JPH0295496A - Treatment of water with immobilized product produced from microorganism, enzyme and magnetic body - Google Patents

Abstract

PURPOSE:To remove contaminants in water such as sewage, waste water, etc., with a high percentage of recovery by separating an immobilized product discharged together with treated water from a reaction tank in a magnetic separation apparatus and performing the water treatment continuously after returning the immobilized product to the reaction tank. CONSTITUTION:Microorganisms or enzymes capable of decomposing contaminants of water are immobilized together with a magnetic body using a high molecular material. After forming the immobilized product to a size at need sufficient for suspending product in water, the product is allowed to contact with the water to be treated in a reaction tank under aerobic or anaerobic condition. Thus, the contaminants are decomposed. The immobilized product discharged together with treated water from the reaction tank is then separated in a magnetic separation apparatus, and separated product is returned to the reaction tank to perform the water treatment continuously. Even if the immobilized product is formed to such small size as permitting suspension in water, by this process, the recovery and reutilization of the product can be performed very easily.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a water treatment method using an immobilized product of microorganisms, enzymes, and magnetic materials, and more specifically, to treatment of easily decomposable organic matter mainly contained in sewage and wastewater. In addition, the present invention relates to a water treatment method using an immobilized product of microorganisms, enzymes, and magnetic material that can decompose and remove persistent substances, toxic substances, nitrogen, phosphorus, etc.

(Prior art and problems to be solved by the invention) Conventionally,
Activated sludge method is generally used to treat relatively large amounts of organic wastewater.

However, in this method, organic toxic substances such as persistent substances and chlorine-containing organic substances, which cause chemical oxygen demand i (Coo) when discharged into the environment, and even ammonia nitrogen are simultaneously or When processing them individually, disassemble them.

Since the growth rate of the microorganisms to be removed is slow, it takes a long time to culture the microorganisms, and it is difficult to culture them at high concentrations.

In addition, in the activated sludge method, surplus activated sludge is usually withdrawn, but at this time, it is impossible to collect and reuse only valuable microorganisms with slow growth concentration from the surplus sludge; The high concentration of pollutants impedes treatment efficiency and makes it difficult to respond to changes in the load of pollutants in influent water.

Furthermore, in the activated sludge method, the pollutants in the inflow water come into direct contact with the microorganisms, so the microorganisms are easily inhibited by various substances, and the environmental conditions such as the hydrogen ion concentration in the tank are also directly affected. There was a problem that stable and efficient processing could not be performed sufficiently.

Therefore, in order to solve these problems with the activated sludge method, a method based on immobilization of microorganisms has been adopted for the removal of difficult-to-decompose substances.

In other words, this method immobilizes microorganisms by embedding them in organic polymers or by bonding them to an insoluble carrier.
By filling the immobilized material into the reaction tank, specific microorganisms are accumulated in the reaction tank at a high concentration and then recovered.

However, according to this method, the size of the immobilized object,
Since the thickness is on the order of a picture, there are problems in that the diffusion of oxygen into the immobilized material is rate-limiting for the removal reaction, and there is a strong tendency for active microorganisms to exist only on the surface of the immobilized material.

In order to solve this problem, it is possible to reduce the size of the immobilized material, but it is extremely difficult to separate only the immobilized material from a mixed system with other organisms such as activated sludge. This is difficult, especially because of the slow growth rate, making it practically impossible to recover and reuse this immobilized material containing valuable microorganisms.

The present invention has been made to solve all of the above-mentioned problems, and allows the recovery of immobilized substances by the above-mentioned microorganisms to be carried out very easily and efficiently. The object of the present invention is to recover immobilized substances with a high yield even in a mixed system, and to remove pollutants in water such as sewage and wastewater with a high recovery rate.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and the means for solving the problems include microorganisms or enzymes that can decompose water pollutants, and magnetic materials. is immobilized with a polymeric substance, and then, if necessary, the immobilized product is formed into a size that is large enough to float in water, and then brought into contact with water in a reaction tank under aerobic or anaerobic conditions. The purpose is to decompose water pollutants, and then the immobilized substances flowing out of the reaction tank along with the treated water are separated by a magnetic separator and returned to the reaction tank for continuous water treatment.

In addition, other means include microorganisms or enzymes that can decompose organic toxic substances and persistent substances such as chlorine-containing compounds, or microorganisms or enzymes that require enrichment culture such as nitrification of ammonia nitrogen and removal of phosphorus. The magnetic material is immobilized using a polymeric substance, and then the immobilized material is formed into a size that will float in water as required, and then placed in an activated sludge tank, and then processed from the activated sludge tank. The immobilized material flowing out with water is separated by a magnetic separator and then returned to the activated sludge tank, and the necessary activated sludge after sedimentation separation is returned to the activated sludge tank for continuous water treatment. There is a particular thing.

(Function) As the present invention is a method using an immobilized substance in which a magnetic substance is immobilized together with microorganisms or enzymes as described above, the immobilized substance holding the magnetic substance can be used for the above-mentioned magnetic separation regardless of its size or shape. It can be easily separated by the device, and therefore, even if the immobilized product is made small enough to float in water, it is very easy to recover and reuse the immobilized product.

(Example) Examples of the present invention will be described below.

Example 1 First, microorganisms, such as magnetite (Fe: +04)
Magnetic products attached and bonded with ferromagnetic materials such as
The operation for producing ferromagnetic hybrid immobilized bacteria (hereinafter referred to as ferromagnetic hybrid) will be described.

First, wet sludge (bacteria) No. 59 is suspended in 20 ml of physiological saline, and magnetite No. 19 is added to this and mixed.

As this wet sludge, general activated sludge cultured in artificial sewage containing glucose is used.

Next, 3,75 of 7cryl 7mid monomer was added to the suspension.
After adding and mixing 9, N was added as a crosslinking agent.

Mix 0.29% of N'-methylenebisacrylic 7amide.

Thereafter, 2.5 ml of 5% β-dimethyl 7-minoprobionitrile as a polymerization accelerator was added, and 2.5 ml of 2.5% potassium beroxonisulfate as a polymerization initiator was added.
Add 5ml.

When this is left to stand at about 37 degrees for about 30 minutes, gel-like immobilized bacteria will be produced. After that, the gel-like material was washed with physiological saline and crushed to 149 μm.
The desired ferromagnetic hybrid can be obtained by sieving only those having a particle diameter of m or more and magnetically separating them.

The properties of the ferromagnetic hybrid thus prepared are shown in Section 1.

The apparent specific gravity of this ferromagnetic hybrid is larger than that of activated sludge, and although it tends to settle somewhat when left to stand still, it is possible to sufficiently suspend it in the reaction tank just by aeration.

The magnetization in Table 1 is the magnetite magnetization (85.3 emu
/q) and the amount added. The magnetization value of this ferromagnetic hybrid can be controlled by increasing or decreasing the amount of magnetite added.

Table 1 Apparent specific gravity '1, 17 (9/cni)
Moisture content '83.8% Magnetite Jt i 35, 3 (mg/C
nt)゛=−−−−−−−−−−−−−−−−−−1−
Estimated magnetization for ゛------(at 1.OT) i 1
5. 9 (emu/dry-9) Next, each of the ferromagnetic hybrids prepared as described above was placed in a reaction tank together with water, and was sufficiently aerated to float.

After that, glucose was added once a day, immediately after addition and once a day.
The operation of measuring the glucose concentration and C00c after 1 day was repeated for about 2 weeks.

The results are shown in Appendix Figure 1 (Runl).

Comparative Example On the other hand, the glucose concentration and C00c were measured in the same manner as in Example 1 using an immobilized product in which only activated sludge was immobilized without adding magnetite. The result is the second
As shown in the figure (Run 2).

As is clear from these FIGS. 1 and 2, the glucose concentration and CODCr concentration in the treated water showed almost the same tendency, and no influence by the addition of magnetite was observed. In addition, glucose was well removed immediately after immobilization, and no major adverse effects due to immobilization were observed.

On the other hand, C00c in the liquid increases with the number of days that have passed. This was because the experiment was conducted under harsh conditions without exchange of water in the tank, and COD cr derived from the elution of some of the fixatives accumulated in the tank along with metabolites. This is thought to be the cause.

Example 2 In this example, in place of the activated sludge cultured in glucose-containing artificial sewage of the above-mentioned example as a microorganism, phenol-degrading bacteria cultured using treated sludge of phenol-containing wastewater as seed sludge is used.

A ferromagnetic hybrid obtained by immobilizing this phenol-degrading bacteria on magnetite in the same manner as in Example 1 above was placed in a reaction tank and suspended by aeration in the same manner as in Example 1 above.

Next, after adding phenol and acclimatizing for about 20 days in a batch manner, the following series of batch experiments were conducted.

That is, first, phenol was added to a reaction tank containing a ferromagnetic hybrid to a predetermined concentration (approximately 80 mg/l), and the change in phenol concentration over time was investigated (Run 3).

Next, activated sludge that had not been acclimatized with phenol was added to the above reaction tank, and a similar batch experiment was conducted to investigate the phenol removal performance of the ferromagnetic material Hyprint in such a mixed system (Run 4).

After completing this experiment, the ferromagnetic hybrid was separated from the above mixed system using a magnet, and its phenol removal performance (Run 5) and phenol removal performance of residual activated sludge (Ru
n6) was similarly investigated by batch experiments.

The DO concentration in each Run was 4.5 mg/1 or more.

Further, the amount of microorganisms (bacteria) in the immobilized product was determined by measuring the amount of T-P contained, and was approximately 700 mg/1. In addition, the pH in all the tanks was adjusted to 7 to 7.4.

The results of Runs 3 to 6 are shown in FIG.

For Runs 3 to 5 where ferromagnetic hybrids exist, the amount of phenol per unit amount of microorganisms is displayed.
As seen in the treatment with activated sludge acclimatized with phenol, phenol is removed almost according to a zero-order reaction. The removal rate coefficients for Runs 3 to 5 are shown in Section 2.

Run3 (ferromagnetic hybrid only) and Run4 (
Since these values are the same for the mixed system of ferromagnetic hybrid and activated sludge, this ferromagnetic hybrid has
Even in a mixed system with activated sludge, phenol could be removed in the same way as when it was used alone, without any particular effect.

In addition, the removal rate coefficient of Run 5 was close to that of Run 4, and almost no phenol could be removed in Run 6 (activated sludge after separation), so most of the ferromagnetic hybrid was recovered by magnetic separation, and phenol was not removed. It became clear that there was almost no leakage, and that the recovered ferromagnetic hybrid could be reused.

Table 2 =-'-” ”-”-'-T Run3,1. 36X10-3 (min-'
)↑－□－胛や□□□□□□□□－□□□□－－－トφ
□□Moan-1→←□轡□□□□□4Run4! 1.
33X 10-3 (min-')-°--
-------l Run5: 1. '20X10-' (min-
In addition, in another experiment, it was confirmed that a ferromagnetic hybrid having the properties shown in Table 1 could be separated from the above-mentioned mixed system using a commercially available magnet at a high rate of 99.3% or more. .

After the series of experiments, the treatment of phenol with the ferromagnetic hybrid was continued for about one month in a semi-batch manner, and at that point, using the ferromagnetic hybrid that had been magnetically separated, Run 3 (ferromagnetic When we conducted a batch experiment for phenol removal in the same way as in the case of hybrid (hybrid only), we found that 2.28
A removal rate coefficient of XIO-3 (min-') was obtained. The reason why the value was larger than that of Run 3 is as follows.
Is it possible that the phenol-degrading bacteria have become acclimatized or something has gone wrong?
In any case, the ferromagnetic hybrid was able to maintain its activity for at least two months.

In the above embodiment, magnetite was used as the ferromagnetic material, but the type of ferromagnetic material is by no means limited to this. Further, the magnetic material is not limited to the ferromagnetic material as in the above embodiment, but it is also possible to use a weakly magnetic material such as a paramagnetic material. When using a weakly magnetic material, it is necessary to increase the magnetic force of the magnetic separation device in accordance with the magnetic force of the weakly magnetic material.

In addition, the type of microorganisms is not limited to the activated sludge cultured in glucose-containing sewage as in Example 1 or the phenol-degrading bacteria as in Example 2, but in short, any microorganisms that can be used for water treatment or can be used for water treatment can be used. In addition, any microorganism that can decompose organic toxic substances such as chlorine-containing compounds, difficult-to-decompose substances, nitrogen, phosphorus, etc. may be used.

Furthermore, instead of such microorganisms, it is also possible to use enzymes derived from these microorganisms.

Furthermore, the immobilizing agent and immobilization method for immobilizing the magnetic material, microorganisms, and enzymes are not limited to the above examples, and the point is to maintain the immobilized state without dispersing them. Any fixing agent or fixing method that can be used may be used.

Further, in the above embodiments, the application to sewage and wastewater treatment has been described, but the application of the present invention is not limited to this, and can be widely used in water treatment in general.

(Effects of the Invention) As described above, the present invention immobilizes microorganisms or enzymes that can be used for water treatment and a magnetic material, and molds the immobilized product into a size that can float in water as necessary. After that, substances that cause water pollution are decomposed by contacting with water in a reaction tank under aerobic or anaerobic conditions, and then, after separating the immobilized substances from the reaction tank using a magnetic separation device, the reaction tank is This method not only improves the removal and recovery of pollutants by immobilizing microorganisms, but also removes the microorganisms and enzymes immobilized with the magnetic material by the magnetic separation device. Reliable separation and therefore recovery of immobilized materials regardless of their size or shape;
Since reuse can be ensured, the recovery rate of pollutants has been significantly improved compared to conventional methods that simply utilize immobilized microorganisms.

Furthermore, microorganisms and enzymes that can decompose organic toxic substances such as chlorine-containing compounds and persistent substances, or microorganisms and enzymes that require enrichment culture such as nitrification of ammonia nitrogen and phosphorus removal, and magnetic materials can be combined. When using a mixed system with activated sludge using immobilized substances, new processing capacity is added to the conventional activated sludge method, and it is also possible to increase the necessary concentration of bacteria. This has the effect of providing a useful water treatment method.

[Brief explanation of the drawing]

FIG. 1 is a graph showing oral changes in glucose, C00e, and concentration of ferromagnetic material Hyfrit in activated sludge. FIG. 2 is a graph showing oral changes in glucose, C0Dc, and J degree using only activated sludge without the addition of magnetite. FIG. 3 is a graph showing the change in phenol concentration over time in the second example. 1st cause lL-': JJ, COD,, SL&Pbe'
('l <, , Applicant: Erzl Products Co., Ltd. Agent, Patent Attorney: Noboru Fujimoto L (F3') Diagram: Glucose, Q'Dg3L skin system), θ)g%
＞”Area map

Claims (1)

[Scope of Claims] 1. A microorganism or an enzyme capable of decomposing water pollutants and a magnetic material are immobilized using a polymeric material, and then the immobilized material is made into a large enough material to float in water as necessary. After the molding process is carried out, water pollutants are decomposed by contact with water in a reaction tank under aerobic or anaerobic conditions, and the immobilized substances flowing out of the reaction tank together with the treated water are separated by a magnetic separation device. A water treatment method using an immobilized product of microorganisms, enzymes, and magnetic material, characterized in that the water is then returned to the reaction tank for continuous water treatment. 2. Microorganisms or enzymes that can decompose organic toxic substances and persistent substances such as chlorine-containing compounds, or microorganisms or enzymes that require enrichment culture such as nitrification of ammonia nitrogen or phosphorus removal, and a magnetic material, Immobilized with a polymer substance,
Next, the immobilized material is shaped into a size that will float in water as necessary, and then placed in an activated sludge tank.
The immobilized material flowing out from the activated sludge tank together with the treated water is separated by a magnetic separator and then returned to the activated sludge tank, and the necessary activated sludge after sedimentation and separation is returned to the activated sludge tank for continuous operation. A water treatment method using an immobilized product of microorganisms, enzymes, and magnetic material, which is characterized in that water treatment is performed on water.