JPH06277693A - Treatment process for high concentration alkali waste water - Google Patents

Abstract

PURPOSE:To provide a highly alkaline waste water treatment process for treating highly alkaline waste water drained from a food plant or the like without the preliminary pretreatment such as dilution and neutralization. CONSTITUTION:Alkali waste water is treated by coloring at least one root of anyone of alkaline bacteria HY-5125, bacillus sp. HY-256 and bacillus sp. HY-333 in alkali waste water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention utilizes alkaline bacteria to neutralize or dilute alkaline wastewater in order to compactly treat highly concentrated alkaline wastewater discharged in the food industry and the like. It relates to a method for treating wastewater with high concentration or high alkali.

[0002]

BACKGROUND ART It is said that an activated sludge treatment method is generally suitable for treating wastewater in the food industry, and this method has been used conventionally. In order to maintain stable activated sludge treatment, the liquid supplied to the activated sludge tank is neutral and the biochemical oxygen demand (BOD) is about 2,000 mg /
It is said that it is preferable to adjust it to 1 or less.

Therefore, in order to carry out the high-concentration alkaline wastewater discharged in the food industry etc. by the conventional activated sludge treatment method, it is necessary to neutralize it to near neutrality in advance, and the concentration suitable for the activated sludge treatment. The process of diluting to 1 is essential.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a high-concentration alkaline wastewater capable of compacting the wastewater treatment apparatus by omitting the neutralization step and the dilution step of the high-concentration alkaline wastewater by using alkaline bacteria. It provides a processing method.

[0005]

In order to solve the above problems, the present invention provides three types of alkaline bacteria HY-512.
5, Bacillus sp. HY-256 and Bacillus sp. HY-
A method for treating high-concentration alkaline wastewater, which is characterized by using one or more kinds of 333. Properties of High Concentration Alkaline Wastewater As shown in Table 1 below as an example, the high concentration alkaline wastewater is a high concentration alkaline wastewater having a high pH, a high alkalinity and a high BOD.

[0006]

[Table 1]

Properties of alkaline bacteria To obtain microorganisms suitable for treating highly concentrated alkaline wastewater,
From the preserved bacteria, the soy sauce factory, and thousands of strains isolated from the natural world, bacteria that grow well in highly concentrated alkaline wastewater under aerobic conditions were selected, and 3 strains were obtained. Morphological, physiological and chemotaxonomic properties of these strains are shown in Tables 2 to 7.

[0008]

[Table 2]

[0009]

[Table 3]

[0010]

[Table 4]

[0011]

[Table 5]

[0012]

[Table 6]

[0013]

[Table 7]

Identification of Alkaline Bacteria The HY-256 and HY-333 strains were identified as Bacillus sp. By classification according to the Volume 2 of the Barge Manual of Systematic Bacteriology. That is, both strains were found to be aerobic, Gram-staining positive, Bacillus, and spore-forming in the genus Bacillus, and then were positive for catalase, negative for VP reaction, positive for gelatin liquefaction, and unable to grow under anaerobic condition. Due to various properties such as inability to grow in the presence of 7% sodium chloride and inability to grow at pH 5.7, Bacillus
It is considered to be a relative of Bacillus, but the acid production from sugar was weak, so it could not be identified.
sp.

The HY-5125 strain was classified according to the Volume 2 of Barge Manual of Systematic Bacteriology and was found to be aerobic Gram-positive cocci and intracellular DN.
Since the GC content of A was 50 mol%, it was considered to be a bacterium belonging to the genus Planococcus ( Planococcus ), but its properties such as motility were different and it could not be identified. HY-5
Table 8 shows the difference in properties between the 125 strains and the genus Planococcus.

[0016]

[Table 8]

Bacillus sp. HY-256 has been deposited as FERM P-13418 at the Patent Microorganism Depositary Center, Institute of Microbial Technology, Institute of Industrial Technology, Ministry of International Trade and Industry, and Bacillus sp. HY-333 has been deposited as FERM P-13419. HY-5125 is FERM P-134
Deposited as 20. The treatment of the highly concentrated alkaline wastewater of the present invention is carried out by aerobically culturing at least one strain of the above-mentioned alkaline bacteria in the wastewater to be treated.
At the beginning of wastewater treatment, a relatively small amount of suitable medium,
For example, a highly concentrated alkaline wastewater is inoculated with the strain and aerobically cultured to prepare an inoculum. This inoculum is then added to the wastewater to be treated and aerobically cultivated. Aerobic culture can be carried out by aeration, as in the case of the usual activated sludge method.

The waste liquid treatment can be carried out batchwise, but by removing most of the treated waste water but adding new waste water to the remaining treated waste water,
Alternatively, it is possible to carry out stepwise or semi-continuously by taking out a part of the wastewater during or after the treatment and adding it to a new wastewater to be treated. Alternatively, it is also possible to carry out a continuous process by continuously adding a new waste liquid to be treated while continuously taking out the treated liquid in one treatment container. In addition, the bacterial cells separated and collected after the treatment can also be recycled.

[0019]

EXAMPLES Next, the present invention will be described more specifically by way of examples. Example 1 . Highly concentrated alkaline wastewater due to alkaline bacteria
Treatment 1) Method for measuring the amount of bacterial cells 20 ml of the culture solution is collected and centrifuged at 18,000 g for 10 minutes. The precipitated portion is mixed and washed with pure water and centrifuged twice, and the final precipitated portion is dried at 105 ° C. for 2 hours and weighed. This amount was defined as the bacterial cell amount (mg).

2) TOC measuring method T of the original liquid was measured by Shimadzu total organic carbon meter TC-5000.
The TOC of the supernatant after bacterial culture was subtracted from OC (total organic carbon) and divided by the TOC of the original solution to obtain the TOC removal rate. 3) Inoculum culture The separated alkaline bacteria were pre-cultured at 30 ° C for 3 days in a medium sterilized by adding 10 ml of high-concentration alkaline waste water to an 18 mm diameter test tube in advance.

4) Treatment of highly concentrated alkaline waste water 100 ml of highly concentrated alkaline waste water in a 500 ml Sakaguchi flask
Was added and the mixture was sterilized by autoclaving at 121 ° C. for 10 minutes. This was added to any Sakaguchi flask so that the total amount of the preculture liquid added was 5 ml. The culture was carried out at 30 ° C. for 3 days with shaking to treat high-concentration alkaline wastewater. Then, the bacterial cell amount, turbidity, and TOC reduction rate were measured.

As the strain, HY-5125, Bacillus s
p. HY-256 and Bacillus sp. HY-333, as well as 3 strains, No. 8 and No. 5414 were used, and treatment was performed in consideration of combinations of all 5 strains. The results are shown in Table 9, and when three strains were used, HY-5125 and Bacillus
It has been shown to be effective to use p. HY-256 and Bacillus sp. HY-333.

[0023]

[Table 9]

Example 2 By activated sludge and alkaline bacteria
Continuous treatment of high-concentration alkaline wastewater using a plant-scale wastewater treatment device with activated sludge bacteria and alkaline bacteria As a result of continuous treatment of high-concentration alkaline wastewater with activated sludge bacteria and alkaline bacteria, the treatment results in Table 10 Got BOD volume load 9 kg-BOD / m ³ ·
In the case of D, the treating ability of the alkaline bacteria was superior to that of the activated sludge bacteria.

[0025]

[Table 10]

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Claims (1)

[Claims] 1. HY of alkaline bacteria in alkaline wastewater
-5125, Bacillus ( Bacillus ) sp. HY-256, and Bacillus sp.