JP2007196172A - Liquid extract of humic substance, solidifying agent, concentrating agent and method for treating organic waste water by using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid extract of a humic substance, in which a component effective for waste water treatment is uniformized and concentrated highly and to provide a method for treating organic waste water in excellent efficiency by using the liquid extract of the humic substance. <P>SOLUTION: The liquid extract of the humic substance is obtained by extracting the humic substance from at least one selected from humus, leaf mold, compost, peat and peaty soil by using an aqueous solution of pH≥7. The method for treating organic waste water comprises a step of injecting the liquid extract of the humic substance at a gas-liquid contact step and/or at a sludge treatment step. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a humic substance extract, a solid treatment agent, a concentration treatment agent, and a method for treating organic wastewater using these, and in particular, general organic wastewater such as public sewage, agricultural settlement drainage, human waste treatment, and industrial wastewater. The present invention relates to a humic substance extract, a solid treatment agent, a concentration treatment agent, and an organic wastewater treatment method using these, which can be applied to the field of treatment.

Conventionally, Patent Document 1 discloses a technique of using humic substances in an activated sludge wastewater treatment system including a flow rate adjustment tank, an aeration tank, a precipitation tank, and a sludge concentration tank. Looking at the addition mode of humic substances, the humic substances are finely ground and added to the microorganism culture tank. Humic substances are a mixture of high-molecular organic acids that are chemically and biologically synthesized from the decomposition products of plant residues and microbial remains in the soil, and are humic acid, high-purity minerals, vitamins, It is described as a high-quality plateau peat containing amino acids and the like. In this system, the sludge introduced into the sludge concentration tank comes into contact with finely ground humic substances. As a result, malodorous components such as organic sulfur compounds such as ammonia, hydrogen sulfide, volatile amines and mercaptans are produced by reducing and decomposing nitrogen, sulfur and fatty acids in sludge by the action of biodegrading enzymes. It is said that it binds to the metal hydrate eluted from the water and is retained in the modified sludge as a stable chain compound, and the generation of malodor is suppressed.
JP 2003-225694 A JP 2001-340887 A

  However, in the technique described in Patent Document 1, the humic substance is used as it is, and even if it is used as a pellet as in Patent Document 2, the humic substance contains many components unnecessary for microbial treatment. Because there are few active ingredients, using a large amount of humic substances in a wastewater treatment system may increase the amount of sludge.

  Further, even if natural humic substances are used as they are or as pellets, the active ingredients are not uniformly contained, so that there is a problem that variations in wastewater treatment efficiency are likely to occur.

  Accordingly, an object of the present invention is to provide a humic substance extract, a solid treatment agent, and a concentration treatment agent in which components effective for wastewater treatment are homogenized and densified.

  Another object of the present invention is to provide an organic material that is excellent in treatment efficiency by using a humic substance extract, solid treatment agent, and concentration treatment agent that are homogenized and densified with effective components for wastewater treatment. It is to provide a method for treating wastewater.

  Other problems of the present invention will become apparent from the following description.

  As a result of intensive studies to solve the above problems of the present invention, the following has been found. That is, the extraction method was discovered by intensively studying the conditions for extracting the effective component of the humic substance. Moreover, as a result of earnestly examining the structure of the extract suitable for wastewater treatment, a specific concentration and structure of the active ingredient were found, and the present invention was achieved.

  Moreover, the said subject is solved by each following invention.

(Claim 1)
A humic substance extract extracted from an humic substance consisting of at least one selected from humus soil, humus soil, compost, peat or peat-like soil with an aqueous solution having a pH of 7 or more.

(Claim 2)
A humic substance extract extracted from a humic substance consisting of at least one selected from humus soil, humus soil, compost, peat or peat-like soil, and the humic substance extract is an acid between pH 3.0 and 6.0 equivalent of 10 meq / L or more, infrared absorption spectrum (IR spectrum) ^{3400 cm} -1 wind dry matter of the ^liquid, 1700 cm ^-1, 1400 cm -1, to have an absorption peak within ± 50 cm ^-1 around the 1100 cm ^-1 Humic substance extract characterized by the following.

(Claim 3)
The humic substance extract according to claim 1 or 2, wherein at least one compound selected from an iron compound, a magnesium compound or a calcium compound is added.

(Claim 4)
The solid processing agent which consists of a solid substance which adds an acid to the humic substance extract of Claim 1, 2, or 3, and precipitates at pH 4 or less.

(Claim 5)
The solid treatment agent according to claim 4, wherein the acid is at least one selected from mineral acids consisting of sulfuric acid, hydrochloric acid or nitric acid.

(Claim 6)
The concentration processing agent which consists of the concentrate which separated the humic substance extract of Claim 1, 2, or 3 by the filtration process.

(Claim 7)
A method for treating organic wastewater, comprising injecting the humic substance extract according to claim 1, 2 or 3 into a gas-liquid contact step and / or a sludge treatment step.

(Claim 8)
A method for treating organic wastewater, comprising injecting the solid treatment agent according to claim 4 or 5 into a gas-liquid contact step and / or a sludge treatment step.

(Claim 9)
A method for treating organic wastewater, comprising injecting the concentrated treatment agent according to claim 6 into a gas-liquid contact step and / or a sludge treatment step.

(Claim 10)
After mixing the humic substance extract according to claim 1, 2 or 3 with sludge generated in an aerobic biological treatment facility with an average hydraulic residence time of 3 hours or more in the container, the gas-liquid A method for treating organic wastewater, which is injected into a contact step and / or a sludge treatment step.

  According to the present invention, it is possible to provide a humic substance extract, a solid treatment agent, and a concentration treatment agent in which components effective for wastewater treatment are homogenized and densified.

  Further, according to the present invention, components effective for wastewater treatment are homogenized and densified using a humic substance extract, a solid treatment agent, and a concentration treatment agent. It is possible to provide a method for treating organic wastewater having improved treatment performance such as suppression and nitrification rate improvement (that is, excellent treatment efficiency). Furthermore, the use of an extract or the like can reliably control the wastewater treatment process, and can provide an organic wastewater treatment method that is easy to operate.

  Embodiments of the present invention will be described below.

<Humic substance extract>
The humic substance extract of the present invention is extracted with an aqueous solution having a pH of 7 or more from a humic substance consisting of at least one selected from humus soil, humus soil, compost, peat, or peat soil.

  In the present invention, as the humic substance, one kind selected from humus soil, humus soil, compost, peat or peat-like soil may be used, or two or more kinds may be combined.

  The liquid used for the extraction may be an aqueous solution having a pH of 7 or higher. As such an aqueous solution, an alkali metal hydroxide such as sodium hydroxide, an alkaline earth metal hydroxide such as magnesium hydroxide, or the like is preferably used. It is done.

In order to produce the humic substance extract of the present invention, as shown in FIG. 1, a production facility including an extraction step 1 and a pH adjustment step 2 is used. The extraction process 1 has an extraction tank, and the above humic substances are added. In the pH adjustment step 2, an aqueous solution having a pH of 7 or more (hereinafter referred to as an extraction aqueous solution) used for extraction is adjusted and added to the extraction tank.

  The mixing ratio of the humic substance and the extraction aqueous solution is preferably in the range of 10 to 1000 parts of the extraction aqueous solution, more preferably in the range of 50 to 100 parts by weight with respect to 1 part of the humic substance.

  When extraction is performed in the extraction step 1, a humic substance extract I is obtained by removing the solid matter by filtration if necessary. The filter cloth or filter paper used for the filtration treatment preferably has an aperture of 0.1 to 1 mm.

This humic substance extract I has an acid equivalent between pH 3.0 and 6.0 of 10 meq / L or more, and the structure is such that the IR spectrum of the air-dried liquid is 3400 cm ⁻¹ , 1700 cm ⁻¹ , 1400 cm ^{− 1} has an absorption peak within plus or minus 50 cm ⁻¹ centering on 1100 cm ⁻¹ .

  FIG. 4 shows an extraction droplet constant curve, and the region where the acid equivalent between pH 3.0 and 6.0 is 10 meq / L or more is clarified by the relationship between 0.1N-NaOH titration amount and pH. ing.

  FIG. 5 shows an IR spectrum of the humic substance (humus soil) extract I. In FIG. 5, (1) is a dry product to be extracted with water, (2) is a dry product to be extracted with a pH 4.0 extract, (3) is a dry product of a portion remaining without being extracted with water, ( 4) shows the dried product of the portion remaining without being extracted by the pH 4.0 extract.

  Moreover, in this invention, as shown in FIG. 1, by adding at least 1 type of compound chosen from an iron compound, a magnesium compound, or a calcium compound to said humic substance extract liquid I, humic substance extract liquid II is obtained. can get. The amount of the compound added to the humic substance extract I is preferably in the range of 1/100 to 1 part, more preferably in the range of 5/100 to 1 part by weight with respect to 1 part of the humic substance.

  Examples of the iron compound include ferric chloride and ferric sulfate. Examples of the magnesium compound include magnesium chloride and magnesium sulfate. Examples of the calcium compound include calcium chloride and calcium carbonate.

The concentration and structure of the humic substance extract II is such that the acid equivalent between pH 3.0 and 6.0 is 10 meq / L or more, and the structure shows that the IR spectrum of the liquid air-dried product is 3400 cm ⁻¹ (OH stretching vibration), ^1700cm -1 (C = O stretching vibration), OH bending vibration, such as 1400 cm ^-1 (acid, C-H bending vibration), 1100 cm ^-1 (ester, C-O stretching vibration of the ether) near ( It has an absorption peak within ± 50 cm ⁻¹ .

  Such humic substance extracts I and II are both liquid substances, and the humic substances are homogenized. Therefore, when used in a wastewater treatment process, there is an effect of stabilizing the treatment efficiency.

<Concentrated treatment agent>
The concentration treatment agent of the present invention can be obtained by concentrating the humic substance extract I or II by concentration treatment such as membrane treatment. FIG. 2 shows a manufacturing process of the concentration treatment agents I and II. As shown in FIG. 2, the manufacturing process includes a concentration process 4 added to the manufacturing process of FIG.

  Concentration in this way is preferable because the humic substance is densified and the amount added can be reduced.

<Solid processing agent>
The solid treatment agent of the present invention comprises a solid substance which is precipitated at pH 4 or less by adding an acid to the above humic substance extract. As the acid, it is preferable to use at least one mineral acid selected from sulfuric acid, hydrochloric acid or nitric acid.

  An example of the manufacturing process of the solid processing agent of this invention is demonstrated based on FIG.

  In FIG. 3, the extraction step 1, the pH adjustment step 2, and the addition step 3 are the same as the method of FIG. In this method, an electrolysis step 5 is introduced, water is electrolyzed into an alkali and an acid, and an alkaline solution is used in the pH adjustment step 2. The acid is used in the addition step 3. When the pH is lowered to 4 or less by the addition of this acid, a solid is precipitated. The solid matter is separated into solid and liquid by the filtration step 6, and the solid matter is used as it is or after washing as necessary to obtain the solid treatment agent of the present invention. The liquid produced by the solid-liquid separation is subjected to a membrane treatment 7 as necessary, concentrated and returned to the electrolysis step 5.

<Method of treating organic wastewater>
FIG. 6 is a flowchart showing an example of the method for treating organic wastewater according to the present invention.

  Inflow water (such as sewage) containing an organic substance is subjected to removal of impurities by the screen 10 and is first subjected to solid-liquid separation in the settling tank 11. First, the top solution of the settling basin 11 is sent to the aeration tank 12 for microbial treatment. The sludge and wastewater suspension sent from the aeration tank 12 is sent to the final sedimentation tank 13 for solid-liquid separation. The sludge settled in the final sedimentation tank 13 is returned to the aeration tank 12, and a part of the returned sludge is removed as excess sludge.

  In the present invention, the wastewater treatment process may include a gas-liquid contact process and a sludge treatment process. In the example of FIG. 6, the gas-liquid contact process is the aeration tank 12. The sludge treatment process includes a treatment system from the screen 10 to the first sedimentation basin 11, a treatment system from the first sedimentation basin 11 to the aeration tank 12, a treatment system from the aeration tank 12 to the final sedimentation basin 13, and a final precipitation basin 13 to the aeration tank 12. In addition, although not shown in the figure, a processing system from the final sedimentation tank 13 to the sludge concentration tank is also included. Moreover, when a sludge culture tank (it is also called an acclimatization tank) is provided in the processing system which returns sludge, the sludge culture tank is included.

  The present invention is characterized by injecting or adding the humic substance extract, the solid treatment agent or the concentration treatment agent into the gas-liquid contact step and / or the sludge treatment step. Also, the above humic substance extract, solid treatment agent or concentration treatment agent can be arbitrarily combined and added or injected.

  After mixing the above humic substance extract with sludge generated in the aerobic biological treatment facility with an average hydraulic residence time of 3 hours or more in the container, the gas-liquid contact step and / or sludge It is also preferable to inject into the processing step. If it does in this way, there exists an effect of improvement of processing performance, such as suppression of the amount of generated sludge, suppression of bad smell generation, and improvement of nitrification speed.

  Examples of the present invention will be described below, but the present invention is not limited to such examples.

<Manufacture of humic substance extract>
Humic substance extract 1
The supernatant obtained by adding 5 parts of water (dry matter weight ratio) to 1 part of the humic compost and stirring and allowing to stand is used as the humic substance extract 1. (Samples of Examples 1 and 6)

Humic substance extracts 2-5
The supernatant obtained by adding 5 parts of water (weight ratio of dry matter) to 1 part of peat humus and stirring and allowing to stand is used as a humic substance extract 2 (samples of Examples 2 and 7).

  The humic substance extract 2 was prepared by adding Mg to the humus extract 2 as shown in Table 1 (sample of Example 3).

  A solution obtained by adding Ca to the humic substance extract 2 as shown in Table 1 is referred to as a humic substance extract 4 (sample of Example 4).

  What added Fe to the humic substance extract 2 as shown in Table 1 is set as the humic substance extract 5 (sample of Example 5).

<Acid equivalent of humic substance extract>
The acid equivalents of the humic substance extracts 1 to 5 were measured by 0.1N-NaOH titration method, and the results are shown in Table 1.

<Experiment details>
The apparatus shown in FIG. 6 was used. Specifically, in order to confirm the effect of the humic substance extract obtained as described above, an inflow sewage sample was examined using an experimental apparatus having a 5 L aeration tank and a sedimentation tank.

  The sample throughput was 500 mL / hour, the extract addition amount (before air tanning) was 1 mL / hour, and the temperature in the aeration tank was set to 20 ° C.

<Evaluation>
The following items were measured and evaluated by the measurement methods shown below. The results are shown in Table 1.

Sludge generation amount (measuring method) SS: JIS K0102 14.1 (suspended material)
(Evaluation methods)
(Excess sludge SS concentration [mg (SS) / L] × (average daily excess sludge withdrawal amount [L / day]) + (MLSS concentration difference before and after experiment [mg (SS) / L]) × (aeration tank Capacity [L]) ÷ (Experiment days [Day])

Odor (measurement method)
50 g of sludge prepared to a moisture content of 85% is divided into 16 equal parts, placed in a 1 L glass bottle, sealed and placed in a thermostatic bath at 30 ° C. At this time, in order to keep the internal pressure of the glass bottle constant, an air bag communicating with outside air is provided outside.

(Evaluation methods)
The gas inside the glass bottle is measured with a hydrogen sulfide measuring tube. At this time, when the hydrogen sulfide concentration is 0.2 ppm or more, the measurement gas is expressed as “hydrogen sulfide odor”, and when it is less than 0.2 ppm, it is expressed as “no odor”.

Nitrification rate (measurement method)
The sludge mixed liquid collected from the aeration tank is put into a 2 L beaker, and the temperature of the liquid is set to 20 ° C., and aeration is performed while stirring to ensure a dissolved oxygen concentration of 2 mg / L or more. In this state, a sample is taken at every elapsed time and analyzed for nitrite nitrogen concentration and nitrate nitrogen concentration. The loss on ignition (MLVSS) of the sample is also analyzed.
Loss on ignition: JIS K0102 14.5
Nitrite ion: JIS K0102 43.1
Nitrate ion: JIS K0102 43.2

(Evaluation methods)
Plotting the relationship between the NO _X and the elapsed time is calculated nitrification rate from the slope [mg (N) / g ( MLVSS) · hr].

The flowchart which shows an example of the manufacturing process of the humic substance extract which concerns on this invention. The flowchart which shows an example of the manufacturing process of the concentration processing agent which concerns on this invention The flowchart which shows an example of the manufacturing process of the solid processing agent which concerns on this invention Diagram showing the extraction droplet constant curve Diagram showing IR spectrum of humic substance extract The flowchart which shows an example of the processing method of the organic wastewater which concerns on this invention

Explanation of symbols

1: Extraction process 2: pH adjustment process 3: Addition process 4: Concentration process 5: Electrolysis process 6: Filtration process 7: Membrane treatment 10: Screen 11: First sedimentation tank 12: Aeration tank 13: Final sedimentation tank

Claims (10)

  A humic substance extract extracted from an humic substance consisting of at least one selected from humus soil, humus soil, compost, peat or peat-like soil with an aqueous solution having a pH of 7 or more. A humic substance extract extracted from a humic substance consisting of at least one selected from humus soil, humus soil, compost, peat or peat-like soil, and the humic substance extract is an acid between pH 3.0 and 6.0 equivalent of 10 meq / L or more, infrared absorption spectrum (IR spectrum) ^{3400 cm} -1 wind dry matter of the ^liquid, 1700 cm ^-1, 1400 cm -1, to have an absorption peak within ± 50 cm ^-1 around the 1100 cm ^-1 Humic substance extract characterized by the following.   The humic substance extract according to claim 1 or 2, wherein at least one compound selected from an iron compound, a magnesium compound or a calcium compound is added.   The solid processing agent which consists of a solid substance which adds an acid to the humic substance extract of Claim 1, 2, or 3, and precipitates at pH 4 or less.   The solid treatment agent according to claim 4, wherein the acid is at least one selected from mineral acids consisting of sulfuric acid, hydrochloric acid or nitric acid.   The concentration processing agent which consists of the concentrate which separated the humic substance extract of Claim 1, 2, or 3 by the filtration process.   A method for treating organic wastewater, comprising injecting the humic substance extract according to claim 1, 2 or 3 into a gas-liquid contact step and / or a sludge treatment step.   A method for treating organic wastewater, comprising injecting the solid treatment agent according to claim 4 or 5 into a gas-liquid contact step and / or a sludge treatment step.   A method for treating organic wastewater, comprising injecting the concentrated treatment agent according to claim 6 into a gas-liquid contact step and / or a sludge treatment step. After mixing the humic substance extract according to claim 1, 2 or 3 with sludge generated in an aerobic biological treatment facility with an average hydraulic residence time of 3 hours or more in the container, the gas-liquid A method for treating organic wastewater, which is injected into a contact step and / or a sludge treatment step.

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