JP3464448B2 - Flocculant - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD [0001] The present invention efficiently aggregates sewage, human waste, industrial wastewater, etc. for solid-liquid separation, and
The present invention relates to an inorganic neutral coagulant that suppresses the odor generated at that time and the odor of discharged solid matter and makes it easier to reuse in soil, fertilizer, and the like.

[0002]

2. Description of the Related Art Conventional flocculants are classified into organic polymer flocculants and inorganic flocculants. Generally, organic polymer flocculants are widely used in order to surpass inorganic flocculants. The organic polymer coagulant causes the treated water and treated soil to have a high viscosity due to the strong viscosity peculiar to the polymer. The macromolecule becomes a pasty substance whose molecular structure becomes huge, and the mechanism of increasing the specific gravity by adhering suspended solids in water and removing it by sedimentation becomes the mainstream. Although mainly including electric (electrical) adsorption, the main component is due to this viscosity.

Although the inorganic coagulant is inferior in cohesive force, it is said that it is used at a low price because it is generally produced by processing waste materials. As the inorganic flocculants, sulfuric acid band (aluminum sulfate), polyaluminum chloride (PAC), and iron chloride type are known. These tend to be used in combination with organic polymer-based flocculants.

[0004]

When water treated with an organic polymer-based flocculant is discharged, it has been a problem that the microbial environment is destroyed. This is because treated water and treated soil are highly viscous. In other words, when the viscosity remains, the organic polymer remains, and the substance that becomes sludge is discharged to nature. Further, since the pasty polymer mixes with the treated soil, water drainage is poor, and the amount of the solidifying agent or the like added for the dehydration treatment increases, resulting in extra cost. Further, if the treated water leans toward the alkali side, a sulfuric acid-based substance is added, and if it leans toward acid, caustic soda is added to adjust the pH, and the treated water cannot be discharged. Then, the discharge of treated water containing ions will harm a healthy environment. Moreover, since the neutralization process takes time, a neutralization tank is provided. However, if the neutralization tank is full during the process, no new process can be performed, and the amount of the additive for adjusting the PH may be strict. Continuous processing was not possible.

Among the inorganic flocculants, aluminum ions or iron ions are used to exert the flocculation effect with inorganic ions. In the sulfuric acid band (aluminum sulfate) produced by reacting waste sulfuric acid with aluminum, aluminum ions have a cohesive effect, and the mechanism c leading to the treatment is due to electric charge adsorption, so that the treated water has no viscosity. However, since the pH value of the treated water is considerably lowered because sulfuric acid is used, caustic soda is used for neutralization. Therefore, a new powerful drug is added to the treated water, and it takes time for neutralization.

A typical coagulant using aluminum ions for coagulation is polyaluminum chloride (PAC).
Similarly, since a decrease in PH is seen, neutralization is required. Poly aluminum chloride for water supply is JIS K 147
Although it is regulated in 5 1996, carcinogenic substances such as trihalomethane were detected at the water purification plant and became a topic. These substances are collectively called organic chlorine compounds. Since polyaluminum chloride is a chloride and the treated water is organic, this coagulant seems to be the cause. There are also iron chloride-based flocculants that use iron ions for flocculation.
It is rarely used compared to seed flocculants. This coagulant also shows a decrease in PH, and in addition, since it is iron, it rapidly oxidizes, causing red water. Moreover, since it is a chloride system, it can be a factor for generating an organic chlorine compound.

[0007] Even in the progress of the flocculating agent technology that has been developed, it is a very difficult problem to suppress the generation of odor. In addition, regarding coagulation and generation of odor, there are two problems, namely, sludge concentration and sludge quality improvement.
Further, in order to solve the odor of these solids, it has been required for a long period of time to generate a large amount of equipment such as an activated sludge method and return sludge necessary for stabilizing treated water. The technique for suppressing the generation of odor in the aggregation process is still insufficient and has many problems. The present invention is an aggregating step of solid-liquid separation by aggregating sewage, in which organic substances such as odor generating sources contained in sewage are oxidized with a complex compound derived from humus, and chelate synthesized, and The purpose is to reduce odor sources by synthesizing sewage organic matter at the same time. Another object of the present invention is to reduce the amount of sewage organic matter and the like to polymerize the sewage, thereby aggregating sludge of higher concentration. Furthermore, it aims at making it easier to reuse the solid matter discharged by decomposition by activating the microorganism group of humus.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The inventions of claims 1 and 2 are as follows.
It mainly uses inorganic flocculants and is suitable for flocculation and sedimentation using existing equipment for treating construction civil sludge.
The flocculant according to the invention of claim 1 is a mud-like viscous substance obtained by adding sulfuric acid compounds such as calcium sulfate, iron sulfate and the like within 10 parts by weight to 100 parts by weight of humus and mixing them under pressure. Then, this is dried to form a solid, and the solid is crushed to obtain a modified humus powder, and 1 to 20 wt% of this modified humus powder is added to aluminum sulfate, aluminum oxide 5 to 60 wt%, calcium sulfate, calcium oxide 5 ~
60 wt% and sodium carbonate 2 to 20 wt% are added. It can be said that the invention of claim 2 reduces the amount of modified humus by adding a cationic polymer and fine powder to the invention of claim 1. The flocs formed by the addition of these flocculants are caked by a press or a centrifuge.

The inventions of claims 3 and 4 are used when a large amount of harmful heavy metals and organic substances are contained, such as in the case of sewage treatment or human waste treatment, and the odor is strong or the conventional flocculants cannot handle it. is there. In the coagulant according to the invention of claim 3, 100 parts by weight of humus are added with a sulfuric acid compound such as calcium sulfate, iron sulfate and the like within 10 parts by weight of each, and mixed under pressure to produce a mud-like viscous substance. Then, this is dried to make a solid, and the solid is crushed to obtain a modified humus powder. Separately, acrylamide is added to the humus and 100 parts by weight of the humus obtained by treating with hydrochloric acid or sulfuric acid is added to iron chloride or sulfuric acid. 1 to 5 parts by weight of iron is added and heated and pressed to form a complex compound of a mud-like viscous substance, which is dried and pulverized to obtain a complex compound powder, and these modified humus powder and complex compound powder are mixed. is there. The aggregating agent according to the invention of claim 4 is
The coagulant according to claim 3, 1 to 30 wt% of aluminum sulfate
%, Calcium sulfate, and sodium carbonate (soda ash) are added. Since the coagulant according to these inventions has a very strong cohesive force, it enables solid-liquid separation without a press or a centrifuge. Moreover, since the harmful substances are confined, the flocs can be discarded as they are.

[0010]

In the deodorizing and aggregating method of sewage using the aggregating agent according to the present invention, the complex compound and the inorganic compound by the modified humus exert the aggregating effect and the deodorizing effect on the sewage. Proteins, amino acids, organic acids, and sugars and macromolecules in sewage undergo a condensation reaction with complex compounds in denatured humus to form solids. The modified humus reacts with the organic substances of the odor source in the sludge to polymerize and become a stable non-volatile substance to suppress the odor. These stable macromolecules aggregate with inorganic flocculants to form flocs as larger particles.
These particles are different from the flocs containing only inorganic flocculants,
Due to the continuous reaction with the complex compound inside the flocs, large and strong flocs are formed.

The inorganic flocculant cannot exert its effect on high-concentration sewage, but the flocculants according to claims 3 and 4 of the present invention dissolve the sewage due to the condensation reaction of the complex compound by the modified humus. The concentration of wastewater is effectively reduced by causing a reaction of polymerizing the substance. As a result, the effect can be exhibited even for high-concentration sewage that could not be conventionally aggregated. Further, the agglomerated particles form a complex complex compound with the complex compound to form larger particles, and at the same time, form a large hard floc by interaction with the inorganic aggregating agent. Therefore, the processing of the post-treatment process is saved.

The amount of the coagulant according to the present invention used is 1 / 10,000 or more of the amount of sewage, usually 100 to 1000 ppm, but the amount may be increased if necessary.
Add a predetermined amount of powder directly to the sewage and stir for 2 minutes or more. The odor is deodorized within a few minutes, but if sewage is in a strong reducing state, it will be deodorized within 30 minutes by aeration and stirring.

In the invention of claim 1, the modified humus is 20
If it exceeds 5 wt%, the viscosity of the solution increases and it becomes difficult for it to aggregate. If it is less than 5 wt%, the cohesive force is weak, and if it exceeds 40 wt%, the flocs are weak and crushable easily. If the amount of calcium sulfate or calcium oxide is less than 5% by weight, the ions are not sufficiently exchanged to form an insoluble precipitate, and if the amount of calcium sulfate or calcium oxide exceeds 60% by weight, the calcium sulfate or calcium oxide itself floats and the solution becomes cloudy. . If sodium carbonate is less than the lower limit (2 wt%), the function of carbonate cannot be exhibited, and if it exceeds the upper limit (20 wt%), the solution becomes alkaline and the aggregation effect is reduced. This invention can be said to be a highly safe inorganic flocculant. According to the second aspect of the present invention, the amount of modified humus in the components can be reduced, and instead of this, an inexpensive cationic polymer is blended and a fine powder that becomes a precipitation nucleus is added. The fine powder is one or more of cement, zeolite, diatomaceous earth, calcium oxide, calcium carbonate and the like. The fine powder becomes a nucleus of what should be aggregated, and it can be rapidly settled by causing a coprecipitation phenomenon. The cationic polymer is sufficiently effective at 1 to 15% by weight, and if the amount is less than the lower limit, the effect is insufficient.
If the upper limit is exceeded, the viscosity of the solution will increase and coagulation and precipitation will not be possible.

The solid matter separated in the coagulation-sedimentation step contains denatured humus, and this denatured humus keeps activating the microorganisms and increasing the bond between sludges. Oxygen and hydrogen peroxide generated in this process are anaerobic. It inhibits the growth of bacteria and suppresses the generation of odor, forms stable sludge, improves dehydration, and forms sludge in which the bioactivity of microorganisms is enhanced. Therefore, the solid matter discharged in this step is easily reused as soil suitable for recycling.

[0015]

EXAMPLES Examples of the aggregating agent according to claims 2 and 4 of the present invention are as follows and are in powder form.

[0016]

[Table 1]

The test results for verifying the aggregating effect, the deodorizing effect, and the adsorption of various ions of the aggregating agent according to the above-mentioned examples are described below. The data used in the experiment were cement powder liquid, Bennite powder liquid, Kokubungawa sled, and Otagawa sled. These are solutions obtained by adding 1 wt% of powder to tap water. 0.1% (1000ppm) to 0.25% (2500ppm) of the aggregating agent according to the present invention was added to each material, stirred for 2 minutes, and allowed to stand for 30 minutes in this solution of 1000cc measuring cylinder. I measured.
A comparison with polyaluminum chloride (PAC) was also added.

[0018]

[Table 2]

In the case of adding 0.1% (1000 ppm), CO in the supernatant liquid was obtained after coagulating sludge from Ota River and Kokubun River.
When D was measured, it was as follows.

[0020]

[Table 3]

Subsequently, various sludges, odors and Escherichia coli contained in the supernatant were measured after aggregating the sludge of Kokubun River and the results were as follows.

[0022]

[Table 4]

[0023]

Industrial Applicability As described above, the present invention is a means which is unprecedented in that it can strengthen the cohesive force and at the same time suppress the odor, and it is possible to obtain a higher concentration at a site where a lot of coagulation is required. The effect of the present invention is great in that sewage can be aggregated, and at the same time, it has a deodorizing effect and further facilitates the reuse of solid matter. "Enzyme humus" is provided by Enzyme Co., Ltd., which is either the humus itself used or processed into pellets. On the other hand, the flocculant according to the present invention (claims 1, 2, and 4) is first insoluble in the solution by ion-exchanging various ions dissolved in the solution with calcium sulfate (anhydrite) or sodium carbonate. It begins with the precipitation of calcium and carbonate compounds (molecular weight 100-5
About 00). This precipitate then forms small aggregates with aluminum sulphate (molecular weight around 1000-5000). This aggregate grows into a larger aggregate due to denatured humus (molecular weight of about 30,000 to 200,000). At this time, it also plays a role of eluting low molecular weight organic substances that have not been ion-exchanged or neutralized substances from the solution by a chelating effect or hydrogen bond. There, the malodor can be removed by adsorption or reaction. Such an effect is not recognized in the conventional "enzyme humus". Next, with the flocculants of claims 2 and 4 of the present invention, flocs (aggregates) that have grown due to humus are collected with complex compounds or cationic polymers to form large and hard flocs (molecular weight of 1 to 5,000,000 or more). ).

The invention of claim 1 does not contain a cationic polymer. One of the drawbacks of cationic polymers is that they are highly toxic to fish. For example, 1 mg /
Almost dead in about a liter. It is said to be a highly safe inorganic flocculant. In the invention of claim 2, the modified humus is relatively reduced, and an inexpensive cationic polymer and a fine powder which becomes a precipitation nucleus are mixed in place of the modified humus, and the amount of the humus used is at a minimum to achieve the deodorizing effect. Can be turned on. Although the cheapest cement is sufficient as the fine powder to be the precipitation nucleus, fine powders of zeolite, diatomaceous earth, calcium oxide, and calcium carbonate are also effective. The cationic polymer exhibits a sufficient effect at 1 to 15% by weight. Below the lower limit, the effect is inadequate, and above the upper limit, the viscosity of the solution increases and aggregation and precipitation cannot be performed. The invention of claim 3 is suitable when only particles to be aggregated are collected in the waste liquid,
The best effect is recognized when the mixing ratio of the humus and the complex compound is basically the same, but an appropriate ratio may be used. The invention of claim 4 is suitable for the case where dissolved ions and dissolved substances are further present in the waste liquid containing the particles to be aggregated, and a step of precipitating these into fine particles is required. .

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-11-277070 (JP, A) JP-A-7-256269 (JP, A) JP-A 64-67212 (JP, A) JP-A 59- 112811 (JP, A) JP 58-79509 (JP, A) JP 52-30274 (JP, A) JP 2002-121555 (JP, A) JP 11-169897 (JP, A) Kaihei 11-169892 (JP, A) JP 8-323382 (JP, A) JP 7-328677 (JP, A) JP 2000-8039 (JP, A) Actual Kai 2-28798 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B01D 21/01 C02F 1/52-1/56

Claims (4)

(57) [Claims] 1. A sulfuric acid compound such as calcium sulfate and iron sulfate and 10 parts by weight of the same chloride compound are added to 100 parts by weight of humus.
Add within 1 part by weight and mix under pressure to produce a mud-like viscous substance, which is dried to form a solid, and the solid is crushed to give a modified humus powder.
And aluminum sulfate, aluminum oxide 5-60wt
%, Calcium sulfate, calcium oxide 5 to 60 wt%, and sodium carbonate 2 to 20 wt%. 2. A sulfuric acid compound such as calcium sulfate and iron sulfate and 10 parts by weight of the same chloride compound are added to 100 parts by weight of humus.
Add within 1 part by weight and mix under pressure to produce a mud-like viscous substance, which is dried to form a solid, and the solid is crushed to give a modified humus powder.
And aluminum sulfate, aluminum oxide 5-60wt
%, Calcium sulfate, calcium oxide 5-60 wt%, sodium carbonate 2-20 wt%, cationic polymer 1-15
1% to 40% by weight of fine powder of cement, zeolite, diatomaceous earth, calcium oxide, calcium carbonate
% Coagulant added. 3. A sulfuric acid compound such as calcium sulfate and iron sulfate and 10 parts by weight of the same chloride compound are added to 100 parts by weight of humus.
Add within 1 part by weight and mix under pressure to produce a mud-like viscous substance, dry this to make a solid, crush the solid to obtain a modified humus powder, add acrylamide to the humus separately, To 100 parts by weight of humus obtained by treating with hydrochloric acid or sulfuric acid, 1 to 5 parts by weight of iron chloride or iron sulfate is added and heated and pressed to form a complex compound of a mud-like viscous substance, which is dried and pulverized to obtain a complex compound powder. Got
An aggregating agent obtained by mixing these modified humus powders and complex compound powders. 4. The coagulant of 1 to 50 wt% according to claim 3,
Aluminum sulfate 1-30 wt%, calcium sulfate (anhydrite) 1-50 wt%, sodium carbonate (soda ash) 1-
Coagulant with 20 wt% added.