Bioflocculant

Abstract

To provide a flocculant that exhibits a function of purifying water quality when added to water to be treated, such as polluted water, wastewater, and drainage, and that does not contain metal-derived components and therefore has a reduced impact on the environment when the purified water is discharged. [Solution] A bioflocculant containing powdered baking soda (sodium bicarbonate), natto bacteria (Bacillus subtilis natto), seashell powder, and crab shell powder as blended ingredients. The blended ratios of powdered baking soda (sodium bicarbonate), seashell powder, and crab shell powder are 5% to 15% by mass, 30% to 60% by mass, and 5% to 20% by mass, and the bioflocculant contains 10% to 15% by mass of live natto bacteria (Bacillus subtilis natto). 5 ~10 9 CFU / g containing bioflocculant.

Description

[Technical Field]

[0001] This invention relates to a wastewater treatment technology for purifying contaminated water (polluted water), wastewater, drainage, etc., and in particular to a flocculant that is added to contaminated water, wastewater, drainage, etc. in order to purify the same, and that exhibits a flocculating function and is used in the purification process.

[0002] Hereinafter, in this specification, contaminated water, wastewater, drainage, etc. that are the subject of purification treatment may be collectively referred to as "water to be treated," and water that has undergone purification treatment, such as by adding a coagulant, may be referred to as "purified water." [Background technology]

[0003] In the field of sewage and wastewater treatment technology for purifying water to be treated, such as contaminated water, wastewater, and drainage water, known methods include sewage and wastewater treatment using flocculants containing metals, sewage and wastewater treatment using polymer-based flocculants, and sewage and wastewater treatment using flocculants derived from natural sources. For example, Patent Documents 1 and 2 disclose flocculants using metals. Patent Document 3 also discloses a bioflocculant.

[0004] Known flocculants that use metals include those containing polyaluminum chloride (PAC), polyaluminum sulfate (PAS), iron chloride (FeCl3), and iron sulfate (FeSO4).

[0005] Polyaluminum chloride (PAC) is an inorganic flocculant containing aluminum that has a stable flocculation effect and is widely used because it is particularly effective in removing turbidity and organic matter.

[0006] Polyaluminum sulfate (PAS) is similar to polyaluminum chloride (PAC), but contains sulfate groups, which are believed to improve flocculation performance under certain conditions.

[0007] Iron chloride (FeCl3) is an iron-based inorganic flocculant that has very effective flocculating power and is said to be particularly effective in removing phosphorus, but pH adjustment may be required.

[0008] Ferrous sulfate (FeSO4), like ferric chloride, is an iron-based coagulant used in sewage and sludge treatment. It is considered cost-effective and effective.

[0009] Since flocculants that use metals contain the above-mentioned metal-based components, it is necessary to consider the environmental impact of the metals contained in the flocculant when the purified water is released. Polymer-based flocculants, such as polyacrylamide (PAM), are sometimes used. Because polymer-based flocculants are polymers, they are said to have a strong flocculating effect with a small amount, improving the dewatering performance of sludge.

[0010] However, it has been pointed out that when polymer flocculants are released into water, they can affect the activity of microorganisms in the water, which can disrupt natural nutrient cycling and decomposition processes and disrupt the balance of the ecosystem.

[0011] It has been pointed out that the treatment effectiveness of naturally occurring coagulants varies depending on the type of contamination in the contaminated water.

[0012] Regardless of the flocculant, there is a demand for one that is inexpensive, inexpensive, and easy to use. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 2024-62310 [Patent Document 2] Japanese Patent Application Publication No. 2023-139777 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-161253 [Patent Document 4] Patent No. 4683356 [Patent Document 5] Patent No. 4528988 [Patent Document 6] Patent No. 3273358 Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention aims to provide a flocculant that performs the function of purifying water when added to water to be treated, such as polluted water, wastewater, and effluent, and that does not contain metal-derived components, thereby reducing the impact on the environment when the purified water is released.

[0015] Examples of water to be treated whose quality is purified by the bioflocculant of the present invention include water whose quality is purified in water purification facilities at waste treatment facilities, water purification facilities used to clean recycled water at various factories, and water whose quality is purified in public facilities such as sewage treatment facilities, water treatment facilities, and water purification facilities for rivers, lakes, and ponds. [Means for solving the problem]

[0016] The inventors of the present application have previously made various proposals in the field of wastewater and wastewater treatment technology, such as a "Muddy Water Purification Apparatus" (Patent Document 4), a "Method for Separating and Treating Dioxins" (Patent Document 5), and a "Method and Apparatus for Purifying Lakes and Ponds" (Patent Document 6).

[0017] Based on these findings, we propose a new flocculant that solves the above-mentioned problems associated with flocculants that use metals, polymer-based flocculants, and naturally occurring flocculants.

[0018] The inventors of the present application have discovered that the problem can be solved by using a bioflocculant made only from materials derived from natural products, such as bacteria found in the food that people eat and bacteria that grow in food products.

[0019] The present invention is exemplified as follows. [1] A bio-flocculant containing powdered baking soda (sodium bicarbonate), natto bacteria (Bacillus subtilis natto), seashell powder, and crab shell powder as its ingredients.

[0020] [2] The product contains 5% to 15% by mass of powdered baking soda (sodium bicarbonate), 30% to 60% by mass of shell powder, and 5% to 20% by mass of crab shell powder, and contains 10% to 15% by mass of live natto bacteria (Bacillus subtilis natto). 5 ~10 9 Contains CFU / g of bioflocculant [1]. [Effects of the Invention]

[0021] According to this invention, it is possible to provide a bio-flocculant, which is a flocculant that performs the function of purifying water when added to water to be treated, such as contaminated water, wastewater, and effluent, and which does not contain metal-derived components, thereby reducing the impact on the environment when the purified water is released.

[0022] This bioflocculant exhibits purification performance equivalent to that of conventional flocculants containing metal-derived components, and can similarly flocculate and precipitate metals contained in contaminated water.

[0023] Because this bioflocculant does not contain any metal-derived components, there is no risk of secondary contamination even when the purified water is discharged, and the environmental impact of discharging the purified water is reduced.

[0024] This bioflocculant is made from naturally derived materials (baking soda, natto bacteria, seashells (powder), crab shells (powder)) and has the following advantages over conventional metal-based flocculants:

[0025] Cost reduction Because bioflocculants do not use metal-derived components, raw materials can be procured inexpensively and processing (drying and crushing) is easy. This reduces overall operating costs. In particular, baking soda is cheap and easy to obtain, and seashells and crab shells are recycled from those discarded by manufacturers, making it possible to easily, cheaply, and stably supply materials.

[0026] Reducing environmental impact Bioflocculants do not use metal-derived components, which significantly reduces harmful effects on the environment. In particular, there is no secondary pollution even when the purified water is discharged, which reduces the environmental impact of discharging the purified water, enabling sustainable water purification.

[0027] Alternative to conventional flocculants Bioflocculants function well as a substitute for conventional metal-based flocculants. In particular, effective flocculation and precipitation are possible through microbial activity and pH adjustment, and the bacteria contained in bioflocculants multiply, so the amount added can be reduced compared to metal-based flocculants, making a significant contribution to reducing the environmental impact.

[0028] Ease of maintenance The use of bioflocculants simplifies the treatment process and makes maintenance easier. It also simplifies operations by eliminating the need for special safety measures associated with the treatment and handling of heavy metals.

[0029] Reusing by-products The bioflocculant of the present invention is not a flocculant that uses metals or the like, and does not contain heavy metals. Therefore, if the water to be treated, such as contaminated water, wastewater, or effluent, does not contain heavy metals, the sediment produced by the bioflocculant will not contain heavy metals and can be safely reused. For example, it can be used as compost or a soil improvement material, which has the advantage of not generating waste.

[0030] Furthermore, even when heavy metals are contained in water to be treated, such as contaminated water, wastewater, or effluent, the bioflocculant of the present invention can efficiently and reliably flocculate, precipitate, and remove the heavy metals contained in the water. Therefore, for example, by mixing the bioflocculant of the present invention with the water to be treated in a primary treatment tank that treats the water, the heavy metals can be flocculated, precipitated, and removed, thereby reducing the amount of heavy metals contained in the flocculated precipitates formed in the secondary and tertiary treatment tanks located downstream of the primary treatment tank.

[0031] By doing this, even if the water to be treated, such as contaminated water, wastewater, or effluent, contains heavy metals, the coagulation and sediment produced in the secondary and tertiary treatment tanks will be free of heavy metals, making it possible to use these as compost or soil improvement materials.

[0032] Furthermore, in the above-mentioned example, the flocculants and sediments produced in the primary treatment tank containing heavy metal flocculants and sediments can be analyzed for the content of heavy metals that require caution and used as compost or soil conditioners while confirming that they meet legal and safety standards. Even in this case, the bioflocculant of the present invention is not a flocculant that uses metals or does not contain heavy metals, so the cost and effort required to use the flocculants and sediments produced in the primary treatment tank containing heavy metal flocculants and sediments as compost or soil conditioners while meeting environmental standards is reduced, and the use of the bioflocculant of the present invention simplifies the treatment process and makes maintenance and management easier.

[0033] Conventional naturally derived flocculants have had varying purification effects on contaminated water containing diatoms (blue-green algae) and heavy metals, but the bioflocculant of the present invention can be more effective by changing the composition of the bioflocculant depending on the contaminated water being treated. DETAILED DESCRIPTION OF THE INVENTION

[0034] The bioflocculant of this embodiment contains powdered baking soda (sodium bicarbonate), Bacillus subtilis natto, seashell powder, and crab shell powder as blended ingredients.

[0035] For example, the bioflocculant described above contains powdered baking soda (sodium bicarbonate) in a blending ratio of 5% to 15% by mass, shell powder in a blending ratio of 30% to 60% by mass, and crab shell powder in a blending ratio of 5% to 20% by mass, and contains 10% to 15% by mass of live natto bacteria (Bacillus subtilis natto). 5 ~10 9 It may contain CFU / g.

[0036] As the powdered baking soda (sodium bicarbonate), commercially available powdered baking soda (sodium bicarbonate) can generally be used.

[0037] Shell powder can be obtained by drying shells from discarded shells and pulverizing them in a powdering device (mill).

[0038] Crab shell powder can be obtained by drying discarded crab shells and pulverizing them using a powdering device (mill).

[0039] As the natto bacteria, commercially available edible natto bacteria can be used.

[0040] The bioflocculant of the present invention can be prepared and manufactured by adding the above-mentioned blending ingredients in the above-mentioned blending ratios to a dry powder mixer and mixing for a predetermined time. For example, when using a dry powder mixer that can mix 20 L in 5 minutes, 200 mL of powdered baking soda (sodium bicarbonate) with a weight of 4,400 g, 6,667 mL of shell powder with a weight of 18,000 g, 4,000 mL of crab shell powder with a weight of 6,000 g, and 4,000 mL of natto bacteria with a weight of 1,600 g (10 viable bacteria count of natto bacteria). 5 ~10 9CFU / g) was added to a dry powder mixer and mixed for 1 hour to obtain 0.015 m of the bioflocculant of the present invention. 3 In addition, if the mixing and stirring machine is enlarged, the processing capacity can be increased, making it possible to scale up production adjustments.

[0041] The specific gravity of powdered baking soda (sodium bicarbonate) is set to 2.2 g / mL, the specific gravity of shell powder to 2.7 g / mL, the specific gravity of crab shell powder to 1.5 g / mL, and the specific gravity of natto bacteria to 0.4 g / mL, and the blending ratio of each compounding component when preparing (manufacturing) the bioflocculant of the present invention can be adjusted.

[0042] In the above case, the blending ratio of powdered baking soda (sodium bicarbonate) is set to 5% by mass to 15% by mass because the baking soda adsorbs and separates the oil contained in the wastewater.

[0043] The reason why the mixing ratio of shell powder is set at 30% to 60% by mass is to allow calcium carbonate (CaCO3), the main component of shell powder, to effectively adsorb heavy metals through the following mechanism: Physical adsorption: The porous structure of calcium carbonate (CaCO3), the main component of shell powder, physically adsorbs heavy metal ions. Chemical adsorption: Calcium carbonate reacts with heavy metal ions to form sparingly soluble heavy metal carbonates. Ion exchange: Calcium ions are exchanged for heavy metal ions. Shell powder is mainly composed of calcium carbonate (CaCO3), and its porous surface promotes the adsorption and coagulation of pollutants. Calcium carbonate, the main component of shell powder, is weakly alkaline, and so it can be used as a biocoagulant to stabilize the pH during the water treatment process.

[0044] Furthermore, the crab shell powder content is set at 5% to 20% by mass from the viewpoint of allowing chitin and chitosan, which are the main components of crab shell powder, to effectively adsorb heavy metals through the following mechanism. Ion exchange: The amino groups of chitosan are exchanged with heavy metal ions. Chelation: Chitosan forms strong bonds with heavy metal ions, immobilizing them. Physical adsorption: The porous structure of chitin physically adsorbs heavy metal ions. As mentioned above, crab shell powder is rich in chitin and its derivative, chitosan. These components have a strong coagulating effect, effectively coagulating fine particles and suspended solids in water. Chitin and chitosan also have antibacterial properties. From these perspectives, the above-mentioned blending ratio is advantageous.

[0045] In addition, the number of live bacteria of natto (Bacillus subtilis natto) was increased to 10 5 ~10 9 The reason for using CFU / g is that the influence of EPS (Extracellular Polymeric Substances) is taken into consideration. EPS (Extracellular Polymeric Substances) produced by Bacillus subtilis natto encapsulates bacteria and organic matter in wastewater, stabilizing the flocs. Since EPS plays an important role in the formation and stabilization of flocs, the number of live Bacillus subtilis natto cells contained in the bioflocculant of the present invention is 10 5 ~10 9 CFU / g is desirable.

[0046] Bacillus subtilis natto has the ability to produce a biofilm that promotes coagulation, which allows for efficient coagulation of pollutants. Maintaining a high bacterial count also provides stable coagulation and organic matter decomposition capabilities, improving the durability of the biocoagulant and reducing the frequency of periodic re-addition. From this perspective, it is advantageous to maintain the viable cell count within the above range.

[0047] Conventional naturally derived flocculants have had varying purification effects on contaminated water containing diatoms (blue-green algae) and heavy metals, but the bioflocculant of the present invention can be more effective by changing the composition of the bioflocculant depending on the contaminated water being treated.

[0048] For example, if the contaminated water being treated is high in oil and fat and has an acidic pH, changing the blend to include more baking soda and crab shell powder will be advantageous in dealing with acidic contaminated water. The baking soda (sodium bicarbonate) contained in this bioflocculant is slightly alkaline in water and helps adjust the pH. This creates an environment that promotes the coagulation of oil and other organic matter. Oil is heavy, so it settles down.

[0049] Additionally, baking soda (sodium bicarbonate) adjusts the pH and optimizes microbial activity, creating conditions for heavy metal precipitation.

[0050] The main component of the shell powder blended into the bioflocculant of this embodiment is calcium carbonate, which is alkaline. When added to the water being treated, the shell powder adjusts the pH and promotes the coagulation of oil and other organic matter. The shell powder's surface also has adsorption properties, allowing it to adsorb oil. The shell powder contributes to pH adjustment and physical adsorption as calcium carbonate, and reacts with heavy metals to form insoluble compounds.

[0051] Shell powder made of calcium carbonate has a porous structure, which allows it to adsorb heavy metal ions. For example, lead (Pb 2+ ), cadmium (Cd 2+ ), copper (Cu 2+ ) and other heavy metal ions are adsorbed onto the surface of the shell powder.

[0052] In addition, when the shell powder dissolves in the treated water, calcium ions (Ca 2+), which reacts with heavy metal ions to form sparingly soluble precipitates. For example, Pb 2+ reacts with CaCO3 to produce a sparingly soluble precipitate called PbCO3 (cerussite).

[0053] The main components of the crab shell powder blended into the bioflocculant of this embodiment are chitin and its derivative, chitosan. Chitin is a natural polysaccharide, and chitosan is a compound produced by its deacetylation. These compounds have the ability to efficiently adsorb heavy metal ions. Crab shell powder reacts with heavy metal ions in water as calcium carbonate to form insoluble heavy metal carbonates and hydroxides.

[0054] Chitosan has amino groups (-NH2) and hydroxyl groups (-OH), which have the ability to strongly bind with heavy metal ions. 2+ , Cd 2+ , Cu 2+ Heavy metal ions such as these are adsorbed by crab shell powder.

[0055] Chitosan can form chelates with heavy metal ions because multiple binding sites within the chitosan molecule surround the heavy metal ions to form stable complexes.

[0056] Synergistic effect of seashell powder and crab shell powder The bioflocculant of this embodiment is formulated with seashell powder and crab shell powder, which produces a synergistic effect.

[0057] The main mechanisms by which both seashell powder and crab shell powder remove heavy metal ions are adsorption and precipitation (in the case of seashell powder) and chelation (in the case of crab shell powder), as described above. Through these processes, the concentration of heavy metals in water is reduced, improving water quality.

[0058] Examples of specific reactions are as follows. Removal of lead Shell powder: Pb 2+ + CaCO3 → PbCO3 (precipitate) Crab shell powder: Pb 2+ + Chitosan → Pb-chitosan complex Removal of copper Shell powder: Cu 2+ + CaCO3 → CuCO3 (precipitate) Crab shell powder: Cu 2+ + Chitosan → Cu-chitosan complex Through these reactions, heavy metal ions are removed from the treated water and captured as solids.

[0059] The Bacillus subtilis natto incorporated in the bioflocculant of this embodiment produces enzymes such as protease and amylase, which decompose organic substances. In addition, the biofilm and exopolysaccharide (EPS) produced by Bacillus subtilis natto have the effect of aggregating oil and other particles.

[0060] Enzymes such as protease and amylase produced by Bacillus subtilis natto decompose oil into small molecules, which are used as nutrients for microorganisms, thereby removing the oil. In addition, due to the aggregation effect of Bacillus subtilis natto, the oil is more likely to precipitate as larger flocs. Bacillus subtilis natto forms a biofilm, produces exopolysaccharide (EPS), promotes the aggregation of organic substances and SS, and has an adsorption effect on heavy metals.

[0061] The following details the water purification mechanism when using sodium bicarbonate, Bacillus subtilis natto, shell powder, and crab shell powder for each item. The water purification mechanism by the bioflocculant of this embodiment with the above-described formulation and composition is as follows. <BOD (Biochemical Oxygen Demand)> Functional formulation component: Bacillus subtilis natto Natto bacteria produce enzymes that decompose organic matter and reduce BOD. When organic matter is decomposed by the enzymes of natto bacteria, the oxygen consumption by microorganisms decreases, and BOD decreases. <COD (Chemical Oxygen Demand)> Functional compounding ingredients: sodium bicarbonate, shell powder, and crab shell powder Shell powder and crab shell powder have the effect of adsorbing and aggregating oil and fat components, thereby removing organic pollutants in the treated water. Sodium bicarbonate emulsifies these substances and promotes decomposition, so COD decreases. <SS (Suspended Solids)> Functional compounding ingredients: sodium bicarbonate, shell powder, and crab shell powder The use of sodium bicarbonate increases the pH of the treated water, and shell powder and crab shell powder adsorb and aggregate suspended solids, so SS is removed. <ph> The active ingredient: baking soda Baking soda (sodium bicarbonate) is weakly alkaline and neutralizes the acidic water quality of the water to be treated, adjusting it to an appropriate pH (usually within the range of 6.5 to 8.5). <Escherichia coli> Functional ingredients: Bacillus subtilis natto The antibacterial substances produced by natto bacteria inhibit the growth of coliform bacteria. The dominance of natto bacteria suppresses the activity of harmful bacteria and reduces the coliform bacteria. <Rin> Active ingredients: seashell powder, crab shell powder The calcium components of seashell powder and crab shell powder can react with phosphate to precipitate calcium phosphate, thereby removing phosphorus from the treated water. <Nitrogen> Functional ingredients: Bacillus subtilis natto Bacteria, including Bacillus subtilis natto, break down nitrogen compounds such as ammonia and nitrate and release them as nitrogen gas, thereby removing nitrogen from the treated water. <Normal hexane> Active ingredients: baking soda, seashell powder, crab shell powder The baking soda emulsifies the oil, and the seashell powder and crab shell powder adsorb and coagulate it, thereby removing normal hexane from the treated water. <Blue-green algae (diatoms)> Active ingredients: natto bacteria, shell powder, crab shell powder The enzymes produced by Bacillus subtilis natto break down the cell walls of blue-green algae and inhibit their growth, while seashell powder and crab shell powder adsorb and aggregate the algae. <Heavy metals> The bioflocculant of this embodiment, which has the above-described blending and composition, can remove the following heavy metals. <Lead (Pb)> Active ingredients: seashell powder, crab shell powder The calcium carbonate component in shell powder and crab shell powder is Pb 2+ It reacts with the chitosan in the crab shell powder to form PbCO3 (cerussite) and precipitate it. 2+ is adsorbed and immobilized. <Cadmium (Cd)> Active ingredients: seashell powder, crab shell powder CaCO3 in seashell powder and crab shell powder is Cd 2+ It reacts with Cd to produce poorly soluble CdCO3, which precipitates. 2+ Adsorbs. <Copper (Cu)> Active ingredients: seashell powder, crab shell powder CaCO3 in seashell powder and crab shell powder is Cu 2+ It reacts with Cu to produce CuCO3, which precipitates. 2+ Adsorbs. <Hexavalent chromium (Cr(VI))> Functional ingredients: Bacillus subtilis natto An enzyme produced by Bacillus subtilis natto reduces Cr(VI) to Cr(III), which reacts with CaCO3 to precipitate as sparingly soluble Cr2O3. <Zinc (Zn)> Active ingredients: seashell powder, crab shell powder CaCO3 in shell powder and crab shell powder is Zn 2+ It reacts with ZnCO3 to produce ZnCO3 and precipitate. 2+ Adsorbs. <Arsenic (As)> Active ingredients: seashell powder, crab shell powder As 3+ or As 5+ reacts with CaCO3 in the shell powder and crab shell powder to precipitate as a poorly soluble As compound. Chitosan adsorbs As. Water purification mechanism by the bioflocculant of this embodiment The mechanism of water purification by the bioflocculant of this embodiment is as follows. <Complex adsorption and precipitation> Shell powder and crab shell powder adsorb and precipitate harmful substances such as heavy metals, phosphorus, and nitrogen, making them more effective than removing them individually. <Microbial decomposition> Natto bacteria decompose organic substances, nitrogen compounds, and oil, thereby reducing BOD, COD, and SS. Also, the production of antibacterial substances suppresses coliform bacteria. <Improvement of Effect by pH Adjustment> By adjusting to an appropriate pH range with sodium bicarbonate, the precipitation of heavy metals is promoted and the activity of natto bacteria is optimized. Due to these synergistic effects, various pollutants are removed simultaneously and the water quality is effectively improved.

[0062] The bioflocculant of this embodiment has the advantages not only of being environmentally friendly but also of being less likely to produce chemical by-products.

[0063] The bioflocculant of this embodiment can exhibit the various effects described above by, for example, adding the powdery bioflocculant of this embodiment in a volume range of 0.5 mL to 30 mL per 1000 liters of the water to be treated. Note that the specific gravity of powdery sodium bicarbonate is 2.2 g / mL, and 1,000 g of powdery sodium bicarbonate corresponds to approximately 454.55 mL of the volume of powdery sodium bicarbonate. The specific gravity of shell powder is 2.7 g / mL, and 3,000 g of shell powder corresponds to approximately 1,111.11 mL of the volume of shell powder. The specific gravity of crab shell powder is 1.5 g / mL, and 1,000 g of crab shell powder corresponds to approximately 666.67 mL of the volume of crab shell powder. The specific gravity of natto bacteria is 0.4 g / mL, and 1,000 g of natto bacteria corresponds to approximately 2,500 mL of the volume of natto bacteria.

[0064] Hereinafter, examples of the present invention will be described. However, the present invention is not limited to the above-described embodiments and the examples described later, and can be variously modified within the technical scope grasped from the description of the claims.

Example

[0065] <Preparation of Bioflocculant> The following blending materials were put into a dry powder mixer and mixed for 1 hour to obtain 6 kg of the bioflocculant of the present invention. Powdered baking soda (sodium bicarbonate): 0.8 kg (363.64 mL) (Commercially available powdered baking soda (sodium bicarbonate) "Product name: Baking Soda, Japanese-made baking soda") Shell powder: 3 kg (1,111.11 mL) (Scallops and oyster shells that would otherwise be disposed of are dried and then powdered in a powder mill) Crab shell powder: 1 kg (666.67 mL) (The shells of king crab and snow crab that would otherwise be disposed of are dried and powdered in a powder mill.) Bacillus subtilis natto: 1kg (2,500mL) (Commercially available natto bacteria (Bacillus subtilis natto) "Product name: Sarasara Kinkatsu Natto Powder". The number of live bacteria of natto bacteria (Bacillus subtilis natto) is 10 5 ~10 9 (CFU / g equivalent.) [Example]

[0066] <Purification function of bioflocculant 1> 30 mL of the bioflocculant of the present invention prepared in Example 1 was added to 1 L of the water to be treated (wastewater from an automobile repair shop) contained in a settling tank, and the mixture was gently stirred and mixed in the settling tank for 3 minutes before being left to stand.

[0067] The values ​​of each item under investigation in the treated water before adding the bioflocculant and the values ​​after stirring and mixing for 3 minutes and leaving it to stand were as shown in Table 1 below.

[0068] [Table 1] By adding bioflocculant and stirring / mixing, the values ​​of all the items examined were reduced, and it was confirmed that the desired purification process had been carried out.

[0069] Based on the results of the study shown in Table 1, when the amount of E. coli, oil, lead (Pb), cadmium (Cd), copper (Cu), and arsenic (As) contained in the water to be treated (1 L) is as shown in Table 2 below, 30 mL of the bioflocculant prepared in Example 1 of the present invention is added to the water to be treated (1 L), and the water is gently stirred and mixed in a settling tank for 3 minutes before being allowed to stand. A computer simulation was performed to determine how these values ​​would decrease, and the results are shown in Table 2 below.

[0070] [Table 2] The simulation results showed that the values ​​of E. coli, oil, lead (Pb), cadmium (Cd), copper (Cu), and arsenic (As) all decreased, indicating that desirable purification treatment was being carried out. [Example]

[0071] <Purification function of bioflocculant 2> 30 mL of the bioflocculant of the present invention prepared in Example 1 was added to 1 L of water to be treated (factory wastewater) contained in a settling tank, and gentle stirring and mixing was carried out in the settling tank for 3 minutes. The values ​​for each item under investigation for the treated water before adding the bioflocculant and the values ​​after 3 minutes of stirring and mixing are shown in Table 3 below. In Japan, water quality environmental standards are set based on the Basic Environment Law. These are the Ministry of the Environment's discharge standards for rivers and lakes (Water Quality Environmental Standards Based on the Basic Environment Law of Japan), and they include the following major standards. The general standard items are as follows: BOD (Biochemical Oxygen Demand) Rivers: 1-10 mg / L, Lakes and ponds: 1-3 mg / L COD (Chemical Oxygen Demand) Rivers: 1-8 mg / L, Lakes and ponds: 1-3 mg / L SS (Suspended solids amount) Rivers: 25-50 mg / L, Lakes and ponds: 5-30 mg / L pH Rivers, lakes and marshes: 6.5~8.5 Coliform count Rivers, lakes and marshes: 1,000 particles / 100 mL or less Heavy metals and other harmful substances Lead (Pb) Rivers, lakes and ponds: 0.01 mg / L or less Cadmium (Cd) Rivers, lakes and ponds: 0.01 mg / L or less Copper (Cu) Rivers, lakes and ponds: 1.0 mg / L or less Hexavalent chromium (Cr(VI)) Rivers, lakes and ponds: 0.05 mg / L or less Zinc (Zn) Rivers, lakes and ponds: 0.5 mg / L or less Arsenic (As) Rivers, lakes and ponds: 0.01 mg / L or less Other criteria oil Rivers, lakes and marshes: Not visible to the naked eye Total phosphorus Rivers: 0.1 to 1.0 mg / L, Lakes and ponds: 0.02 to 0.1 mg / L Total Nitrogen Rivers: 0.4 to 1.5 mg / L, Lakes and ponds: 0.1 to 1.0 mg / L Factory wastewater regulations More detailed regulations are in place for wastewater from factories and businesses, including the following standards: pH: 5.8 to 8.6 BOD: 30 mg / L or less (varies depending on industry and size) COD: 160 mg / L or less (varies depending on industry and size) SS: 100 mg / L or less Oil content: No floating oil can be visually confirmed These standards are set out in the Ministry of the Environment's Water Pollution Control Act and related regulations. The values ​​investigated in this example were compared with the above-mentioned emission standard values, as shown in Table 3 below.

[0072] [Table 3] By adding bioflocculant and stirring / mixing, the values ​​of all the items under consideration were reduced, and it was confirmed that the desired purification process was carried out and that the purification was progressing to values ​​that met the river discharge standards.

[0073] Based on the results of the study shown in Table 3, when the amount of E. coli, oil, lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), and arsenic (As) contained in the water to be treated (1 L) is as shown in Table 2 below, 30 mL of the bioflocculant prepared in Example 1 of the present invention is added to the water to be treated (1 L), and the water is gently stirred and mixed in a settling tank for 3 minutes before being allowed to stand. A computer simulation was performed to determine how these values ​​would decrease, and the results are shown in Table 4 below.

[0074] [Table 4] The simulation results showed that the above-mentioned standards would be met for E. coli, oil, lead (Pb), cadmium (Cd), copper (Cu), and arsenic (As).< / ph>

Claims

1. A bioflocculant containing powdered baking soda (sodium bicarbonate), natto bacteria (Bacillus subtilis natto), seashell powder, and crab shell powder as its ingredients.

2. The product contains 5% to 15% by mass of powdered baking soda (sodium bicarbonate), 30% to 60% by mass of shell powder, and 5% to 20% by mass of crab shell powder, and contains 10% live natto bacteria (Bacillus subtilis natto). ５ ~10 ９ 2. The bioflocculant of claim 1, comprising: CFU / g.

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