JPH07236802A - Sewage treatment aid - Google Patents

Abstract

PURPOSE:To efficiently treat sewage without generating environmental pollution and without using a special device. CONSTITUTION:A sewage treatment aid containing zeolite, calcium chloride or oxide, aluminum oxide, iron oxide or chloride and phosphoric acid is added to sewage together with a conventional flocculant. As a result, flocs are formed within a short time and an emulsified oil component suspended in sewage can be efficiently removed. Since no sulfate ion remains in supernatant water even if aluminum sulfate is used as a flocculant, sewage can be discharged without employing a sulfate ion removing process. Even sewage containing a large amt. of calcium can be suitably treated by adding phosphoric acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid treatment aid applicable to the treatment of waste liquid after washing in the machinery industry, the semiconductor industry, etc., the waste liquid of livestock industry such as swine urine, domestic waste water, and other various waste liquids.

[0002]

2. Description of the Related Art Conventionally, the treatment of factory wastewater, sewage, etc.
The wastewater is allowed to stand in a sedimentation tank, and the sludge that has settled is concentrated, or after it has been subjected to coagulation by adding a coagulant such as van sulphate and dehydration, it is incinerated, and the supernatant is aerated by the activated sludge method, etc. After removal, it is discharged. Such a treatment requires large-scale equipment, and it was difficult to prepare such equipment in a medium-sized factory.

Further, in recent years, due to CFC regulations, a cleaning aqueous solution such as a surfactant is used as a CFC substitute for cleaning machined products and semiconductor devices. The waste liquid after washing with such a washing aqueous solution generally contains oil as emulsified colloidal particles in water, and therefore does not precipitate even when left standing and cannot be removed by the activated sludge method. As a method for removing such colloidal particles, there is a method of aggregating with a flocculant such as vanadium sulfate to precipitate and remove from water, but such a method is effective for a relatively small amount of colloid. However, colloidal particles could not be completely removed with emulsions such as machining waste liquid.

[0004]

Therefore, the inventors of the present invention have developed a method for treating a waste liquid by sequentially adding a coagulant consisting of a metal salt, an inorganic coagulant, a polymer coagulant, etc., and treating them. We have developed a waste liquid treatment device for implementing the waste liquid method. According to the waste liquid treatment method using such a waste liquid treatment device, colloidal particles turbid in the waste liquid can be efficiently removed. However, such a device is expensive even if it is small, and when the device is introduced, the cost of the device is reflected in the product, and the product related to the manufacturing process becomes expensive.

In order to improve the above-mentioned points of improvement, the present invention can efficiently remove colloidal particles and the like contained in a large amount of wastewater by adding them to conventional coagulants. It is an object of the present invention to provide a sewage treatment auxiliary agent that can reduce the price of a product because the sewage can be treated economically without using a special device. Furthermore,
INDUSTRIAL APPLICABILITY The present invention can reduce the amount of sulfate ions remaining in the supernatant after removing the colloidal particles even when treated with a flocculant containing sulfuric acid such as sulphate and remove the sulfate ions from the supernatant. It is an object of the present invention to provide a sewage treatment auxiliary agent capable of performing a rapid and low-cost treatment because the step of performing the treatment can be omitted.

[0006]

The sewage treatment aid of the present invention which achieves the above object is a sewage treatment aid which is added to sewage together with a coagulant to agglomerate the substance contained in the sewage. , Calcium chloride or calcium oxide. Furthermore, the wastewater treatment aid of the present invention preferably contains aluminum oxide, iron oxide or iron chloride, phosphoric acid or water.

The sewage treatment aid is preferably used as a coagulant composed of a metal salt, an inorganic coagulant, or a coagulant composed of a polymer. Hereinafter, the wastewater treatment aid of the present application will be described. The wastewater treatment aid is added to the wastewater together with the coagulant to remove the colloidal particles contained in the wastewater. Sewage treatment aids contain zeolite and calcium chloride or calcium oxide.

As the zeolite (aluminosilicate), either natural zeolite or artificial zeolite can be applied. Zeolite collects colloidal particles in wastewater to form flocs and facilitates precipitation (increasing apparent specific gravity of flocs). Even if the colloidal particles are contained in a large amount in the wastewater, almost all the colloidal particles in the wastewater can be removed by the zeolite together with the coagulant. Zeolites whose surface is treated with calcium chloride may be used. The zeolite surface-treated with calcium chloride can obtain a higher aggregation effect. Content of zeolite in auxiliary agent (excluding water) is 40% by weight
The following are preferred: This is because the same effect can be obtained even if the content is 40% by weight or more, and the viscosity becomes high and the handling becomes difficult.

Further, although zeolite has been used as a conventional flocculating agent, in this case, if artificial zeolite is used, a large amount of artificial zeolite must be used in order to obtain the same flocculating effect as when natural zeolite is used. However, in the sewage treatment aid of the present application, even artificial zeolite can obtain the same aggregating effect in the same amount as natural zeolite, and artificial zeolite should be used just like natural zeolite. You can

Calcium chloride or calcium oxide has an effect of taking in and precipitating anions in wastewater to remove colloids from the wastewater. In particular, when a flocculant containing a sulfate ion such as van sulphate which is commonly used as a flocculant is used, these substances react with the sulfate ion to cause precipitation and leave the sulfate ion in the supernatant. There is no. For this reason, it is possible to prevent the occurrence of secondary pollution, and even when it is treated with a flocculant such as vanadium sulfate, the conventional post-treatment for removing sulfate ions from the supernatant is omitted. be able to. Calcium chloride or calcium oxide is contained in an amount of 20 to 50% by weight based on the total amount of the auxiliary agent (excluding water), and particularly preferably 4
It is preferably contained in an amount of about 0% by weight. If it is 20% by weight or less, it does not act effectively on the coagulant, and 50% by weight
This is because the effects obtained by including the above are the same.

Further, the sewage treatment aid may contain aluminum oxide, iron oxide or iron chloride. These supplement the action of zeolite, and in particular, they combine with cations in wastewater to promote removal of cations from wastewater. In addition, by including these substances, it is possible to omit the post-step of adjusting the pH when discharging the supernatant after forming flocs into sewage or the like. The content of each auxiliary agent (excluding water) is preferably 0.1 to 5% by weight for aluminum oxide and 0.1 to 5% by weight for iron oxide or iron chloride. The content of these can be changed depending on the content of sewage and depending on the type of coagulant that treats sewage, but if the content is in the above range, it is applied to most sewage and also to various coagulants. It can be applied correspondingly.

Further, the wastewater treatment aid contains phosphoric acid. Phosphoric acid can be preferably used because, when treating hard water or the like containing a large amount of calcium, calcium ions and phosphate ions are combined and agglomerated by an aggregating agent. Phosphoric acid is added for pH adjustment, and the content of the auxiliary agent (excluding water) varies depending on the waste liquid to be treated, but is approximately 0.5 to 50% by weight. This is because if the amount is 0.5% by weight or less, the treatment cannot be completed, and even if the amount is 50% by weight or more, the same effect can be obtained.

Such components can be mixed with water to form a wastewater treatment aid. The amount of water mixed can be about the same as the weight of the composition. By mixing with water, the constituents are easily dispersed in the wastewater when treating the wastewater.
Such a wastewater treatment aid is used together with a commonly used flocculant, and can effectively perform wastewater treatment.
As the aggregating agent, any one of a metal salt complex, an inorganic aggregating agent, a polymer aggregating agent and the like can be applied. Examples of the metal salt complex include vanadium sulfate (aluminum sulfate), polyaluminum chloride, iron (III) chloride, iron (II) sulfate, sodium aluminate, polyiron and the like. As the inorganic coagulant, zeolite, diatomaceous earth, (active) alumina, silica (gel), titanium oxide,
Activated carbon, activated clay, porous glass, fly ash and the like can be mentioned. As the polymer flocculant, polyacrylamide, polyethylene oxide, nonionic polymer flocculant such as urea formalin resin, sodium polyacrylate, polyacrylamide hydrolyzate, partially sulfomethylated polyacrylamide, poly (2acrylamide) 2-methylpropane Examples thereof include polyanionic polymer flocculants such as sulfates, sodium alginate, and CMC, and polycationic polymer flocculants such as polyaminoalkylmethacrylate, polyethyleneimine, halogen-based polydiallylammonium, aineon, and chitosan.

The sewage treatment aid is added to the sewage together with the coagulant and applied to the treatment. Although each constituent of the wastewater treatment aid may be directly added to the wastewater, calcium chloride or calcium oxide is previously dissolved in water to form an aqueous solution, and aluminum oxide, iron oxide and phosphoric acid are added to the aqueous solution, and then zeolite is added. Mix it to make a sewage treatment aid.
Alternatively, a sewage treatment aid may be prepared by dissolving a substance other than zeolite in water to form an aqueous solution, and mixing the aqueous solution with surface-treated natural zeolite or artificial zeolite.

In the case of sewage containing a large amount of calcium ions, zeolite obtained by adding phosphoric acid to the sewage may be added to the sewage in advance, and then another substance may be added and then a coagulant may be added to treat the sewage. The amount of the sewage treatment aid used varies depending on the type of the coagulant and the type of sewage, but about 1 to 30% by weight is added to the coagulant for treatment. If it is 1% by weight or less, sulfate ions remain in the supernatant, the floc formation is not sufficient, and the effect obtained even if 30% by weight or more is added is the same, and the COD of the supernatant is increased. Because it will be.

When treating sewage using such a sewage treatment aid, the sewage treatment aid is put into a treatment tank filled with sewage together with the coagulant, and the rotary blades suspended in the treated sewage are driven by a motor. Stir using a rotating stirrer,
Alternatively, a water flow is generated in the treatment tank by stirring with a blower using air. In particular, bubbling agitation of blower agitation can generate a desired water flow such as rectification or turbulent flow in the dirty water at any time, can immediately form flocs, and easily form large flocs. This is preferable because the flock formed is not easily broken. The processing time of the blower stirring can be shortened by 30 seconds to 2 minutes and a half compared with the processing time of the stirring by the rotating blade. Further, although the rotary blades are easily damaged, the durability of the apparatus can be improved in the case of stirring with a blower.

Further, such a wastewater treatment aid can be stored in a water-soluble paper container or the like for use. The paper container is paper-made after modifying the carboxymethylated pulp into water-insoluble,
By using a sheet or the like that has been made water-soluble again, a container having a size that is easy to handle, for example, a volume of 10 l or the like can be prepared. A paper container of such a material containing a flocculant and the powder of the above-mentioned sewage treatment aid such as zeolite or calcium chloride together with a foaming agent is used. Then, the paper container is melted and the coagulant and the wastewater treatment aid are dispersed in the wastewater by directly adding the required number to the wastewater in accordance with the amount of wastewater and the amount of polluted water in the wastewater. At this time, a water flow can be generated in the wastewater by the foaming agent to promote the dispersion of the coagulant and the like. The fibers of the paper container that have dissolved in the water settle with the flocs and can be removed from the supernatant of the wastewater.

Further, such a paper container may be formed separately in a small chamber so that the coagulant can be stored according to the type.
That is, a first coagulant for treating sewage first, such as van sulphate soil, is placed on top. Next, the sewage treatment auxiliary agent is stored, and further, the second coagulant is stored under the room in which the sewage treatment auxiliary agent is stored, and the foaming agent is stored at the bottom. Alternatively,
The foaming agent may be stored together with the coagulant and the wastewater treatment aid. Further, a wastewater treatment aid, a foaming agent, etc. can be stored together with each coagulant. The separation membrane that separates each room of such a paper container adjusts the paper thickness so that the coagulant, wastewater treatment aid, foaming agent, etc. individually stored in the paper container are sequentially dispersed in the wastewater. May be provided. As described above, by storing the coagulant and the like in a small room in a divided manner, the coagulant and the like are dispersed and dissolved in the wastewater with a time lag in a desired order, and thus the wastewater is sequentially treated with an optional coagulant. It is possible. Example 1 The following constituents were dissolved in 60 ml of water in 1 liter of waste water in which machine oil was emulsified with a detergent, and then zeolite 40 was used.
After adding and stirring the sewage treatment aid containing g, a nonionic flocculant (trade name: Sun Poly N500: manufactured by Sankyo Kasei Co., Ltd.)
20 cc of 0.1 wt% aqueous solution of was added and stirred.

Calcium chloride 2 g Aluminum oxide 4 g Iron oxide 4 g After 10 minutes, the light transmittance of the supernatant liquid after removing flocs was measured. The results are shown in Fig. 1.

As a comparative example, sewage was treated with the same flocculant as in Example 1, and after 10 minutes, the light transmittance of the supernatant liquid after removing flocs was measured. The results are shown in Figure 2. The light transmittance of sewage is shown in FIG. Example 2 After dissolving 40 g of natural zeolite in 60 ml of water in 1 liter of sewage mixed with an emulsion of detergent, mineral oil, water-soluble cutting oil, etc., 3 m of an aqueous solution containing 40% by weight of calcium chloride was dissolved.
l, 0.1 g of aluminum oxide, and 0.1 g of iron oxide were added and stirred, and then 0.1 of a nonionic flocculant (trade name: Sunpoly N500: manufactured by Sankyo Kasei Co., Ltd.)
A 20% by weight aqueous solution was added and the mixture was stirred.

After 10 minutes, the sulfate ion contained in the supernatant after removing the flocs was 10 ppm. As a comparative example, sewage was treated with the same flocculant as in Example 1, and 10
After minutes, the sulfate ion contained in the supernatant liquid after removing the flocs was 200 ppm. From the results, it was found that by using the wastewater treatment aid of the present invention, the wastewater can be treated in a short time and the substances mixed in the wastewater can be removed with high accuracy. It was also found that the removal rate of sulfate ions was 95% or more.

[0022]

When the sewage mixed with water by emulsifying oil or the like is treated, an auxiliary agent is added together with the coagulant. The auxiliary agent contains zeolite, calcium chloride or calcium oxide, aluminum oxide, iron oxide or iron chloride, and phosphate. Such auxiliaries are applicable to any coagulant such as those made of metal salts, those made of other inorganic substances, those made of nonionic polymers, etc., without any special equipment and immediately. Flock can be formed in the sewage and sewage can be treated at an early stage. Further, since the sulfate ion contained in the flocculant is collected, the residual amount of the sulfate ion in the supernatant of the sewage after the floc formation becomes small. For this reason, it is possible to perform an appropriate treatment without causing secondary pollution, and further, it is possible to omit the step of removing sulfate ions, the step of pH adjustment, etc., and efficiently treat the wastewater. be able to.

[0023]

As is apparent from the above description, according to the wastewater treatment aid of the present invention, by adding it to the coagulant, the colloidal particles contained in the wastewater in a large amount can be efficiently removed. Therefore, sewage can be treated economically without using a special device. Moreover, even when treated with vanadium sulfate or the like, it is possible to reduce the amount of sulfate ions remaining in the supernatant after removal of the colloidal particles, omit the step of removing sulfate ions, and reduce the pH.
It can be drained to sewage without any adjustment.

[Brief description of drawings]

FIG. 1 is a diagram showing a sewage treatment effect according to an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional sewage treatment effect.

FIG. 3 is a diagram showing a state of sewage.

Claims (8)

[Claims] 1. A sewage treatment aid which is added to sewage together with a coagulant to agglomerate substances contained in the sewage, the sewage treatment comprising zeolite and calcium chloride or calcium oxide. Auxiliary agent. 2. The sewage treatment aid according to claim 1, wherein the sewage treatment aid contains aluminum oxide. 3. The sewage treatment aid according to claim 1 or 2, wherein the sewage treatment aid contains iron oxide or iron chloride. 4. The sewage treatment aid according to claim 1, wherein the sewage treatment aid contains phosphoric acid. 5. The sewage treatment aid according to any one of claims 1 to 4, wherein the sewage treatment aid contains water. 6. The sewage treatment auxiliary agent according to claim 1, wherein the coagulant comprises a metal salt. 7. The sewage treatment auxiliary agent according to claim 1, wherein the coagulant is an inorganic coagulant. 8. The sewage treatment auxiliary agent according to claim 1, wherein the coagulant comprises a polymer.