JP4642102B2 - Aerobic wastewater treatment agent and treatment composition, method for producing the same, and aerobic wastewater treatment method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an aerobic wastewater treatment agent and a treatment agent composition, a production method thereof, and an aerobic wastewater treatment method.

  In recent years, for example, a humic acid activated sludge method using a humic acid preparation has been proposed as a method for treating aerobic wastewater such as public sewerage, agricultural settlement wastewater, and food factory wastewater. This method is basically a method in which a humic acid preparation is put into an aeration tank of a standard activated sludge method, and there is an advantage that it can be applied to many processing apparatuses because it is not necessary to change the processing apparatus significantly ( Patent Documents 1, 2, and 3).

Here, the humic acid preparation contains humic acid or a humic acid salt-containing substance, for example, 10% by mass or more as humic acid. Examples of substances containing humic acid or humic acid salts include natural products such as juvenile charcoal, dry distillation products such as juvenile charcoal, coal and coke, oxidative decomposition products, or alkali metal salts or alkaline earth metals of the oxidative decomposition products. There are many compounds such as synthetic compounds such as salts, metabolites of bacterial groups, and organic substances derived from animals and plants (Patent Documents 4 and 5).
JP-A-8-323382 Japanese Patent Laid-Open No. 9-66292 JP 2006-272171 A Japanese Patent Laid-Open No. 60-18565 Japanese Patent Laid-Open No. 51-72987

  However, conventional humic acid formulations have advantages and disadvantages. Even if it is the same kind of humic acid preparation, even if it is the same kind of effluent, the proper amount of use differs depending on the kind of humic acid preparation. For this reason, problems such as bulking, activated sludge levitation, decay, and dismantling have occurred due to variations in the composition and concentration of organic matter in the wastewater.

Here, it is said that bulking is induced by an increase in spherocillus, which is one of inactive sludge organisms. The activated sludge levitation phenomenon is that the activated sludge excessively causes nitrification, creating bubbles of N ₂ gas and CO ₂ gas, and reducing the density of the activated sludge. The spoilage phenomenon is that the color tone of activated sludge becomes black, H ₂ S gas is generated, and a strange odor is exhibited. The dismantling phenomenon is that flocs of activated sludge are dispersed into small clouds.

  As countermeasures for these troubles, changes in the operating conditions of the treatment equipment-reduction of biochemical oxygen consumption (BOD load) by reducing the amount of influent wastewater, aeration and aeration time of the aeration tank, return amount of activated sludge, etc. Although it is conceivable, since it is a treatment method involving microorganisms, it takes several weeks to several months to solve the problem, and during that period, it is discharged as a deteriorated water quality.

  That is, the object of the present invention is to improve the settling and separation of activated sludge, which is an indicator of solid-liquid separation of activated sludge and treated water, and to reduce the amount of generated excess sludge and a treatment agent for aerobic wastewater. It is providing a processing agent composition, its manufacturing method, and the processing method of aerobic waste water using the same.

  The treatment agent for aerobic waste water according to the present invention comprises a calcium, magnesium or potassium salt of nitrate of young charcoal, a melanic index of 2.0 to 3.0, and an organic carbon concentration of the water extract of 800. It is -2000 mg / L.

  The treatment agent for aerobic wastewater having the above-described configuration has the effect of improving the settling and separation of activated sludge, which is an index of solid-liquid separation of activated sludge and treated water, and reducing the amount of generated excess sludge.

  The treatment agent can reduce troubles such as bulking, activated sludge floating phenomenon, decay phenomenon, and demolition phenomenon in wastewater treatment such as public sewerage, agricultural settlement wastewater, and food factory wastewater.

  The method for producing an aerobic wastewater treatment agent according to the present invention includes at least one element selected from nitrates of young charcoal obtained by oxidizing and decomposing young charcoal with nitric acid, and calcium, magnesium and potassium. And a step of cooling the mixture with an inorganic compound containing one after heating at a temperature of 60 to 120 ° C. for 0.5 to 6 hours.

  In the manufacturing method of the aerobic wastewater treatment agent comprising the above steps, it is possible to improve the sedimentation separability of activated sludge, which is an indicator of solid-liquid separation of activated sludge and treated water, and reduce the amount of generated excess sludge. An aerobic wastewater treatment agent can be obtained.

  The aerobic wastewater treatment method according to the present invention is a biochemical method for treating wastewater per day by converting the treatment agent for aerobic wastewater or the composition for treating aerobic wastewater into the amount of the treatment agent. It includes 0.4 to 1.5% by mass with respect to the oxygen consumption amount, or a step of dividing or supplying the oxygen consumption amount to an aeration tank of a batch type or continuous type aeration apparatus.

  The method for treating aerobic wastewater comprising the above steps has the effect of improving the settling and separation of activated sludge, which is an indicator of solid-liquid separation of activated sludge and treated water, and reducing the amount of generated excess sludge.

  ADVANTAGE OF THE INVENTION According to this invention, the sedimentation-separation property of activated sludge can be improved and the excess sludge generation amount which generate | occur | produces can be reduced.

  Below, embodiment of the processing agent of aerobic waste water concerning the present invention is described.

  The aerobic wastewater treatment agent according to this embodiment is composed of calcium, magnesium, or potassium salt of nitrate of young charcoal, the melanic index is 2.0 to 3.0, and the organic carbon concentration of the water extract is 800 to 2000 mg / L.

  The treatment agent for aerobic wastewater having the above-described configuration has the effect of improving the settling and separation of activated sludge, which is an index of solid-liquid separation of activated sludge and treated water, and reducing the amount of generated excess sludge.

[Method of manufacturing aerobic wastewater treatment material]
The aerobic wastewater treatment agent according to the present embodiment (hereinafter, simply referred to as “treatment agent”) is characterized by being composed of a calcium, magnesium or potassium salt of nitrate of young charcoal. A manufacturing method will be described.

  Here, the “young coal” is a coal having a low carbon content, and is a coal having a carbon content of 83% by mass or less, and preferably a carbon content of 78% by mass or less. If the young coal is a coal with a carbon content of 78% by mass or less, the coalification is still in progress and the aromatic condensed ring is still small, on the contrary, the proportion of side chains and main chains of aliphatic hydrocarbons is high and nitric acid. It has the advantage that it is easily oxidatively decomposed, and also has a physical effect that there are many oxygen functional groups and a large pore volume in the coal, so that it has high hydrophilicity and is easily mixed with waste water.

  Young coal is, for example, peat, lignite, lignite, subbituminous coal, etc., and a mixture of one or more of these is used. Currently, peat, lignite, and lignite are less consumed, although half of the world's coal resources are these young coals. Therefore, it is preferable to use peat, lignite, and lignite for the purpose of promoting effective utilization of peat, lignite, and lignite.

  Here, it is preferable to mix 200 to 600 kg of concentrated nitric acid per 1000 kg of the young charcoal and mix for 10 to 60 minutes. By doing so, side chains and main chains of aliphatic hydrocarbons in young charcoal are chemically cleaved to lower the molecular weight, and by introducing a nitro group as a substituent, hydrophilicity is increased, Furthermore, the effect of making some of the young charcoal water-soluble can be obtained.

  Further, “juvenile charcoal nitrate” is a reaction product obtained by oxidizing and decomposing young charcoal with nitric acid. For example, when the young coal is lignite, the reaction product obtained by blending 100 to 700 kg of concentrated nitric acid of 40 to 98 mass% with 1000 kg of lignite having an average particle size of 1 mm or less and mixing for 10 to 60 minutes. That's it. By this mixing operation, the mixture self-heats and once rises to about 110 ° C., but the temperature is lowered as the oxidative decomposition reaction ends, so that the end point of the reaction can be predicted.

  Furthermore, the reaction product obtained by mixing 330-530 kg of concentrated nitric acid with 1000 kg of lignite with an average particle size of 1 mm or less, and the reaction product obtained by mixing for 20 to 40 minutes is nitrated uniformly. This is preferable because it is possible to stably obtain a nitrate of young charcoal.

  In addition, “calcium, magnesium or potassium salt of nitrate” refers to a heated mixture of nitrate of young charcoal and an inorganic compound containing at least one element selected from calcium, magnesium and potassium. It is. For example, a nitrate of young charcoal and an inorganic compound containing at least one element selected from calcium, magnesium, and potassium are not particularly limited, and for example, obtained by mixing with a kneader such as a kneader or Banbury. The obtained mixture was heated at a temperature of 60 to 120 ° C. for 0.5 to 6 hours, and then cooled to room temperature.

  Furthermore, the above mixture is maintained at a temperature of 80 to 90 ° C. for 3 to 5 hours and then cooled to room temperature, which stably prevents ignition of nitrate by unreacted nitric acid. Preferred for reasons.

  The proportion of the mixture is preferably 55 to 540 kg of inorganic compound per 1000 kg of nitrate of young charcoal. Such a mixing ratio facilitates the formation of humic acid salts, and also neutralizes unreacted nitric acid, so that the pH of the treatment agent becomes about 10 alkaline, thereby improving the safety and storage stability of subsequent handling. Is done.

  Furthermore, it is preferable that an inorganic compound is 110-410 kg per 1000 kg of nitrates of young charcoal. If the inorganic compound is 110 kg or more per 1000 kg of nitrate of young charcoal, the effect associated with the addition is sufficient, and if it is 410 kg or less, an improvement effect commensurate with the addition amount is easily manifested.

[Average granule]
The mixture is preferably granulated into particles having an average particle size of 0.5 to 8 mm before heat treatment. By granulating the average particle size to 0.5 to 8 mm, it becomes possible to manufacture a stronger processing agent by heat treatment in a subsequent process. The granulation is not particularly limited. For example, a rolling granulation method using a dish granulator, a drum granulator, or the like, or a compression granulation method using a briquetting machine, a tableting machine, or the like. Etc. are used.

  Further, it is preferably granulated into particles having an average particle diameter of 2 to 5 mm. If the particle size is 2 mm or more, it will not be blown by the wind when using the final product, and it will be convenient. If the particle size is 5 mm or less, it will be easy to manufacture and shorten the granulation time. There is no need to use a special granulator or additive.

[Moisture content of granulated product]
Furthermore, it is preferable that the moisture content of the granulated product before the heat treatment is adjusted to 12 to 20% by mass. If the water content of the granulated product is 12% by mass or more, sufficient compressive strength of the treatment agent can be obtained. As a result, for example, the treatment agent is pulverized during transportation and storage, and powdering occurs. Or a problem such as floating on the surface of the activated sludge mixed water when it is introduced into the aeration tank. Moreover, if the moisture content of a granulated material is 20 mass% or less, the appropriate viscosity of a processing agent can be hold | maintained and handling is easy.

  Here, examples of inorganic compounds containing at least one element selected from calcium, magnesium, and potassium include calcium carbonate, calcium hydroxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, potassium hydroxide, and potassium carbonate. is there. Among these inorganic compounds, calcium carbonate, magnesium carbonate, and potassium carbonate are preferable because they are easily available at a relatively low cost.

[Melanic Index]
The treating agent according to the present embodiment has a melanic index (hereinafter referred to as “MI”) of 2.0 to 3.0.

  Here, MI is an index used for classification of humic acid, and is a ratio (wavelength 450 nm / wavelength 520 nm) of wavelengths 450 nm and 520 nm of the water extract. {Shinichi Kumada, Chemistry of Soil Organic Matter 2nd Annual Conference Publishing Center (1981), Japan Soil Fertilizer Journal No. 71 No. 1 p. 82-85 (2000)}.

More specifically, the MI according to the present embodiment is calculated by the following method.
The sample is pulverized into a 250 μm sieve product using a mortar and 250 μm sieve. About 10 g is taken into a weighing bottle with a known mass and weighed accurately. The weighing bottle is left in a dryer maintained at a temperature of 105 ° C. for about 12 hours, and then returned to room temperature in a desiccator and then weighed again. The moisture content of the sample is determined by regarding the reduced mass as moisture. Next, 0.10 g of the above-mentioned 250 μm sieving product in a 50 ml centrifuge tube is added with a dry mass equivalent amount of 0.10 g and 0.5 mass% sodium hydroxide 45 ml, and shaken at a temperature of 20 ° C. for about 1 hour at a speed of 250 rpm. After that, centrifugation was carried out at 4000 rpm for about 10 minutes. Filter through 5C filter paper. The absorbance at 450 nm and the absorbance at 520 nm of the filtrate are measured using distilled water as a blank. In this case, if the absorbance at 450 nm shows 1.0 or more, 0.1 wt% aqueous sodium hydroxide solution is added to adjust the absorbance to 0.8 or more and less than 1.0, and then the absorbance at 520 nm is measured. To do. The ratio of (absorbance at 450 nm / absorbance at 520 nm) is calculated and set as MI.

  If MI is 2.0 or more, it has sufficient active groups such as alcoholic hydroxyl groups and methoxyl groups, so that water solubility is improved, and good wastewater treatment is possible with a small amount of use. Moreover, if MI is 3.0 or less, the hygroscopic property of a processing agent can be made low and the quality at the time of a preservation | save can be maintained.

  MI can be increased or decreased by 2.0 to 3.0 depending on the amount of nitric acid when producing nitrate of young charcoal, and MI increases as the amount of nitric acid is increased. Many conventional humic acid formulations have an MI of 1.7 or less.

  Further, it is preferable that MI is 2.1 to 2.5 because nitric acid can be used in an appropriate amount and the cost can be kept low.

[Organic carbon concentration]
Moreover, the treatment agent according to the present embodiment is characterized in that the organic carbon concentration (hereinafter referred to as “TOC”) of the water extract is 800 to 2000 mg / L.

The method for measuring the organic carbon concentration of the water extract is defined as follows.
The sample was crushed to a 250 μm sieve using a mortar and 250 μm sieve, and 10.00 g in terms of dry mass and 100 ml of pure water were placed in a shake flask and shaken at a room temperature of 20 ° C. for about 1 hour at a speed of 250 rpm. After that, no. Filter with 5C filter paper, measure the organic carbon concentration in the filtrate, and use that value as the organic carbon concentration of the water extract.

  If the TOC is 800 mg / L or more, good wastewater treatment can be performed within a period of about 80 days, and the amount of treatment agent used can be reduced. Specifically, when the processing agent of this embodiment is used, processing can be performed in about 40 days. In addition, if the TOC is 2000 mg / L or less, the rate of molecular cleavage of high molecular weight humic acid or humic acid salt decreases, so that it becomes insolubilized and stays in the activated sludge of the aeration tank and flows away into the treated water. Is suppressed, and good wastewater treatment becomes possible.

  As a method of adjusting the TOC of the treating agent to 800 to 2000 mg / L, it can be performed by changing the kind of the young charcoal or combining the young charcoal having different carbon contents.

  The carbon content increases in the order of peat, lignite, lignite, and subbituminous coal, and the higher the carbon content, the lower the aliphatic hydrocarbons and the higher the proportion of aromatic hydrocarbons. Therefore, when the TOC of the processing agent using lignite is small, for example, when the TOC is reduced, a part or all of the lignite is replaced with, for example, lignite to have a predetermined TOC.

  Young charcoal is a natural product, and the quality varies among types, lots, and lots depending on the production area. Therefore, even if it is a processing agent manufactured on the same conditions, the quantity of humic acid or humic acid salt may differ remarkably, and the effect of waste water treatment may differ.

  In the present embodiment, the amount of humic acid or humic acid salt is stabilized by controlling the TOC to 800 to 2000 mg / L. That is, the present invention is characterized in that the TOC index is used and the variation in the amount of humic acid or humic acid salt is adjusted in advance to facilitate handling.

  Furthermore, it is preferable that TOC is 850-1500 mg / L. If the TOC is 850 mg / L or more, the hydrophilicity and water-solubility of the undissolved part of the humic acid or humic acid salt is high, and if it is 1500 mg / L or less, the water-soluble part is small and most of the input amount is It does not flow out with the treated water, and in any case, it is possible to suppress the amount of the treatment agent charged into the aeration tank.

[Additive composition]
The treatment agent of this embodiment preferably contains 3 to 11% by mass of iron or iron compound in terms of Fe and 7 to 18% by mass of silicon or silicon compound in terms of SiO ₂ . By making both iron or an iron compound and silicon or a silicon compound exist in such a ratio, the growth of microorganisms can be promoted, and the effect of this embodiment is promoted.

Furthermore, it is preferable to contain 4 to 10% by mass of iron or an iron compound in terms of Fe and 8 to 16% by mass of silicon or a silicon compound in terms of SiO ₂ . If the amount of iron or iron compound, silicon or silicon compound is in the above range, the time required for the change of the microflora of the microorganism is shortened, and as a result, the improvement of the sedimentation separation property is promoted.

  The amount of iron or iron compound is adjusted by, for example, mixing iron oxide, iron hydroxide, iron carbonate, iron ore, steelmaking slag powder, or the like. Although mixing is not specifically limited, Mixers, such as a ribbon mixer, a planetary mixer, a V-type mixer, a kneader, are used. These are preferably mixed prior to granulation after nitrate oxidation of young charcoal and an inorganic compound containing at least one element selected from calcium, magnesium or potassium.

  For adjusting the amount of silicon or silicon compound, for example, powders of natural clay, zeolite, silica, shale, serpentinite and the like are used. Similarly to iron or iron compounds, this may be mixed with nitrate after oxidation of young charcoal and mixed with an inorganic compound containing at least one element selected from calcium, magnesium or potassium and before granulation. preferable.

In the present embodiment, the amount of iron or iron compound is measured by the following method.
2-5 g of the sample pulverized in a mortar is accurately taken in a tall beaker, added with 15 ml of hydrochloric acid and 5 ml of nitric acid, covered with a watch glass and gradually heated on a hot plate. When the violent reaction is over, shift the watch glass and continue to evaporate to dryness. Add again 15 ml of hydrochloric acid and 5 ml of nitric acid while washing the inner wall of the beaker, and repeat heating and decomposition. Next, 25 ml of hydrochloric acid (1 + 5) is added, dissolved by heating, cooled, transferred to a 100 ml volumetric flask with pure water, pure water is added to the marked line, and then filtered through filter paper. An aliquot of the sample (30 to 600 micrograms as iron) is accurately placed in a 100 ml volumetric flask, 0.5 molar hydrochloric acid is added up to the marked line, and the absorbance at a wavelength of 248.3 nm is measured with an atomic absorption analyzer. For the standard iron solution, the amount of iron is determined from a calibration curve created simultaneously under the same conditions as for the sample solution. Here, the above-mentioned “hydrochloric acid (1 + 5)” means a dilute hydrochloric acid aqueous solution in which 5 volumes of pure water is mixed with 1 volume of hydrochloric acid (35 mass% HCl), and the same applies to the following. .

The amount of silicon or silicon compound is measured by the following method.
Accurately take 0.5 to 1 g of the sample crushed in a mortar, add 5 parts by mass or more of anhydrous sodium carbonate, mix and transfer to a platinum crucible, heat at low temperature, then gradually ignite and melt completely. Stop heating after about 30 minutes. After standing to cool, place in a beaker with a platinum crucible, dissolve the solid mass with hot water, wash away the platinum crucible, and add hydrochloric acid to make it strongly acidic. Accurately take a whole or a constant amount of the sample liquid in a porcelain evaporating dish and evaporate to dryness on a water bath. After adding several ml of hydrochloric acid (1 + 1) to this and evaporating to dryness several times, it is put into a dryer at 110-120 ° C., dehydrated and allowed to cool. Next, about 50 ml of hydrochloric acid (1 + 4) is added and heated to dissolve, and then quickly filtered. The precipitate is washed twice with warm hydrochloric acid (1 + 10), and then washed with hot water until there is no chloride reaction. After the precipitate is dried and ignited, the mass is accurately measured, and this is defined as the amount of SiO ₂ .

[Processing agent shape]
The treatment agent of this embodiment may be in the form of powder, granules, or a form held on a carrier. The powdery product having an average particle diameter of less than 1.0 mm has an advantage that the contact area with the waste water is wide. Further, in the case of a granular product having an average particle diameter of 1.0 mm to 4.0 mm, an ordinary waste water treatment apparatus is usually installed outdoors, and thus has an advantage that it is not easily affected by wind or the like at the time of charging.

  Moreover, the holding | maintenance goods to a support | carrier, ie, a processing agent composition, have the advantage that it can circulate with activated sludge in an aeration tank. For holding products on the carrier, for example, a mixture containing a processing agent, a thermoplastic resin such as polyethylene, and a processing agent and a foaming agent such as azodicarbonamide is extruded and cut into appropriate dimensions, for example, 1 to 2 mm. Can be manufactured.

[Processing method]
Next, an aerobic wastewater treatment method using the treatment agent according to the embodiment will be described.

The daily use amount of the treatment agent of the present embodiment is preferably 0.4 to 1.5% by mass of the BOD load (kg of BOD flowing in per day per 1 m ³ aeration tank). It is preferable to add this amount all at once or in a divided manner at the start of aeration in the case of the batch activated sludge method, or any time in the case of the continuous type.

  Here, BOD is one of water quality indicators, and is a numerical value of the amount of oxygen consumed when microorganisms decompose organic substances. The amount of microorganisms that can be decomposed among organic substances present in water.

  If the amount of the treatment agent used per day is 0.4% by mass or more, good wastewater treatment can be performed in a short time. Moreover, if it is 1.5 mass% or less, the effect of improving the sedimentation-separation property of activated sludge and reducing the excess sludge generation amount will be acquired.

In the case of the treatment agent composition, the daily use amount is 0.4 to 0.4 of the BOD load (kg of BOD flowing in per day per 1 m ³ aeration tank) in terms of the treatment agent amount. It is preferable that it is 1.5 mass%.

  Particularly preferably, the amount of the treatment agent used daily is 0.8 to 1.2% by mass of the BOD load for the reason that the addition is continued economically while maintaining the addition effect.

  Moreover, it is preferable to put it into the aeration tank once a day because it is a simple work and the work time is short.

  In the case of a product to be held on a carrier, instead of putting it in every day, for example, a product to be held in a carrier having a volume corresponding to 10 to 50% of the volume of the aeration tank is put in at once, and then It is preferable to exchange from half to full amount every month. Thereby, the processing agent consumed by microorganisms can be replenished suitably.

  Here, the batch activated sludge method has a function of an aeration tank for aeration of air or oxygen in a single tank and a settling tank for solid-liquid separation of the activated sludge mixed water, inflow of waste water, aeration, sedimentation, In this method, treatment water is discharged repeatedly as one cycle. Further, the continuous activated sludge method is a treatment method having a dedicated aeration tank and a precipitation tank, respectively, and means a method other than the batch type.

<Function and effect>
Hereinafter, the effects of the aerobic wastewater treatment agent and the treatment agent composition, the production method thereof, and the aerobic wastewater treatment method according to the above embodiment will be described.

  The aerobic wastewater treatment agent according to the above embodiment is composed of calcium, magnesium or potassium salts of nitrates of young charcoal, the melanic index is 2.0 to 3.0, and the organic carbon concentration of the water extract is 800 to 2000 mg / L.

  The treatment agent for aerobic wastewater having the above-described configuration has the effect of improving the settling and separation of activated sludge, which is an index of solid-liquid separation of activated sludge and treated water, and reducing the amount of generated excess sludge. Therefore, it is used for the treatment of organic wastewater such as public sewage, agricultural settlement wastewater, food factory wastewater, specifically domestic wastewater, sewage, starch processing water, edible oil-containing wastewater, gelatin-containing wastewater, sugar-containing wastewater, etc. it can.

  In the treatment agent, the melanic index may be 2.1 to 2.5, and the organic carbon concentration of the water extract may be 850 to 1500 mg / L. If it does in this way, water solubility improves, it becomes possible to perform favorable waste_water | drain processing with little usage-amount, the hygroscopic property of a processing agent can be made low, and the quality at the time of a preservation | save can be maintained. Moreover, it becomes insolubilized, stays in the activated sludge of the aeration tank, and is prevented from flowing away into the treated water, thereby enabling good waste water treatment.

In the above treating agent, iron or iron compound in terms of Fe 3 to 11 wt%, a silicon or silicon compound may contain 7-18% by weight in terms of SiO _2. In this way, the growth of microorganisms can be promoted, and the effect of this embodiment is promoted.

  Moreover, in the said processing agent, if it is an aerobic wastewater processing agent composition characterized by including the said aerobic wastewater processing agent and a thermoplastic resin, it can be circulated with activated sludge in an aeration tank. .

  The method for producing an aerobic wastewater treatment agent according to the embodiment includes at least one element selected from nitrates of young charcoal obtained by oxidizing and decomposing young charcoal with nitric acid, and calcium, magnesium and potassium. It is characterized by including a step of cooling the mixture with the inorganic compound containing, after heating at a temperature of 60 to 120 ° C. for 0.5 to 6 hours.

  In the manufacturing method of the aerobic wastewater treatment agent consisting of the above steps, it is possible to improve the sedimentation separation of activated sludge, which is an index of solid-liquid separation of activated sludge and treated water, and reduce the amount of generated excess sludge. An aerobic wastewater treatment agent can be obtained.

  Moreover, in the manufacturing method of the treatment agent for aerobic waste water, the young coal is a mixture of one or more selected from peat, lignite or lignite, and concentrated nitric acid is added per 1000 kg of the young coal. A step of blending 200 to 600 kg and mixing for 10 to 60 minutes may be further included. In this way, side chains and main chains of aliphatic hydrocarbons in young charcoal are chemically cleaved to lower the molecular weight, and by introducing a nitro group as a substituent, hydrophilicity is increased. Can obtain the effect of water-solubilizing a part of the young charcoal.

  Moreover, in the manufacturing method of the treatment agent for aerobic waste water, the mixture may contain 55 to 540 kg of an inorganic compound per 1000 kg of nitrate of young coal. In this way, the formation of humic acid salt is facilitated, and unreacted nitric acid is also neutralized, so that the pH of the treatment agent becomes alkaline at about 10. Therefore, the safety and storage stability of the subsequent handling are improved. The

  Moreover, in the manufacturing method of the processing agent of the aerobic waste water, the mixture before the heat treatment may be a granulated product having an average particle size of 0.5 to 8 mm. If it does in this way, manufacture of a firmer processing agent will become possible by the heat processing of a post process.

  Moreover, in the manufacturing method of the said aerobic waste_water | drain processing agent, 12-20 mass% may be sufficient as the moisture content of the said granulated material. In this way, it is possible to obtain a sufficient compressive strength of the treatment agent. For example, the treatment agent is pulverized during transportation or storage, and powdering occurs, or activated sludge mixed water is added to the aeration tank. Problems such as floating on the surface can be prevented. Moreover, the appropriate viscosity of a processing agent can be hold | maintained and handling is easy.

The method for producing an aerobic wastewater treatment agent according to the embodiment includes at least one element selected from nitrates of young charcoal obtained by oxidizing and decomposing young charcoal with nitric acid, and calcium, magnesium and potassium. A mixture with an inorganic compound containing 3 to 11% by mass of iron or an iron compound converted to Fe and 7 to 18% by mass of silicon or a silicon compound converted to SiO ₂ . If it does in this way, the growth of microorganisms can be promoted and the effect that the effect of this embodiment is promoted can be acquired.

  Furthermore, the method for treating aerobic wastewater according to the above embodiment is a biochemical method for treating wastewater per day by converting the treatment agent for aerobic wastewater or the composition for treating aerobic wastewater into the amount of the treatment agent. It is characterized by including 0.4 to 1.5% by mass with respect to the total oxygen consumption, and a step of batching or dividing and charging into an aeration tank of a batch type or continuous type aeration apparatus.

  The method for treating aerobic wastewater comprising the above steps has the effect of improving the settling and separation of activated sludge, which is an indicator of solid-liquid separation of activated sludge and treated water, and reducing the amount of generated excess sludge.

  Hereinabove, the treatment agent and the treatment agent composition for aerobic wastewater, the production method thereof, and the treatment method for aerobic wastewater according to the present invention have been described with reference to the embodiments, but the present invention is not limited thereto. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples.

[Example 1]
In a draft, 500 g of lignite having a carbon content of 77% by mass ground to less than 250 μm was placed in a 2 liter beaker, and 220 g of 48% by mass nitric acid was added while cooling in an ice water bath. After the reaction temperature reached 84 ° C., it was confirmed by a thermometer inserted in the beaker that the temperature was lowered.

And after cooling for 30 minutes as it was from the time of 84 degreeC, 180 g of calcium carbonate was added and mixed with the small kneader. Next, granulation (water content 15% by mass, average particle size 3.5 mm) is performed using a dish-type granulator, and a heat treatment is performed at 90 ° C. for 5 hours using a thermostatic bath. Manufactured. Table 1 shows the measurement results of Fe, SiO ₂ , MI, and TOC of the obtained treatment agent.

(Wastewater treatment test)
After putting 1 kg of activated sludge obtained from a confectionery food processing company into the aeration tank of a continuous wastewater treatment device consisting of an aeration tank (volume 6 liters, internal temperature adjusted to 25 ° C.) and a settling tank (volume 2 liters) The company's food wastewater was fed and processed. At that time, the amount of wastewater delivered was 0.8 kg BOD / m ³ per day for the first 45 days, and the day after that, taking into account that the BOD of wastewater fluctuates between 800 and 1000 mg / L. The amount was increased or decreased to 1.5 kg BOD / m ³ per unit. The treatment agent was used in an amount corresponding to 0.5% by mass of the BOD load, that is, 0.023 g was added for the first 45 days, and 0.045 g was added every day thereafter for 90 days. The amount of air to be aerated was adjusted so that the dissolved oxygen in the mixed water containing activated sludge in the aeration tank was 2 to 3 mg / L.

  The mixed water containing the activated sludge that flowed out of the aeration tank was subjected to sedimentation and separation of the activated sludge in the settling tank, and the supernatant was used as treated water. The following characteristics were measured for this treated water. The results are shown in Table 1.

  The suspended matter (abbreviated as SS) of the treated water was measured in accordance with Appendix 8 of the Environmental Agency Notification No. 59 of 1971. Moreover, the BOD of the treated water was measured according to JIS K01021 21. In addition, the diaphragm electrode method was utilized for the measurement of the dissolved oxygen amount of treated water.

  The stimulated odor in the aeration tank was sealed on the 90th day with a lid on the upper surface of the aeration tank, and after 5 minutes, the lid was removed to smell the odor and the presence or absence of the irritating odor was measured. The results are shown in Table 1.

  Sediment separation of activated sludge is determined by collecting the mixed water containing activated sludge in the aeration tank into a 500 ml graduated cylinder, plugging it, gently shaking and mixing, then placing it on a stationary table and after 5 minutes. 30 minutes later, the interface between the supernatant and the suspension is read, the volume of the suspension is measured, the volume% of the suspension with respect to 500 ml at the start of the test is calculated, SV5 (5 minutes standing), SV30 (30 minutes standing). The results are shown in Table 1.

  The amount of excess sludge generated is withdrawn from the increase in sediment in the sedimentation tank by a pump, and this is suction filtered using a glass fiber filter with a pore size of 1 micron, and the residue on the filter is removed at 105-110 ° C. for 2 hours. After drying, the mass was measured. This measurement was performed once a week during the period of the wastewater treatment test, and the accumulated amount is shown in Table 1.

[Example 2]
The same treatment as in Example 1 except that lignite with a carbon content of 71% by mass was used instead of lignite with a carbon content of 77% by mass, and 160 g of magnesium carbonate was used instead of 180g of calcium carbonate. Agents were manufactured and tested as described above.

[Example 3]
Instead of lignite, lignite with a carbon content of 66% by mass was used, and the same treatment agent as in Example 1 was produced except that the heat treatment conditions were changed to 80 ° C for 4 hours. went.

[Example 4]
Implemented except that instead of lignite, a mixture of lignite with a carbon content of 66 mass% and subbituminous coal with a carbon content of 81 mass%, the former: latter mass ratio of 60:40 was used. The same treatment agent as in Example 1 was produced and the above test was performed.

[Example 5]
As in Example 1, a mixture of 500 g of brown coal and 180 g of calcium carbonate was produced. This mixture was mixed with 80 g of iron slag powder and 100 g of shale powder, and then granulated using a briquetting machine (water content 13 mass%, average particle size 3.5 mm). A treatment agent was produced by heating and holding for a time, and the test was performed in the same manner as in Example 1.

[Example 6]
50 g of the treatment agent produced by the method of Example 1 was pulverized to less than 250 μm with a mortar, and 100 g of polystyrene resin, 837 g of polypropylene resin, 3 g of surfactant (stearic acid), and 10 g of foaming agent (azodicarbonamide) were added. A processing agent comprising a cylindrical foamed extrudate having a diameter of 5 mm and a length of 5 mm, mixed and melted by a screw extruder having a diameter of 60 mm, cooled and solidified in a water tank while being extruded and foamed from a strand die having 10 extrusion holes having a diameter of 4 mm. A composition was prepared. Using this treating agent composition, a wastewater treatment test was conducted as follows.

  That is, the test was performed in the same manner as in Example 1 except that 974 g of the treatment agent composition having the same bulk volume as that corresponding to 25% of the aeration tank volume was charged and half of the charged amount was replaced with a new one every 30 days. went.

[Example 7]
A treating agent was produced in the same manner as in Example 5 except that lignite having a carbon content of 62% by mass and nitric acid having 65% by mass were used instead of lignite, and the above test was performed.

Table 1 shows the measurement results of Fe, SiO ₂ , MI, and TOC of the treating agents obtained in Examples 2-7. Table 1 also shows the results of the wastewater treatment test.

[Comparative Example 1]
A treatment agent similar to that of Example 1 was produced and the above test was performed except that anthracite having a carbon content of 94% by mass was used instead of lignite.

[Comparative Example 2]
A treatment agent similar to that of Example 1 was produced and the above test was performed except that lignite with a carbon content of 77% by mass pulverized to less than 250 μm was used as it was.

[Comparative Example 3]
A treatment agent similar to that of Example 1 was produced and the above test was performed except that a simple mechanical mixture of 500 g of brown coal, 80 g of iron slag powder, and 100 g of shale powder was used as the treatment agent.

<Discussion>
As shown in the results of the wastewater treatment test in Table 1, in the treated water of Examples 1 to 7 according to the present invention, the suspended matter in the treated water is as low as 16 mg / L or less, and the BOD of the treated water is also 10 mg / L or less. Yes, good treated water was obtained. There was no irritating odor in the aeration tank.

  The sedimentation separability of the activated sludge was as low as 50% by volume or less after standing for 5 minutes, and was about half that of the comparative example after standing for 30 minutes. In addition, the amount of excess sludge generated was suppressed to 45 g or less.

  In particular, in Example 2, since MI is 2.1 and TOC is 900 mg / L, good results are obtained for treated water.

Further, in Example 5, since iron slag powder and shale powder are mixed, Fe in the treatment agent is 6.7% by mass and SiO ₂ is 9.2% by mass. Good results were obtained for the amount of excess sludge generated.

  The results of the wastewater treatment tests of Comparative Examples 1 to 3 are inferior to the results of the good examples as described above.

  This is because the comparative example 1 uses young charcoal with a high carbon content, so that the MI value is out of the range of 2.0 to 3.0 and the TOC value is out of the range of 800 to 2000 mg / L. Conceivable. Moreover, in the comparative example 2, it is thought that it is because the oxidative decomposition by nitric acid is not performed and the inorganic compound is not mixed. Moreover, in the comparative example 3, it is thought that it is because heating mixing is not performed.

Claims (9)

Calcium nitrate oxide young charcoal, made from the salts of magnesium or potassium, camera Nick index 2.1 to 2.5, organic carbon concentration of the water extract Ri 850-1500 mg / L der, iron or iron A treatment agent for aerobic wastewater containing 3 to 11% by mass of a compound in terms of Fe and 7 to 18% by mass of silicon or a silicon compound in terms of SiO ₂ . Aerobic wastewater treatment agent according to claim 1, aerobic wastewater treatment composition which comprises a thermoplastic resin. It is a manufacturing method of the processing agent of aerobic waste water according to claim 1,
A mixture of a nitrate of young charcoal obtained by oxidative decomposition of young charcoal with nitric acid and an inorganic compound containing at least one element selected from calcium, magnesium and potassium, at a temperature of 60 to 120 ° C., The manufacturing method of the processing agent of aerobic waste water characterized by including the process cooled after heating for 0.5 to 6 hours. The young charcoal is a mixture of one or more selected from peat, lignite or lignite, and 200 to 600 kg of concentrated nitric acid is blended per 1000 kg of the young charcoal and mixed for 10 to 60 minutes. The manufacturing method of the processing agent of aerobic waste water of Claim 3 characterized by the above-mentioned. The said mixture contains 55-540 kg of inorganic compounds per 1000 kg of nitrates of juvenile charcoal, The manufacturing method of the processing agent of aerobic waste water of Claim 4 characterized by the above-mentioned. 6. The method for producing a treatment agent for aerobic waste water according to claim 5 , wherein the mixture before the heat treatment is a granulated product having an average particle size of 0.5 to 8 mm. The method for producing a treatment agent for aerobic waste water according to claim 6 , wherein the granulated product has a water content of 12 to 20% by mass. It is a manufacturing method of the processing agent of aerobic waste water according to claim 1 ,
A mixture of a young charcoal nitrate obtained by oxidative decomposition of young charcoal with nitric acid and an inorganic compound containing at least one element selected from calcium, magnesium and potassium, iron or iron compound into Fe Convert to 3-11 mass%, the production method of the aerobic waste water treatment agent, characterized in that the silicon or silicon compound containing 7 to 18 mass% in terms of SiO _2. Aerobic wastewater treatment agent according to claim 1, or aerobic waste water treatment composition according to claim 2, in terms of the amount of the treating agent, per day biochemical oxygen consumption wastewater A method for treating aerobic wastewater, comprising a step of adding 0.4 to 1.5% by mass, in batch or divided, to an aeration tank of a batch type or continuous type aeration apparatus.