Method for disposing of waste milk and processing device for waste milk

Abstract

To facilitate maintenance and management, this invention provides a method and apparatus for treating waste milk that can mix waste milk wastewater with a coagulant in a simple and compact configuration and treat it appropriately. [Solution] The method includes the steps of: mixing the waste milk waste liquid in a state in which an inorganic coagulant aqueous solution, which is a diluted aqueous solution of an inorganic coagulant, is stored or poured into a coagulation treatment tank, by dropping it into the inorganic coagulant aqueous solution, thereby entraining air, and causing the emulsifying components in the waste milk waste liquid to coagulate and produce a primary treated waste liquid; and mixing the primary treated waste liquid in a state in which a polymer coagulant aqueous solution, which is a diluted aqueous solution of a polymer coagulant, is stored or poured into a coagulation treatment tank, by dropping it into the polymer coagulant aqueous solution, thereby entraining air, and causing the emulsifying components and coagulating components in the primary treated waste liquid to further coagulate waste solid components and a secondary treated waste liquid.

Description

Technical Field

[0001] The present invention relates to a method for treating waste milk and a waste milk treatment apparatus for separating and treating waste milk waste liquid, which is waste liquid containing waste milk generated during milking operations, by destroying the emulsified state and aggregating the emulsified components.

Background Art

[0002] As a conventional method for treating wastewater containing a polymer emulsion, an inorganic flocculant and a neutralizing agent are added to the wastewater containing the polymer emulsion to form a primary flocculate, and then a water-soluble polymer carboxylate and a polyvalent metal salt are sequentially added to the wastewater to form a secondary flocculate (see Patent Document 1).

[0003] This conventional method for coagulating wastewater containing a polymer emulsion has the effect that the flocculate can be easily and quickly separated from water, and the clarity of the separated water is high.

[0004] In addition, as a conventional wastewater treatment facility, there has been proposed a facility for treating wastewater containing protein, which includes a storage tank for storing the wastewater, a pH sensor for detecting the pH of the wastewater in the storage tank, and a flocculant supply device for supplying an amount of flocculant corresponding to the detection value of the pH sensor to the storage tank (see Patent Document 2).

[0005] According to this conventional wastewater treatment facility, it has the effect that the protein component can be aggregated more effectively than before in the treatment of wastewater containing a protein component.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

[0007] The problem to be solved with regard to the disposal method and disposal device for waste milk is that, conventionally, in order to mix waste liquid containing waste milk (waste milk waste liquid) with a coagulant, a large amount of waste milk waste liquid is collected in a large storage tank and stirred using a stirrer equipped with stirring blades, resulting in a large and complex device system, and no simpler and more rational configuration has been proposed to facilitate maintenance and management.

[0008] Therefore, the object of the present invention is to provide a method for processing waste milk and a processing apparatus for waste milk that can mix waste milk waste liquid and a coagulant in a simple and compact configuration that facilitates maintenance and management, and can efficiently and appropriately separate solid components by coagulating the emulsified components of waste milk waste liquid. [Means for solving the problem]

[0009] To achieve the above objective, the present invention comprises the following configuration. According to one embodiment of the waste milk treatment method of the present invention, the waste milk treatment method is a waste liquid containing waste milk generated during milking operations, which is separated by breaking the emulsified state and coagulating the emulsified components, and is characterized by comprising the steps of: in a coagulation treatment tank in which an inorganic coagulant aqueous solution, which is a diluted aqueous solution of an inorganic coagulant, is stored or poured in, the waste milk waste liquid is dropped into the inorganic coagulant aqueous solution and mixed in a manner that entrains air, thereby coagulating the emulsified components in the waste milk waste liquid to produce a primary treated waste liquid; and in a coagulation treatment tank in which a polymer coagulant aqueous solution, which is a diluted aqueous solution of a polymer coagulant, is stored or poured in, the primary treated waste liquid is dropped into the polymer coagulant aqueous solution and mixed in a manner that entrains air, thereby further coagulating the emulsified components and coagulated components in the primary treated waste liquid to produce waste solid components and a secondary treated waste liquid.

[0010] Furthermore, according to one embodiment of the waste milk processing apparatus of the present invention, a waste milk processing apparatus that separates waste milk wastewater, which is waste liquid containing waste milk generated during milking operations, by breaking the emulsified state and coagulating the emulsified components, comprising: a waste milk wastewater tank for temporarily receiving and storing the waste milk wastewater; a primary coagulant storage container for storing an inorganic coagulant aqueous solution, which is a diluted aqueous solution of an inorganic coagulant; and a coagulation processing tank to which the inorganic coagulant aqueous solution is supplied from the primary coagulant storage container, and the waste milk wastewater is introduced while the inorganic coagulant aqueous solution is stored or poured in, mixing in a state in which air is entrained, thereby coagulating the emulsified components in the waste milk wastewater and producing primary treated wastewater. The present invention may be characterized by comprising: waste milk waste liquid input means for dropping the waste milk waste liquid into the coagulation treatment tank; a secondary coagulant storage container for storing a polymer coagulant aqueous solution, which is a diluted aqueous solution of a polymer coagulant; a coagulation treatment tank to which the polymer coagulant aqueous solution is supplied from the secondary coagulant storage container, and to which the primary treated waste liquid is added while the polymer coagulant aqueous solution is stored or poured in, thereby mixing in a manner that entrains air, and further coagulating the emulsifying and coagulating components in the primary treated waste liquid to produce waste solid components and secondary treated waste liquid; and a primary treated waste liquid input means for dropping the primary treated waste liquid into the coagulation treatment tank.

[0011] Furthermore, according to one embodiment of the waste milk processing apparatus of the present invention, the waste milk waste liquid input means is characterized by comprising a pipe provided such that the discharge port for the waste milk waste liquid is located above the coagulation treatment tank, and a pump device connected to the pipe to pump up the waste milk waste liquid.

[0012] Furthermore, according to one embodiment of the waste milk processing apparatus of the present invention, the primary treated waste liquid input means is characterized by comprising a primary discharge passage provided so as to be in communication with the lower part of the coagulation treatment tank and having a primary discharge port located on the upper side of the coagulation treatment tank, and an on / off valve provided in the primary discharge passage, so as to discharge the primary treated waste liquid from the coagulation treatment tank, which is installed on the upper side of the coagulation treatment tank, to the coagulation treatment tank.

[0013] Furthermore, according to one embodiment of the waste milk processing apparatus according to the present invention, the flow path size of the discharge passage is set such that the amount of the primary treated waste liquid input into the coagulation treatment tank per unit time is greater than the amount of the waste milk waste liquid input into the coagulation treatment tank per unit time. [Effects of the Invention]

[0014] The waste milk treatment method and waste milk treatment apparatus according to the present invention offer particularly advantageous effects, such as being able to mix waste milk waste liquid and a coagulant in a simple and compact configuration that facilitates maintenance, and being able to efficiently and appropriately separate and treat the solid components by coagulating the emulsified components of the waste milk waste liquid. [Brief explanation of the drawing]

[0015] [Figure 1] This is a block diagram showing an example of the form of a waste milk processing device according to the present invention. [Figure 2] This is a perspective view showing an example of the configuration of a waste milk processing device according to the present invention (an example of a configuration in which two units are installed in parallel). [Modes for carrying out the invention]

[0016] The following describes in detail, based on the attached drawings (Figures 1 and 2), examples of the configuration of the waste milk processing method and waste milk processing apparatus according to the present invention.

[0017] The waste milk treatment method according to the present invention separates the waste milk waste liquid 11, which is a waste liquid containing waste milk generated during milking operations, by breaking down its emulsified state and coagulating the emulsified components. The method comprises two steps: a pretreatment step in which the emulsified components in the waste milk waste liquid 11 are coagulated with an inorganic coagulant, and a posttreatment step in which the components are further coagulated with a polymer coagulant.

[0018] And in the above-described pretreatment step, in the coagulation treatment tank 20 in which the aqueous inorganic flocculant solution 21, which is a diluted aqueous solution of an inorganic flocculant, is stored or being poured in, the waste milk waste liquid 11 is dropped into the aqueous inorganic flocculant solution 21 to be mixed in a state of entraining air, and the emulsified components in the waste milk waste liquid 11 are coagulated to produce a primary treated waste liquid 12.

[0019] Further, in the above-described post-treatment step, in the flocculation treatment tank 30 in which the aqueous polymer flocculant solution 31, which is a diluted aqueous solution of a polymer flocculant, is stored or being poured in, the primary treated waste liquid 12 is dropped into the aqueous polymer flocculant solution 31 to be mixed in a state of entraining air, and the emulsified components and coagulated components in the primary treated waste liquid 12 are further flocculated to produce a waste solid component 41 (floc) and a secondary treated waste liquid 42.

[0020] According to the method for treating waste milk according to the present invention, without requiring a special mixing device such as a stirrer equipped with stirring blades, and with a simple device configuration provided based on a simple and reasonable charging method, the waste milk waste liquid 11 and the aqueous inorganic flocculant solution 21 can be appropriately mixed, and the primary treated waste liquid 12 and the aqueous polymer flocculant solution 31 can be appropriately mixed, achieving a particularly remarkable effect.

[0021] That is, although it is considered to be related to the specific properties and concentration of the waste milk waste liquid 11, by diluting the inorganic flocculant to use it as the aqueous inorganic flocculant solution 21 and dropping the waste milk waste liquid 11 into the aqueous inorganic flocculant solution 21 in a state of entraining air, they can be mixed, and a particularly advantageous effect that the emulsified components in the waste milk waste liquid 11 can be appropriately coagulated is achieved. Also, although it is considered to be related to the specific properties and concentration of the primary treated waste liquid 12, by diluting the polymer flocculant to use it as the aqueous polymer flocculant solution 31 and dropping the primary treated waste liquid 12 into the aqueous polymer flocculant solution 31 in a state of entraining air, they can be mixed, and a particularly advantageous effect that the emulsified components and coagulated components in the primary treated waste liquid 12 can be appropriately flocculated is achieved.

[0022] Thus, in the present invention, since the device configuration is simple, there is a structure in which problems such as clogging of the waste milk waste liquid 11 and the primary treated waste liquid 12 in pipes and the like are unlikely to occur, and there is a particularly advantageous effect that maintenance management is easy to perform. Further, as the overall configuration of the waste milk treatment device, the power of a stirrer equipped with a conventional stirring blade is not required, and it can be simply provided, reducing the manufacturing cost. In the case of a conventional stirrer equipped with a stirring blade, if the stirring is strong, the coagulated matter will break, but in the present invention, since it only needs to be left after mixing, there is no such concern.

[0023] Furthermore, according to the present invention, the waste milk waste liquid 11 stored in the waste milk waste liquid tank 10 is divided into small portions and batch-processed sequentially and continuously a number of times. For this reason, the coagulation treatment tank 20 and the aggregation treatment tank 30 can be miniaturized, and auxiliary equipment including a power device such as a pump device can also be a small-capacity and small-sized one, enabling the compactification of the device system.

[0024] Incidentally, the method of the present invention basically utilizes the energy of the flow of the input waste milk waste liquid 11 and the primary treated waste liquid 12 to generate appropriate turbulent flow for mixing. Therefore, when increasing the size of the coagulation treatment tank 20 or the aggregation treatment tank 30, it is necessary to increase the size of the device for injecting the waste milk waste liquid 11 and the primary treated waste liquid 12 accordingly, and although it is possible to configure it in such a way, it is not practical. Therefore, inevitably, the method of the present invention is more suitable for the case where the sizes of the coagulation treatment tank 20 and the aggregation treatment tank 30 are small. As an example, in the embodiments shown in FIGS. 1 and 2, as a guide for the processing amount that can appropriately mix the waste milk waste liquid 11 and the aqueous inorganic flocculant solution 21, the processing amount of the waste milk waste liquid 11 per time is set to about 3 liters corresponding to one dairy cow, so that a space-saving and simple-structured device can be obtained.

[0025] Furthermore, compared to the conventional method of processing a large amount of waste milk liquid 11 all at once, the present invention processes the waste milk liquid 11 in small amounts. As a result, the present invention allows for the immediate processing of waste milk after milking, preventing spoilage and enabling more hygienic processing.

[0026] Next, an example of the configuration of the waste milk processing device according to the present invention will be described in detail based on the attached drawings (Figures 1 and 2).

[0027] 10 is a waste milk wastewater tank, installed to temporarily receive and store waste milk wastewater 11. In dairy farming, the milking process involves a system cleaning process, usually performed twice a day, and a milking process for each individual cow, which are repeated. The cleaning process (system cleaning) generates wastewater from the cleaning solution. In the milking process, the following steps are performed sequentially: cluster attachment, massage, teat cleaning, pre-milking for raw milk analysis, milking, post-dipping, and unit cleaning. In each step except for the milking process where the milk is sent to the bulk tank, wastewater including waste milk and cleaning solution is generated.

[0028] The aforementioned waste liquids are collected and stored in a temporary receiving jar (not shown) in this embodiment as waste milk waste liquid 11 containing waste milk. The waste milk waste liquid 11 collected in this temporary receiving jar is then sent via a pump or the like to a waste milk waste liquid tank 10 of a waste milk processing device configured as a milk component removal device, and stored in the waste milk waste liquid tank 10. In addition, since the present invention processes the waste milk waste liquid 11 in small amounts, both the temporary receiving jar and the waste milk waste liquid tank 10 have the advantage of being smaller than conventional ones.

[0029] In the example configuration shown in Figure 1, the waste milk waste liquid 11 from the waste liquid 100 from the milking machine is supplied to the waste milk waste liquid tank 10 via a three-way valve 101 and waste liquid piping 102. In addition, the waste liquid 100 from the milking machine may also consist only of wash water drainage 110 that does not contain waste milk, and this wash water drainage 110 can be drained via a three-way valve 101 and wash water drainage piping 103.

[0030] Container 22 is a primary flocculant storage container, where an inorganic flocculant aqueous solution 21, which is a diluted aqueous solution of an inorganic flocculant, is stored. As this inorganic flocculant aqueous solution 21, for example, a commonly used polyaluminum chloride diluted with water can be used. The concentration of the polyaluminum chloride is set to, for example, about 1%. Note that the inorganic flocculant is not limited to polyaluminum chloride; for example, polyferrous sulfate, polyferrous chloride, and polyaluminum sulfate can be used.

[0031] 20 is a coagulation treatment tank, where an inorganic coagulant aqueous solution 21 is supplied from the primary coagulant storage container 22. The inorganic coagulant aqueous solution 21 is mixed with waste milk waste liquid 11 while it is stored or being poured in, incorporating air, and the emulsifying components in the waste milk waste liquid 11 coagulate to produce primary treated waste liquid 12. In this embodiment, the inorganic coagulant aqueous solution 21 is pumped up from the primary coagulant storage container 22 by a pump device 23a and supplied to the coagulation treatment tank 20.

[0032] The form of the coagulation treatment tank 20 is not particularly limited, but in this embodiment, as shown in Figure 2, it is provided in the shape of a bucket with rounded corners in a plan view (cross-section cut horizontally), and the side walls gradually narrow downwards, with the bottom opening to communicate with a primary discharge passage 26 which can be opened and closed later. The top surface is covered with a lid 24 to prevent liquid from spilling, and the lid 24 is connected to the piping 17 of the waste milk waste liquid input means 15, which will be described later, as well as the supply piping 23b for the inorganic coagulant aqueous solution 21 and the piping 62 for washing water, so that each liquid can be supplied into the coagulation treatment tank 20.

[0033] Reference numeral 15 denotes a waste milk waste liquid input means, which is provided to drop the waste milk waste liquid 11 into the coagulation treatment tank 20. In this embodiment, the waste milk waste liquid input means 15 comprises a pipe 17 provided such that the outlet 18 for the waste milk waste liquid 11 is located above the coagulation treatment tank 20, and a pump device 16 connected to the pipe 17 to pump up the waste milk waste liquid 11.

[0034] In other words, the discharge port 18 for the waste milk liquid 11 is located in a required height space above the coagulation treatment tank 20, so that the waste milk liquid 11 can be introduced into the inorganic coagulant aqueous solution 21 stored in the coagulation treatment tank 20 from a height of, for example, 15 to 20 cm above the liquid surface. With this configuration, the waste milk liquid 11 can be introduced into the inorganic coagulant aqueous solution 21 while entraining air, which effectively generates turbulence and allows for more efficient and appropriate mixing.

[0035] Container 32 is a secondary flocculant storage container, where a polymer flocculant aqueous solution 31, which is a diluted aqueous solution of a polymer flocculant, is stored. As this polymer flocculant aqueous solution 31, for example, a commonly used acrylamide-sodium acrylate copolymer diluted with water can be used. The concentration of the acrylamide-sodium acrylate copolymer is set to, for example, about 0.05%. Note that the polymer flocculant is not limited to acrylamide-sodium acrylate copolymer; for example, acrylamide-acrylamide 2-methylpropanesulfonate and polyacrylates can be used.

[0036] 30 is a coagulation treatment tank, where a polymer flocculant aqueous solution 31 is supplied from a secondary flocculant storage container 32. The polymer flocculant aqueous solution 31 is mixed with the primary treated waste liquid 12 while it is stored or being poured in, and air is incorporated into the mixture. This further coagulates the emulsifying and coagulating components in the primary treated waste liquid 12, producing waste solid components 41 (flocs) and secondary treated waste liquid 42. In this embodiment, the polymer flocculant aqueous solution 31 is pumped up from the secondary flocculant storage container 32 by a pump device 33a and supplied to the coagulation treatment tank 30.

[0037] The form of the coagulation treatment tank 30 is not particularly limited, but in this embodiment, as shown in Figure 2, it is provided in the same way as the coagulation treatment tank 20, with a square shape in plan view (cross-section cut horizontally), and the side walls are formed in a bucket shape that gradually narrows downwards, and the bottom is open to communicate with the secondary discharge passage 36 which can be opened and closed, as described later. The top surface is covered with a lid 34 to prevent liquid from spilling, and the primary discharge passage 26 of the primary treated waste liquid input means 25, as well as the supply pipe 33b for the polymer coagulant aqueous solution 31 and the washing water pipe 62 are connected to the lid 34, so that the respective liquids can be supplied.

[0038] Furthermore, 25 is a primary treated wastewater input means, and is provided to drop and input the primary treated wastewater 12 into the coagulation treatment tank 30. In this embodiment, the primary treated wastewater input means 25 includes a primary discharge passage 26 that communicates with the lower part of the coagulation treatment tank 20 and has a primary discharge port 28 located on the upper side of the coagulation treatment tank 30, and a primary on / off valve 27 provided in the primary discharge passage 26, so as to discharge the primary treated wastewater 12 from the coagulation treatment tank 20, which is installed above the coagulation treatment tank 30, into the coagulation treatment tank 30.

[0039] In other words, the primary discharge port 28 of the primary treated wastewater input means 25 is located at a required height above the coagulation treatment tank 30, so that the primary treated wastewater 12 can be introduced into the liquid surface of the polymer coagulant aqueous solution 31 stored in the coagulation treatment tank 30 from a height of, for example, 15 to 20 cm above the liquid surface. With this configuration, the primary treated wastewater 12 can be introduced into the polymer coagulant aqueous solution 31 while incorporating air, thus enabling more efficient and appropriate mixing.

[0040] Furthermore, 35 is a secondary treated waste liquid discharge means, and is provided to discharge the waste solid components 41 and the secondary treated waste liquid 42 by dropping them into the separation tank 40. In this embodiment, the secondary treated waste liquid discharge means 35 includes a secondary discharge passage 36 that communicates with the lower part of the coagulation treatment tank 30 and has a secondary discharge port 38 located above the separation tank 40, and a secondary on / off valve 37 provided in the secondary discharge passage 36, so as to discharge the secondary treated waste liquid 42 from the coagulation treatment tank 30 installed above the separation tank 40 to the separation tank 40. Note that in Figure 2, the piping connected to the separation tank 40, which will be described later, in the secondary discharge passage 36 is not shown.

[0041] The separation tank 40 can be composed of a flocculation collection box 45, which has four side walls and a bottom made of a grid-like or mesh-like material and is designed to be breathable, and which holds a flexible container (not shown), which is a flocculation collection bag that also serves as a filter for filtering flocs, in an open state, and a separated water receiving tray (not shown) that receives the treated water (secondary treated waste liquid 42) from which the flocs (waste solid components 41) have been separated. In this embodiment, within the flocculation collection box 45 of the separation tank 40, a slope 46 (a part that guides the flexible container so that a part of its inner surface becomes sloped when it is placed) as shown in Figure 2 is provided in the part into which the waste solid components 41 and secondary treated waste liquid 42 flow in, so as to prevent the flocculated waste solid components 41 from breaking, the waste solid components 41 and secondary treated waste liquid 42 can be smoothly introduced into the flexible container. Furthermore, at the point where the secondary discharge passage 36 is connected in the separation tank 40, it is preferable to have a plate (not shown) that guides the flow of the secondary treated waste liquid 42 in order to weaken its flow force and widen the flow.

[0042] Next, we will explain this embodiment in more detail by showing an example of the quantities of waste milk liquid 11, inorganic coagulant aqueous solution 21, and polymer coagulant aqueous solution 31.

[0043] A required amount of inorganic coagulant aqueous solution 21 is pumped into the coagulation treatment tank 20 using a pump device 23a. In this embodiment, for example, 3 liters of inorganic coagulant aqueous solution 21 are added. When the inorganic coagulant aqueous solution 21 has accumulated in the coagulation treatment tank 20, or when the inorganic coagulant aqueous solution 21 has been poured into the coagulation treatment tank 20, a required amount of waste milk waste liquid 11 is added by dropping it from a required height so that it hits the inorganic coagulant aqueous solution 21, and the mixture is mixed in such a way that air is incorporated by the water flow of the waste milk waste liquid 11. In this embodiment, the waste milk waste liquid 11 is pumped up using a pump device 16 and dropped so that it hits the inorganic coagulant aqueous solution 21, for example, 3 liters are added. Then, it is left for a required time, for example 3 minutes in this embodiment, to allow the emulsifying components to coagulate and produce primary treated waste liquid 12.

[0044] A required amount of polymer flocculant aqueous solution 31 is pumped up by a pump device 33a and poured into a coagulation treatment tank 30 located below the coagulation treatment tank 20. In this embodiment, for example, 660cc of polymer flocculant aqueous solution 31 is added. When the polymer flocculant aqueous solution 31 has accumulated in the coagulation treatment tank 30, or when the polymer flocculant aqueous solution 31 has been poured into the coagulation treatment tank 30, a required amount of primary treated waste liquid 12 is poured into the polymer flocculant aqueous solution 31 by dropping it from a required high position, and the mixture is mixed by entraining air with the water flow of the primary treated waste liquid 12. In this embodiment, the primary treated waste liquid 12 is dropped by opening the primary on-off valve 27 provided in the primary discharge passage 26 so that gravity is applied to it, so that it hits the polymer flocculant aqueous solution 31, and for example, 6 liters (the combined amount of inorganic flocculant aqueous solution 21 and waste milk waste liquid 11) is added. Then, for the required time, in this embodiment for example 1 minute, the mixture is left to stand to further aggregate the emulsifying and coagulating components, thereby producing waste solid components and secondary treated waste liquid 42.

[0045] Then, the waste solid components 41 and the secondary treated waste liquid 42 generated in the coagulation treatment tank 30 are flowed into a separation tank 40 located below the coagulation treatment tank 30. In this separation tank 40, the waste solid components 41 are filtered and separated by the aforementioned flexible container, and the secondary treated waste liquid 42, which flows as a liquid, is discharged. The above process is repeated, and when the series of operations is completed, tap water 60 is sprayed from a spray nozzle 65 through the washing water shut-off valve 61 and the washing water piping 62 to wash the coagulation treatment tank 20 and the coagulation treatment tank 30. Note that 70 is a float switch and is positioned so that the amount of each liquid in each tank is maintained within the required range.

[0046] In the embodiments described above, specific examples will be given regarding the appropriate ranges for the input amount (total amount), input time, and input amount per unit time (flow rate) for each liquid, such as the waste milk waste liquid 11, that is supplied and introduced.

[0047] This section describes an evaluation experiment in which waste milk waste liquid 11 is introduced into a coagulation treatment tank 20 containing an inorganic coagulant aqueous solution 21 by a waste milk waste liquid input means 15. The experiment aims to confirm the mixing state of the waste milk waste liquid 11 and the inorganic coagulant aqueous solution 21, as well as the coagulation state of the emulsifying components, and to determine an appropriate range for the flow rate, assuming the same conditions such as the diameter and installation location of the piping 17 of the waste milk waste liquid input means 15, and when the flow rate of the waste milk waste liquid 11 is changed by changing the output of the pump device 16 in the coagulation treatment tank 20, either in a state where the inorganic coagulant aqueous solution 21 is (A) stored or (B) poured in. In pattern (B), the introduction of the inorganic coagulant aqueous solution 21 and the waste milk waste liquid 11 into the coagulation treatment tank 20 was set to be completed simultaneously. For the waste milk waste liquid 11 used in this evaluation experiment, a 20% milk solution was used, which is considered to be the average concentration of waste milk from dairy farmers, as the concentration of emulsifying components in milk is fundamentally involved in coagulation.

[0048] Specifically, the amounts of the inorganic coagulant aqueous solution 21 and the waste milk waste liquid 11 were set to approximately 3 liters (3000 ml) each, and the input time for the inorganic coagulant aqueous solution 21 was uniformly set to 130 seconds. Experiments were then conducted for each case where the input time for the waste milk waste liquid 11 was set to 30 seconds, 60 seconds, 90 seconds, and 120 seconds. As a result, the flow rate of the inorganic coagulant aqueous solution 21 was uniformly set to approximately 23 ml / s, and the flow rates of the waste milk waste liquid 11 were set to approximately 100 ml / s, approximately 50 ml / s, approximately 33 ml / s, and approximately 25 ml / s, respectively.

[0049] According to this, when the flow rate of the waste milk liquid 11 was approximately 100 ml / s and approximately 50 ml / s, the waste milk liquid 11 and the inorganic coagulant aqueous solution 21 were properly mixed, and the emulsified components were properly coagulated. Furthermore, when the flow rate of the waste milk liquid 11 was approximately 33 ml / s, the treatment state was slightly inferior, and when it was approximately 25 ml / s, the treatment state was poor. In addition, there was little difference between the differences between patterns (A) and (B), but it was observed that pattern (B) treated the waste milk liquid better when the flow rate of the waste milk liquid 11 was approximately 33 ml / s. From the experimental results above, it was confirmed that if the flow rate is above the required level, the waste milk liquid 11 and the inorganic coagulant aqueous solution 21 are properly mixed, and the emulsified components are properly coagulated.

[0050] In the configuration examples shown in Figures 1 and 2, for example, the amount of polymer flocculant aqueous solution 31 is set to approximately 660 ml, the injection time is uniformly set to 85 seconds, and the flow rate is approximately 7.8 ml / s, and the pump device 33a is also miniaturized. Furthermore, the waste milk waste liquid tank 10 is, for example, a temporary receiving and storage tank with a maximum capacity of 40 liters, and is also miniaturized.

[0051] Furthermore, in this embodiment, the flow path size of the primary discharge channel 26 is set such that the amount of primary treated waste liquid 12 added to the coagulation treatment tank 30 per unit time is greater than the amount of waste milk waste liquid 11 added to the coagulation treatment tank 20 per unit time. In this embodiment, where the amounts of inorganic coagulant aqueous solution 21 and waste milk waste liquid 11 are each approximately 3 liters (3000 ml), as an example, the input time for waste milk waste liquid 11 was set to 40 seconds, and the input time for primary treated waste liquid 12 was set to approximately 5 seconds. This allowed for the appropriate and efficient treatment of waste milk waste liquid 11.

[0052] Next, an example of a waste milk treatment method, which involves appropriately controlling the pH value and separating the waste milk by breaking down the emulsified state of the waste milk wastewater 11, which is a waste liquid containing waste milk generated during milking operations, and coagulating the emulsified components, will be described in detail below based on Figures 1 and 2.

[0053] According to the present invention, in the step of mixing an inorganic coagulant aqueous solution 21, which is a diluted aqueous solution of an inorganic coagulant, with waste milk waste liquid 11 in a coagulation treatment tank 20, and coagulating the emulsifying components in the waste milk waste liquid 11 to produce primary treated waste liquid 12, the pH value of the primary treated waste liquid 12 is adjusted to a range of 4.0 to 4.8 by adjusting the supply of the inorganic coagulant aqueous solution 21 to the coagulation treatment tank 20 (supply amount or concentration of inorganic coagulant).

[0054] According to this method, by adding the inorganic coagulant aqueous solution 21, the state after the emulsified components in the waste milk waste liquid 11 have coagulated, and the pH value of the resulting primary treated waste liquid 12 can be optimized, thus reducing the likelihood of coagulation failure. Therefore, it is possible to appropriately and effectively coagulate the emulsified components of the waste liquid containing waste milk, and this has the particularly advantageous effect of further enhancing the effect of separating and treating the solid components. In addition, even if there are individual differences among dairy cows, the pH value can be adjusted sequentially during treatment, eliminating the need to store the waste in large tanks (waste milk waste liquid treatment tanks) as in the past to equalize the components, and allowing for a smaller device.

[0055] Furthermore, according to an embodiment of the present invention, the pH value measured to adjust the supply of the inorganic coagulant aqueous solution 21 to the coagulation treatment tank 20 is measured for the waste milk waste liquid 11 before it is supplied to the coagulation treatment tank 20, and the supply of the inorganic coagulant aqueous solution 21 to the coagulation treatment tank 20 can be adjusted based on the pH value of the waste milk waste liquid 11.

[0056] Furthermore, according to an embodiment of the present invention, the pH value measured to adjust the supply of the inorganic coagulant aqueous solution 21 to the condensation treatment tank 20 is measured for a portion of the primary treated waste liquid 12 that is generated in a process that produces primary treated waste liquid 12, and is set as a step prior to that process. Based on the pH value of the portion of primary treated waste liquid 12, the supply of the inorganic coagulant aqueous solution 21 to the condensation treatment tank 20 can be adjusted so that the pH value of the entire amount of primary treated waste liquid 12 is in the range of 4.0 to 4.8.

[0057] In this way, by measuring the pH value of the waste milk waste liquid 11, or the pH value of a portion of the primary treated waste liquid 12, it becomes possible to appropriately calculate the required amount and concentration of the inorganic coagulant aqueous solution 21 so that the pH value of the entire amount of primary treated waste liquid 12 produced after treatment in the coagulation treatment tank 20 is optimal. Furthermore, in addition to calculation methods, the amount and concentration can also be estimated from historical values ​​(empirical values) that have been collected in advance.

[0058] Furthermore, as explained above, the process of producing the primary treated waste liquid 12 may include the following steps: In a coagulation treatment tank 20 where an inorganic coagulant aqueous solution 21 is stored or poured in, the waste milk waste liquid 11 is dropped into the inorganic coagulant aqueous solution 21, mixing in a manner that entrains air, and the emulsified components in the waste milk waste liquid 11 coagulate to produce the primary treated waste liquid 12; and in a coagulation treatment tank 30 where a polymer coagulant aqueous solution 31, which is a diluted aqueous solution of a polymer coagulant, is stored or poured in, the primary treated waste liquid 12 is dropped into the polymer coagulant aqueous solution 31, mixing in a manner that entrains air, and the emulsified components and coagulated components in the primary treated waste liquid 12 coagulate to produce waste solid components 41 and secondary treated waste liquid 42. According to this, as described above, the waste milk waste liquid 11 and the inorganic coagulant aqueous solution 21, and the primary treated waste liquid 12 and the polymer coagulant aqueous solution 31 can be appropriately mixed.

[0059] Next, an example of the configuration of the waste milk processing apparatus capable of pH adjustment according to the present invention, relating to the pH sensor 50, will be described in detail with reference to Figure 1. Even in this waste milk processing apparatus capable of pH adjustment, as mentioned above, it basically comprises a waste milk waste liquid tank 10, a primary coagulant storage container 22, a coagulation treatment tank 20, an inorganic coagulant aqueous solution supply means 23 (such as a pump device 23a), and a waste milk waste liquid input means 15. In this example, the inorganic coagulant aqueous solution supply means 23 comprises a pump device 23a and a supply pipe 23b as components.

[0060] Reference numeral 50 denotes a pH sensor, which is located in the waste milk waste liquid tank 10 or in the coagulation treatment tank 20. Information related to the pH value measured by either of the pH sensors 50 is input, and a control device 55 (see Figure 2) is provided to control the inorganic coagulant aqueous solution supply means 23 so as to fluctuate the supply of the inorganic coagulant aqueous solution 21 to the coagulation treatment tank 20 based on that pH value. In this embodiment, the control device 55 also has the function of controlling the supply of the inorganic coagulant aqueous solution 21 by controlling the pump device 23a, and is provided to control the entire waste milk processing device, including other controls.

[0061] According to this method, the pH value can be appropriately adjusted, which, as mentioned above, reduces the likelihood of coagulation failure. This allows for proper and effective coagulation of emulsified components in wastewater containing discarded milk, resulting in a particularly advantageous effect of enhancing the effectiveness of separating solid components.

[0062] In other words, in one embodiment of the present invention, the treatment in the coagulation treatment tank 20 is carried out in two stages, the pH value is measured after the first mixing when one-third of the total volume has been mixed, and the amount and concentration of the inorganic coagulant aqueous solution 21 added in the second mixing is adjusted so that the pH value after the second mixing when the entire amount has been mixed is 4.0 to 4.8 (preferably 4.2 to 4.6).

[0063] Next, we will explain specific examples, showing numerical values ​​such as the volume of each liquid. In this embodiment, the coagulation treatment tank 20 is, as an example, generally mixed with 3 liters each of waste milk liquid 11 and inorganic coagulant aqueous solution 21, but this process is carried out in two stages. First, 1 liter of inorganic coagulant aqueous solution 21 with a 1% inorganic coagulant concentration is added to the coagulation treatment tank 20. Next, 1 liter of waste milk liquid 11 is added to the coagulation treatment tank 20, and the pH value is measured by the pH sensor 50.

[0064] Then, if the pH value is optimal (4.0-4.8), add the remaining 2 liters of the inorganic coagulant aqueous solution 21, followed by 2 liters of waste milk liquid 11, and let it stand for 3 minutes. This allows the emulsifying components to coagulate properly. If the pH value deviates from the optimal value, the required concentration of inorganic coagulant is calculated based on the pH value after the first mixing, or estimated by comparing it with past data, and the concentration of inorganic coagulant is adjusted by adding the remaining inorganic coagulant aqueous solution 21 in the second mixing step, so that the final pH value is the optimal value. This allows the pH value to be adjusted appropriately, so that the emulsified components can coagulate properly.

[0065] At this time, the method for adjusting the concentration of the inorganic coagulant can be either by adjusting the amount of the remaining inorganic coagulant aqueous solution 21 supplied in the second addition, or by adjusting the concentration of the inorganic coagulant aqueous solution 21 itself before adding it. That is, since the inorganic coagulant aqueous solution 21 is acidic (pH value of about 2.5), the acidity of the primary treated waste liquid 12 can be increased by increasing the amount of inorganic coagulant aqueous solution 21 supplied to the coagulation treatment tank 20, and the acidity of the primary treated waste liquid 12 can be decreased by decreasing the amount supplied. Also, since the inorganic coagulant aqueous solution 21 is acidic, depending on the pH value of the corresponding waste milk waste liquid 11, the acidity may be lowered by adding a required amount of water to the inorganic coagulant aqueous solution 21 or the coagulation treatment tank 20 to dilute it, or the acidity may be increased by adding and mixing a required amount of inorganic coagulant to the inorganic coagulant aqueous solution 21.

[0066] According to this method, the emulsifying components of the wastewater containing the aforementioned waste milk (waste milk wastewater) can be appropriately and effectively coagulated, and the pH value can be adjusted sequentially even if there are individual differences among dairy cows. Therefore, it is not necessary to store the waste milk wastewater in a large tank (waste milk wastewater treatment tank) as in the conventional method in order to homogenize the components of the waste milk wastewater, which has the particularly advantageous effect of allowing for a smaller device. Furthermore, if the milk concentration and pH value can be determined from information such as that from dairy robots, it is not necessary to perform the coagulation treatment in the coagulation treatment tank 20 in two stages.

[0067] Although various preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. [Explanation of Symbols]

[0068] 10 Waste milk waste liquid tank 11. Waste milk liquid 12. Primary treated waste liquid 15. Means for inputting waste milk waste liquid 16 Pumping equipment 17 Piping 18 Outlet 20 Condensation treatment tank 21. Inorganic coagulant aqueous solution 22 Primary flocculant storage container 23. Inorganic flocculant aqueous solution supply means 23a Pumping device 23b Supply piping 24 Lid 25. Means for inputting primary treated waste liquid 26 Primary discharge channel 27 Primary shut-off valve 28 Primary outlet 30 Coagulation treatment tank 31. Aqueous solution of polymer flocculant 32 Secondary flocculant storage container 33a Pumping device 33b Supply piping 34 Lid 35 Discharge method for secondary treated waste liquid 36 Secondary discharge channel 37 Secondary shut-off valve 38 Secondary discharge port 40 Separation tank 41 Waste Solid Components 42. Secondary treated waste liquid 45. Aggregate collection box 46 Slopes 50 pH sensors 55 Control device 60 Tap water 61. Wash water shut-off valve 62 Piping for cleaning water 65 spray nozzles 70 Float switch 100 Wastewater from the milking machine side 101 Three-way valve 102 Waste liquid piping 103 Drainage piping for cleaning water 110 Drainage of washing water

Claims

1. A method for treating waste milk, which is a waste liquid containing waste milk generated during milking operations, by breaking down the emulsified state of the waste milk waste liquid and coagulating the emulsified components to separate them, In a coagulation treatment tank in which an inorganic coagulant aqueous solution, which is a diluted aqueous solution of an inorganic coagulant, is stored or poured, the waste milk waste liquid is dropped into the inorganic coagulant aqueous solution and mixed in a manner that entrains air, thereby coagulating the emulsifying components in the waste milk waste liquid and producing a primary treated waste liquid. A method for treating waste milk, characterized by comprising the steps of: in a coagulation treatment tank in which a polymer flocculant aqueous solution, which is a diluted aqueous solution of a polymer flocculant, is stored or poured in, the primary treated waste liquid is dropped into the polymer flocculant aqueous solution and mixed in a manner that entrains air, thereby further coagulating the emulsifying and coagulating components in the primary treated waste liquid to produce waste solid components and secondary treated waste liquid.

2. A waste milk processing device that separates waste milk wastewater, which is waste liquid containing waste milk generated during milking operations, by breaking down the emulsified state and coagulating the emulsified components, A waste milk waste liquid tank for temporarily receiving and storing the aforementioned waste milk waste liquid, A primary coagulant storage container in which an aqueous solution of an inorganic coagulant, which is a diluted aqueous solution of an inorganic coagulant, A coagulation treatment tank is provided in which the inorganic coagulant aqueous solution is supplied from the primary coagulant storage container, and while the inorganic coagulant aqueous solution is stored or poured in, the waste milk waste liquid is added, causing air to be incorporated and the mixture to coagulate the emulsifying components in the waste milk waste liquid to produce primary treated waste liquid. A waste milk waste liquid input means for dropping the aforementioned waste milk waste liquid into the coagulation treatment tank, A secondary flocculant storage container in which a polymer flocculant aqueous solution, which is a diluted aqueous solution of a polymer flocculant, A coagulation treatment tank is provided in which the polymer coagulant aqueous solution is supplied from the secondary coagulant storage container, and while the polymer coagulant aqueous solution is stored or poured in, the primary treated wastewater is added and mixed in a manner that entrains air, further coagulating the emulsifying and coagulating components in the primary treated wastewater to produce waste solid components and secondary treated wastewater. A waste milk processing apparatus characterized by comprising a primary treated waste liquid input means for dropping and introducing the primary treated waste liquid into the coagulation treatment tank.

3. The waste milk processing apparatus according to claim 1, characterized in that the waste milk waste liquid input means comprises a pipe provided such that the outlet for the waste milk waste liquid is located above the coagulation treatment tank, and a pump device connected to the pipe to pump up the waste milk waste liquid.

4. The waste milk processing apparatus according to claim 1, characterized in that the primary treated waste liquid input means comprises a primary discharge passage provided so as to communicate with the lower part of the coagulation treatment tank and have a primary discharge port located above the coagulation treatment tank, so as to discharge the primary treated waste liquid from the coagulation treatment tank, which is installed above the coagulation treatment tank, to the coagulation treatment tank, and a primary on / off valve provided in the discharge passage.

5. The waste milk processing apparatus according to claim 2, characterized in that the flow path size of the discharge path is set such that the amount of the primary treated waste liquid input to the coagulation treatment tank per unit time is greater than the amount of the waste milk waste liquid input to the coagulation treatment tank per unit time.

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