Concentration measurement systems; waste treatment systems; methods for concentration measurement and waste treatment.

Abstract

Invention details;

Description

Concentration measurement system, waste treatment system, concentration measurement method, and waste treatment method

[0001] The present disclosure relates to a concentration measurement system, a waste treatment system, a concentration measurement method, and a waste treatment method. This application claims priority based on Japanese Patent Application No. 2021-047335, filed with the Japan Patent Office on March 22, 2021, the contents of which are incorporated herein by reference.

[0002] For example, Patent Document 1 discloses a sensor for detecting the ammonia concentration, a sensor for detecting the sodium concentration, a sensor for detecting the organic acid concentration, and a sensor for detecting the hydrogen ion concentration contained in a solid-liquid mixture (slurry), which is a mixture of a liquid and a solid.

[0003] Japanese Patent Application Laid-Open No. 2020-163280

[0004] Incidentally, concentration detection using various sensors is performed after the liquid is separated from the solid-liquid mixture (solids are removed) using a centrifuge or the like. However, when a centrifuge is used, it takes a long time to separate the liquid from the solid-liquid mixture, making it difficult to quickly measure the concentration of a solute (such as ammonia) from the solid-liquid mixture. Furthermore, preparing a centrifuge tends to increase installation costs.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a concentration measurement system and a concentration measurement method that can quickly measure the concentration of a solute from a solid-liquid mixture and reduce installation costs.

[0006] In order to achieve the above-mentioned object, the concentration measurement system according to the present disclosure is a concentration measurement system that measures the concentration of a solute contained in a liquid of a solid-liquid mixture, which is a mixture of a liquid and a solid, and includes a solid-liquid separation device that separates the liquid from the solid-liquid mixture, and a concentration measurement device that measures the concentration of the solute contained in the liquid separated by the solid-liquid separation device, and the solid-liquid separation device includes a porous body having pores formed therein that can be impregnated with the liquid.

[0007] In order to achieve the above-mentioned object, the concentration measurement method according to the present disclosure is a concentration measurement method for measuring the concentration of a solute contained in a liquid of a solid-liquid mixture, which is a mixture of a liquid and a solid, and includes the steps of separating the liquid from the solid-liquid mixture using a porous body having pores formed therein that can be impregnated with the liquid, and measuring the concentration of the solute contained in the liquid separated from the solid-liquid mixture.

[0008] According to the concentration measurement system and concentration measurement method of the present disclosure, the concentration of a solute can be quickly measured from a solid-liquid mixture, and installation costs can be reduced.

[0009] FIG. 1 is a diagram schematically showing the configuration of a concentration measurement system according to a first embodiment of the present disclosure. FIG. 2 is a diagram schematically showing the configuration of a concentration measurement device according to the first embodiment of the present disclosure. FIG. 3 is a graph showing the relationship between wavelength and absorbance. FIG. 4 is a graph showing the relationship between wavelength and amount of absorbance change. FIG. 5 is a graph showing the relationship between wavelength and amount of absorbance change. FIG. 6 is a diagram schematically showing the configuration of an optical concentration measurement device according to a second embodiment of the present disclosure. FIG. 7 is a diagram schematically showing the configuration of an optical concentration measurement device according to a third embodiment of the present disclosure. FIG. 8 is a graph showing the relationship between solute concentration and absorbance. FIG. 9 is a diagram schematically showing the configuration of a concentration measurement system according to a fourth embodiment of the present disclosure. FIG. 10 is a diagram schematically showing the configuration of a waste treatment system according to a fifth embodiment of the present disclosure. FIG. 11 is a diagram schematically showing the configuration of a waste treatment system according to a sixth embodiment of the present disclosure. FIG. 12 is a flowchart showing a concentration measurement method according to an embodiment. FIG. 13 is a flowchart showing a waste treatment method according to an embodiment.

[0010] Hereinafter, a concentration measurement system, a waste disposal system, a concentration measurement method, and a waste disposal method according to embodiments of the present disclosure will be described with reference to the drawings. The embodiments show one aspect of the present disclosure, and are not intended to limit the present disclosure. Any modifications can be made within the scope of the technical concept of the present disclosure.

[0011] (Embodiment 1) <Configuration of Concentration Measurement System According to Embodiment 1> Fig. 1 is a diagram schematically illustrating the configuration of a concentration measurement system 1 according to Embodiment 1 of the present disclosure. The concentration measurement system 1 measures the concentration of a solute contained in liquid X1 of a solid-liquid mixture A, which is a mixture of liquid X1 and solid Y1. The solid-liquid mixture A is not particularly limited, and may be, for example, a modified product obtained by hydrolyzing waste, or a low-molecular-weight product obtained by low-molecular-weight conversion of this modified product by microorganisms. In Embodiment 1, an example will be described in which the solid-liquid mixture A includes low-molecular-weight products.

[0012] 1, the concentration measurement system 1 includes a solid-liquid separator 2, a diluter 4, and a concentration measurement device 6. In the embodiment illustrated in FIG. 1, the concentration measurement system 1 further includes a sampling device 42 that samples a solid-liquid mixture A from a distributed low-molecular-weight product fA.

[0013] The solid-liquid separator 2 includes a porous body 8 having a plurality of pores 10 formed therein that can be impregnated with the liquid X1. The porous body 8 is configured to be easily elastically deformable, and is, for example, a sponge. The solid-liquid separator 2 separates the liquid X1 from the solid-liquid mixture A by bringing the solid-liquid mixture A collected by the collection device 42 into contact with the porous body 8 and impregnating the pores 10 of the porous body 8 with the liquid X1. Note that a chemical (such as a flocculant) may be added to the solid-liquid mixture A before contacting it with the porous body 8 for solid-liquid separation.

[0014] 1 , the solid-liquid separator 2 further includes a dehydrator 12 that dehydrates the liquid X1 from the porous body 8. The dehydrator 12 dehydrates the liquid X1 from the porous body 8, for example, by compressing the porous body 8 (sponge). Hereinafter, the liquid X1 dehydrated from the porous body 8 by the dehydrator 12 will be referred to as separated liquid X2.

[0015] The solid-liquid separator 2 is configured to keep the suspended solids concentration in the separation liquid X2 at 5% or less by adjusting, for example, the porosity of the porous body 8, the diameter of the pores 10, and the magnitude of the compressive force acting on the porous body 8 from the dehydrator 12. The suspended solids are, for example, solids Y1 with a particle size of 1 μm or more and 2 mm or less. The suspended solids concentration is calculated by dividing the mass of the suspended solids contained in the separation liquid X2 by the mass of the separation liquid X2.

[0016] 1 , the solid-liquid separator 2 further includes a nonwoven fabric 14. The nonwoven fabric 14 is disposed upstream of the porous body 8 in the flow direction of the liquid X1 in the solid-liquid separator 2. In other words, the solid-liquid separator 2 is configured to bring the solid-liquid mixture A that has flowed through the nonwoven fabric 14 into contact with the porous body 8.

[0017] The porous body 8 included in the solid-liquid separation device 2 is not limited to the sponge of embodiment 1. In some embodiments, the porous body 8 is a separation membrane that prevents the inflow of solid Y1 contained in the solid-liquid mixture A and allows the flow of liquid X1 contained in the solid-liquid mixture A. The pores formed in the separation membrane are temporarily impregnated with liquid X1 when liquid X1 flows through the separation membrane.

[0018] The dilution device 4 dilutes the separation liquid X2 to produce a diluted liquid X3. The dilution device 4 dilutes the separation liquid X2 with, for example, pure water W, but the separation liquid X2 may be diluted with something other than pure water W. By providing the dilution device 4, the influence of suspended solids contained in the separation liquid X2 can be suppressed when the concentration is measured by the concentration measuring device 6. Furthermore, a chemical agent for improving color development may be added to the pure water W used to dilute the separation liquid X2. With this configuration, the accuracy of the concentration measurement by the concentration measuring device 6 can be improved.

[0019] The concentration measuring device 6 measures the concentration of a solute contained in the liquid X1 separated by the solid-liquid separator 2 and diluted by the dilution device 4. In the embodiment illustrated in Fig. 1, the concentration measuring device 6 measures the concentration of a solute contained in the diluted liquid X3 supplied from the dilution device 4. Here, an example configuration of the concentration measuring device 6 will be described with reference to Fig. 2. Fig. 2 is a diagram schematically illustrating the configuration of the concentration measuring device 6 according to the first embodiment of the present disclosure.

[0020] 2 , the concentration measuring device 6 is an optical concentration measuring device 24(6) including a cell 16 to which the dilution liquid X3 is supplied, a light source 18 that irradiates the cell 16 with light 17, a detector 20 that receives the light 17 that has passed through the cell 16, and a concentration calculating device 22 that calculates the concentration of a solute contained in the dilution liquid X3 based on the light 17 received by the detector 20. The optical concentration measuring device 24 includes an optical fiber 25 that transmits the light 17 irradiated from the light source 18 to the detector 20 via the cell 16. The optical concentration measuring device 24 may be configured to continuously measure the concentration of a solute from the dilution liquid X3 flowing through the cell 16, or may be configured to batchwise measure the concentration of a solute from the dilution liquid X3 filled in the cell 16.

[0021] The concentration calculation device 22 is electrically connected to the detector 20 and acquires detection information detected by the detector 20. Such a concentration calculation device 22 is a computer such as an electronic control device, and includes a processor such as a CPU or GPU (not shown), memory such as ROM or RAM, and an I / O interface. The concentration calculation device 22 calculates the concentration of the solute contained in the diluted liquid X3 by the processor operating (calculating, etc.) according to the instructions of a program loaded into the memory. The method for calculating this concentration is not particularly limited, but a spectral statistical analysis method including a change in absorbance per wavelength change or partial least squares regression is applicable.

[0022] In some embodiments, the concentration calculation device 22 of the optical concentration measurement device 24 calculates the concentration of the solute contained in the diluted liquid X3 based on the amount of change in absorbance calculated by differentiating the absorbance contained in the detection information detected by the detector 20 with respect to wavelength.

[0023] Fig. 3 is a graph showing the relationship between wavelength and absorbance. Fig. 4 is a graph showing the relationship between wavelength and absorbance change. In Fig. 3, the horizontal axis represents wavelength, and the vertical axis represents absorbance. In Fig. 4, the horizontal axis represents wavelength, and the vertical axis represents absorbance change. In Fig. 3, A1 represents the absorbance of sludge (solid-liquid mixture A) to which acetic acid (solute) has not been added, A2 represents the absorbance of sludge to which acetic acid has been added, and A3 represents the absorbance of acetic acid added to the sludge. In Fig. 4, A1' represents the absorbance change of sludge to which acetic acid has not been added, A2' represents the absorbance change of sludge to which acetic acid has been added, and A3' represents the absorbance change of acetic acid added to the sludge.

[0024] Concentration measurement by the optical concentration measuring device 24 may be performed based on absorbance at a predetermined set wavelength B1. However, as shown in FIG. 3 , the absorbance at the set wavelength B1 may be affected by absorbance at a wavelength B2 different from the set wavelength B1. In this case, it becomes difficult to measure the concentration of acetic acid (solute) based on absorbance at the set wavelength B1. In particular, when the sludge (solid-liquid mixture A) is municipal solid waste that has been broken down into smaller molecules by microorganisms, it may be very difficult to measure the concentration based on absorbance because the municipal solid waste contains many components such as food waste, paper waste, and plastic waste.

[0025] 4, the amount of change in absorbance at the set wavelength B1 is not affected by, or is very small affected by, the amount of change in absorbance at the wavelength B2. Therefore, by measuring the concentration of acetic acid (solute) based on the amount of change in absorbance at the set wavelength B1, it is possible to improve the measurement accuracy compared to measuring the concentration of acetic acid (solute) based on the absorbance at the set wavelength B1.

[0026] In some embodiments, the concentration calculation device 22 of the optical concentration measurement device 24 measures the concentration of the solute contained in the diluted liquid X3 based on the sum of the areas of the absorbance change amounts that have peaks within a predetermined wavelength range. This concentration measurement method will be specifically described using Figure 5.

[0027] Figure 5 is a graph showing the relationship between wavelength and absorbance change. In Figure 5, the horizontal axis represents wavelength and the vertical axis represents absorbance change. In Figure 5, the absorbance change of furfural is shown as A4', and the absorbance change of 5-hydroxymethylfurfural is shown as A5'.

[0028] Furfural and 5-hydroxymethylfurfural have similar functional groups, and therefore, as shown in Figure 5, the waveform of the absorbance change amount A4' of furfural and the waveform of the absorbance change amount A5' of 5-hydroxymethylfurfural have peaks at wavelengths close to each other.

[0029] In the concentration calculation device 22, a lower limit wavelength B3 and an upper limit wavelength B4 are preset so as to include the peaks of the waveform of furfural and the peaks of the waveform of 5-hydroxymethylfurfural.

[0030] Then, the concentration calculation device 22 calculates the concentration of the solute containing furfural and 5-hydroxymethylfurfural based on the sum of the area of ​​the amount of absorbance change A4 of furfural and the area of ​​the amount of absorbance change A5 of 5-hydroxymethylfurfural, which are included between the lower limit wavelength B3 and the upper limit wavelength B4. In other words, the concentration calculation device 22 groups furfural and 5-hydroxymethylfurfural together as furals and calculates the concentration of the furals.

[0031] This configuration makes it easier to calculate the concentrations of furfural and 5-hydroxymethylfurfural compared to when the concentrations are calculated individually, thereby reducing the cost of the optical concentration measurement device 24.

[0032] <Actions and Effects of Concentration Measurement System According to Embodiment 1> The actions and effects of the concentration measurement system 1 according to Embodiment 1 of the present disclosure will be described. According to Embodiment 1, by bringing the porous body 8 into contact with the solid-liquid mixture A, the liquid X1 is impregnated into the pores 10 of the porous body 8, and the liquid X1 can be quickly separated from the solid-liquid mixture A. Therefore, the concentration of the solute contained in the liquid X1 in the solid-liquid mixture A can be quickly measured. Furthermore, since the porous body 8 is less expensive than a centrifugal separator, the installation cost of the solid-liquid separator 2 can be reduced.

[0033] According to the first embodiment, the liquid X1 required for measuring the concentration of the solute can be quickly extracted (obtained) by dehydrating the liquid X1 from the porous body 8 using the dehydration device 12.

[0034] If the particle size of the solid Y1 contained in the solid-liquid mixture A becomes large, it may hinder the impregnation of the liquid X1 into the pores 10 of the porous body 8. According to the first embodiment, the solid-liquid mixture A comes into contact with the nonwoven fabric 14 before coming into contact with the porous body 8, and therefore the solid Y1 with a large particle size is removed by the nonwoven fabric 14. This allows the liquid X1 to smoothly impregnate into the pores 10 of the porous body 8.

[0035] According to the first embodiment, the concentration measuring device 6 is an optical concentration measuring device 24, and therefore can measure the concentration of the solute contained in the dilution liquid X3 in the cell 16 using light absorption, diffraction, scattering, etc. Note that the concentration measuring device 6 is not limited to the optical concentration measuring device 24, as long as it is capable of measuring the concentration of the solute contained in the dilution liquid X3. The concentration measuring device 6 may be, for example, an electric potential measuring device that measures the concentration of the solute contained in the dilution liquid X3 based on a change in the electric potential of the dilution liquid X3.

[0036] According to the findings of the present inventors, if the concentration of the solute of the low-molecular-weight substance falls within a predetermined range, the state is suitable for low-molecular-weight reduction by microorganisms. On the other hand, if the concentration of the solute of the low-molecular-weight substance falls outside this range, the state is unsuitable for low-molecular-weight reduction by microorganisms. According to the first embodiment, the concentration measurement system 1 measures the concentration of the solute of the low-molecular-weight substance, and therefore, based on this measurement value, it is possible to quickly determine whether the state is suitable for low-molecular-weight reduction by microorganisms.

[0037] According to embodiment 1, the concentration measurement system 1 is equipped with a collection device 42 that collects a solid-liquid mixture A from a circulating low-molecular-weight material fA, so that a solid-liquid mixture A can be collected from a stirred low-molecular-weight material.

[0038] If the concentration of the solute contained in the liquid X1 of the solid-liquid mixture A is too high, it may be difficult for the concentration measuring device 6 to measure the concentration of the solute. According to the first embodiment, the concentration measuring device 6 measures the concentration of the solute contained in the diluted liquid X3 obtained by diluting the separation liquid X2 by the dilution device 4. Therefore, even if the concentration of the solute contained in the liquid X1 of the solid-liquid mixture A is higher than the concentration that can be measured by the concentration measuring device 6, the concentration of the solute can be measured.

[0039] The dilution device 4 is not an essential component of the concentration measurement system 1 according to the present disclosure. In some embodiments, the concentration measurement device 6 measures the concentration of the solute contained in the separated liquid X2 separated by the solid-liquid separator 2.

[0040] (Embodiment 2) A concentration measurement system 1 according to embodiment 2 will be described. The concentration measurement system 1 according to embodiment 2 is a system in which the configuration of the optical concentration measurement device 24 according to embodiment 1 is further limited. In embodiment 2, the same components as those in embodiment 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0041] <Configuration of Concentration Measurement System According to Second Embodiment> Fig. 6 is a diagram schematically illustrating the configuration of an optical concentration measurement device 24 according to a second embodiment of the present disclosure. As shown in Fig. 6, the cell 16 is configured to be filled with pure water W. In the example illustrated in Fig. 6, the optical concentration measurement device 24 includes a pure water supply device 30 that supplies the pure water W to the cell 16. Note that the present disclosure is not limited to the configuration of the second embodiment as long as the cell 16 is configured to be filled with pure water W. For example, the cell 16 may be configured to be filled with the pure water W supplied to the dilution device 4 described above.

[0042] The pure water supply device 30 supplies pure water W to the cell 16 when the diluting liquid X3 is not being supplied to the cell 16, specifically when the optical concentration measuring device 24 is in a maintenance state or a standby state. Then, when the cell 16 is filled with the pure water W, the light source 18 irradiates the cell 16 filled with the pure water W with light 17. Then, the detector 20 receives correction light, which is the light 17 that has passed through the cell 16 filled with the pure water W.

[0043] The concentration calculation device 22 acquires the detection information of the correction light detected by the detector 20. The concentration calculation device 22 pre-stores comparison information for comparison with the detection information of the correction light. The comparison information is, for example, detection information detected when a cell 16 that has never received dilution liquid X3 is filled with pure water W and irradiated with light 17. Alternatively, the comparison information is detection information of the correction light detected during the previous maintenance. The concentration calculation device 22 corrects (zero-point correction) the absorbance of the dilution liquid X3 detected by the detector 20 using a difference Δ1 obtained by comparing the comparison information with the detection information of the correction light. For example, the concentration calculation device 22 offsets (shifts) the absorbance of the dilution liquid by the difference Δ1. The concentration calculation device 22 then calculates the concentration of the solute contained in the dilution liquid X3 based on the absorbance change calculated by differentiating the zero-point corrected absorbance with respect to wavelength. Note that the zero-point correction may be performed by a device other than the concentration calculation device 22.

[0044] <Functions and Effects of the Concentration Measurement System According to the Second Embodiment> Even if the optical concentration measurement device 24 measures the same concentration of a solute at both a first timing and a second timing that follows the first timing, for example, the degree of contamination of the cell 16 may differ between the first timing and the second timing, and the concentration of the solute measured at the first timing may be slightly different from the concentration of the solute measured at the second timing. In contrast, according to the second embodiment, the solute concentration is zero-point corrected, thereby suppressing the influence of differences in measurement timing.

[0045] (Embodiment 3) Next, a concentration measurement system 1 according to embodiment 3 will be described. The concentration measurement system 1 according to embodiment 3 is a system in which the configuration of the optical concentration measurement device 24 according to embodiment 2 is further limited. The optical concentration measurement device 24 further includes a calibration liquid cell 32. In embodiment 3, the same components as those in embodiment 2 are given the same reference numerals, and detailed description thereof will be omitted. In another embodiment, the optical concentration measurement device 24 of the concentration measurement system 1 according to embodiment 1 further includes a calibration liquid cell 32.

[0046] <Configuration of Concentration Measurement System According to Embodiment 3> Fig. 7 is a diagram schematically showing the configuration of an optical concentration measurement device 24 according to Embodiment 3 of the present disclosure. As shown in Fig. 7, the optical concentration measurement device 24 further includes a calibration solution cell 32 disposed between the cell 16 and the detector 20. The calibration solution cell 32 is connected to each of the cell 16 and the detector 20 via an optical fiber 25. Light 17 irradiated onto the cell 16 from the light source 18 passes through the calibration solution cell 32 and is then received by the detector 20.

[0047] The calibration solution cell 32 is supplied with a calibration solution having a known solute concentration when the diluent liquid X3 is not supplied to the cell 16, specifically when the optical concentration measuring device 24 is in a maintenance state or standby state. Such a calibration solution is, for example, the diluent liquid X3, the solute concentration of which has already been measured. When the calibration solution is supplied to the calibration solution cell 32, the light source 18 irradiates the cell 16 to which the diluent liquid X3 has not been supplied with light 17. The detector 20 then receives the calibration light, which is the light 17 that has passed through the cell 16 to which the diluent liquid X3 has not been supplied and the calibration solution cell 32 to which the calibration solution has been supplied. Note that when the detector 20 receives the calibration light, the cell may be filled with pure water W or may be empty.

[0048] 8 is a graph Gr showing the relationship between solute concentration and absorbance, where the circular plots represent the net absorbance of the calibration solution (the absorbance actually detected by the detector 20) and the rectangular plots represent the theoretical absorbance of the calibration solution (the absorbance that should be detected by the detector 20).

[0049] As shown in FIG. 8 , graph Gr plots the net absorbance p1 when the solute concentration in the calibration solution is a first concentration C1, the net absorbance p2 when the solute concentration is a second concentration C2, and the net absorbance p3 when the solute concentration is a third concentration C3. Also, graph Gr plots a virtual straight line L1 that passes through the three net absorbances p1, p2, and p3. Similarly, graph Gr plots the theoretical absorbance p4 when the solute concentration in the calibration solution is a first concentration C1, the theoretical absorbance p5 when the solute concentration is a second concentration C2, and the theoretical absorbance p6 when the solute concentration is a third concentration C3. Also, graph Gr plots a virtual straight line L2 that passes through the three theoretical absorbances p4, p5, and p6. In the graph Gr shown in FIG. 8 , the concentrations increase in the order of first concentration C1 < second concentration C2 < third concentration C3.

[0050] The concentration calculation device 22 corrects the absorbance of the diluted liquid X3 detected by the detector 20 using the sensitivity difference Δ2 obtained by comparing the slope of the line L1 with the slope of the line L2 (sensitivity correction). For example, as illustrated in FIG. 8 , the concentration calculation device 22 creates a line L2a by changing the slope of the line L2 to the slope of the line L1, and obtains the absorbance plotted on this line L2a. In the example illustrated in FIG. 8 , the zero point p7 on the line L2 where the solute concentration is zero and the zero point p8 on the line L2a where the solute concentration is zero are located at the same position. The concentration calculation device 22 then calculates the concentration of the solute contained in the diluted liquid X3 based on the absorbance change calculated by differentiating the sensitivity-corrected absorbance with respect to wavelength. Note that sensitivity correction may be performed by a device other than the concentration calculation device 22.

[0051] <Functions and Effects of the Concentration Measurement System According to the Third Embodiment> It may not be easy for the detector 20 to maintain the detection sensitivity for receiving the light 17. According to the third embodiment, the absorbance of the diluted liquid X3 detected by the detector 20 is sensitivity corrected, so that the difference in detection sensitivity can be suppressed.

[0052] (Embodiment 4) Next, a concentration measurement system 1 according to embodiment 4 will be described. The concentration measurement system 1 according to embodiment 4 is obtained by adding a cleaning line 34 to embodiment 1. In embodiment 4, the same components as those in embodiment 1 are given the same reference numerals, and detailed description thereof will be omitted. In another embodiment, the concentration measurement system 1 is obtained by adding a cleaning line 34 to embodiment 2 or 3.

[0053] <Configuration of Concentration Measurement System According to Fourth Embodiment> Fig. 9 is a diagram schematically illustrating the configuration of a concentration measurement system 1 according to a fourth embodiment of the present disclosure. As shown in Fig. 9, the concentration measurement system 1 further includes a cleaning line 34 through which a cleaning fluid flows. In the embodiment illustrated in Fig. 9, the cleaning line 34 includes a first cleaning line 36 (34) through which a first cleaning fluid f1 for cleaning the solid-liquid separation device 2 flows, a second cleaning line 38 (34) through which a second cleaning fluid f2 for cleaning the dilution device 4 flows, and a third cleaning line 40 (34) through which a third cleaning fluid f3 for cleaning the concentration measurement device 6 flows.

[0054] The first cleaning fluid f1 is, for example, pure water or nitrogen-containing water such as ammonia water. That is, the solid-liquid separation device 2 is cleaned with pure water or nitrogen-containing water. The second cleaning fluid f2 is, for example, nitrogen-containing water, and the dilution device 4 is cleaned with nitrogen-containing water. The third cleaning fluid f3 is, for example, nitrogen-containing water, and the concentration measurement device 6 is cleaned with nitrogen-containing water. Although not shown, the concentration measurement system 1 may further include a drying device for drying each of the solid-liquid separation device 2, the dilution device 4, and the concentration measurement device 6.

[0055] <Actions and Effects of the Concentration Measurement System According to the Fourth Embodiment> According to the fourth embodiment, the provision of the first cleaning line 36 prevents the liquid X1 and the solid Y1 from remaining in the solid-liquid separator 2 (particularly the porous body 8). In particular, the solid Y1 adsorbed to the porous body 8 can be removed. Furthermore, the provision of the second cleaning line 38 prevents the separated liquid X2 and the fine solid Y1 contained in the separated liquid X2 from remaining in the dilution device 4. Furthermore, the provision of the third cleaning line 40 prevents the dilution liquid X3 and the fine solid Y1 contained in the dilution liquid X3 from remaining in the concentration measurement device 6. This makes it possible to extend the period during which the solid-liquid separator 2, the dilution device 4, and the concentration measurement device 6 are each in a good condition.

[0056] In the fourth embodiment, the cleaning line 34 includes the first cleaning line 36, the second cleaning line 38, and the third cleaning line 40, but the present disclosure is not limited to this embodiment. The cleaning line 34 may include at least one of the first cleaning line 36 and the third cleaning line 40, and may include, for example, only the first cleaning line 36.

[0057] (Fifth Embodiment) <Configuration of a Waste Treatment System According to a Fifth Embodiment> Next, a waste treatment system 50 according to a fifth embodiment will be described. Fig. 10 is a diagram schematically showing the configuration of a waste treatment system 50 according to a fifth embodiment of the present disclosure. As shown in Fig. 10, the waste treatment system 50 includes a reformer 52, a microbial reaction device (biogas fermenter 100), the concentration measurement system 1 according to the first embodiment, and an adjustment device 54. Note that in another embodiment, the waste treatment system 50 includes the concentration measurement system 1 according to any one of the second to fourth embodiments, instead of the concentration measurement system 1 according to the first embodiment.

[0058] The reformer 52 receives waste directly from, for example, a waste collection vehicle or a plant, and batchwise hydrolyzes the waste using steam. Specifically, it is a batch-type reformer including a housing 60 including an inlet 56 through which the waste is introduced and an outlet 58 through which the hydrolyzed waste is discharged. The inlet 56 and the outlet 58 are each provided with an on-off valve (not shown), and the housing 60 can be sealed by closing the on-off valve. The hydrolysis of the waste in the reformer 52 may be wet hydrolysis, in which steam contacts the waste to heat it, or dry hydrolysis, in which steam does not contact the waste but indirectly heats it. In the case of dry hydrolysis, moisture in the waste within the housing 60 evaporates to form steam, and the waste within the housing 60 is uniformly heated by the steam. Furthermore, moisture is required for hydrolysis, and this moisture is supplied by the steam adhering to the surface of the waste. Although one reformer 52 is shown in FIG. 10, a configuration in which a plurality of reformers 52 are connected in series, a configuration in which a plurality of reformers 52 are connected in parallel, or a configuration in which a series connection configuration and a parallel connection configuration are combined may also be used.

[0059] The microbial reaction device uses microorganisms to reduce the modified material Z1, which is waste hydrolyzed by the reforming device 52, into smaller molecules. In other words, the microbial reaction device reduces the modified material Z1 to produce smaller molecules. In embodiment 5, the microbial reaction device is a biogas fermenter 100. The biogas fermenter 100 reduces the modified material Z1 using microorganisms to produce smaller molecules such as methane fermentation sludge, and also produces biogas such as methane as a valuable resource. Note that the microbial reaction device is not limited to the biogas fermenter 100. The microbial reaction device may be a saccharification tank that produces sugar as a valuable resource from carbohydrates such as starch and cellulose, or a composting device that produces compost by composting.

[0060] 10, the biogas fermenter 100 is connected to a reformer 52 via a reforming line 53 through which the reformed material Z1 flows. The reforming line 53 is provided with an adjusting valve 55 for adjusting the amount of the reformed material Z1 supplied to the biogas fermenter 100. The opening of this adjusting valve 55 is adjusted in accordance with instructions transmitted from an adjusting device 54, as will be described later.

[0061] In the embodiment illustrated in Figure 10, the biogas fermenter 100 is equipped with a circulation line 102 that removes a portion of the contents containing low-molecular-weight substances to the outside and returns them to the biogas fermenter 100. Specifically, the circulation line 102 connects an outlet 104 formed in the lower part of the biogas fermenter 100 to an inlet 106 formed in an upper part of the biogas fermenter 100 that is positioned above the lower part. The circulation line 102 removes a portion of the contents to the outside of the biogas fermenter 100 via the outlet 104. Then, a portion of the contents circulating through the circulation line 102 is returned to the biogas fermenter 100 via the inlet 106. In this manner, the contents of the biogas fermenter 100 are agitated by circulating a portion of the contents through the circulation line 102.

[0062] The circulation line 102 is provided with a sampling line 107 that branches off from the circulation line 102 and connects to the solid-liquid separator 2 of the concentration measurement system 1. This sampling line 107 is provided with, for example, a pump, and functions as a sampling device 42 that samples a portion of the contents circulating through the circulation line 102 as a solid-liquid mixture A. The concentration measurement system 1 measures the concentration of a solute contained in liquid X1 of the contents (solid-liquid mixture A) of the biogas fermenter 100.

[0063] 10 , the concentration measurement system 1 further includes a waste liquid line 108 connecting the circulation line 102 and the concentration measurement device 6. The waste liquid line 108 connects the circulation line 102 to the downstream side of the collection line 107 in the direction in which a portion of the contents of the biogas fermenter 100 flows. By providing such a waste liquid line 108 on the circulation line 102, the dilution liquid X3 that has flowed through the concentration measurement device 6 returns to the circulation line 102 via the waste liquid line 108. Although not shown, the dilution liquid X3 that has flowed through the concentration measurement device 6 may be sent to a waste liquid treatment device that treats the dilution liquid X3 as waste instead of returning to the circulation line 102.

[0064] The adjusting device 54 adjusts the amount and timing of the reformate Z1 supplied to the biogas fermenter 100 based on the solute concentration measured by the concentration measurement system 1. The adjusting device 54 is a computer such as an electronic control device, and includes a processor such as a CPU or GPU (not shown), memory such as ROM or RAM, and an I / O interface. In the embodiment illustrated in FIG. 10 , the adjusting device 54 is electrically connected to the concentration measurement device 6 (optical concentration measurement device 24) and the adjusting valve 55 of the concentration measurement system 1. The adjusting device 54 calculates the aperture of the adjusting valve 55 by the processor operating (e.g., performing calculations) according to instructions from a program loaded into the memory based on the solute concentration measured by the concentration measurement device 6. The adjusting device 54 then instructs the adjusting valve 55 to adjust to the calculated aperture. The adjusting device 54 may be installed within the plant together with the reformer 52 and the biogas fermenter 100, or may be installed at a location separate from the plant. The adjusting device 54 may also be configured on a cloud server.

[0065] The concentration measurement system 1 will be described below using an example in which it measures the concentration of volatile fatty acids (VFAs) contained in the contents of the biogas fermenter 100. In some embodiments, the concentration measurement device 6 of the concentration measurement system 1 measures only the concentration of volatile fatty acids contained in the dilution liquid X3. The concentration of volatile fatty acids may be a major factor affecting the microorganisms in the biogas fermenter 100. With this configuration, by limiting the measurement target of the concentration measurement device 6 to volatile fatty acids, the measurement costs (time and expenses) incurred by the concentration measurement system 1 to obtain measured values ​​can be reduced. Note that the present disclosure does not limit the measurement target of the concentration measurement system 1 to volatile fatty acids. The concentration measurement system 1 may measure the concentrations of the above-mentioned furals and phenols, or may measure the concentrations of multiple solutes.

[0066] An example of adjustment of the modified material Z1 by the adjusting device 54 will be described. When the concentration of volatile fatty acids measured by the concentration measurement system 1 becomes lower than a preset lower limit (e.g., 1000 ppm), the adjusting device 54 increases the aperture of the adjusting valve 55 to increase the amount of modified material Z1 supplied to the biogas fermenter 100. This makes it possible to prevent the death of microorganisms due to a lack of modified material Z1 (feed) in the biogas fermenter 100. On the other hand, when the concentration of volatile fatty acids measured by the concentration measurement system 1 becomes higher than a preset upper limit (e.g., 10000 ppm), the adjusting device 54 decreases the aperture of the adjusting valve 55 to reduce the amount of modified material Z1 supplied to the biogas fermenter 100. This makes it possible to prevent the death of microorganisms due to the contents of the biogas fermenter 100 becoming rancid.

[0067] <Functions and Effects of the Waste Treatment System According to Embodiment 5> According to Embodiment 5, the concentration measurement system 1 measures the concentration of volatile fatty acids contained in the content of the biogas fermenter 100. Then, based on the measured concentration of the volatile fatty acids, the adjustment device 54 adjusts the amount and timing of supplying the modified material Z1 to the biogas fermenter 100. This makes it possible to continuously maintain the biogas fermenter 100 in a state suitable for degradation by microorganisms.

[0068] When the waste treatment system 50 includes the reformer 52 and the biogas fermenter 100, the reformer 52 has the effect of amplifying the influence of the raw material (waste) composition, so if the system is configured only with the reformer 52 and the biogas fermenter 100, a failure in the reforming operation will amplify small fluctuations in the inlet composition, often making it difficult to stably operate the biogas fermenter 100. According to the fifth embodiment, the waste treatment system 50 includes, in addition to the reformer 52 and the biogas fermenter 100, the concentration measurement system 1 and the adjustment device 54, so that the biogas fermenter 100 can be continuously maintained in a state suitable for degradation by microorganisms.

[0069] In some embodiments, the waste treatment system 50 is configured to set the hydrolysis conditions (temperature, pressure, time, stirring rotation speed, etc.) in the reformer 52 based on the measured values ​​of the concentration measurement system 1. With this configuration, the reformed material Z1 under conditions suitable for the microbial reaction can be supplied to the biogas fermenter 100, and valuable resources can be efficiently produced by the microbial reaction.

[0070] In the fifth embodiment, the concentration measurement system 1 is configured to measure the concentration of solutes (volatile fatty acids) contained in the contents of the biogas fermenter 100, but the present disclosure is not limited to this configuration. The concentration measurement system 1 measures the concentration of solutes contained in the liquid X1 of the solid-liquid mixture A produced in the waste treatment system 50. Although not shown, in some embodiments, the concentration measurement system 1 measures the concentration of solutes contained in the reformed product Z1 flowing through the reforming line 53.

[0071] (Embodiment 6) <Configuration of waste treatment system according to embodiment 6> A waste treatment system 50 according to embodiment 6 will be described. The waste treatment system 50 according to embodiment 6 differs from the waste treatment system 50 according to embodiment 5 in that an adjustment device 54 is configured to adjust the supply amount and timing of easily decomposable materials Z2 supplied to the biogas fermenter 100. In embodiment 6, the same components as those in embodiment 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0072] Here, we will explain easily decomposed materials Z2 and difficult to decompose materials Z3. Easily decomposed materials Z2 are those of the modified material Z1 supplied to the biogas fermenter 100 that can be decomposed into smaller molecules by microorganisms within a predetermined time, such as sugars such as glucose. Difficult to decompose materials Z3 are those that take longer to be decomposed into smaller molecules by microorganisms in the biogas fermenter 100 than the easily decomposed materials Z2, such as casein and cellulose. The predetermined time may be any time that can be determined, such as 100 hours.

[0073] Fig. 11 is a diagram schematically showing the configuration of a waste treatment system 50 according to a sixth embodiment of the present disclosure. As shown in Fig. 11, the waste treatment system 50 further includes a separation device 62, an easily decomposable material tank 64 for storing easily decomposable materials Z2, and a difficult to decompose material tank 66 for storing difficult to decompose materials Z3. The easily decomposable material tank 64 and the difficult to decompose material tank 66 are arranged in parallel with each other between the reformer 52 and the biogas fermenter 100.

[0074] The separator 62 is disposed between the reformer 52 and the biogas fermenter 100. The separator 62 separates the reformed product Z1 supplied from the reformer 52 into easily decomposed products Z2 and less decomposed products Z3. The separator 62 is, for example, a screen that separates the reformed product Z1 into large particle size components and small particle size components having particle sizes smaller than those of the large particle size components.

[0075] The small particle size components separated by the separator 62 are supplied to a decomposable material tank 64 as easily decomposable materials Z2. The easily decomposable material tank 64 is connected to the biogas fermenter 100 via a decomposable material line 68 through which the easily decomposable materials Z2 flow. The easily decomposable material line 68 is provided with an easily decomposable material regulating valve 70 for regulating the amount of easily decomposable materials Z2 supplied from the easily decomposable material tank 64 to the biogas fermenter 100. The easily decomposable material regulating valve 70 has a configuration similar to the above-described regulating valve 55, and its opening is adjusted according to instructions transmitted from the adjusting device 54. In other words, the adjusting device 54 adjusts the amount and timing of the easily decomposable materials Z2 supplied to the biogas fermenter 100 based on the concentration of volatile fatty acids measured by the concentration measurement system 1. The easily decomposable materials Z2 (small particle size components) supplied to the biogas fermenter 100 are decomposed into smaller molecules to generate biogas G. The biogas G generated in the biogas fermenter 100 is stored in a gas holder 72.

[0076] The large particle size components separated by the separator 62 are supplied to a non-decomposable material tank 66 as non-decomposable material Z3. The main components of the large particle size components are those derived from plastic waste and those that cannot be broken down into smaller molecules in the biogas fermenter 100, such as metals. In other words, the large particle size components are unsuitable for microbial reaction, while the small particle size components are suitable for microbial reaction. In the embodiment shown in Figure 11, the non-decomposable material tank 66 is connected to the biogas fermenter 100 via a non-decomposable material line 69 through which the non-decomposable material Z3 flows.

[0077] <Actions and Effects of Waste Treatment System According to Sixth Embodiment> Whether the biogas fermenter 100 is in a suitable state for degradation by microorganisms is often determined by the amount and timing of easily decomposed materials Z2 supplied to the biogas fermenter 100. According to the sixth embodiment, the adjustment device 54 adjusts the amount of easily decomposed materials Z2 supplied to the biogas fermenter 100 and the timing of supplying the easily decomposed materials Z2 to the biogas fermenter 100 based on the concentration of volatile fatty acids measured by the concentration measurement system 1, so that the biogas fermenter 100 can be continuously maintained in a suitable state for degradation by microorganisms.

[0078] Furthermore, according to the sixth embodiment, by providing the separation device 62, it is possible to supply easily decomposed materials Z2 with higher purity and fluidity to the biogas fermenter 100 compared to when the separation device 62 is not provided. This allows the biogas fermenter 100 to be quickly brought into a state suitable for degradation by microorganisms. Furthermore, by providing the separation device 62, it is possible to separate the difficult-to-decompose materials Z3 from the modified material Z1 and reduce the amount of unsuitable materials for reaction supplied to the biogas fermenter 100. As a result, the risk of degradation being inhibited in the biogas fermenter 100 is reduced, and degradation can be carried out efficiently.

[0079] 11, the waste treatment system 50 is equipped with a separation device 62, an easily decomposable material tank 64, and a less decomposable material tank 66, and describes an ideal form in which the easily decomposable material Z2 and the less decomposable material Z3 are clearly separated and stored in separate tanks, but complete separation is not necessarily required. The waste treatment system 50 can achieve the same effects as those described above by configuring it so that the supply amount of the easily decomposable material Z2, which reacts particularly quickly, can be adjusted.

[0080] 11 , the concentration measurement system 1 measures the concentration of solutes contained in the liquid X1 of the contents (solid-liquid mixture A) of the biogas fermenter 100, but the present disclosure is not limited to this configuration. In some embodiments, the concentration measurement system 1 measures the concentration of solutes contained in the liquid of modified product Z1 (solid-liquid mixture A), which is waste hydrolyzed by the reformer 52. In this case, the modified product Z1 (hydrothermal hydrolysis treatment product) may be collected from a line that supplies the modified product Z1 from the reformer 52 to the separator 62, or the easily decomposable product Z2 (mixing and adjustment tank slurry) may be collected from the easily decomposable product tank 64.

[0081] <Concentration measurement method> A concentration measurement method according to the present disclosure is a method for measuring the concentration of a solute contained in liquid X1 of a solid-liquid mixture A, which is a mixture of liquid X1 and solid Y1. Fig. 12 is a flowchart showing a concentration measurement method according to one embodiment. As shown in Fig. 12, the concentration measurement method includes a solid-liquid separation step S2, a dilution step S4, and a concentration measurement step S6.

[0082] In the solid-liquid separation step S2, the liquid X1 is separated from the solid-liquid mixture A using a porous body 8 having pores 10 formed therein that can be impregnated with the liquid X1. Specifically, the porous body 8 is brought into contact with the solid-liquid mixture A. In the dilution step S4, the liquid X1 separated from the solid-liquid mixture A in the solid-liquid separation step S2 is diluted to produce a diluted liquid X3. In the concentration measurement step S6, the concentration of the solute contained in the diluted liquid X3 produced in the dilution step S4 is measured.

[0083] According to this concentration measurement method, by bringing the porous body 8 into contact with the solid-liquid mixture A, the liquid X1 is impregnated into the pores 10 formed in the porous body 8, and the liquid X1 can be quickly separated from the solid-liquid mixture A. This makes it possible to quickly measure the concentration of the solute contained in the liquid X1 in the solid-liquid mixture A. Furthermore, since the porous body 8 is less expensive than a centrifugal separator, the cost of the equipment required to perform the solid-liquid separation step S2 can be reduced.

[0084] The dilution step S4 is not an essential step in the concentration measurement method according to the present disclosure. In some embodiments, the concentration measurement step S6 measures the concentration of the solute contained in the separation liquid X2 separated in the solid-liquid separation step S2.

[0085] <Waste Treatment Method> Figure 13 is a flowchart showing a waste treatment method according to one embodiment. As shown in Figure 13, the waste treatment method includes a hydrolysis step S52, a molecular weight reduction step S54, the concentration measurement method described above (solid-liquid separation step S2, dilution step S4, and concentration measurement step S6), and an adjustment step S56. The solid-liquid mixture A is a low-molecular-weight product obtained by reducing the molecular weight of the modified product Z1 using microorganisms. In other words, the concentration measurement method measures the concentration of a solute contained in the liquid of the low-molecular-weight product.

[0086] In the hydrolysis step S52, the waste is hydrolyzed. In the molecular reduction step S54, the modified product Z1, which is the waste hydrolyzed in the hydrolysis step S52, is reduced to smaller molecules by microorganisms. In the adjustment step S56, the amount and timing of the modified product Z1 reduced to smaller molecules in the molecular reduction step S54 are adjusted based on the concentration of the solute measured by the concentration measurement method. In the embodiment illustrated in FIG. 13, the adjustment step S56 is performed after the hydrolysis step S52 and before the molecular reduction step S54.

[0087] According to this waste treatment method, in the molecular-decomposition step S54, it is possible to continuously maintain a state suitable for the decomposition of the modified substance by microorganisms into molecular-decomposition substances.

[0088] The contents described in each of the above embodiments can be understood, for example, as follows.

[0089] [1] A concentration measurement system according to the present disclosure is a concentration measurement system (1) for measuring the concentration of a solute contained in a solid-liquid mixture (A) that is a mixture of a liquid (X1) and a solid (Y1), and includes: a solid-liquid separator (2) that separates the liquid from the solid-liquid mixture; and a concentration measurement device (6) that measures the concentration of the solute contained in the liquid separated by the solid-liquid separator, wherein the solid-liquid separator includes a porous body (8) having pores (10) formed therein that can be impregnated with the liquid.

[0090] According to the configuration described in [1] above, by contacting the porous body with a solid-liquid mixture, the liquid penetrates the pores formed in the porous body, allowing the liquid to be quickly separated from the solid-liquid mixture. This allows the concentration of solutes contained in the liquid in the solid-liquid mixture to be quickly measured. Furthermore, since porous bodies are less expensive than centrifugal separators, the installation costs of a solid-liquid separator can be reduced.

[0091] [2] In some embodiments, the configuration described in [1] above further comprises (4) diluting the liquid separated by the solid-liquid separator, and the concentration measuring device measures the concentration of the solute contained in the liquid separated by the solid-liquid separator and diluted by the dilution device.

[0092] When the concentration of the solute contained in the liquid of the solid-liquid mixture is too high, it may be difficult for the concentration measuring device to measure the concentration of the solute. According to the configuration described in [2] above, the concentration measuring device measures the concentration of the solute contained in the liquid diluted by the dilution device. Therefore, even if the concentration of the solute contained in the liquid of the solid-liquid mixture is higher than the concentration that can be measured by the concentration measuring device, the concentration measuring device can measure the concentration of the solute.

[0093] [3] In some embodiments, in the configuration described in [1] or [2] above, the solid-liquid separation device further includes a dehydration device (12) that dehydrates the liquid from the porous body.

[0094] According to the configuration described in [3] above, by dehydrating the liquid from the porous body using the dehydration device, it is possible to quickly extract the liquid necessary for measuring the concentration of the solute.

[0095] [4] In some embodiments, in the configuration described in any one of [1] to [3] above, the solid-liquid separation device further includes a nonwoven fabric (14), and the nonwoven fabric is arranged upstream of the porous body in the flow direction of the liquid in the solid-liquid separation device.

[0096] If the particle size of the solids contained in the solid-liquid mixture becomes large, it may hinder the impregnation of the liquid into the pores of the porous body. According to the configuration described in [4] above, the solid-liquid mixture comes into contact with the nonwoven fabric before coming into contact with the porous body, so that the solids with large particle sizes are removed by the nonwoven fabric. This allows the liquid to smoothly impregnate the pores of the porous body.

[0097] [5] In some embodiments, the configuration according to any one of [1] to [4] above further comprises a cleaning line (34) through which cleaning fluids (f1, f3) for cleaning at least one of the solid-liquid separator and the concentration measuring device flow.

[0098] According to the configuration described in [5] above, the liquid separated from the solid-liquid mixture is prevented from remaining in at least one of the solid-liquid separator and the concentration measuring device, thereby extending the period during which at least one of the solid-liquid separator and the concentration measuring device remains in a good condition.

[0099] [6] In some embodiments, in the configuration described in any one of [1] to [5] above, the concentration measuring device is an optical concentration measuring device (24) including: a cell (16) to which a separated liquid (X2) that is the liquid separated in the solid-liquid separator is supplied; a light source (18) that irradiates the cell with light; and a detector (20) that receives the light that has passed through the cell.

[0100] According to the configuration described in [6] above, the concentration measurement system can apply an optical concentration measurement device that measures the concentration of a solute contained in a separation liquid in a cell using light absorption, diffraction, scattering, etc.

[0101] [7] In some embodiments, in the configuration described in [6] above, the optical concentration measurement device measures the concentration of the solute contained in the separation liquid based on the amount of change in absorbance calculated by differentiating the absorbance with respect to wavelength.

[0102] The absorbance at a specific wavelength may be affected by the absorbance at wavelengths other than the specific wavelength. In contrast, the amount of change in absorbance at a specific wavelength is not affected by the amount of change in absorbance at wavelengths other than the specific wavelength, or is very small. According to the configuration described in [7] above, the optical concentration measuring device measures the concentration of the solute contained in the separation liquid based on the amount of change in absorbance, thereby improving measurement accuracy compared to when the concentration of the solute contained in the separation liquid is measured based on absorbance.

[0103] [8] In some embodiments, in the configuration described in [7] above, the optical concentration measuring device measures the concentration of the solute contained in the separation liquid based on the sum of the areas of the absorbance change amounts having peaks within a predetermined wavelength range.

[0104] According to the configuration described in [8] above, the concentration of a solute contained in a diluted liquid is measured based on the sum of the areas of the absorbance change amounts having peaks within a predetermined wavelength range. That is, multiple solutes are grouped together as a single solute (for example, furfural and 5-hydroxymethylfurfural are grouped together as furals), and the concentration of this single solute is measured. This makes it easier to measure the concentration of a solute than when the concentrations of multiple solutes are measured individually.

[0105] [9] In some embodiments, in the configuration described in any one of [6] to [8] above, the cell is configured to be filled with a correction liquid different from the separation liquid, the light source is configured to irradiate the cell filled with the correction liquid with the light, the detector is configured to receive correction light which is the light that has passed through the cell filled with the correction liquid, and the optical concentration measuring device is configured to correct the detection value of the detector based on the correction light received by the detector.

[0106] Even if an optical concentration measuring device measures the same concentration of a solute at both a first timing and a second timing that follows the first timing, the concentration of the solute measured at the first timing may be slightly different from the concentration of the solute measured at the second timing. According to the configuration described in [9] above, the concentration of the solute is corrected based on the correction light that has passed through a cell filled with a correction liquid, thereby suppressing the influence of differences in measurement timing.

[0107]

[10] In some embodiments, in the configuration described in any one of [6] to [9] above, the optical concentration measuring device further includes a calibration liquid cell (32) arranged between the cell and the detector, and the calibration liquid cell is supplied with a calibration liquid of known concentration when the separation liquid is not supplied to the cell, the detector is configured to receive calibration light which is the light that has passed through both the cell to which the separation liquid is not supplied and the calibration liquid cell to which the calibration liquid is supplied, and the optical concentration measuring device is configured to correct the detection value of the detector based on the calibration light received by the detector.

[0108] In some cases, it is not easy for the detector of an optical concentration measuring device to maintain the detection sensitivity for receiving light. According to the configuration described in

[10] above, the detection value of the detector is corrected based on the calibration light that has passed through both the cell to which no separation liquid has been supplied and the calibration liquid cell to which the calibration liquid has been supplied, thereby suppressing the difference in detection sensitivity.

[0109]

[11] In some embodiments, in the configuration according to any one of the above [1] to

[10] , the solid-liquid mixture contains low-molecular-weight substances that have been low-molecular-weighted by microorganisms.

[0110] According to the findings of the present inventors, if the concentration of the solute of the low-molecular-weight substance falls within a predetermined range, the state is suitable for low-molecular-weight degradation by microorganisms. On the other hand, if the concentration of the solute of the low-molecular-weight substance falls outside this range, the state is unsuitable for low-molecular-weight degradation by microorganisms. According to the configuration described in

[11] above, the concentration of the solute of the low-molecular-weight substance is measured, and it is possible to quickly determine whether the state is suitable for low-molecular-weight degradation by microorganisms based on this measurement value.

[0111]

[12] In some embodiments, the configuration according to the above

[11] further comprises a collection device (42) that collects the solid-liquid mixture from the circulating low-molecular-weight product (fA).

[0112] According to the configuration described in

[12] above, a solid-liquid mixture is collected from distributed low molecular weight materials, so that a solid-liquid mixture can be collected from low molecular weight materials in an agitated state.

[0113]

[13] In some embodiments, in the configuration described in any one of [1] to

[12] above, the solid-liquid mixture contains a modified product (Z1) obtained by hydrolyzing waste.

[0114] The conditions for hydrolyzing the waste may be determined based on the concentration of the solute contained in the modified product. According to the configuration described in

[13] above, the concentration of the solute contained in the modified product is measured, so that the conditions for hydrolyzing the waste can be quickly determined based on this measurement value.

[0115]

[14] A waste treatment system (50) according to the present disclosure comprises: at least one reforming device (52) for hydrolyzing waste; a microbial reaction device (100) for microorganisms that convert the waste, i.e., the modified material hydrolyzed in the at least one reforming device, into smaller molecules; a concentration measurement system according to any one of claims 1 to 13; and an adjustment device (54) that adjusts the amount and timing of the modified material to be supplied to the microbial reaction device based on the measurement value of the concentration measurement device, wherein the solid-liquid mixture contains at least one of the modified material and smaller molecules that are obtained by converting the modified material into smaller molecules by the microorganisms.

[0116] According to the configuration described in

[14] above, the microbial reaction device can be continuously maintained in a state suitable for the degradation of the modified substance by the microorganisms into smaller molecules.

[0117]

[15] A concentration measurement method according to the present disclosure is a concentration measurement method for measuring the concentration of a solute contained in a liquid of a solid-liquid mixture, which is a mixture of a liquid and a solid, and includes the steps of: separating the liquid from the solid-liquid mixture using a porous body having pores formed therein that can be impregnated with the liquid (S2); and measuring the concentration of the solute contained in the liquid separated from the solid-liquid mixture (S6).

[0118] According to the method described in

[15] above, by contacting a porous body with a solid-liquid mixture, the pores formed in the porous body are impregnated with the liquid, thereby enabling the liquid to be rapidly separated from the solid-liquid mixture. Therefore, the concentration of the solute contained in the liquid in the solid-liquid mixture can be rapidly measured. Furthermore, since porous bodies are less expensive than centrifugal separators, the cost of the equipment required to separate the liquid from the solid-liquid mixture can be reduced.

[0119]

[16] The waste treatment method according to the present disclosure comprises: a hydrolysis step (S52) of hydrolyzing waste; a molecular reduction step (S54) of reducing the hydrolyzed modified material, which is the waste, into smaller molecules using microorganisms; the concentration measurement method described in

[15] above; and an adjustment step (S56) of adjusting the amount and timing of the modified material to be reduced in the molecular reduction step based on the measured concentration of the solute, wherein the solid-liquid mixture contains at least one of the modified material and reduced molecules obtained by reducing the modified material by microorganisms.

[0120] According to the method described in

[16] above, it is possible to continuously maintain a state suitable for the degradation of the modified substance by microorganisms into smaller molecules in the molecular degradation step.

[0121] 1 Concentration measurement system 2 Solid-liquid separation device 4 Dilution device 6 Concentration measurement device 8 Porous body 10 Pore 12 Dehydration device 14 Nonwoven fabric 16 Cell 18 Light source 20 Detector 24 Optical concentration measurement device 32 Calibration liquid cell 34 Cleaning line 42 Sampling device 50 Waste treatment system 52 Modification device 54 Adjustment device 62 Separation device 64 Easily decomposed product tank 66 Difficult to decompose product tank 100 Biogas fermenter (microbial reaction device) A Solid-liquid mixture X1 Liquid X3 Dilution liquid Y1 Solid Z1 Modified product Z2 Easily decomposed product Z3 Difficult to decompose product f1 First cleaning fluid f2 Second cleaning fluid f3 Third cleaning fluid S2 Solid-liquid separation step S4 Dilution step S6 Concentration measurement step S52 Hydrolysis step S54: Decomposition step S56: Adjustment step

Claims

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