JPS61209093A - Pretreatment of anaerobic treatment - Google Patents

Abstract

PURPOSE:To advance treatment efficiently, by grinding the solid substance contained in org. sewage so as to obtain an average particle size of 30mum or less. CONSTITUTION:A solid substance is ground so as to obtain an untreated group with a particle size of 500-1,000mum, a group with 50-100mum (ground by a homomixer), a group with 20-30mum, a group with 5-10mum and a group with 1-2mum on the basis of an average particle size. Anaerobic treatment is applied to these groups to enable the enhancement of treatment effect.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for efficiently proceeding anaerobic treatment of organic sewage by physically crushing solids in the organic sewage. This relates to a processing method.

[Conventional technology]

Anaerobic treatment is classified into anaerobic digestion method and anaerobic lagoon method. Of these, anaerobic digestion method is used to treat industrial wastewater with a high concentration of organic matter, such as alcohol distillation wastewater, hair washing wastewater, human waste, etc. There is.

Although the anaerobic digestion method has the advantage that the sludge produced can be used as organic fertilizer and there are no hygiene problems, it unfortunately still has unresolved problems such as the long processing time required. .

Therefore, in order to solve the above-mentioned problems, extensive research is being continued from various directions, and one of the results of this research is the method disclosed in Japanese Patent Publication No. 1319/1983. . This method performs anaerobic digestion (1
) The decomposition process involves adding alkali to organic waste and heat-treating it, (2) the liquefaction process involves bringing the decomposed slurry into contact with liquefaction bacteria, and (3) the gasification process involves bringing the liquefied slurry into contact with a gasification garden. By allowing the anaerobic digestion to proceed, it helps to improve the efficiency of the anaerobic digestion and shorten the time required for processing, but the point is that it was studied from the standpoint of understanding the anaerobic digestion reaction itself and trying to adjust it. It is.

By the way, when performing such anaerobic treatment, it is common to carry out the treatment while stirring the inside of the treatment tank. This stirring operation is performed to remove organic matter from organic wastewater in order to further improve the anaerobic treatment efficiency.

The main purpose is to uniformly disperse solids, anaerobic digestion, etc. in the treatment tank.

[Problem that the invention seeks to solve]

However, in the above-mentioned general stirring operation, the effect of pulverizing organic substances and solid substances into finer particles is not achieved, so the organic substances and solid substances are merely mixed and dispersed. Even if the above-mentioned stirring is performed, the contact relationship between the organic matter and the anaerobic digestive bacteria that digest it is not necessarily guaranteed effectively, and it is difficult to combine it with the fl improvement method as disclosed above. Even if it were, the current situation is that it has not yet reached the point where it has achieved the expected effect of improving processing efficiency. Under these circumstances, the emergence of a new method that would ensure reliable and effective contact between the organic matter in organic wastewater and the anaerobic bacteria that digest it has been awaited.

The present invention was made in consideration of these circumstances, and it improves the efficiency of anaerobic treatment by physically crushing solids in organic wastewater to ensure effective contact between organic matter and anaerobic digestive bacteria. The aim is to improve the

[Means for solving problems]

However, the gist of the pretreatment method for anaerobic treatment according to the present invention lies in pulverizing the solids contained in organic wastewater to an average particle size of 30 μm or less.

[Effect]

Next, we will clarify the structure, operation, and effects of the present invention while tracing the process that led to the completion of the present invention.

The present inventors have been conducting research for many years not only with the aim of improving the efficiency of anaerobic digestion but also with water treatment in general. I learned that pulverization can greatly improve the processing efficiency. Now, the next issue is how to set the degree of pulverization, in other words, the preferred size of the solid material. Therefore, in order to specify the degree of pulverization,
The degree of pulverization was adjusted by changing the pulverization means, and various organic wastewaters with different solid particle sizes (treated as average particle sizes) were used. After studying the treatment efficiency of anaerobic digestion and conducting further intensive research, the present invention was completed.

The circumstances during this time will be explained in more detail.

The present inventors have determined that the average particle diameter is (1) 500-10
00 μm untreated group, (2350-100 μm group (same as below 2 crushed with homomixer), (3) 20-30 μm
Group, (4) 5-10 μm group, and (5) 1-2 μm group were prepared and subjected to anaerobic treatment, and as is clear from Table 1 below, the average particle size was 20-30 μm. It was found that the anaerobic treatment efficiency of the pulverized material was dramatically improved compared to that of the pulverized material to a size of 50 to 100 μm. Inferring from this knowledge, we have come to the conclusion that the treatment efficiency can be improved by pulverizing the solids of organic wastewater to approximately 30 μm or less. 3 solid foods
When the diameter is 0 μm or less, the surface area of the solid material increases, which increases the number of active areas for anaerobic digestive bacteria, which is thought to ultimately improve the anaerobic treatment efficiency as a whole.

Furthermore, during this pulverization, enzymes such as proteases and cellulases that are bound in the solids and anaerobic digestive bacteria are partially released, and as a result, carbohydrates and proteins in the wastewater are digested, which also improves the treatment efficiency. This is thought to be a contributing factor.

Focusing on such enzymatic action, treatment efficiency can be further improved by actively adding enzymes such as protease and cellulase before and after anaerobic treatment. The enzyme referred to herein may be any enzyme, including cellulase and protease, as long as it decomposes carbohydrates, proteins, lipids, etc. contained in organic wastewater.

The present invention will be made clearer by describing examples below.

〔Example〕

Using shochu distillation waste liquid, this was (1) a target group (untreated group), and (2) the shochu distillation waste liquid was mixed with a homomixer [manufactured by Tokushu Kika Kogyo Co., Ltd., type: HV-M type]. A group that was agitated and pulverized at aooorpm for 2 minutes, (3) a group that was agitated and pulverized at 3QQQrpm for the same 3 minutes, (4) a group that was agitated and pulverized at 3000 rpm for 6 minutes, and (5) a group that was agitated and pulverized at aooorpm for 15 minutes. Roughly divided into two parts: BOD: 297571v//i', COD: 1
2937 da/l, 55230807 da/1. The total organic matter content was 56,681 M1/l), and was investigated as follows.

When anaerobic treatment was performed using the shochu distillation waste liquid 51 from (1) to (5) above, the results shown in Table 1 were obtained. However, total organic matter amount: 17 g/day addition, BOD: 8.94
The conditions were as follows: addition: g/day, volumetric load: 1.44 kQ/day. In particular, the relationship between the number of processing days and the amount of gas generated is shown in diagram VJ1.

As is clear from Table 1 and FIG. 1, the A3 to &5 groups had better results than the &1 and &2 groups in terms of both COD and gas generation.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to improve the efficiency of anaerobic treatment of organic wastewater.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the number of processing days and the amount of gas generated.

Claims (1)

[Claims] The average particle size of solids contained in organic wastewater is 30μ.
A pretreatment method for anaerobic treatment, characterized by pulverizing it to a size of less than m.