JPH03161097A - Continuous purification treatment process for soil water - Google Patents

Abstract

PURPOSE:To treat concentration and other conditions of water to be treated, as the pre-stage of contact aeration treatment, to the state optimum to the following aeration treatment by introducing an acid additive containing various kinds of metal salts and non-metal salts as main components into the soil water to be treated, introducing a neutralizer and mixing it therein, and carrying out neutralization. CONSTITUTION:An acid additive containing various kinds of metal salts and non-metal salts prepared by dissolving a mineral containing various kinds of metal oxides and non-metal oxides including SiO2, Al2O3, Fe2O3, K2O and MgO as main components by an oxidation reaction tank 3 is mixed with soil water to be treated from which insoluble matters are removed by a solid-liquid separator 2. Flocculent matters are settled in a settling tank 5 and affected by microbe groups adhered to contact materials 18, 18... trimming the inside of a contact aeration tank 6 to carry out effective purification. The treatment for high concentration organic soil water, which cannot be carried out by the microbe treatment only, and the treatment of organic soil water having large load variation can be carried out with high efficiency in a small equipment by said process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuous purification method for wastewater contaminated with organic matter. [Prior Art] In recent years, a method of purifying wastewater using the so-called contact aeration method, which utilizes the self-purifying action of microorganisms on wastewater, has been adopted. In this method, a large number of contact materials made of string-like bodies formed to allow microorganisms to easily adhere to them is placed in a contact aeration tank, and the wastewater to be treated is fed into these contact materials to prevent microorganisms from adhering to the contact materials. This is a method of purifying wastewater mainly through the oxidizing action of aerobic bacteria. The purification effect of wastewater by microorganisms is carried out by the oxidation (nitrification) and reduction (denitrification) effects of aerobic bacteria and anaerobic bacteria in the microbial group attached to the contact material, respectively. Maintaining an appropriate growth balance of bacterial groups and algae that occur along with this,
It is necessary for plankton, protozoa, micrometazoa, etc. to coexist and maintain an appropriate balance in order for the above purification effect to be carried out effectively. The inventor of the present invention has conducted research on contact materials suitable for maintaining the above-mentioned balance of the above-mentioned microbial groups, and has developed a core body made of vinylidene chloride resin, polyamide resin, polyester resin, polypropylene, polyvinyl chloride, nylon, etc. We have developed a contact material consisting of a core and a number of thin ring-shaped fibers made of the same material and extending radially from the periphery of the core. The contact material has a form suitable for stably maintaining the growth balance of the bacterial group,
Moreover, since the diameter can be made to a size suitable for the above, it has been found that the adaptability to changes in the concentration of wastewater is high. This led to the development of a purification method in which the above-mentioned contact materials are arranged at appropriate intervals in multi-stage contact aeration tanks, and wastewater is circulated through them for purification. However, as a result of repeated experiments with the above purification method, even when using the above-mentioned excellent contact material, if the concentration of the wastewater to be treated becomes extremely high, it is still not suitable. It was found that the growth of aerobic bacteria becomes difficult, resulting in an imbalance between aerobic and anaerobic bacteria, making it difficult to perform aeration smoothly. In addition, such contact aeration method reduces the biochemical oxygen demand ff
Although it is very effective in reducing i (BOD), it cannot be expected to have a large effect in reducing chemical oxygen demand fi (COD), and as mentioned above, the loading amount of BOD and/or COD etc. There are also problems in which it is not possible to respond immediately to extreme fluctuations in . [Problems to be Solved by the Invention] However, in order to make the contact aeration method, which has such an excellent effect, work effectively, the wastewater to be treated must be prepared in advance within the range of conditions that will work effectively. Therefore, we assumed that it would be appropriate to configure it so that it could undergo contact aeration treatment. Therefore, the purpose of the present invention is to establish a method that includes, as a preliminary step to contact aeration treatment, a process in which the concentration and other conditions of the wastewater to be treated are brought to an optimal state for subsequent aeration treatment. This was done as a. [Means for Solving the Problems] First, the chemical treatment process in the first half of the present invention is based on Sing.
Alarm. Fe*Os. KsO and MgO
An acidic additive containing various metal salts and non-metal salts obtained by dissolving minerals containing various metal oxides and non-metal oxides as main components in an inorganic acid aqueous solution is added to the wastewater to be treated. After mixing, a neutralizing agent is added and mixed into the sewage to be treated to perform neutralization treatment, thereby decomposing and precipitating the organic substances dissolved in the sewage to be treated, This is a process in which the wastewater is coagulated together with the suspended solids in the wastewater to be treated, and then the agglomerates thus generated are separated. The action of the above process has not been fully elucidated theoretically, but by mixing the acidic additive and the subsequent neutralizing agent, water-soluble organic matter is decomposed, forming insoluble matter and dissolved intermediates. The former undissolved substances can be separated by filtering through a suitable filter material or by precipitation in a sedimentation tank or the like.

The above-mentioned dissolution intermediate products will be decomposed and removed in the subsequent contact aeration process. Minerals containing various metal oxides and non-metal oxides used in the above process include, for example, mica, rocks containing mica (e.g. granite), sacrificial rocks such as mica or granite (e.g. vermiculite), or minerals containing these. This includes soils that have been further weathered from saprophytes. It is preferable to use vermiculite in which mica-based minerals have been weathered, or soil in which this vermiculite has been further weathered, because it is inexpensive and has high reactivity with inorganic acids. Furthermore, since it is better to use black mica in terms of its precipitation and agglomeration effect, it is particularly preferable to use black mica sacrificial rock and soil in which this sacrificial rock has been further weathered. To produce the acidic additive used in this process, for example, vermiculite, which is weathered mica-based mineral, is mixed with a mineral acid such as sulfuric acid or hydrochloric acid, e.g.
5% sulfuric acid aqueous solution, vermiculite: sulfuric acid aqueous solution,
Add at a weight ratio of 4:3 to 4 and leave for several days with occasional stirring, or heat to 100°C and leave for several days while stirring. When processed in this way, Si. Al, Mg. Fe. K. Elements such as Na and oxides are eluted into the sulfuric acid aqueous solution, producing the above metal and nonmetal sulfates, oxides, double salts, and complexes. Furthermore, in addition to the above, Li, 2r. V. Ti%
Ni. Go. P. Ba, S. Although sulfates such as Ge are also produced, there are no harmful heavy metals. The aqueous solution thus obtained can be used as the above-mentioned acidic additive as it is or after being concentrated or diluted. In this process, as described above, the acidic additive is added to the wastewater to be treated, and the dissolved organic matter contained in the wastewater to be treated is decomposed, precipitated, and coagulated to be removed. As mentioned above, the relatively small amount of dissolved intermediate products that are generated in the above process and remain in the wastewater to be treated are decomposed and removed in the subsequent contact aeration treatment. ．． By the way, the method of this invention combines the chemical treatment process described above and the catalytic aeration treatment described below, and makes it possible to treat a wide range of wastewater containing dissolved organic matter. Examples of wastewater to be treated include kitchen wastewater, deep urine,
Targets include wastewater from livestock farming, fish farming, hospitals, etc. Of course, the sewage to be treated must be other than the wastewater mentioned above.
However, the wastewater to be treated is as described above, and this chemical treatment process decomposes the relatively high concentration of dissolved organic matter dissolved in the wastewater to be treated, and is used in the subsequent aeration process. Since the purpose is to achieve a treatment within a suitable range of conditions, it is appropriate to adjust the amount of the acidic additive added as follows. In other words, the amount of acidic additive added to the wastewater to be treated differs slightly depending on conditions such as the type and concentration of the wastewater to be treated, but in general, the amount of solids after concentration and drying per 100cc of the wastewater to be treated is As a substance, 0.01 to log, especially 0.1 to Ig
Use. When acidic additives are added to wastewater to be treated, carbon dioxide gas is generated, which is thought to be evidence of the decomposition of organic matter, and when neutralized with alkali as described above, flocs float to the surface of the liquid. If the flocs are left as they are, they will settle out over time, and the wastewater to be treated will become clear. The flocs can be removed by settling, for example in a settling tank, or filtered through a filter medium such as sand, calcined vermiculite, zeolite or activated carbon. Next, the aeration process in the second half of the present invention is as follows. That is, the treated wastewater obtained in the above-mentioned chemical treatment process is treated with an appropriate number of contact materials consisting of a core and a number of thin fiber rings extending radially from its outer periphery at appropriate intervals. The water is sequentially supplied to multiple stages of contact aeration tanks arranged in the air tank, and is passed gently between the contact materials in each stage of aeration tanks for continuous purification. The above-mentioned contact aeration tank, for example, connects and communicates four tanks in sequence. The contact material used includes, for example, a core made of vinylidene chloride and a large number of thin ring-shaped fibers extending radially from the outer periphery of the core. The above-mentioned contact material is attached, for example, to a support member having vibrator bodies fixed in parallel to the upper and lower parts. Specifically, the upper and lower pipe bodies are connected at their upper and lower ends, respectively, and arranged at regular intervals vertically and horizontally. That is, each contact material is arranged vertically, and the horizontal spacing between them is approximately constant in both the vertical and horizontal directions. And the contact material is
Install it in each contact aeration tank while attached to the support member in this way. When the treated wastewater, which has been treated in the first half of the chemical treatment process and whose organic matter concentration has been reduced, is supplied to the first contact aeration tank, it comes into contact with the contact material installed inside the tank, and each contact Purification progresses further due to the action of bacteria attached to the wood. The above-mentioned contact material consists of a core body and a large number of thin ring-shaped fibers extending radially from the outer periphery of the core body, and by leaving the above-mentioned rings in various sizes, oxygen can be removed. An appropriate balance can be created between the outer area where ingestion is easy and the inner area where ingestion is not possible, and the balance between the growth of aerobic and anaerobic bacteria attached thereto is maintained appropriately. As a result, the remaining BOD of the wastewater to be treated
and COD is effectively removed. In addition, since oxidation and reduction actions (for example, nitrification of ammonia nitrogen by nitrifying bacteria and denitrification by denitrifying bacteria) occur in parallel,
Denitrification of wastewater, which is currently a cost problem, is the BO mentioned above.
In parallel with the elimination of D and COD, this will be achieved without increasing costs. Furthermore, the contact material used in this process has the structure described above, and the thin ring-shaped fibers formed around the core are adaptable to slight changes in the concentration of wastewater and the growth of microorganisms. Furthermore, since the specific surface area and spatial volume of the ring are extremely large, it is suitable for attaching many types of microorganisms and small organisms. For example, organisms other than microorganisms such as algae can proliferate and become suspended, so BOD and CO in wastewater are
Not only D, but also nitrogen and phosphorus can be removed, so there is no problem in discharging purified water into rivers, etc. As described above, in the latter half of the process, the wastewater to be treated is treated in the chemical treatment process to an appropriately low concentration in which microorganisms and other living organisms can be actively active, so the wastewater is arranged in multiple stages. In the contact aeration tank, the purification effect can be effectively carried out at the optimum concentration for the microorganisms that adhere to the contact material at each stage. [Example] An example of the present invention will be described below based on the drawings. First, we will provide an overview of the equipment used in each of the following examples. As shown in FIG. 1, a regulating tank 1, a solid-liquid separator 2 composed of a screen, an oxidation reaction tank 3, a neutralization tank 4, a settling tank 5,
A four-stage contact aeration tank 6, sand filter 817, and fresh water tank 8 are installed in this order. The above-mentioned adjustment tank 1 is a facility that first receives wastewater to be purified, such as gray water, and absorbs changes in the amount of inflow, and adjusts the amount supplied to the subsequent stages. This adjustment tank
is quickly passed through the solid-liquid separator 2 via the meter 9. The measuring device 9 is used to adjust the amount of sewage to be treated per unit time according to the capacity of the next stage and subsequent stages. The solid-liquid separator 2 is constructed of a screen as described above, and the solid components separated here are removed and incinerated. In addition, a separate blower device IO is provided, and this blower device IO is installed separately.
It may be possible to move the vibrator to the vicinity of the tanks 6a, 6b, 6c, and 6d in each stage of the oxidation reaction tank 3, neutralization II 4, and contact aeration tank 6.
Extend the above vibrator lla further to the bottom of each
Auxiliary pipe 1lb. llb... is branched and extended, and each nozzle vipe l is arranged along the bottom at its end.
Connect ie, 11c... Above nozzle pipe ll
c has a large number of nozzle holes arranged in the length direction. The purpose of the nozzle vip llc is to blow out air from the nozzle hole to stir the oxidizing agent or neutralizing agent in the oxidation reaction tank 3 and neutralization tank 4, respectively, in order to uniformly mix them in the wastewater to be treated. Also contact aeration tank 6
Here, the purpose is to supply sufficient oxygen to the wastewater to be treated in the tanks 6a, 6b, 6c, and 6d of each stage by blowing air from the nozzle holes. An acidic additive storage tank 13 equipped with a charging bomb 12 is connected to the axification reaction tank 3, and a neutralizing agent storage tank 15 equipped with a charging bomb 14 is connected to the neutralization tank 4. The neutralizing agent storage tank 15 is further equipped with a stirring device 1 that rotates stirring blades using a motor to prevent the neutralizing agent from settling.
6 shall be equipped. In addition, a pipe 17 is connected to the bottom of the settling tank 5, and the settled sludge is drawn out by a pump. The sand filter 7 is filled with sand and stones. In addition, tanks 6a, 6b, 6c in each stage of the contact aeration tank 6,
6d is filled with a support stand 19 having a large number of contact materials 18, 18, . . . attached at regular intervals vertically and horizontally. As shown in FIG. 2, the contact material 18 includes a core body 18a made of vinylidene chloride and a number of contact rings 18b extending radially from the outer periphery of the core body 18a. 18b...
・It is composed of. Said contact ring 18b. 18b・
... is similarly composed of vinylidene trichloride. Further, the support stand l9 is, as shown in FIG.
Posts 19a installed at the four corners. 19a... and supporting plates 19b, 19b disposed at their upper ends and midway down, and the large number of contact members 18, 18... are spaced apart from each other at regular intervals vertically and horizontally. Each upper and lower end is attached to the support plate 1
9b. 19b, respectively.

Next, an example of purification treatment performed using the above equipment will be explained. This is an example of purification treatment for cafeteria wastewater. Organic matter amount: 2. O
OOppm of wastewater to be treated is first received into the adjustment tank 1, where fluctuations in the amount received are absorbed. From the above adjustment ill, check the scale 9 for lrr? It is fed to the oxidation reaction tank 3 via the solid-liquid separator 2 while adjusting the supply amount to /h. Above solid-liquid separator 2
Now, filter this through the screen that makes up the sample to remove insoluble matter. The wastewater to be treated from which insoluble matter has been removed in the solid-liquid separator 2 is sent to the oxidation reaction tank 3, where an acidic additive is added and mixed. The acidic additive is supplied from an acidic additive storage tank l3 by a charging pump 12. And oxidation reaction tank 3
Then, the acidic additive is sufficiently mixed into the wastewater to be treated by the air jetted from the nozzle hole of the nozzle pipe 11c. As the acidic additive, the trade name "SABRO" (manufactured and sold by Shimanishi Kaken Co., Ltd.) was used, and it was added in an amount to give a concentration of 50091) Im in the wastewater to be treated. After the acidic additive has been added and sufficiently stirred and mixed as described above, the wastewater to be treated is transferred to the neutralization tank 4, and a neutralizing agent is added thereto. The neutralizing agent is supplied from a neutralizing agent storage tank 15 by an input pump l4. In the neutralization tank 4, the neutralizing agent is sufficiently mixed with the wastewater to be treated by air jetted from the nozzle hole of the nozzle pipe lie. Quicklime (CaO) was used as a neutralizing agent and was added until the pH reached 7.5. However, organic substances dissolved in the wastewater to be treated precipitate out,
It becomes an insoluble substance and agglomerates. The wastewater to be treated is transferred to the settling tank 5, where it is allowed to stay for 30 minutes, and the aggregates are allowed to settle. After the above 30 minutes have elapsed, the supernatant of the wastewater to be treated is sent to the contact aeration tank 6 in the next stage.
The amount of organic matter in the wastewater to be treated at this time was 480 ppm.
Met. The sewage to be treated sent to the contact aeration tank 6 is first affected by various microorganisms attached to the contact materials 18, 18, etc. installed in the first tank 6a, and dissolved organic matter is removed. and the dissolved intermediate products are gradually decomposed and sequentially transferred to the subsequent tank 6b.
, 6c, and 6d, the microorganisms adhering to the contact materials 18, 18, etc. adapt to the organic matter concentration at each stage, and are acted upon to effect effective purification. The contact aeration tank 6 is adjusted so that the wastewater to be treated passes through it in 24 hours. The wastewater to be treated, which is sent from the final stage tank 6d of this contact aeration tank 6 to the next stage sand filter 7, has an organic matter content of 30 p.
It is processed to pm. The organic matter contained in this treated water is sludge such as dead bacteria. Next, this wastewater to be treated is passed through a sand filter 7. The amount of organic matter in the water to be treated after passing through is 20pp+m. This treated water is supplied to the fresh water tank. [Effects of the Invention] Therefore, according to the present invention, treatment of highly concentrated organic wastewater that cannot be achieved by microbial treatment alone or treatment of organic wastewater with large load fluctuations can be carried out with high efficiency using small equipment.

[Brief explanation of the drawing]

The drawings show a facility according to an embodiment of the present invention; FIG. 1 is a schematic explanatory diagram thereof, FIG. 2 is a schematic sectional view of the contact material, and FIG. 3 is a schematic perspective view of the stand with the contact material attached. This is a diagram. l...adjustment tank, 2...solid-liquid fraction iii! , 3...
・Oxidation reaction tank, 4... Neutralization tank, 5... Sedimentation tank, 6.
...Contact aeration tank, 6a, 6b, 6c, 6d...
Tank, 7... Sand filter, 8... Fresh water tank, 9... Measuring device. 10...Blower device, 11a...Pipe,
llb... Auxiliary pipe, l l c ''-nozzle vibe, 12.14... Injection pump, 13% l5... Storage tank. 16... Stirring device, l7... Pipe, 1
8... Contact material, 18a... Core body, 18b... Contact ring, l9... Support stand, 19a... Support column,
19b...Support plate.

Claims (1)

[Claims] SiO_2, Al_2O_3, Fe_2O_3, K_
An acidic additive containing various metal salts and non-metal salts as main components obtained by dissolving minerals containing various metal oxides and non-metal oxides mainly containing 2O and MgO in an inorganic acid aqueous solution. After being poured into the wastewater to be treated and mixed, a neutralizing agent is added and mixed into the wastewater to be treated to perform neutralization treatment, thereby decomposing the organic matter dissolved in the wastewater to be treated. The wastewater to be treated is precipitated and coagulated together with the suspended matter in the sewage to be treated, and then the aggregates thus generated are separated, and the sewage to be treated that has undergone the above treatment is distributed from the periphery of the core body to the outer periphery. An appropriate number of contact materials made of thin fibers formed radially toward each other are sequentially supplied to multiple stages of contact aeration tanks arranged at appropriate intervals, and the contact material in each stage of contact aeration tanks is A method for continuous purification of sewage in which the wastewater is passed slowly through the water to decompose the remaining dissolved organic matter, and then the decomposed aggregates are separated.