JPS61238397A - Treatment of excretion sewage of domestic animal - Google Patents

Abstract

PURPOSE:To treat sewage without diluting the same, by adding a flocculant and a powdery mineral substance to sewage and adjusting the pH of sewage to 5-6 by an acid before performing the permeation treatment of said sewage by a reverse osmosis membrane. CONSTITUTION:Sewage 2 such as pig excretion sewage is introduced into a tank 6 provided with a stirrer 4 and a pH meter 5 by a pump 3. Subsequently, an inorg. flocculant 7 such as polyaluminum chloride, a cationic polymer flocculant 8 and a powdery mineral substance 9 such as porous ceramics are added to the tank 6 and, after acid such as hydrochloric acid was added to sewage to adjust the pH thereof to 5-6, the treated sewage is sent to a tubular reverse osmosis membrane apparatus 11 by a pump 10 to be transmitted therethrough. The transmitted water is sent to a batchwise contact oxidizing apparatus 15 by a pump 14 to undergo biological treatment.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a treatment method for diluting wastewater from livestock, especially pigs. [Prior Art] Properties of livestock waste and wastewater, Although it varies depending on the type of pig and the breeding conditions, in particular, pig waste and sewage are listed in Table 1 (
It has the components shown in a) and (t)), and usually contains a large number of suspended solids, organic matter, and high salt content, and is viscous.

Table 1 1a) Summary Table 1 (1=) Such BOD containing various organic substances and inorganic substances,
It has been extremely difficult to obtain wastewater that meets environmental standards by treating swine wastewater with a high concentration of COD. In particular, there is a concern that nitrogen content may cause the occurrence of rice blast disease in rice cultivation, so advanced treatment is required. Generally, biological treatments such as the activated sludge method, rotating disk method, or the ±1 permeation method are used to treat pig waste and wastewater.

[Problem that the invention seeks to solve]

However, in the biological treatment method, BOD 1 that can be treated
BOD is 1500 ppm, and speciation is the limit, but the BOD of pig manure and sewage is 8000 to 9000 ppm.
This must be diluted 5 to 6 times and processed. As a result, the capacity of wastewater to be treated increases, and
A large area is required to install the treatment equipment, which increases investment costs. ,Also.

The soil infiltration method does not require dilution, but has drawbacks such as soil clogging and impossibility due to the high concentration of organic matter contained.

In view of the above circumstances, it is an object of the present invention to provide a method for treating livestock waste and wastewater that does not require a large area for installation and that performs biological treatment without dilution.

[Means for Solving the Problems] The present invention has been made to achieve the above-mentioned object, and its gist is to solve the problem without diluting livestock excrement and sewage.
Mineral powder such as inorganic flocculant and polymer flocculant and porous ceramics are added to this, and the particle size is adjusted to 5 to 6 with phosphoric acid, and this is permeated with a tubular reverse osmosis membrane. , this permeated treated water is subjected to batch catalytic oxidation method ζ
Hereinafter, there will be described a method for treating livestock excreta and sewage by biological treatment. [Specific structure and operation of the invention] The present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an apparatus for implementing the method of the present invention, and reference numeral 1 in the figure is a storage tank 2 for sewage from pig excrement (hereinafter referred to as sewage). A sewage 2H pump 3 introduces a concentration tank 6ζ provided with an agitator 4 and a total of 5.

The wastewater 2 introduced into the concentration tank 6I is stirred, and an inorganic flocculant (for example, polyaluminum chloride) 7, a cationic polymer flocculant 8. Porous Cera is mineral powder such as Tuxus (200
~300 mesh) 9 is added, and - is adjusted to 5 to 6 using a columnar (eg HCt) 5a. This adjusted wastewater is sent to the first tubular type reverse osmosis membrane device by the pump 10, and a considerable portion of it is sent to the first reverse osmosis membrane device.
The water permeates through the reverse osmosis membrane 1a and is stored in the reverse osmosis membrane permeate storage tank 12f.

This permeated water 13 is intermittently sent in fixed amounts by a pump 14 to the batch type catalytic oxidation device I5 for biological treatment, while the sludge 11-16 that does not pass through the reverse osmosis membrane 11a is circulated to the concentration tank 6. However, in the process, a predetermined reverse osmosis pressure is obtained from the pressure regulating valve 17+.

In the above operation, when adding the inorganic flocculant and the cationic polymer flocculant, it is necessary to collect the organic substances t-a constituting the viscous substances in the wastewater 2 and form flocs.
The purpose of this is to remove approximately 45 yen of OD and lower the osmotic pressure of the liquid6.Additionally, mineral powder such as porous ceramics is added to the reverse osmosis membrane 11a of the tubular reverse osmosis membrane device 11. This is to exhibit a precoat effect during permeation, and to further increase the amount of permeation due to the decrease in osmotic pressure.

Moreover, the reason why - is adjusted to 5 to 6 is as follows. That is, the material of the reverse osmosis membrane 11a is mainly cellulose acetate. On the other hand, the sewage 2 contains high concentrations of organic and inorganic nitrogen, and is alkaline at 8.5 to 9.0, and unfractionated NH3 is permeated into the permeate.
- exhibits high alkalinity with a value of 9.0 to 9.5. The above-mentioned cellulose acetate is hydrolyzed in alkaline conditions, which erodes the membrane surface of the reverse osmosis membrane and significantly reduces the quality of permeated water.Therefore, the water is made slightly acidic with a rating of 5 to 6 to prevent hydrolysis of the reverse osmosis membrane. and protect the membrane surface.

Moreover, the reason why a tubular type reverse osmosis membrane is used is as follows. In other words, there are several types of reverse osmosis membranes: holofiber (hollow fiber), spiral membrane (6t shape), plate ant frame (flat membrane), and tubular membrane (tubular membrane). The type has a large membrane area and can increase the amount of permeated water, but the wastewater 2Vi which is the target of the present invention
Sixth, the reverse osmosis membrane cannot be used because it contains a large amount of suspended matter and becomes clogged with dust in a short period of time. On the other hand, since the tubular type reverse osmosis membrane is a tubular module with a small amount of permeated water, it is possible to physically clean the membrane surface, making it suitable for the sewage treatment of the present invention. The type catalytic oxidizer 15 was used because it does not require a settling tank and has a small footprint.

However, if the settling ability of sludge decreases and the aeration tank sludge zone rises, there is a concern that the cycle of sedimentation separation and discharge will be disrupted, causing the settled sludge to flow out during discharge. Therefore, a fixed bed 15a with a large surface area is provided, and the microorganisms attached to the fixed bed 15a perform contact oxidation, and the sludge is released into the discharged water t;sb.
Be sure to strain it to prevent it from spilling out. Nari, l 5
c is air for aeration. Invention I This method uses a reverse osmosis membrane to treat wastewater without diluting it, so Table 2 shows pig excrement wastewater: 6m/
As shown in the comparison with the conventional activated sludge method when processing BOD 851 kg/day, it can be seen that this method is significantly superior.

Table 2 Next, the present invention will be explained by showing examples and comparative examples.

[Example: Approximately 0.2 liters of polyaluminum chloride, approximately 0.2 liters of polyaluminum chloride, approximately 0.2 liters of Higashi polymer flocculant: approximately 200 to 300 wt. The pH was adjusted to 6 to 7 using HCl, and without sedimentation, a cellulose acetate membrane was attached to a Tatubular type reverse osmosis membrane device (removal rate: 50), and permeation treatment was carried out. The permeate was then subjected to biological treatment using a batch contact oxidizer. , the results are shown in Table 3.

As is clear from the table, treated effluent, BOD,
COD, SS, and Totat-N are all low (,
In addition, there is a large amount of water passing through the reverse osmosis membrane, which can become clogged in a short period of time.
When the amount of water permeated through the membrane decreased, by purifying it, it returned to its original state, showing that the membrane was not altered.

Table 3 [Comparative Example 1] Same procedure as in Example 1 except that aluminum chloride, IMOLOCK, and activated carbon were not added, and sewage treatment was carried out in the same manner as in Example 1. Shown in the table.

As is clear from Table 4, 10Ij! BOD compared to case 1
All of the cicadas are a little tall. Furthermore, the permeation rate curve of the reverse osmosis membrane was low, and a decrease in permeation rate was observed in a relatively short period of time6.Also, after long-term operation, a decrease in performance, which was thought to be due to deterioration of the membrane, was observed.

[Effects] As described above, the method of the present invention allows wastewater to be permeated and separated in a slurry state by adjusting the addition of flocculants and precoating agents without diluting it using a tubular reverse osmosis membrane device. Since the permeate water is biologically treated using a batch type catalytic oxidation device, the reverse osmosis membrane is not clogged.
It has many advantages, such as no deterioration due to deterioration (, BOD etc. can be treated to a low level, and the installation area of the equipment is small (low construction cost).

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for carrying out the method according to the invention. 2... Pig excrement stains (sewage), 4...
Stirrer, 5...-Total, 5a...Acid, 6
...Concentration tank, 7...Inorganic flocculant, 8.
...Polymer flocculant% 9 ... Mineral powder, 10 ... Pump, If ... Tubular reverse osmosis membrane device, lla ...・Reverse osmosis membrane, 12
... Reverse osmosis membrane permeated water storage tank, 13 ... Permeated water, 14 ... Pump, 15 ... Batch type catalytic oxidation device, 15a ...・Fixed floor, 15b・
...Discharged water, 15c...Fume air, 1
6...Slurry.

Claims (1)

[Claims] Without diluting livestock waste wastewater, inorganic flocculants, polymer flocculants, and mineral powders such as porous ceramics are added to it, and the pH is adjusted to 5 to 6 with acid. 1. A method for treating livestock manure sewage, which comprises performing permeation treatment using a type reverse osmosis membrane, and subjecting the permeated treated water to biological treatment by a batch catalytic oxidation method.