JP3369915B2 - Night soil treatment equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention can stabilize the septic tank sludge, improve the decomposition of organic matter in raw urine, particularly high molecular weight organic matter, do not generate a bad odor, and improve solid-liquid separation, Moreover, the present invention relates to a urine treatment apparatus in which sedimentation separation is improved by improving solid-liquid separability, and consequently the amount of sludge to be dehydrated can be reduced.

[0002]

2. Description of the Related Art Conventionally, human waste treatment facilities have been required to complete treatment through complicated steps for the purpose of treating high concentration human waste pollutants at high levels.

In recent years, however, the amount of pumped urine (live urine) has rapidly decreased due to the irrigation of household toilets due to the wave of urbanization even in distant areas of the city, and instead it has become an agricultural settlement wastewater treatment facility. The amount of sludge from the combined septic tank represented by is rapidly increasing.

The role of the human waste treatment facility is required to treat raw urine and septic tank sludge, and a treatment method in a simplified process corresponding to the changing situation is required.

The combined septic tank sludge is an excess sludge for biological wastewater treatment, and simplification of equipment can be expected by treating it together with the treatment of excess sludge at a night soil treatment plant.

[0006] However, septic tank sludge has a characteristic that its properties are not stable, and that the characteristics of the surplus sludge differ according to the priority species of organisms depending on the wastewater treatment method,
Alternatively, depending on the case, there is a characteristic that a toxic substance to bacterial cells is contained or the concentration of heavy metals is high.

[0007] Conventionally, as a means for simplifying human waste treatment facilities,
A method has been proposed in which septic tank sludge is mixed with excess sewage treated sludge and raw urine to coagulate and dehydrate (Japanese Patent Publication No. 7-4598).
(See the official gazette).

[0008]

[Problems to be Solved by the Invention] However, Japanese Patent Publication No. 7-4
According to the method described in Japanese Patent No. 598, the entire amount including the excess sludge is dehydrated. However, if the total amount of dehydration is performed, there is a problem that the equipment becomes excessively large. That is, it is difficult to make the dehydration work unmanned, and because of such difficulty, if the dehydration work is to be completed only by the daytime work, the dehydration equipment must be oversized. In addition, if the entire amount is dehydrated as described above, the amount of the dehydrated cake inevitably increases, and its treatment becomes a problem. Further, in order to cope with the change in the properties of the septic tank sludge, there is a problem that the amount of the polymeric dehydration auxiliary agent must be excessively added in consideration of the maximum load. Furthermore, dehydrated sludge contains a large amount of high molecular weight dehydration aid and raw urine organic matter (especially high molecular weight organic matter such as proteins, starch, lipids, etc.). There is a problem that tends to occur. Furthermore, in recent years, it has been instructed to prohibit incineration of excess sludge from the human waste treatment plant from the viewpoint of preventing environmental pollution, and it becomes more difficult to treat excess sludge that produces a foul odor.

Therefore, the present invention provides stabilization of septic tank sludge,
An object of the present invention is to provide a human waste treatment device that can improve the decomposition of organic matter, particularly high molecular weight organic matter, in raw urine, generate no offensive odor, and improve solid-liquid separation.

It is another object of the present invention to provide a human waste treatment device which improves solid-liquid separability, thereby improving sedimentation separation and consequently reducing the amount of sludge to be dehydrated. .

A further object of the present invention is to provide a waste urine treatment apparatus in which sludge properties are stabilized and the amount of the polymeric dehydration aid added can be reduced.

Still another object of the present invention is to provide a human waste treatment device in which organic matter is decomposed and a process such as composting process of dehydrated sludge, which is easy to perform incineration, is facilitated.

[0013]

In the treatment apparatus for human waste water according to the present invention, which solves the above-mentioned problems, human waste water containing at least raw urine and septic tank sludge is introduced and an additive containing a dephosphorizing agent is added and mixed. An addition section, a pre-reaction means for introducing and mixing the waste urine wastewater to which the additive has been added and mixed in the addition section, and an oxidation treatment, and the waste water treated by the pre-reaction means in a supernatant and sludge.
A sludge settling tank for performing gravity-type solid-liquid separation, a dehydrating means for dewatering the sludge separated in the sludge settling tank, and a reaction means for introducing the supernatant liquid separated in the sludge settling tank to perform nitrification denitrification treatment. Having a solid-liquid separation means for solid-liquid separating the suspension sent from the reaction means into a sludge and a treatment liquid, and returning excess sludge generated in the reaction means to the addition section or its preceding step It is characterized by having a returning means.

[0014]

In a preferred aspect of the present invention, the solid-liquid separation means is a membrane separation means, and the membrane separation means has an activated carbon treatment means for decolorization.

As another preferred embodiment of the present invention,
In the addition section, an additive containing a silica component is added together with the dephosphorizing agent.

In a more preferred aspect, the additive containing the silica component is a solution of an inorganic salt containing the silica component and the magnesium component, and the additive containing the silica component is a composite crystal mineral of silica. It is a silica-based coagulating liquid obtained from a silica-based raw material composed of an amorphous mineral, and the additive containing the silica component is a soil compact mainly composed of humus.

[0018]

[0019]

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The human waste wastewater to be treated in the present invention contains at least raw urine and septic tank sludge, and the septic tank sludge can contain combined septic tank sludge. In the present invention,
The human waste wastewater consisting of septic tank sludge or live urine may include miscellaneous wastewater.

FIG. 1 is a block diagram showing an example of an embodiment of the present invention, and FIG. 2 is a block diagram showing another example of an embodiment of the present invention.

FIGS. 1 and 2 show an example in which both raw urine and septic tank sludge are received. In FIG. 1, 1 is a first pretreatment means for introducing septic tank sludge to remove impurities. Reference numeral 2 is a second pretreatment means for introducing live urine to remove impurities.

The first and second pretreatment means 1 and 2 are sand,
It is a means for removing contaminants such as stones, paper, fibers, rubber products, hair, and other dust, and its configuration is not limited.

The first and second pretreatment means 1 and 2 may be provided separately, but one may be shared.

Reference numeral 3 is an additive addition section, 4 is a dephosphorization addition equipment, and 5 is an addition equipment of an additive containing a silica component.

Examples of the dephosphorizing agent include polyiron chloride (polyiron) and ferric chloride.

As the additive containing a silica component, first, a solution of an inorganic salt containing a silica component and a magnesium component can be used. For example, a mixed solution of silicate and magnesium salt can be used.

Secondly, as an additive containing a silica component, it is also preferable to use a silica-based coagulating liquid obtained from a silica-based raw material composed of a silica composite crystal mineral / amorphous mineral. The silica-based coagulating liquid may be prepared by dissolving blast furnace slag or the like in a reducing acid or a neutral acid, preferably dilute sulfuric acid. As a specific example of the dissolution method, Japanese Patent No. 255859
The method described in No. 1 is mentioned. Further, as the additive containing a silica component, a crystal mineral containing a silica component, for example, trade name “Fuyomineral” can be used.

Thirdly, as the additive containing a silica component, a soil compact mainly composed of humus can be used.

The addition amount of the additive containing the silica component is preferably in the range of 1.0 to 200 mg / l as silica with respect to the mixed liquid of raw urine, septic tank sludge and excess sludge.

Additives containing a silica component include silica (Si
O ₂ ), calcium, magnesium, and aluminum are contained as main components, and these components contribute to aggregation of raw urine and septic tank sludge, and prioritization of useful bacteria.

In the present invention, 6 is a pre-reaction means,
The pre-reaction means 6 is for reacting the waste urine wastewater to which the additives have been added and mixed prior to the subsequent biological treatment (nitrification denitrification treatment). Specifically, it is contained in the waste urine wastewater by the pre-reaction. Oxidative decomposition of organic substances reduces liquid viscosity and improves solid-liquid separation. In addition, the high-molecular organic matter is oxidatively decomposed by the pre-reaction to suppress the malodor. Further, by pre-reaction, one or more aerobic or facultative anaerobic bacteria occupy the preferential species to suppress the anaerobicization of the septic tank sludge and stabilize the properties.

As a pre-reaction means for carrying out such an oxidation treatment, as shown in FIG. 3, a pre-reaction tank 601 is provided, and urine wastewater is drawn out from the pre-reaction tank 601 by a circulation pump 602 to the outside of the pre-reaction again. A preferable example is a method in which an air mixing unit 603 is provided in the process of returning to the tank 601 to mix air into the circulation line and mix air into the human waste wastewater in the previous reaction tank.

Although not shown, a method is also preferable in which an air diffuser is provided in the pre-reaction tank, air is supplied to the air diffuser, and air is mixed into the waste effluent in the pre-reaction tank.

In the present invention, a dephosphorizing agent is used as an additive. When polyiron, which is usually used as such a dephosphorizing agent, is used, sludge is separated without passing through the pre-reaction means through the addition part. However, there is a problem in that the polyiron does not function as a coagulant due to the reaction in a reducing atmosphere. That is, if air is not supplied, the atmosphere becomes a vigorous reducing atmosphere. In the reducing atmosphere, iron easily forms a complex with an organic substance and does not form iron phosphate.

On the other hand, if the pre-reaction treatment is carried out, it becomes in an oxidized state and does not oxidize and decompose organic matter to form an iron complex. Therefore, polyiron functions as an aggregating agent and the effect of dephosphorization is further improved. . Further, in the present invention, the equipment cost is significantly reduced as compared with the case where dephosphorization after nitrification denitrification is separately provided.

Further, when the above-mentioned additive containing the silica component is used as an additive, a facultatively anaerobic useful bacterium (specifically, Bacillus genus) occupies a priority species in the pre-reaction tank. This makes it difficult for anaerobic bacteria and spoilage bacteria to survive. Therefore, even in sludge with strong anaerobic property such as septic tank sludge, the properties are stabilized by facultative anaerobic useful bacteria occupying the priority species. Since the above-mentioned useful bacteria are excellent in degradability of high molecular weight organic substances (proteins, starch, lipids, etc.), the reaction does not proceed in the anaerobic direction, which makes it difficult to survive the anaerobic bacteria and spoilage bacteria. It can prevent spoilage.

In the present invention, the tank capacity of the pre-reaction tank is the amount of water in the case of continuously introducing human waste water (in the present invention, the amount of water is the amount of the mixed liquid of human waste waste water and excess sludge consisting of raw urine and septic tank sludge). 1)
It is preferable to set the capacity to 3 days or more and 3 days or less. An environment where one or more bacterial cells contained in human waste wastewater are facultative anaerobic or oxidatively treated, and the priority species is the one in which human urine wastewater load fluctuations are suppressed if it is more than one day. Because you can make. It is within 3 days, preferably within 2 days, because too large a capacity causes an increase in cost.

After the pre-reaction, the example of FIG. 1 has a sludge settling tank 7 for solid-liquid separation into a supernatant and sludge, and a dehydrating means 8 for dehydrating the sludge separated in the sludge settling tank 7.

As the sludge settling tank 7, an ordinary gravity settling settling tank can be used. In the present invention, since the solid-liquid separation property of sludge is improved, the sludge settling tank 7 cleanly separates the supernatant liquid and the sludge. Therefore,
As a result, the amount of sludge to be dehydrated by the dehydrating means 8 is reduced.

A high molecular weight dehydration aid is used in the dehydrating means 8. However, when the sludge properties are stabilized, the amount of the high molecular weight dehydration aid added can be reduced.

The sludge (cake) that has been further dehydrated is a sludge in which organic matter is decomposed and useful bacteria are preferentially present, so that it is in an environment where spoilage bacteria cannot live, and therefore,
The dehydrated sludge can be easily composted, and it has the effect of facilitating the process of incineration.

Furthermore, since the present invention has the returning means 8A for returning the excess sludge generated in the reaction means which will be described later to the addition section 3 or the preceding step thereof, the excess sludge can be dehydrated and pretreated. The generated septic tank sludge can be dehydrated at the same time, and the cost of the dehydration equipment can be reduced.

The separated liquid separated by the dehydrating means is returned to the biological reaction means 9 for reprocessing. Next, in the example of FIG.
A dehydrating means 8 for directly dehydrating the wastewater treated by the pre-reaction means 6 is provided.

The sludge capable of performing such direct dehydration is a sludge having an extremely improved solid-liquid separation property, and such direct dehydration has a drawback that the load on the dehydrator is increased as compared with the example of FIG. However, there is an effect that the facility cost is reduced because the sludge settling tank is not provided. Also with this method, dehydration of the excess sludge and dehydration of the mixed septic tank sludge generated in the pretreatment can be performed at the same time, and the cost of the dehydration equipment can be reduced as compared with the conventional method.

The aforementioned sludge settling tank 7 (FIG. 1) and dewatering means 8
The reaction means 9 following (FIG. 2) is mainly composed of a nitrification denitrification treatment tank, and the structure of the nitrification denitrification treatment tank is not particularly limited.

In the present invention, the presence of the above-mentioned pre-reaction means 6 accelerates the oxidative decomposition of the organic matter, so that the load of the organic matter is reduced in the nitrification / denitrification treatment tank and the viscosity is not increased. Stable processing becomes possible.

Further, when an additive containing a silica component is used, a treatment system is formed so that the biota of the useful microorganism or the useful bacterium occupy the priority species, so that the useful bacterium is also used in the nitrification denitrification treatment tank. Became a priority species,
The biota is stable and stable treatment is possible.

Reference numeral 10 denotes a solid-liquid separation means. As the solid-liquid separation means, a gravity sedimentation type precipitation tank or a membrane separation means can be adopted, and it may be selected according to the characteristics of the treatment liquid. In this example, the case where the membrane separation means is adopted will be described.

The membrane separation means is a means for solid-liquid separation of the suspension (activated sludge) sent from the biological reaction means 9, but as described above, the treatment in the nitrification denitrification tank is stable, Clogging is also reduced, the recovery effect of the membrane flux by cleaning is stabilized, and it is possible to stabilize the membrane treatment.

The type of membrane used for the membrane separating means may be any of ultrafiltration membranes, microfiltration membranes, reverse osmosis membranes and the like, and the method of use thereof may be a type installed in a tank (so-called submerged membrane type) or a tank. It may be installed outside. The form of the membrane may be either flat membrane or tubular.

The activated sludge is separated into the permeate and the concentrated sludge by the membrane separation means, but the concentrated sludge is returned to the reaction means 9, and a part of it is excess sludge as described above in the addition section 3 or the preceding step thereof. Will be returned to.

The permeate separated by the membrane separating means is further highly treated if necessary. For example, the decolorization treatment is mainly performed in the activated carbon treatment means 11 as shown in the figure, and the treated water is reused or discharged.

[0055]

EXAMPLES Examples of the present invention will be described. The present invention is not limited to the embodiments.

Example 1 Using the treatment apparatus shown in FIG. 1, surplus sludge for biological treatment was mixed with the waste sewage wastewater consisting of pretreated septic tank sludge and raw urine, and introduced into the addition section.

The respective volume ratios in the mixed liquid of septic tank sludge, raw urine, and excess sludge are as follows: septic tank sludge: raw urine: excess sludge = 6:
It was 3: 1.

The properties of the mixed solution introduced into the addition section were as follows. The analysis method was in accordance with JISK0102.

PH 7.96 BOD 3,050ppm COD 2,300ppm TP 150ppm SS 2,930ppm

The additives added in the addition section were polyiron and silica-based additives.

In this example, a silica-based additive having the following composition was used. SiO ₂ 10,000 to 12,000ppm Al ₂ O ₃ 1,600 to 2,600ppm CaO 600 to 1,000ppm MgO 600 to 1,200ppm

However, monomer silica in the dissolved silica in the above additives accounted for 80% or more. The amount of polyiron added and the amount of silica-based additive added were as follows. Addition amount of polyiron: 1% with respect to the mixed liquid (as liquid) Addition amount of silica-based additive: 100 mg / l of silica with respect to the mixed liquid.

The capacity of the pre-reaction tank was set to a two-day retention capacity with respect to the total amount of the mixed solution.

Under the above conditions, experiments were carried out with and without the pre-reaction tank.

In each case, the supernatant of the sludge settling tank was analyzed to compare the treatment effects. In order to compare the sludge settability in the sludge settling tank, SV ₃₆₀ , SV
₁₂₀₀ , SV ₂₈₈₀ was examined. Experimental results ──────────────────────────────────── When the pre-reaction tank is installed If not ──────────────────────────────────── pH 7.3 8.01 BOD 370ppm 2,860ppm COD 490ppm 2,220ppm T -P 14ppm 20ppm SS 810ppm 2,450ppm SV ₃₆₀ 56 99 SV ₁₂₀₀ 50 97 SV ₂₈₈₀ 45 94 ──────────────────────────────── ──────

From the above results, it can be seen that the sludge settling property is greatly improved. Further, the values of BOD and COD were significantly reduced, but this was due to the decomposition of BOD and COD, and as a result, it was confirmed that the liquid viscosity was also reduced.

[0067]

As described above, according to the present invention, stabilization of septic tank sludge, improvement of decomposition of organic matter in raw urine, particularly high molecular weight organic matter, generation of offensive odor, and improvement of solid-liquid separation are achieved. It is possible to provide a human waste treatment device.

Further, according to the present invention, by improving the solid-liquid separation property, sedimentation separation is improved, and as a result, the amount of sludge to be dehydrated can be reduced, and a human waste treatment device can be provided. .

Further, according to the present invention, it is possible to provide a human waste treatment device in which sludge properties are stabilized and the amount of the polymeric dehydration aid added can be reduced.

Furthermore, according to the present invention, it is possible to provide a human waste treatment device in which organic matter is decomposed and a process such as a composting process of dehydrated sludge, which is easy to perform incineration, is facilitated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an embodiment of the present invention.

FIG. 2 is a block diagram showing another example of the embodiment of the present invention.

FIG. 3 is an explanatory view showing an example of a pre-reaction tank.

[Explanation of symbols]

1: First pretreatment means 2: Second pretreatment means 3: Addition department 4: Addition equipment for dephosphorizing agent 5: Addition equipment for additives containing silica component 6: Pre-reaction means 7: Sludge settling tank 8: Dehydration means 9: Reaction means 10: Solid-liquid separation means 11: Activated carbon treatment means

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-108692 (JP, A) JP-A-63-28500 (JP, A) JP-A-57-194096 (JP, A) JP-A-6- 226290 (JP, A) JP 7-124584 (JP, A) Actual development 1-6 1998 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) C02F 3/34 101 C02F 3/12

Claims (6)

(57) [Claims] 1. An addition unit for introducing and mixing human urine wastewater containing at least raw urine and septic tank sludge to add and mix an additive containing a dephosphorization agent, and introducing urine wastewater to which the additive has been added and mixed in the adding unit. And a sludge settling tank for performing gravity solid-liquid separation of the wastewater treated by the pre-reaction section into a supernatant and sludge, and a sludge separated in the sludge settling tank. Dewatering means for dehydrating, reaction means for introducing nitric acid denitrification treatment by introducing the supernatant liquid separated in the sludge settling tank, solid-liquid for solid-liquid separation of the suspension sent from the reaction means into sludge and treatment liquid An apparatus for treating waste urine wastewater, comprising: a separating means, and a returning means for returning the excess sludge generated in the reaction means to the addition section or the preceding step thereof. 2. The treatment apparatus for human waste wastewater according to claim 1 , wherein the solid-liquid separation means is a membrane separation means, and the activated carbon treatment means for decolorization is provided after the membrane separation means. 3. An additive containing a silica component together with a dephosphorizing agent is added in the adding section.
Is an apparatus for treating human waste wastewater according to 2 . 4. The treatment apparatus for human waste water according to claim 3, wherein the additive containing a silica component is a solution of an inorganic salt containing a silica component and a magnesium component. 5. The additive comprising the silica component, according to claim, characterized in that a silica-based aggregation liquor from silica-based material comprising a composite crystalline mineral and non-crystalline minerals silica 3
An apparatus for treating human waste water as described. 6. The method of claim 3 in which the additive containing the silica component, characterized in that it is a soil molded body consisting mainly of humic
An apparatus for treating human waste water as described.