds to the newly increased COD amount when the solubilization test is performed.)

  As a result of performing solubilization performance with cellulase as a base enzyme and sequentially adding the above-mentioned enzymes, the addition of amylase and lipase did not contribute much to the increase in COD, but the addition of protease and pectinase As a result, it was found that the addition of protease and pectinase is effective for solubilization of teacups. (Final solubilization rate of 78%)

  Moreover, when the enzyme activity of each enzyme alone was examined after the above test, it was as shown in Table 3.

From Table 3, it was found that pectinase alone exhibited extremely high solubilizing ability compared to cellulase, and corresponded to the results in Table 2. In addition, it is clear that proteases also exhibit higher solubilizing ability than cellulase, and when compared with Table 2, these enzymes do not interfere with each other and efficiently solubilize teacups. Can also be read. (Fermentation inhibition occurs between amylase and cellulase, and the action of lipase overlaps with cellulase and protease, and the additional effect is considered to be lower than the single use effect.)
Cellulase also showed high activity following the addition of protease and pectinase, and it was confirmed that when used together with protease and pectinase, it contributes to highly efficient solubilization.

  Therefore, as proposed in the present application, it is preferable that the addition of an enzyme treatment liquid mainly composed of pectinase and protease to the teacup-containing wastewater greatly contributes to the solubilization of the teacup and further preferably contains cellulase. all right.

  According to the present invention, tea can be solubilized in a compact and energy-saving manner, and methane fermentation can be performed, so that waste can be efficiently processed.

Claims (2)

  A method for solubilizing teacup-containing wastewater, comprising adding an enzyme treatment solution containing pectinase and protease as main components to teacup-containing wastewater.   The method for solubilizing teacup-containing wastewater according to claim 1, wherein the enzyme treatment liquid further contains cellulase.