JPS59209699A - Filthy water disposal - Google Patents

Abstract

PURPOSE:To consistently perform filthy water disposal and sludge disposal for contriving the improvement in the efficiency of disposal, by subjecting filthy water being mixed with powdery carbon particles to biochemical treatment using air, adding a combustible coagulant to excess sludge, and burning cake after being dehydrated. CONSTITUTION:Filthy water is continuously or intermittently mixed with powdery carbon particles in a conduit 1, introduced into an aerator tank 3 and aerated therein with air or oxygen-rich air. The interior of the tank 3 is made aerobic to decompose organic substance existent in filthy water with microbes implanted on the introduced powdery carbon particles. Hence, the filthy water is purified. The treated water together with sludge is then introduced into a precipitation tank 6 to separately precipitate solid matter. Excess sludge is introduced into a sludge reservoir tank 10, a combustible macromolecular coagulant is further added in a conduit 12, and then the sludge is supplied to a dehydrator 13. Dehydrated cake is carried to a burning oven 15 and burnt therein. Oxygen-contg. waste gas from the aerator tank 3 is introduced into the burning oven 15 to use the oxygen incorporated in said waste gas oxygen for combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a biological treatment for wastewater. I! This article describes methods and treatment of excess sludge.

For biochemical treatment of sewage, aerobic microorganisms floating in the aeration tank are used to purify the debris, and the amount of microorganisms in the aeration tank is not raised above a certain limit. , there are eight limits to processing power.

Recently, with the aim of improving the shortcomings of activated sludge and stabilizing and improving the immediate production, efforts have been made to increase the settling area in the aeration tank and to reduce the sedimentation rate of generated sludge. A fluidized bed activated/RI mud method is beginning to be provided in which granular materials are mixed into an aeration tank and biochemically treated for the purpose of improving sigma. This method involves keeping the fluidized medium in the aeration chamber at all times and discharging excess sludge separated from the fluidized medium to the outside of the aeration tank. There is a method in which the sludge is discharged in a mixed state, separated by sedimentation in a settling tank, and a portion of the sludge is returned to the tank, and the remaining sludge is used as surplus sludge.

In the former σ) method in which the fluidizing medium is kept within the aeration side, C-1, the fluidizing medium is conventionally activated carbon 1 coal coke.

Sand, etc. are used, but in either case, the minimum particle size of the fluidizing medium must be limited to prevent it from flowing out of the aeration tank -- the structure of the aeration tank and the overflow area must be devised, and the maintenance and management of the tank is complicated. There was a new drawback.

On the other hand, in the latter method, in which the flowing MilJ medium is flowed out of the aeration tank in a mixed state with sludge, powdered activated carbon, clay powder, etc. are conventionally known as the fluidizing medium.

In this case, it is necessary to additionally replenish an amount commensurate with the amount of fluidized medium discharged in a mixed state with surplus sludge in accordance with the flow of wastewater into the aeration tank. However, when powdered γ-occupied charcoal is used as a fluid medium, the activated carbon itself has a physicochemical adsorption effect (due to its purifying effect on the bath gas component), but the activated carbon itself has a In addition, if the sludge is separated from the sludge and is not reused, it will become more expensive.
In addition, it is necessary to install a device to reproduce the equipment, and the recycling cost is not cheap. In addition, when clay is used as a fluid medium, it does not cost as much as an activated carbon type fluid medium, but it has the disadvantages that the increase in sludge caused by the addition of clay powder can be avoided and the disposal cost increases. In addition, even if the sludge is incinerated, the calorific value of the sludge decreases due to the increase in inorganic content due to clay powder, and a large amount of combustion improver is required.Furthermore, the increased ash content after incineration makes it difficult to use it as a mimic. It requires complicated equipment, is difficult to maintain, and even if it is disposed of as it is mixed with sludge, the sludge J(t) increases, which increases the processing cost including the cost of the fluidizing medium. For this reason, the bIL excited bed live pouring mud method was not widely adopted.

On the other hand, as a method of disposing of the sludge generated by biochemical treatment of sewage, it can be returned to farmland or landfilled.

Biochemically treated sludge, which is becoming increasingly difficult to maintain and contains a large amount of organic matter, is too soft for use in ponds and emits a foul odor, so it is not necessarily a good method, and untreated sludge is not suitable for environmental reasons. The investment amount was 100 million.

As one measure to deal with these problems, many small schools have adopted the method of incinerating the dehydrated cake, turning it into ashes, and then dumping it. However, when incinerating dehydrated cakes, a combustion aid for the strips, mainly heavy oil, is required. Ta.

In part, biochemically treated sludge has poor permeability and high compressibility, resulting in a high water content in the I-filtration cake, which also increases fuel costs. Therefore, in order to carry out efficient dehydration treatment, it is necessary to perform dehydration treatment using shavings or a filter aid, and a number of methods have been proposed and adopted. Among them, method V1 of adding maple porridge Nichichi and slaked lime, which is currently used for raw, has good dehydration properties and low water rate, and the combustion improver of poly J11 is safe and easy to use. ,
Shiki et al. 1c has a large amount of ash from the incineration workers, and there are 8 problems in which 61 (1h chromium) is generated.On the other hand, M machine's method of dehydration treatment using Yuki Mosaishu i41 straddle , there is no increase in ash content in 7A Luo, but the moisture content of the dehydrated cake is high;
The heat was dissipated by the evaporation of water in the cake, and the calorific value of the cake itself was not high enough to cause combustion, so a combustion improver was still required.

Recently, as an improved method for treating these sludges, flammable and
In addition, a method has been proposed in which dehydration is performed using a filter aid such as highly rigid pulverized coal9 coal coke or petroleum coke and a flammable polymer coagulant, and the resulting dehydrated cake is also removed. There is. In this method, the rigidity of the filter aid 11 is;
I/Kome, high pressure 3'j r high dehydration is circular and Kuji, C'
□Shin 71j J station i resident horse Zuni is also good e? 5. It is possible to become sexually active. The water rate of the water distribution cake is low, and 0-':lI→sukeJ-tl'r means that the fruit is all about Roe's desire/Kome VC1's free fever firefly trade dehydration cake, 74 However, when incinerating the dehydrated cake, you can use heavy oil or other auxiliary methods.

However, this method only takes into consideration the dewatering and incineration of sludge, and regardless of the biochemical treatment method for sewage that is the source of P2 sludge, carbon powder is added as a filter aid immediately before the filter step 8. Special cooperation was required.

The first object of the present invention is to improve the efficiency of a consistent process through the biochemical treatment process of sewage, the filtration process of the sludge, and the combustion treatment process, and to reduce the processing cost of energy-saving sewage. It is necessary to provide a treated γ stem.

Conventionally, the sludge dewatering process [Iyu ('')
j(rζζ) flammable carbonaceous powder τ, 7
Addition of eIh as a flow 'frVJ bed body during treatment of generated W ″,
, 11) The series of operations for dehydrating the sludge and mixed matter and incinerating and ashing the resulting weakly dehydrated cake is circular, and this equipment has been problematic in the conventional fluidized bed activated sludge method. By changing from a temporary floor to filtration and incineration, the ability of biological treatment is lowered and the sedimentation of f'i mud is reduced. ψ The dehydration and purification ability are improved, and in sludge dewatering, high pressure and pre-dehydration are enabled, and a self-combustible dehydrated cake can be obtained, and an auxiliary combustion fan is required for incineration of the dehydrated cake. We were able to provide a series of sewage treatment systems that produce less incinerated ash.

In other words, the patent collapsed due to the suppression of C1 with such a large effect by combining ten sewage treatment systems, which were individually known in fragments, into a series of sewage treatment systems.
I didn't know until now.

Carbon 45f grains F used in the A invention, b'L arterial activity (Fluid medium in the G mud method, force dehydration aid RIJ during sludge dehydration, and:
゛It is not something that waits for the element as a combustion improver at the time of command.
Although it is not 1, it is %"!'A.
1. I stirred the inside of my mind, l/(: , jf),
A large flow of nW agitation requires 99% of the sludge to be mixed with the sludge in the settling tank, which improves the sedimentation and separation properties of the sludge. It is essential that the material be a granular material that enhances the dehydration aid.Pulverized coal coke, petroleum coke, and petroleum coke that have been conventionally used as dehydration aids can be used by correcting these conditions. In particular, coke is a residue from the distillation of crude oil, contains more than 90% carbon, and has an extremely low ash content of 0.4% or less. It is added as a dehydration aid in the system to increase dewatering efficiency, and since a combustion aid is not necessary when incinerating sludge, and the amount of ash can be reduced, it can be used as a waste at final disposal. In addition, petroleum coke is suitable for door + 1 father I Ekisina θ 1 Yotochi and must be l'ko 〇 these vn coal'rRN in o,) i> iAl n
'; ji, m 'GCL 7-C, 1: ) VC5
7. Effect as dehydration aid, combustion aid 11111. /
In addition to rice, efficiency in biological treatment is the same as above; 3-戊')-(
i-core stand: It is necessary to take J'J I'C into account when setting.

First, the first biochemical treatment. )
The more carbon powder particles Qλ, the 5. The settling of sludge in the 1st and 1st minute is improved, but when it is too much, 11,] % + Flow in VR Stirring A Half Energy
- There are many ri, 1 lko, 1
・;Si element 4 minutes Il'j1 fruit, the more yga water, the greater the effect, but if there are too many νC, the moon r.
For P punishment, 30-1204 in the heavy political ratio is the most important.

During the Kid's process, carbon powder (4579) was added.
: The higher the amount, the lower the residual moisture content of the dehydrated cake.
If one door is passed, the conversion rate will be faster, but if there are more than 9
C: d) The treatment of the mud itself is degraded, requiring a large amount of dewatering equipment, and the waste of heat energy is also uneconomical. The experiment was repeated with many types of rock, additives, and 1-grain-cut VC;
0 to 200% is preferable, especially p(, 40 to 100% is M
It was suitable and rare.

Finally, we conducted many experiments on the flammability of the dehydrated cake itself. As a result, the more carbon particles there are, the better the flammability becomes, but it is not thermoeconomically preferable.

On the other hand, if there are too few carbon particles, self-combustion will not occur and a large amount of combustion improver such as heavy oil will be required. Generally 1. When using a filter press type or belt press type dehydrator, which is often used, the residual moisture in the dehydrated cake is 1.
It is about 40 to 80% of the former bale, and in order to make it self-combust, the carbon powder must be about 20 to 100% by weight of the solid content excluding it. child.

For the three processes of biochemical treatment, filtration and dehydration, and incineration, coal powder is strangely preferable. On the other hand, it is fortunate that the llj and l4 ratios fell within the range of 30 to 1009b. As mentioned above, by using a fluidized bed medium for biochemical treatment, the sedimentation properties of sludge are improved, and the concentration of returned sludge can be increased. Therefore, compared to the general activated sludge method, it is less able to maintain a high number of microorganisms in one aeration tank, and as the number of microorganisms increases, the oxygen demand in the aeration tank increases. Therefore, the oxygen supply will need to be increased accordingly. In water washing, if air is used as the oxygen source, this can be countered by increasing the amount of air supplied to the lower aeration tank, but it is preferable to use a gas that improves the oxygen level, i.e.,
By introducing oxygen-enriched air, the amount of dissolved oxygen in the liquid can be increased, reducing the -1-purification l:I heat, and also shortening +++1 during aeration. , ld, it is also possible to turn the device into a sheave.

However, conventionally, for example, when using air enriched with oxygen a = 90% or more, the oxygen utilization efficiency was 90~90%.
At 95%, residual V was released into the atmosphere as exhaust gas containing about 40 to 5096 oxygen.

The second object of the invention is to effectively utilize the exhaust gas produced by oxygen-enriched air as an oxygen source for an incinerator.

To explain the invention in detail with reference to the drawings, sewage is mixed continuously or intermittently with carbon powder in a conduit 1 and subjected to an aeration process 3. The sewage water shown here is sewage, human waste,
It refers to organic wastewater that has been treated in advance to a state where it can be biologically treated, such as domestic wastewater, industrial wastewater, or r. For example, in the case of sewage, VC refers to sewage that has been subjected to sedimentation, screening, and initial settling treatment. In addition, the carbon powder at this time was I
H-contact is applied to the aeration tank 3, and dissolved oxygen is supplied by exposing it to the aeration tank 3 so that it does not become too tight even when mixed. At the same time, the inside of the tank is stirred and mixed to keep it aerobic, and the microorganisms that have settled on the introduced carbon particles decompose the 44 imitated carbon in the C2 sewage and purify the sewage. .

The water treated in the aeration cycle 3 is separated by sedimentation into sludge containing carbon particles and C1 silt. The supernatant water from the separation is discharged as treated water through the conductor 7. Some of the settled sludge is returned to the aeration tank 3 as return sludge while remaining mixed with carbon powder.
A pure white imitation with a VC glaze.

On the other hand, the remaining sludge is led to the sludge storage chamber 10 via the bone canal 8 as surplus sludge and mud. Furthermore, the sludge was added with a combustible polymer flocculant at 4.12 centimeters, and then added to the dehydrator 13.
The line will be connected to the

In this case, it depends on the polymer coagulant 7JO-Rh and the sludge injection shape VC, but the sub-burst ratio is 0.5 to 1 with respect to solid revolution JΔ゛ other than vJ carbon ω grains in the sludge. .5;
If you add water, you will be able to perform efficient dehydration.

Dehydrator 13μ, incineration of dehydrated cake 1 possible/In this case,
Highly dehydrated by high pressure di-R with filter press,
It is preferable to make a dehydrated cake because the cake moisture content is low and it takes a long time to fully heat, but even if you use a belt-free one-pan permanent cake, it will result in a dehydrated cake with a low moisture content. With the adjustment made by Ms. Yuka, a sufficiently natural dehydrated cake can be obtained.

After dehydration, the dehydrated cake is returned to the sedimentation chamber 6 via a conduit 18, and the dehydrated cake is transported to an incinerator 15. Incinerator 15
VC & j, combustion air is fed from conduit 17, incineration ash t:i is 1. It is discharged from pipe 16 and disposed of. In advance, so that the dehydrated cake becomes self-combustible,
There is no need to supply a heat aid such as electric oil to the incinerator 15 in the case where the carbon powder is injected into the incinerator 15. However, when igniting the incinerator 15, the combustion It goes without saying that a combustion aid is necessary for enclosing air production υ.

19. Exhaust gas request when oxygen is used in aeration tank 3
By passing the oxygen into the conduit 17 of the incinerator 15, oxygen in the exhaust gas can be effectively used as phosphorus for combustion.

In addition, General I (sewage and other sewage often contains sulfur), but when the dehydrated cake is burned, sulfur oxides are included in the ZF gas, causing air pollution.
C. It is necessary to perform one nod gas treatment using calcium. However, if calcium lbs, such as slaked lime, is added to the dehydrated cake, 0aSO4 can be produced in the Le6 incinerator.
It is possible to reduce the amount of sulfur oxides in the gas, so even if the sulfur oxide in the gas is reduced, the sulfur oxide in the combustion gas will be reduced, especially when the A system is strict. In this case, before adding the flocculant in the 4 tube 12, add slaked lime in advance.
In addition, dehydration and incineration may be performed. In this case, 1/C is the heat generation of the dehydrated cake i￥ because the tri lime is inorganic.
I: decreases. Therefore, the amount of carbon powder added may be adjusted so that a self-combustible dehydrated cake is obtained.

On the other hand, sludge may be generated before and after the biochemical treatment of sewage, human waste, and water. If the sludge is to be dehydrated and incinerated at the same time, it is sufficient to introduce these sludges into the sludge storage phase 10, mix them, and perform the -C treatment. It is also possible to newly add carbon powder, flocculant, etc. and perform dehydration treatment.

In addition to the above, the present invention uses low-cost carbon powder to improve and stabilize the raw material, improve the '+' lf properties of sludge sediment molecules, and simplify the equipment, and enables V to be used in sludge dewatering treatment. , less cooling of the auxiliary agent, high compression, sieve dehydration possible,
Furthermore, combustion aids such as heavy oil are not required when incinerating dehydrated cakes, and there is little incineration ash.Furthermore, it can be effectively used for incinerating sludge, which is the waste gas of biochemical treatment, and the overall treatment efficiency is high. This is a low-cost, labor-saving sewage treatment system that has been completed.

Next, an explanation will be given based on an example of the present nine colors.

Example 1 Into a horizontal aeration tank containing 6000 mg/A' of activated sludge from a sewage treatment plant and having a volume of 500 a and capable of naturally returning sludge, ten million coke containing 70% or more of particle sizes of 0.05 to Q, 3 rkM was added. 1 ky me, B'OD 140
m g/e primary 6-g water at 280 l/Hr
, air at 1700 l/Hr, oil coke at 1
At the rate of 200g of daily digging, the treated water is 1〆 and the sludge is flowing out.When it comes to it, I use it as sludge - CJ went out. , r
BOD 16-20 mg
/ It was A'. In addition, the solid content of the excess sludge at this time was 45% of the solid content excluding the oil coke nuden contained therein.

On the other hand, the same amount of activated sludge was put into the same volume of one-body gas phase, no oil coke was added, and air was blown at 8004/hr.
When the same primary treated water is added (BOD 20 m
g/ 11+ treated water +c n, 1351/
It was only possible to supply primary treated water under 9 hours.

Furthermore, each sludge was settled at 10:00.
After shrinkage, excluding oil coke, 1 liter solids per PC)
When 1.0% was added and stirred with a water bottle and filtered and dehydrated using a belt press type dehydration tester, the following vines were obtained.

*The 1st shift in India is filled with oil coke.

In addition, η Q: Lower calorific value of dry cake (kl/kg-DB) d: Cake water content ratio (kg Ha 07kg -' DB) 1: Evaporation retention (9-1420 to 600 td/) η: Incinerator efficiency (96 ) rM m's floor incinerator ノFJ '/' 7e '-A
Since pJ is B and furnace efficiency is 40 to 45 l, furnace efficiency is 40%.
As the above formula? : The filled dehydrated cake is self-combustible. In other words, the sludge containing C olefin coke on top of the sludge of 7 B and 11 does not require auxiliary heating and can be incinerated [IT ij
f: is.

Example 2 Activated sludge was applied to 6000 m of the same aeration tank as Example 1.
Add g/l, o, 05-'a, sas grains (pulverized coal containing 7096 or more l + tg, add 370/l/Hr of sewage treatment water, ItD harden, 13 yen f degrees) Air with a concentration of 30% was introduced at 10001/ur, pulverized coal was supplied at a rate of υ450g per day, and the temperature was acclimatized for 4 days (1), BO'D135XQg,/el.
ll-sub-treated water was obtained with 'Bonxsn+g/4 of the treated water. Furthermore, if this excess sludge is concentrated for 10 hours,
The sludge concentration was 3.4%. Of the 1 fd of this sludge, the amount of pulverized coal contained in it was 89% of the total weight of the sludge. Of the solid content of this collected sludge, a cationic polymer flocculant was added and stirred at a weight ratio of 196 to the mold light excluding the pulverized coal MM contained therein, and filter press As a result of filtration and dehydration using a small test machine, the result is a dry cake. The overspeed is 4.50 icy/
/ Ni・Seven.

Cake moisture 61.3%, dry cake low heat generation f4330
M/IC9-DS, and was self-combustible according to the formula shown in Example 1.

[Brief explanation of drawings]

The drawings show the sewage treatment of the present invention and its LRI mud M
70-sheet of jN method. Code explanation 1, j, 5, 7, 8.9.11, 12.14, 15.1
6.17.19 Conduit 3 @Ni 6 1O sludge storage 13 Dehydrator/, 5''' 17

Claims (1)

[Scope of Claims] (1+ Carbon powder is added continuously or intermittently to wastewater, and an aerobic biochemical treatment is performed using air or oxygen-enriched air, and the wastewater is generated from the treatment a. The surplus sludge K containing carbon powder is temporarily dehydrated by adding a flammable flocculant, and the dehydrated cake is further incinerated.
``Method for treating sewage. (2) The above carbon powder addition bay is removed from the solid content of generated excess sludge, and the carbon powder is 30 to 100% of the total content of the carbon powder. A method for treating sewage according to Claim No. +1), wherein the carbon powder is pulverized coal. (4) A method for treating sewage according to Claim No. ) The wastewater treatment method according to claim (1), wherein the carbon powder is coal coke. (5) The carbon powder is petroleum coke.
The method for treating sewage as described in item (m) above. (6) So≠→Now≠When oxygen-enriched air is turned on and aerobic biochemical treatment is carried out, the above dehydrated cake is baked with 1:i silicon gas and the above dehydrated cake is heated. The sewage treatment method described in claim (1) to Hisa and Hara.