JP5005239B2 - Estimating water quality of influent sewage by phosphorus elution from activated sludge, nutrient source addition equipment in advanced sewage treatment equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sewage treatment technique in advanced sewage treatment such as AO and A ₂ O that can remove phosphorus that cannot be sufficiently removed by a standard activated sludge method, and relates to phosphorus accumulating bacteria related to phosphorus removal in influent sewage. Activated sludge by advanced sewage treatment to estimate the concentration of nutrient source materials (for example, acetic acid, etc.) and adjust the amount of nutrient source materials to increase the activity of phosphorus accumulating bacteria in the advanced sewage treatment equipment. The present invention relates to a method for estimating the quality of influent sewage by elution of phosphorus from the inside, a nutrient source addition device in an advanced sewage treatment device, and an advanced sewage treatment device.

  The conventional advanced processing apparatuses include those shown in FIGS. First, in FIG. 6, sewage (sewage) flows into the adjustment tank 1, sewage in the adjustment tank 1 is sent to the anaerobic tank 3 by the adjustment pump 2, and overflow water from the anaerobic tank 3 flows into the aerobic tank 4. After aerobic treatment with activated sludge by the apparatus 5, the overflow water is sent to the settling tank 6, and the supernatant water of the inflow water is discharged to the outside as treated water. Excess sludge precipitated in the settling tank 6 is sent to the sludge concentration storage tank 7, and the supernatant water is returned to the adjustment tank 1. (For example, see Patent Document 1)

  7 is a biological dephosphorization apparatus, in which sewage inflow water flows into the anaerobic tank 3, the liquid in the anaerobic tank 3 is sent to the aerobic tank 4, and the overflow water is finally settled. The return sludge from the final sedimentation basin 6 flows into the anaerobic tank 3 and the overflow water from the final sedimentation basin 6 is drained as treated water. This apparatus is provided with a phosphorus concentration measurement system, a flow rate measurement system, and a flocculant injection system. The phosphorus concentration measurement system takes the liquid in the aerobic tank 4 with a pump 4a and sends it to a solid-liquid separator 4b for solid content. The liquid from which the water is removed is measured by the phosphorus concentration meter 4 c, and the flow rate of the overflow water from the aerobic tank 4 is measured by the flow meter 8. This advanced processing apparatus is provided with a flocculant storage tank 9 and supplies the flocculant (aluminum, iron-based inorganic flocculant: polyaluminum chloride (PAC)) to the aerobic tank 4 by operating the pump 9a. . In the flocculant injection amount control device 8a, the pump 9a is controlled based on the measurement values of the phosphorus concentration meter 4c and the flow meter 8, and the flocculant injection amount is set. (For example, see Patent Document 2)

Japanese Patent Laid-Open No. 06-126296 (paragraphs [0006], [0007], FIG. 2) Japanese Patent Laid-Open No. 09-174086 (the whole specification, FIG. 1)

  In biological phosphorus removal in advanced treatment of sewage and sewage, phosphorus accumulating bacteria involved in phosphorus removal exhale phosphorus outside the cells in the anaerobic tank and take in organic acids, and in the aerobic tank in the cells in the anaerobic tank Phosphorus is removed by taking in more phosphorus than was consumed by consuming organic acid. However, in the conventional sewage advanced treatment apparatus, it was not considered whether the amount of organic acid contained in the inflowing sewage in the anaerobic tank had an amount commensurate with the amount of activity of the phosphorus accumulating bacteria.

  Moreover, the latter conventional example is a flocculant-added activated sludge method, which detects the phosphorus concentration in the aerobic tank and the flow rate of the overflow water from the aerobic tank and injects an optimal amount of flocculant to remove phosphorus. However, the phosphorus removal method using such a flocculant (PAC) does not supply the flocculant by grasping the activity of the phosphorus accumulating bacteria. Therefore, in the conventional example, in order to maintain the quality of the treated water, a flocculant (PAC) was injected more than necessary into the aerobic tank, and the activity amount of phosphorus accumulating bacteria might be inhibited. In addition, a large amount of sludge including a flocculant is generated, and the cost of sludge treatment increases, which is not necessarily a preferable phosphorus removal method, and there is room for improvement.

The present invention has been made in view of the above-described problems, and estimates the concentration of a nutrient source material necessary for the activity of the phosphorus accumulating bacteria contained in the inflowing sewage, thereby increasing the activity amount of the phosphorus accumulating bacteria in the anaerobic tank. In order to estimate the amount of nutrients necessary for the activities of phosphorus accumulating bacteria contained in the inflowing sewage using concentrated activated sludge, the influent sewage is extracted by phosphorus elution from the activated sludge. It provides a quality estimation method of the inflow sewage to estimate the organic acid concentration in the aim of this quality estimation method using, providing nutrients added equipment in sewage advanced treatment apparatus for adjusting the nutrient source material weight To do.

The present invention was made in order to achieve the above-mentioned problems, and the invention of claim 1 is a sludge concentration step in which activated sludge containing phosphorus-accumulating bacteria is denitrified to obtain a concentrated sludge;
An anaerobic process in which a predetermined amount of inflowing sewage that is a measurement sample is placed in a collection container and the concentrated sludge is introduced, and an inner solution of each collection container is anaerobic,
A phosphoric acid concentration measuring step for measuring a phosphoric acid concentration in a filtered solution obtained by filtering the inner solution in the collection container;
A method for estimating the water quality of influent sewage by elution of phosphorus from activated sludge, comprising an arithmetic processing step for obtaining a concentration of reactive organic acids of phosphorus accumulating bacteria contained in the influent sewage from the phosphoric acid concentration.

In addition, the invention of claim 2 is a sludge concentration step in which the activated sludge containing phosphorus accumulating bacteria is denitrified into a concentrated sludge,
First to third collection containers having a predetermined capacity are prepared, the concentrated sludge containing the phosphorus accumulating bacteria obtained in the concentration step is introduced into the first collection container, and a nutrient source material is introduced into the second collection container The concentrated sludge is charged in a predetermined amount, and the concentrated sludge is charged in a third sampling container with a predetermined amount of inflowing sewage, and the inner solution in each sampling container is stirred and anaerobic. An anaerobic process and
After the anaerobic step has elapsed for a predetermined time, a measurement step of measuring the phosphoric acid concentration in the filtered solution obtained by filtering the inner solution of each of the collection containers;
The phosphoric acid concentration in the filtrate obtained from the first and second collection containers in the measurement step and the phosphoric acid concentration of the sample in the filtrate corresponding to the third collection container are processed to calculate phosphorus accumulation. It is a method for estimating the water quality of influent sewage by elution of phosphorus from activated sludge, comprising an arithmetic processing step for determining the concentration of fungi-reactive organic acids.

  The invention according to claim 3 is the method for estimating the quality of influent sewage by phosphorus elution from activated sludge according to claim 2, wherein the nutrient source material is an organic acid such as acetic acid and salts thereof. is there.

The invention according to claim 4 is the water quality estimation method for influent sewage by phosphorus elution from activated sludge according to claim 3, wherein the calculation processing step is based on the following calculation formula [Equation 4]. .

  The invention of claim 5 is characterized in that the phosphorus-accumulating bacterium-reactive organic acid is an organic acid that is incorporated in a process in which the phosphorus-accumulating bacterium releases phosphorus outside the cell in an anaerobic state. The water quality estimation method for influent sewage by elution of phosphorus from activated sludge as described in 1, 2, 3 or 4.

Further, the invention of claim 6 is a method for estimating the quality of influent sewage by phosphorus elution from the activated sludge according to claim 2,
Ypo4, which is the ratio of phosphorus elution amount / absorbed organic acid amount, is obtained from the phosphoric acid concentration in the filtered solution obtained from the first and second collection containers in the phosphoric acid concentration measuring step by the following equation [Equation 5]. This is a method for estimating the water quality of influent sewage by elution of phosphorus from activated sludge.

The invention of claim 7 is the water quality estimation method of influent sewage by phosphorus elution from the activated sludge according to claim 6,
A fourth collection container is provided in addition to the first to third collection containers, the nutrient substance is excessively added to the fourth collection container, and concentrated sludge is supplied to the fourth collection container to fill the water. The solution in the 4 collection container is made anaerobic for a predetermined time while stirring, and after the filtration process, the solution in the 4th collection container is separated into solids and filtrate, and the filtration obtained from the 4th collection container In addition to measuring the phosphoric acid concentration in the liquid, the initial phosphoric acid phosphorus concentration of the concentrated sludge was measured by a phosphoric acid concentration measuring step, and each phosphoric acid concentration and the Ypo4 were calculated according to the following equation [Equation 6]. A method for estimating the quality of influent sewage by elution of phosphorus from activated sludge, characterized by determining the amount.

  The invention according to claim 8 is the method for estimating the quality of influent sewage by elution of phosphorus from the activated sludge according to claim 7, wherein a phosphorus-accumulating bacterium is obtained using a second collection container instead of the fourth collection container. 8. The method for estimating the quality of influent sewage by elution of phosphorus from activated sludge according to claim 7, wherein the amount is determined.

The invention of claim 9 is an addition device for estimating phosphorus-accumulating bacteria reactive organic acids contained in the inflowing sewage flowing into the advanced sewage treatment device and adding a nutrient source material to the anaerobic tank,
Sampling means for sampling the final excess sludge that has settled in the final sedimentation basin after the sewage advanced treatment device;
Sludge concentrating means to deconcentrate activated sludge containing phosphorus accumulating bacteria collected by the collecting means;
First to third collection containers of a predetermined capacity;
The concentrated sludge obtained from the sludge concentration step is charged with the first collection container, the second collection container with a predetermined amount of nutrient source material, and a predetermined amount of inflow sewage as a measurement sample. Anaerobic means for charging the third collection container and making the solution in each collection container anaerobic;
An optical measuring means for measuring a phosphoric acid concentration in a filtered solution obtained by filtering the inner solution of each container after the anaerobic means has passed for a predetermined time;
The optical measuring means computes the phosphoric acid concentration in the filtrate obtained from the first and second collection containers and the phosphoric acid concentration in the filtrate corresponding to the third collection container. Arithmetic processing means for determining the concentration of reactive organic acids of the phosphorus-accumulating bacteria,
An acetic acid injecting means for injecting a nutrient source material into the anaerobic tank of the advanced sewage treatment apparatus according to the phosphorus accumulating bacteria reactive organic acid concentration obtained by the arithmetic processing means. It is a nutrient source addition device.

  The invention of claim 10 is a data table in which the acetic acid injecting means records a nutrient source substance amount to be injected according to the concentration of phosphorus accumulating bacteria reactive organic acids. It is a nutrient source addition device in an advanced sewage treatment device.

  The invention according to claim 11 is the nutrient source addition apparatus in the advanced sewage treatment apparatus according to claim 9 or 10, wherein the nutrient source material is an organic acid such as acetic acid and salts thereof.

  The invention of claim 12 is characterized in that the phosphorus-accumulating bacteria-reactive organic acids are organic acids taken in the process of anaerobic phosphorus-accumulating bacteria releasing phosphorus outside the cells. , 10 or 11 is a nutrient source addition device in the advanced sewage treatment apparatus.

  According to the inventions of claims 1 to 5, in the sewage advanced treatment apparatus, the concentration of the nutrient source substance of the phosphorus accumulating bacteria mixed in the inflowing sewage is utilized using the activated sludge obtained from the final surplus sludge of the sewage advanced treatment apparatus, The activated sludge is concentrated, the inflowing sewage and the concentrated sludge are anaerobically measured, the phosphorus concentration eluted from the activated sludge is measured, the phosphorus concentration is calculated, and the phosphorus accumulating bacteria as the total organic acid in the influent sewage It is possible to determine the amount of reactive organic acids (PRA amount), and as in the past, without detecting acetic acid etc. in the influent sewage by expensive chromatography, the PRA amount is measured and the nutrient source in the influent sewage There is an advantage that the amount of substance can be estimated and the time required for measurement can be shortened. In addition, the PRA measurement has an advantage that it is possible to estimate the activity amount of the phosphorus accumulating bacteria. Moreover, when measuring the amount of PRA in the inflowing sewage, it is possible to measure with high accuracy by preparing and measuring a blank, a standard solution, and first to third collection containers that are samples when compared to quantitative analysis. .

  According to the invention of claim 6, Ypo4 is easily obtained, Ypo4 is phosphorus elution amount (mgP) / absorbing organic acid (mgCODcr), and if Ypo4 is lower than 0.4, There is a possibility that the amount of phosphorus accumulating bacteria (Xpao) may be low, which may interfere with the measurement of PRA, and the value of Ypo4 is effective for grasping the amount of phosphorus accumulating bacteria in the advanced processing apparatus.

  Moreover, according to the invention of Claims 7 and 8, the 4th collection container is provided in the process of Claim 2, or the concentrated sludge which added the nutrient substance excessively using the 2nd collection container is used. The amount of phosphorus accumulating bacteria (Xpao) can be easily determined from the phosphoric acid concentration, the initial phosphoric acid phosphorus concentration of this concentrated sludge, and the value of Ypo4. The value of Xpao represents the amount of activity of phosphorus accumulating bacteria in the advanced treatment equipment. It is effective for grasping and is a numerical value effective for grasping whether or not sludge is sufficiently dephosphorized.

  Further, according to the inventions of claims 9 to 12, in the sewage advanced treatment apparatus, the concentration of the nutrient source substance of the phosphorus accumulating bacteria mixed in the inflowing sewage is determined by the phosphorus eluted from the activated sludge obtained from the sewage advanced treatment apparatus. It is possible to measure the concentration and calculate the concentration of phosphorus to calculate the amount of PRA as the total amount of organic acid in the influent sewage, and to detect acetic acid, etc., which are nutrients in the influent sewage, by expensive chromatography Without being able to estimate, it is possible to determine the supply amount of acetic acid, which is a nutrient source material, from this estimated PRA value and supply it from the nutrient source addition device to the anaerobic tank of the advanced sewage treatment device There is an advantage that the phosphorus accumulating bacterium activity amount of the phosphorus accumulating bacterium in the advanced sewage treatment apparatus is increased, and dephosphorization can be effectively performed without using a phosphorus flocculant.

Hereinafter, the water quality estimation method of the inflow sewage by phosphorus elution from activated sludge according to the present invention, embodiments of the nutrients added equipment in sewage advanced treatment apparatus will be described with reference to the drawings.

  First, in order to facilitate understanding of the present invention, phosphorus accumulating bacteria and phosphorus accumulating bacteria reactive organic acids will be described, and the principle of estimating phosphorus accumulating bacteria reactive organic acids will be described. Phosphorus-accumulating bacteria release phosphorus out of the cell in an anaerobic state, take up organic acids in sewage, and absorb more phosphorus in the aerobic tank than the phosphorus exhaled in the anaerobic tank using the incorporated organic acid as a nutrient source. It is a useful bacterium that removes phosphorus. The generic name of organic acids taken up by phosphorus accumulating bacteria is referred to as phosphorus accumulating bacteria reactive organic acids (hereinafter referred to as PRA), and PRA is an organic acid such as acetic acid and propionic acid contained in sewage. .

  Moreover, the property of phosphorus accumulation bacteria is demonstrated with reference to FIG. 3, FIG. 3 and 4 show the elapsed time (minutes) in which the horizontal axis is in an anaerobic state, and the vertical axis shows the phosphorus elution concentration (mg / l). As shown in FIGS. 3 and 4, the phosphorus accumulating bacteria have a characteristic that when the sewage is anaerobic, phosphorus is eluted from the phosphorus accumulating bacteria into the sewage, and the phosphorus concentration becomes a constant value with time. In FIG. 3, the phosphorus concentration is constant after approximately 100 minutes. In short, when either organic acid in sewage or polyphosphoric acid in phosphorus accumulating bacteria is depleted, the phosphorus elution reaction by phosphorus accumulating bacteria is stopped, and the phosphorus concentration is considered to be constant.

  In FIG. 4, the activated sludge concentration (MLSS1000) reaches a constant value in approximately 80 minutes, whereas the activated sludge concentration (MLSS2000) reaches a constant value in approximately 40 minutes. As is clear from this result, by increasing the sludge concentration in the anaerobic sewage, there is no concern about the deficiency of polyphosphate in the cells taken up by the phosphorus accumulating bacteria contained in the concentrated sludge. The reason for stopping the phosphorus elution reaction is thought to be limited to the depletion of organic acids, etc. in the sewage, and the final phosphorus release concentration at which the phosphorus elution concentration is constant is proportional to the amount of organic acid in the sewage. Conceivable. That is, it is possible to measure the organic acid concentration quantitatively from the phosphorus release concentration. Further, as apparent from FIG. 4, if the activated sludge concentration is made high, the phosphorus elution concentration becomes constant in a short time, so that the PRA concentration in the sewage can be quickly estimated in a short time.

  One embodiment of the present invention is a method for estimating a PRA concentration in sewage in principle, a sludge concentration step in which activated sludge containing phosphorus-accumulating bacteria is denitrified, and an inflow that is a measurement sample into a collection container An anaerobic process in which a predetermined amount of sewage is filled and the concentrated sludge is introduced to make the inner solution of each collection container anaerobic, and the phosphoric acid in the filtered solution obtained by filtering the inner solution in the collection container Water quality of influent sewage due to phosphorus elution from activated sludge having a phosphoric acid concentration measuring step for measuring the concentration and an arithmetic processing step for obtaining the concentration of reactive organic acids in the influent sewage contained in the influent sewage from the phosphoric acid concentration There is an estimation method.

  Next, a method for estimating the quality of influent sewage by elution of phosphorus from activated sludge, which is a main embodiment of the present invention, will be described with reference to FIG. FIG. 1 shows a process for estimating the PRA concentration in the inflowing sewage and a process for injecting acetic acid as a nutrient source into the sewage according to the PRA concentration. Phosphorus removal can be performed efficiently. Each step in FIG. 1 is executed by computer control. The nutrient material is an organic acid such as acetic acid and salts thereof. In this embodiment, sodium acetate is used, but the present invention is not limited to this.

First, step S1 is a return sludge collection step of collecting return sludge (activated sludge) that sends activated sludge obtained from the final sedimentation basin of an advanced treatment apparatus such as A ₂ O to an anaerobic tank. It progresses to step S2 after a return sludge collection process. Step S2 is a return sludge concentration step in which the collected activated sludge is denitrified concentrated sludge. On the other hand, in the sewage inflow water collecting step in step S3, the inflow sewage flowing into the advanced processing apparatus is collected. It should be noted that in step S2, after making the concentrated sludge, the nitric acid and nitrous acid in the sludge may be denitrified by elapse of a predetermined time (about 30 minutes). Also good.

  Next, first to third collection containers having a predetermined volume are prepared. For convenience, the volume of the first to third collection containers is set to 100 ml. In step S4, 1 ml of a predetermined volume of nutrient source (sodium acetate smg / ml) is supplied to the second collection container. In terms of acetic acid, this corresponds to 0.74 s (mg / ml). The third collection container is supplied with a predetermined volume (Vml) of sewage inflow water as a measurement sample collected in step S3. Subsequently, in steps S5 to S7, the concentrated sludge is supplied to the first to third collection containers until they are full and stirred, and the first to third collection containers are set in an anaerobic state. After a predetermined time (about 30 minutes) has elapsed, the filtering steps of steps S8, S10, and S12 are performed.

  The filtrate from the filtration process of steps S8, S10, and S12 is supplied to a predetermined container, and the phosphorus concentration is measured in steps S9, S11, and S13, which are phosphorus concentration measurement processes. Phosphorus concentration can be measured simultaneously by an absorptiometric method or a colorimetric analysis method. As the predetermined container for storing the filtrate, a light transmissive container is used. It is assumed that the phosphorus concentration is AmgP / l in step S9, the phosphorus concentration is BmgP / l in step S11, and the phosphorus concentration is CmgP / l in step S13. The phosphorus concentration values A, B, and C (mgP / l) in steps S9, S11, and S13 are subjected to a phosphorus concentration calculation process in accordance with the following calculation formula [Equation 7] in step S14, and the PRA amount is calculated. In a quantitative analysis, the first container corresponds to a blank, the second container corresponds to a standard solution, and the third container serves as a sample. The calculation of the amount of PRA is obtained by a phosphorus accumulating bacterium reactive organic acid concentration measuring means that performs the arithmetic processing of [Equation 7] on a computer.

  Here, the equation of [Equation 7] will be explained. B-A represents the phosphorus elution concentration by adding 0.74 s (mg) of acetic acid, and 0.74 s / (B-A) represents the acetic acid concentration relative to the phosphorus elution concentration. Seeking the ratio. By multiplying this value by the phosphorus concentration elution concentration C (mgP / l) obtained from the sample (third collection container), the PRA value is obtained. The phosphorus elution concentration from the sample is a value obtained by correcting the phosphoric acid phosphorus taken from the phosphorus accumulating bacteria in the sample and the elution phosphoric acid phosphorus derived from the concentrated sludge (phosphorus accumulating bacteria) itself from the phosphorus elution C of the sample. −D · V / 100) −A · (100−V) / 100. In addition, although a separate collection container may be used for the measurement of D, for example, the first collection container is used and only the sample is introduced without introducing the concentrated sludge, and the filtration is performed without anaerobic conditions. This is a value obtained by measuring the phosphoric acid concentration (mgP / l) of the filtrate, and is the phosphoric acid concentration of the sample itself. Further, since the amount of the sample is V (ml), the arithmetic expression of [Equation 7] is obtained by converting to mg / L. For example, if s = 1, A = 7, B = 15, C = 10, D = 2, and V = 30, the PRA amount is 13.9 (mgCOD / l).

  In step S14, the inflowing sewage PRA amount is calculated in the phosphorus concentration measurement step, and in step S15, the PRA to addition amount conversion straight line L in FIG. 5 corresponds to the PRA amount from the stored data table. A necessary addition amount of a nutrient material (organic matter: acetic acid or the like) is read out, and a predetermined addition amount is supplied to the anaerobic tank of the advanced processing apparatus. By supplying nutrient source materials, the activity of phosphorus accumulating bacteria in the advanced treatment apparatus is activated, and phosphorus is efficiently removed from the inflowing sewage.

  With reference to FIG. 5, calculation of the necessary addition amount of the nutrient material will be described. In FIG. 5, the horizontal axis represents the amount of PRA, and the vertical axis represents the necessary addition amount or no addition requirement of acetic acid (organic substance). FIG. 5 shows a PRA vs. addition amount conversion line L, and the required addition amount for the PRA value in the inflowing sewage is read from the conversion line L. If the measured value of the PRA amount is the required amount (a), the intersection La of the required amount (a) and the conversion line L is the required addition amount. In this case, the required addition amount is a boundary point. ing. If the measured PRA amount and the required amount (a) are in the relationship of required amount (a) <(measured PRA amount), it indicates that sufficient nutrient source substances are contained in the inflowing sewage, and acetic acid The addition of (organic matter) is unnecessary, and if the relationship of required amount (a)> (measured PRA amount) is satisfied, it indicates that addition of acetic acid (organic matter) is necessary. For example, if the measured PRA amount is (b), the deficient amount relative to the required amount (a) is calculated by comparing the required amount (a) with the (measured PRA amount) (b). ) Is calculated, and the necessary addition amount (d) to compensate for this can be calculated.

  Further, the phosphorus elution amount by the phosphorus accumulating bacteria and the absorbed organic acid have a relationship of phosphorus elution amount (mgP) / absorbed organic acid amount (mgCODcr), and it is 0.4 (referred to as Ypo4) to be IWA (International The water association model is theoretically given, and this ratio (Ypo4) varies depending on various conditions such as season and water temperature, but the organic acid concentration can be calculated from the phosphorus elution amount. Ypo4 can be obtained from Ypo4 calculation means according to the relational expression of Ypo4 = (BA) /0.74 s / 10 = (BA) /7.4 s. A and B in this relational expression are phosphorus concentration values A and B (mgP / l) as shown in the processing flow of FIG. The unit of Ypo4 is mgP / mgCOD. In the relational expression of Ypo4, since the volume of the collection container is 100 ml, it is converted to 1L. The phosphorus concentration values A and B obtained from steps S9 and S11 in the processing flow of FIG. 1 can be obtained by introducing them into the Ypo4 calculating means. This calculation process can be automatically calculated and displayed using the calculation process of the computer. If this Ypo4 is lower than 0.4, it is suspected that the amount of phosphorus accumulating bacteria (hereinafter referred to as Xpao) is low. The measurement of the amount of PRA is performed under the condition that a phosphorus accumulating bacterium having a concentration capable of reacting the entire amount of acetic acid added to the second collection container in a short time is added. For example, when Xpao is low, the total amount of acetic acid does not react, so the value of B-A is low, and Ypo4 is also lower than the true value. In this case, the correct PRA cannot be measured.

  The PRA measurement is also effective as a method for calculating the amount of phosphorus accumulating bacteria activity. Contrary to the measurement of PRA, sodium acetate was added in excess (about 50 mg for a 100 ml second collection container), and phosphoric acid after t hours was defined as P1 (mgP / L), and the excess sludge was phosphoric acid. When the initial phosphorus value is PO (mgP / L), using the IWA activated sludge model, the following equation [Equation 8] is established, and Xpao can be calculated from the equation [Equation 8]. For advanced sewage treatment, introduction of PRA is effective for grasping the amount of phosphorus accumulating bacteria. In the PRA measurement, a fourth collection container is prepared in addition to the first to third collection containers in the processing flow of FIG. 1, and the following processing is performed. First, a nutrient substance (for example, acetic acid) is added to the fourth collection container in an excess amount than the amount added to the second collection container, and the treatment is performed under the same conditions as the other first to third collection containers. Done. That is, the concentrated sludge is supplied to the fourth collection container in full water, and the solution in the fourth collection container is made anaerobic while stirring, and after passing through the filtration step, the solution in the fourth collection container is filtered with the solid content. And the concentration of phosphorus in the filtrate obtained from the fourth collection container is measured. Through this step, the amount of phosphoric acid phosphorus released by the phosphorus accumulating bacteria in the fourth collection container in a certain time depends on the amount of phosphorus accumulating bacteria. Using the phosphoric acid phosphorus amount (P1) at time t measured in this way, the amount of phosphorus accumulating bacteria can be estimated by the following arithmetic expression [Equation 8]. The Xpao calculation means of the calculation formula [Equation 8] is incorporated in a computer and can take in and process each data. The initial amount of phosphoric acid phosphorus (P0) is obtained, for example, by previously filtering concentrated sludge and measuring the concentration of phosphoric acid phosphorus in the filtrate. Thus, grasping the amount of phosphorus accumulating bacteria Xpao as a numerical value is important for removing phosphorus in the advanced processing apparatus. Moreover, in this embodiment, although the 4th collection container was used, without adjusting a 4th collection container, for example by adjusting the conditions of addition amount using a 2nd collection container, it is 1st-1st. It is also possible to measure by using a third collection container and controlling the processing steps.

Next, with reference to FIG. 2, it will be explained in nutrients added equipment in sewage advanced treatment apparatus according to an embodiment of the present invention. The sewage advanced treatment apparatus 10 is a treatment apparatus that performs biological phosphorus removal by the A2O method. An anaerobic tank 10a, an anaerobic tank 10b, and an aerobic tank 10c are sequentially provided as treatment tanks, and the treatment of the aerobic tank 10c is performed. Water is sent to the anoxic tank 10b as a circulating liquid, and organic matter in the sewage is denitrified and phosphorus removed by the advanced sewage treatment device 10 and sent to the final sedimentation basin 11, and the supernatant water is discharged as treated water. Is done. The activated sludge settled in the final sedimentation tank 11 is returned to the anaerobic tank 10a as return sludge (activated sludge). A nutrient source addition device 20 is installed in the preceding stage of the sewage advanced treatment device 10.

  The nutrient source addition apparatus 20 is provided with a phosphorus concentration calculating means 25 and a phosphorus concentration / nutrient source amount reading means (data table) 26 by a computer. The nutrient source addition apparatus 20 includes an activated sludge concentrator 21 that samples and concentrates activated sludge to obtain concentrated sludge, and first to third collection containers 22 to 24 having the same volume, and the first collection container. The concentrated sludge is supplied to the full water, the nutrient container material such as sodium acetate is supplied to the second collection container 23, the concentrated sludge is supplied to the full water, and the third collection container 24 is supplied with the sample. Some influent sewage is supplied, and concentrated sludge is supplied to full water. The first to third collection containers 22 to 24 are maintained in an anaerobic state by stirring the inner solution. The first to third collection containers 22 to 24 are provided with filtration devices 22a to 24a for filtering the inner solution after the concentrated sludge and the like of the inner solution is anaerobic for about 30 minutes. Concentrated sludge or the like that has been in an anaerobic state for a predetermined time is filtered by the filtering devices 22a to 24a, and a filtrate is obtained at the bottom of the filtering devices 22a to 24a. After filtration, the solid matter in the filtration devices 22a to 24a is discharged out of the system.

  The bottoms of the filtration devices 22a to 24a are provided with a window through which light is transmitted. Light of a predetermined wavelength is irradiated through these windows to the filtrate, and the phosphorus concentration is measured by an absorptiometric method or a colorimetric analysis method. . The phosphorus concentration A, B, C is obtained from the measuring machine. These phosphorus concentration values A, B, and C are input to a phosphorus concentration calculation means 25 by a computer and are processed to calculate a PRA value. As for the PRA value, the nutrient concentration corresponding to the PRA value is calculated by the phosphorus concentration / nutrient source reading means 26. The phosphorus concentration calculation means 25 performs the calculation processing of the above [Equation 7]. The nutrient source amount is output, for example, as a DC voltage level, and is input to the adding device 27, and a predetermined amount of nutrient source material, for example, acetic acid, is supplied to the anaerobic tank 10a. In the anaerobic tank 10a, the nutrient substance of the phosphorus accumulating bacteria is sufficiently supplied, the activity of the phosphorus accumulating bacteria becomes active, and the organic acid containing acetic acid supplied in the inflow water is taken into the cells, and the aerobic tank 10c. The organic acid is consumed, phosphorus is taken up into the microbial cells, and phosphorus in the inflowing sewage is removed. From the final sedimentation basin 11, treated water that has been dephosphorized is drained. Influent sewage can be treated without the use of phosphorus flocculants.

  Further, according to the present invention, a nutrient source addition device 20 is provided in front of the advanced sewage treatment apparatus, and a computer having a phosphorus concentration calculating means 25 and a phosphorus concentration / nutrient source reading means (data table) 26 is provided. By providing, the nutrient source addition apparatus 20 is controlled, and the nutrient source substance of the phosphorus accumulating bacteria in the advanced sewage treatment apparatus can be set to an optimum amount, and phosphorus in the inflowing sewage can be removed.

  The required amount (a) shown in FIG. 5 is calculated based on the phosphorus concentration to be treated in the inflowing sewage, but the phosphorus concentration in the inflowing sewage is appropriately determined based on the latest measured value or empirical value. The amount of supplemental nutrient material has been determined. In this addition, the PRA amount (a) and the deficiency necessary for the phosphorus treatment are combined with the arithmetic expression [Equation 8] for calculating the active amount of the phosphorus accumulating bacterium (phosphorus accumulating bacterium amount Xpao) taking it in as necessary. By determining (c) and calculating the required addition amount (d), more effective phosphorus removal is possible. In these arithmetic processes, phosphorus can be removed under optimum processing conditions by inputting each measurement data to a computer and executing the arithmetic expression [Equation 8]. Further, in the process of calculating the amount of phosphorus-accumulating bacteria Xpao, each value (A, B, 0.74 s) is taken into the computer having the Ypo4 calculation means of Ypo4 = (BA) /7.4 s shown above. Then, the value of Ypo4 can be obtained. Each value of Ypo4 and the amount of phosphorus accumulating bacteria Xpao may be displayed on a display device of a computer to indicate the phosphorus removal ability of the advanced processing device. In addition, when the computer sets the processing conditions for removing phosphorus, Ypo4 and the amount of phosphorus accumulating bacteria Xpao may be used as the processing conditions for supplying the nutrient source material, and further, the temperature or inflow amount of the processing solution in the tank is processed. It is also possible to incorporate in conditions.

Of course, in the advanced sewage treatment apparatus of the present embodiment, organic nitrogen and ammonia nitrogen in the sewage are fed into the aerobic tank 10c through the anaerobic tank 10a and the oxygen-free tank 10b without using a flocculant. It is changed to nitrifying nitrogen (NO ₃ ⁻ ) by the action of oxygen and nitrifying bacteria, and further changed to harmless nitrogen gas by the action of denitrifying bacteria and released into the atmosphere.

Further, the above-mentioned advanced sewage treatment apparatus has been described A _{2 O} processor, even AO processing apparatus can utilize the present invention. Furthermore, you may combine the phosphorus removal process by a flocculant.

  As an application example of the present invention, it can be used for an advanced treatment apparatus such as sewage, sewage or human waste.

It is a figure which shows the processing flow of one Embodiment of the water quality estimation method of inflow sewage by the phosphorus elution from the activated sludge which concerns on this invention. It is a figure which shows the nutrient source addition apparatus and sewage advanced treatment apparatus in the advanced sewage treatment apparatus which shows one Embodiment of this invention. It is explanatory drawing which showed phosphorus elution from the anaerobic sludge in this invention. It is explanatory drawing which showed the difference in phosphorus elution density | concentration by making sludge water from which the density | concentration in this invention differs in an anaerobic state. It is explanatory drawing explaining the mechanism which supplies a nutrient source substance to the anaerobic tank in the sewage advanced treatment apparatus of this invention. It is explanatory drawing of the sewage treatment apparatus by the conventional advanced treatment. It is explanatory drawing which shows the outline | summary of the biological dephosphorization apparatus by the conventional advanced process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sewage advanced processing apparatus 10a Anaerobic tank 10b Anoxic tank 10c Aerobic tank 11 Final sedimentation tank 20 Nutrient source addition apparatus 21 Activated sludge concentrator 22 First collection container 23 Second collection container 24 Third collection container 22a 24a Filtration device 25 Phosphorus concentration calculation means 26 Phosphorus concentration vs. nutrient source reading means (data table)

Claims (12)

A sludge concentration step for denitrifying activated sludge containing phosphorus accumulating bacteria,
An anaerobic process in which a predetermined amount of inflowing sewage that is a measurement sample is placed in a collection container and the concentrated sludge is introduced, and an inner solution of each collection container is anaerobic,
A phosphoric acid concentration measuring step for measuring a phosphoric acid concentration in a filtered solution obtained by filtering the solution in the collection container;
A method for estimating the water quality of influent sewage by elution of phosphorus from activated sludge, comprising an arithmetic processing step for obtaining the concentration of reactive organic acids in the influent sewage contained in the influent sewage from the phosphoric acid concentration. A sludge concentration step for denitrifying activated sludge containing phosphorus accumulating bacteria,
First to third collection containers having a predetermined capacity are prepared, the concentrated sludge containing the phosphorus accumulating bacteria obtained in the concentration step is introduced into the first collection container, and a nutrient source material is introduced into the second collection container The concentrated sludge is charged in a predetermined amount, and the concentrated sludge is charged in a third sampling container with a predetermined amount of inflowing sewage, and the solution in each sampling container is stirred and anaerobic. An anaerobic process to state,
After the anaerobic step has passed for a predetermined time, a phosphoric acid concentration measuring step for measuring the phosphoric acid concentration in the filtered solution obtained by filtering the inner solution of each sampling container;
The phosphoric acid concentration in the filtrate obtained from the first and second sampling containers in the phosphoric acid concentration measuring step and the phosphoric acid concentration of the sample in the filtrate corresponding to the third sampling container are processed. A method for estimating the water quality of influent sewage by elution of phosphorus from activated sludge, comprising an arithmetic processing step for determining the concentration of reactive organic acids with phosphorus-accumulating bacteria.   The method for estimating the quality of influent sewage by phosphorus elution from activated sludge according to claim 2, wherein the nutrient material is an organic acid such as acetic acid or a salt thereof. 4. The method for estimating the quality of influent sewage by phosphorus elution from activated sludge according to claim 3, wherein the arithmetic processing step is based on the following arithmetic expression [Equation 1].

  5. The phosphorus-accumulating bacterium-reactive organic acid is an organic acid that is incorporated in a process in which an anaerobic phosphorus-accumulating bacterium releases phosphorus out of the microbial cell. Estimating water quality of influent sewage by elution of phosphorus from activated sludge. In the method for estimating the quality of influent sewage by elution of phosphorus from the activated sludge according to claim 2,
Ypo4, which is the ratio of phosphorus elution amount / absorbed organic acid amount, is determined from the phosphoric acid concentrations in the filtered solutions obtained from the first and second collection containers in the phosphoric acid concentration measuring step by the following equation [Equation 2]. A method for estimating water quality of influent sewage by elution of phosphorus from activated sludge.

In the method for estimating the quality of influent sewage by phosphorus elution from the activated sludge according to claim 6,
A fourth collection container is provided in addition to the first to third collection containers, the nutrient substance is excessively added to the fourth collection container, and concentrated sludge is supplied to the fourth collection container to fill the water. The solution in the 4 collection container is made anaerobic for a predetermined time while stirring, and after the filtration process, the solution in the 4th collection container is separated into solids and filtrate, and the filtration obtained from the 4th collection container In addition to measuring the phosphoric acid concentration in the liquid, the initial phosphoric acid phosphorus concentration of the concentrated sludge was measured by the phosphoric acid concentration measuring step, and each phosphoric acid concentration and the Ypo4 were calculated according to the following equation [Equation 3]. A method for estimating the quality of influent sewage by elution of phosphorus from activated sludge, characterized by determining the amount.

  The method for estimating the quality of influent sewage by elution of phosphorus from activated sludge according to claim 7, wherein the amount of phosphorus accumulating bacteria is determined using the second collection container instead of the fourth collection container. Of water quality of influent sewage by phosphorus elution from activated sludge. In the addition device that estimates the phosphorus-accumulating bacteria reactive organic acids contained in the inflow sewage flowing into the advanced sewage treatment device and adds the nutrient source material to the anaerobic tank,
Sampling means for sampling activated sludge settled in the final sedimentation basin after the advanced sewage treatment device,
Sludge concentrating means to deconcentrate activated sludge containing phosphorus accumulating bacteria collected by the collecting means;
First to third collection containers of a predetermined capacity;
The concentrated sludge obtained from the sludge concentration step is charged with the first collection container, the second collection container with a predetermined amount of nutrient source material, and a predetermined amount of inflow sewage as a measurement sample. Anaerobic means for charging the third collection container and making the solution in each collection container anaerobic;
An optical measuring means for measuring a phosphoric acid concentration in a filtered solution obtained by filtering the inner solution of each container after the anaerobic means has passed for a predetermined time; and
The optical measuring means computes the phosphoric acid concentration in the filtrate obtained from the first and second collection containers and the phosphoric acid concentration in the filtrate corresponding to the third collection container. Arithmetic processing means for determining the concentration of reactive organic acids of the phosphorus-accumulating bacteria,
An acetic acid injecting means for injecting a nutrient source material into the anaerobic tank of the advanced sewage treatment apparatus according to the phosphorus accumulating bacteria reactive organic acid concentration obtained by the arithmetic processing means. Nutrient source addition equipment.   10. The nutrient source addition apparatus in the advanced sewage treatment apparatus according to claim 9, wherein the acetic acid injecting means is a data table in which the amount of nutrient source substances to be injected according to the concentration of phosphorus-accumulating bacteria-reactive organic acids is recorded. .   The nutrient source addition apparatus in the sewage advanced treatment apparatus according to claim 9 or 10, wherein the nutrient source substance is an organic acid such as acetic acid and salts thereof. The sewage advanced treatment according to claim 9, 10 or 11, wherein the phosphorus-accumulating bacteria-reactive organic acids are organic acids taken up in the process of anaerobic phosphorus-accumulating bacteria releasing phosphorus outside the cells. Nutrient source addition device in the device.

Images