JP2015009204A - Effluent treatment apparatus and effluent treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an effluent treatment apparatus capable, even in a case where an effluent including abundant organic matters is treated, of maintaining performances of a pipeline or heat exchanger, etc. over an extended period.SOLUTION: The effluent treatment apparatus of the present invention includes: an enzymolysis treatment tank 2 for enzymolyzing organic matters within an effluent; a heat exchanger 12 for recovering heat from the effluent; a transmission water passage 27 for transmitting the effluent within the enzymolysis treatment tank 2 into the heat exchanger 12; and a return water passage 28 for returning, to the enzymolysis treatment tank 2, the effluent from which heat has been recovered by the heat exchanger 12.

Description

  The present invention relates to a wastewater treatment apparatus and a wastewater treatment method for treating wastewater containing organic matter.

  As a method for treating wastewater containing a large amount of organic matter such as industrial wastewater and domestic wastewater, an activated sludge treatment method utilizing the purification ability of microorganisms and bacteria is known.

  In this type of wastewater treatment method, as a method that can efficiently and stably treat even high-load wastewater that contains a large amount of starch or the like, for example, Patent Document 1 listed below discloses wastewater in two aerobic treatment tanks. There has been proposed a method of ensuring a long drainage purification treatment time by circulating between the aerobic treatment tank and the filtration treatment tank. Furthermore, in this method, in order to efficiently perform the treatment in the aerobic treatment tank, it has also been proposed to subject the wastewater to an enzymatic decomposition treatment as a pretreatment.

JP 2011-235220 A

  By the way, since the temperature of the waste water discharged from the noodle factory is relatively high at 40 to 50 ° C., it is desirable to recover the thermal energy in the waste water using a heat exchanger or the like and effectively use it.

  However, when heat is recovered from wastewater containing organic substances such as starch, the temperature of the wastewater decreases, and accordingly, the viscosity of starch and the like in the wastewater increases. As a result, if starch or the like adheres to pipes or heat exchangers, and if fiber waste in the drainage adheres to the attached starch or the like, the drainage flow rate of the pipes or the performance of the heat exchanger may be reduced. is there.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to improve the performance of pipes, heat exchangers and the like over a long period of time even when treating wastewater containing a large amount of organic matter. An object is to provide a wastewater treatment device and a wastewater treatment method that can be maintained.

  The invention of claim 1 includes an enzymatic decomposition treatment tank that enzymatically decomposes organic matter in waste water, a heat exchanger that recovers heat from the waste water, and a feed channel that sends waste water in the enzymatic decomposition treatment tank to the heat exchanger. A waste water treatment apparatus comprising a return water channel for returning waste water heat-recovered by the heat exchanger to the enzymatic decomposition treatment tank.

  By sending the wastewater in the enzymatic decomposition treatment tank to the heat exchanger via the feed channel, the wastewater sent to the heat exchanger includes the one that has been enzymatically decomposed, and is completely enzymatically decomposed. Compared with the case of sending wastewater as it is, the viscosity in wastewater can be reduced by enzymatic decomposition of organic matter. Thereby, the fall of the waste_water | drain flow volume in the heat exchanger, a feed water channel, or a return water channel, clogging of waste_water | drain, and the performance fall of the heat exchanger accompanying this can be prevented. In particular, even when the temperature of the wastewater recovered by the heat exchanger is lowered, the wastewater viscosity does not increase, so that the fluidity of the wastewater in the heat exchanger and the return channel can be improved.

  Moreover, the temperature of the waste water in the enzyme decomposition treatment tank can be lowered to a temperature at which enzyme decomposition is easily activated by returning the waste water heat-recovered by the heat exchanger to the enzyme decomposition treatment tank through the return channel. Moreover, since the wastewater is stirred in the process of passing the wastewater in the enzymatic decomposition treatment tank through the heat exchanger and refluxing again to the enzymatic decomposition treatment tank, a large reaction tank for ensuring the reaction time should be added. And the enzyme decomposition treatment can be sufficiently performed.

  The invention according to claim 2 is the waste water treatment apparatus according to claim 1, wherein the enzymatic decomposition treatment is performed from the heat exchanger so that the temperature of the waste water in the enzymatic decomposition treatment tank falls within a temperature range suitable for enzymatic decomposition. It is configured to return drainage to the tank.

  By returning the wastewater to the enzyme decomposition treatment tank so that the temperature of the wastewater in the enzyme decomposition treatment tank is within a temperature range suitable for enzyme decomposition, the decomposition treatment in the enzyme decomposition treatment tank can be promoted.

  According to a third aspect of the present invention, in the wastewater treatment apparatus according to the second aspect of the present invention, there is provided wastewater temperature adjusting means for adjusting the temperature of the wastewater returned to the enzyme decomposition treatment tank.

  By providing the drainage temperature adjusting means, the drainage temperature in the enzyme decomposition treatment tank can be adjusted more reliably.

  The invention of claim 4 is the wastewater treatment apparatus according to any one of claims 1 to 3, wherein the enzymatic decomposition treatment tank is divided, and the wastewater having a high temperature and the wastewater having a temperature lowered by the heat exchanger, And the feed channel is provided with a water intake port for taking the waste water from the enzymatic decomposition treatment tank in the vicinity of the drain inlet from which the waste water flows into the enzymatic decomposition treatment tank. .

  A feed channel is provided near the drainage inlet where the wastewater flows from the drainage source to the enzyme decomposition treatment tank, and the inside of the enzyme decomposition treatment tank is divided into The influent wastewater can be sent to the heat exchanger in a high temperature state (and not mixed with the low temperature wastewater that is returned to the enzymatic decomposition treatment tank through the heat exchanger), so that heat can be efficiently recovered. It becomes possible.

  The invention of claim 5 is the wastewater treatment apparatus according to any one of claims 1 to 4, further comprising an aerobic treatment tank that aerobically treats the wastewater that has been enzymatically decomposed in the enzyme decomposition treatment tank. Is.

  In the wastewater treatment equipment equipped with an aerobic treatment tank, the enzymatic decomposition treatment in the enzymatic decomposition treatment tank is performed, so that the wastewater treatment time in the subsequent aerobic treatment tank can be shortened and energy saving of aeration power is also expected. it can.

  In the invention of claim 6, the organic matter in the wastewater is enzymatically decomposed in an enzymatic decomposition treatment tank, the wastewater in the enzymatic decomposition treatment tank is sent to a heat exchanger, heat is recovered from the wastewater, and the heat recovered wastewater Is a wastewater treatment method for returning the water to the enzymatic decomposition treatment.

  By sending the wastewater in the enzymatic decomposition treatment tank to the heat exchanger, the wastewater sent to the heat exchanger will include the one that has been enzymatically decomposed. Compared with the case of sending, the viscosity in waste water can be reduced by enzymatic decomposition of organic matter. Thereby, the fall of the waste_water | drain flow volume in a heat exchanger, piping, etc., the clogging of waste_water | drain, and the performance fall of the heat exchanger accompanying this can be prevented. In particular, even when the temperature of the wastewater recovered by the heat exchanger is lowered, the wastewater viscosity does not increase, so that the fluidity of the wastewater in the heat exchanger and the return channel can be improved.

  Moreover, the temperature of the wastewater in the enzymatic decomposition treatment tank can be adjusted to a temperature range in which the enzymatic decomposition is activated by returning the wastewater whose temperature has been recovered by the heat exchanger and the temperature is lowered to the enzymatic decomposition treatment tank. Moreover, since the wastewater is stirred in the process of passing the wastewater in the enzymatic decomposition treatment tank through the heat exchanger and refluxing again to the enzymatic decomposition treatment tank, a large reaction tank for ensuring the reaction time should be added. And the enzyme decomposition treatment can be sufficiently performed.

  According to the present invention, wastewater whose viscosity is reduced by enzymatic decomposition in the enzymatic decomposition treatment tank is sent to the heat exchanger, thereby preventing a decrease in the wastewater flow rate and clogging of the wastewater in the heat exchanger and piping. It is possible to maintain the performance of heat exchangers and pipes well over a long period of time. Moreover, by returning the wastewater collected by the heat exchanger to the enzymatic decomposition treatment tank, the temperature of the wastewater in the enzymatic decomposition treatment tank can be adjusted to a temperature range in which the enzymatic decomposition treatment is easily activated. Thereby, since the viscosity fall of the waste_water | drain sent to a heat exchanger is accelerated | stimulated, the further performance improvement, such as a heat exchanger, can be anticipated. Moreover, with the improvement of the performance of the heat exchanger and the like, the temperature of the waste water in the enzymatic decomposition treatment tank can be reliably adjusted. Thus, according to the present invention, the wastewater in the enzymatic decomposition treatment tank is sent to the heat exchanger and recirculated to the enzymatic decomposition treatment tank, thereby improving the performance of the heat exchanger and the like in the enzymatic decomposition treatment tank. The activation of the enzymatic decomposition treatment can be realized, and further improvement in the performance of the wastewater treatment by these synergistic effects can be expected. In addition, according to the present invention, it is possible to maintain long-term performance such as piping and heat exchangers and promote wastewater treatment efficiency without taking a large facility measure.

1 is a schematic diagram of an overall configuration of a wastewater treatment apparatus according to an embodiment of the present invention. It is a figure which closes up and shows a part of waste water treatment equipment concerning this embodiment.

  Hereinafter, the contents of the waste water treatment apparatus and the waste water treatment method according to the present invention will be described.

FIG. 1 is a schematic view of the overall configuration of a wastewater treatment apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the wastewater treatment apparatus 1 according to this embodiment includes an enzyme decomposition treatment tank 2, an aerobic treatment tank 3, a coagulation sedimentation tank 4, a filtration device 5, a sludge storage tank 6, and a sludge treatment. The apparatus 7 and the heat pump system 8 are provided as main components.

  Wastewater discharged from production facilities such as a factory, which is a wastewater source, first flows into the enzymatic decomposition treatment tank 2. In addition, a degrading enzyme (enzyme solution) is introduced into the enzyme decomposing treatment tank 2 from the enzyme injection device 9, and in the enzyme decomposing treatment tank 2, the organic matter in the waste water is discharged by the introduced degrading enzyme. Enzymatic degradation is performed. In this embodiment, since high-load wastewater containing a large amount of starch discharged from a food factory such as a noodle factory flows in, amylase which is a starch degrading enzyme is used as a degrading enzyme to be injected into the enzymatic decomposing treatment tank 2. Used. Furthermore, in this embodiment, the aeration apparatus 10 performs aeration in the enzyme decomposition treatment tank 2 so that the enzyme decomposition treatment is promoted.

  In addition, the waste_water | drain processed with the waste water treatment apparatus which concerns on this invention is not restricted to the waste_water | drain containing many starches. As long as the wastewater contains organic matter, in addition to industrial wastewater discharged from factories, it may be domestic wastewater discharged from ordinary households. In addition, a degrading enzyme to be injected can be appropriately selected from a proteolytic enzyme, a lipolytic enzyme, a plant fiber degrading enzyme and the like according to an organic substance contained in the waste water.

  Wastewater that has been enzymatically decomposed in the enzymatic decomposition treatment tank 2 is sent to the aerobic treatment tank 3. In the aerobic treatment tank 3, aeration is performed by the aeration apparatus 10, and organic matter decomposition treatment (aerobic treatment) of wastewater by aerobic microorganisms is performed.

  Then, the waste water that has been subjected to the aerobic treatment in the aerobic treatment tank 3 is sent to the coagulation sedimentation tank 4. In the coagulation sedimentation tank 4, a polymer coagulant is introduced into the waste water, and the aggregate produced thereby is precipitated and solid-liquid separated. The separated sludge is stored in the sludge storage tank 6, and the separated liquid (drainage) is sent to the filtration device 5. In the filtration device 5, the separated liquid is filtered, a part thereof is returned to the aerobic treatment tank 3, and the rest is discharged as treated water. Moreover, the sludge stored in the sludge storage tank 6 is sent to the sludge treatment device 7, and the dewatering process is performed by the sludge treatment device 7. Thereby, the separated liquid (drainage) separated from the sludge is returned to the aerobic treatment tank 3, and the sludge is treated as waste.

  The heat pump system 8 is a so-called heat recovery type heat pump system. Specifically, the heat pump system 8 includes a heat pump 11, a cooling side heat exchanger 12, a heating side heat exchanger 13, and the like. The heat pump 11 includes a compressor 14, a heater 15, an expansion valve 16, and a cooler 17, and these devices are connected via a refrigerant passage 18, and the refrigerant passage 18 is filled with a refrigerant. Has been. The heat pump 11 and the cooling side heat exchanger 12 form a heat exchange circuit 19 described later, and the heat pump 11 and the heating side heat exchanger 13 form a water supply circuit 20 described later. Both the heat exchangers 12 and 13 are plate-type heat exchangers in which, for example, a metal plate whose surface is processed into irregularities is combined to form a passage for the warm refrigerant body. In addition, P in FIG. 1 indicates a pump for sending various media in each water channel.

  In FIG. 1, the compressor 14 adiabatically compresses the refrigerant into a high-temperature / high-pressure gas (supercritical state), and the heater 15 (hydrothermal exchange unit) has a high-temperature / high-pressure supplied from the compressor 14. The feed water is heated by exchanging heat between the high-pressure gas (supercritical state) and the feed water introduced into the heat pump 11. The expansion valve 16 is a valve that expands the low-temperature / high-pressure gas (supercritical state) refrigerant in the heater 15 into a low-temperature / low-pressure liquid. The cooler 17 (cold heat exchanger) evaporates the refrigerant by exchanging heat between the low-temperature and low-pressure refrigerant that has passed through the expansion valve 16 and the heat transfer medium of the heat exchange circuit 19 described later.

  The cooler 17 constitutes a part of the heat exchange circuit 19. In other words, the heat exchange circuit 19 is formed by being connected by a pipe that circulates between the cooling side heat exchanger 12 and the cooler 17, and is connected between the cooling side heat exchanger 12 and the cooler 17. 1 Heat transfer medium (low temperature refrigerant) circulates. Thereby, the heat transfer medium cooled by the cooler 17 is introduced into the cooling side heat exchanger 12, and the heat transfer medium is heated by exchanging heat with the warm waste water as described later. . As the heat transfer medium, for example, a liquid such as water can be used.

  Further, the heater 15 constitutes a part of the water supply circuit 20. That is, the water supply circuit 20 is formed by being connected by a pipe that circulates between the heating side heat exchanger 13 and the heater 15, and the second side between the heating side heat exchanger 13 and the heater 15. A heat transfer medium (high-temperature refrigerant) circulates. Thereby, the heat transfer medium heated by the heater 15 is introduced into the heating-side heat exchanger 13 and heat exchange is performed with the raw water supplied as described later, whereby the heat transfer medium is To be cooled. As the heat transfer medium, for example, a liquid such as water can be used.

  The hot waste water supplied to the cooling side heat exchanger 12 is waste water supplied from the above-described enzymatic decomposition treatment tank 2. The warm drainage supplied from the enzymatic decomposition treatment tank 2 is temporarily stored in the warm drainage storage tank 21 and supplied to the cooling side heat exchanger 12. In the cooling side heat exchanger 12, the warm drainage circulates through the piping, and the heat from the warm drainage exchanges heat with the low-temperature refrigerant circulating in the heat exchange circuit 19, and the warm drainage cools. Is done. Then, the cooled waste water is returned to the enzymatic decomposition treatment tank 2.

  In addition, a foreign substance removing device 25 that prevents foreign substances from flowing into the cooling side heat exchanger 12 is provided on the upstream side of the warm drainage storage tank 21. This foreign matter removing device 25 has a function of separating foreign matter using a swirling flow or a filter. The warm wastewater introduced into the swirl type foreign matter removing device 25 generates a swirl flow, and dust and residual solids in the warm drainage are separated according to the swirl flow and discharged out of the casing. Thereby, it is possible to prevent foreign matters such as dust and residual solids in the hot waste water from being mixed into the cooling side heat exchanger 12. A part of the waste water from which the foreign matter has been removed by the foreign matter removing device 25 is returned to the enzymatic decomposition treatment tank 2 without passing through the cooling side heat exchanger 12.

  The heating-side heat exchanger 13 is configured such that raw water flows through a pipe, and the raw water is heat-exchanged with the high-temperature refrigerant circulating in the water supply circuit 20 and heated. Moreover, the heated raw material water (high temperature water) is once stored in the high temperature water storage tank 23 provided downstream, and is supplied to a production process as needed.

FIG. 2 is a close-up view of a part of the waste water treatment apparatus according to the present embodiment.
As shown in FIG. 2, the enzymatic decomposition treatment tank 2 and the cooling side heat exchanger 12 are connected to each other via a feed water channel 27 and a return water channel 28. The wastewater is sent from the enzymatic decomposition treatment tank 2 to the cooling side heat exchanger 12 through the feed water passage 27, is returned to the enzymatic decomposition treatment tank 2 from the cooling side heat exchanger 12 through the return water passage 28, It is designed to reflux.

  Here, the temperature state of the wastewater will be described. First, the temperature of the wastewater discharged from the production facility is 40 to 50 ° C. After this waste water flows into the enzyme decomposition treatment tank 2, it is sent to the cooling side heat exchanger 12 via the feed water channel 27, and the temperature is lowered by 5 to 10 ° C. by heat recovery. When the waste water whose temperature has been reduced by heat recovery is returned to the enzymatic decomposition treatment tank 2 through the return water channel 28, the temperature of the waste water is controlled to 35 to 40 ° C. which is a temperature range suitable for the enzymatic decomposition of amylase. The

  In this way, the wastewater whose temperature has been recovered through heat recovery is returned to the enzyme decomposition treatment tank 2, so that the temperature of the wastewater in the enzyme decomposition treatment tank 2 is lowered and controlled to a temperature suitable for enzyme decomposition. Thereby, the decomposition treatment in the enzyme decomposition treatment tank 2 is promoted. In addition, the waste water is stirred in the process of refluxing the waste water in the enzymatic decomposition treatment tank 2 from the cooling side heat exchanger 12 to the enzymatic decomposition treatment tank 2 again. Thereby, it is possible to sufficiently perform the enzymatic decomposition treatment without adding a large reaction tank for securing the reaction time.

Moreover, in this embodiment, the waste_water | drain temperature adjustment means 30 which adjusts the temperature of the waste_water | drain returned to the enzyme decomposition processing tank 2 is provided. As shown in FIG. 2, the waste water temperature adjusting means 30 includes a bypass water channel 31 that sends a part of the waste water directly from the feed water channel 27 to the return water channel 28 without passing through the cooling side heat exchanger 12. In addition, a drainage flow rate adjustment valve 32 is provided in the bypass channel 31, and the drainage flow rate adjustment valve 32 detects temperature of the heat transfer medium in the return side pipe where the heat transfer medium returns to the cooler 17. It is automatically controlled based on the detection result. The temperature change of the heat transfer medium in the pipe to which the heat transfer medium is returned to the cooler 17 is interlocked with the drainage temperature returned through the return water channel 28. For this reason, it is possible to estimate the waste water temperature of the return water channel 28 by detecting the temperature of the heat transfer medium in the pipe by the temperature detecting means 33. For example, when the temperature detected by the temperature detection means 33 is lower than a preset reference temperature (when the temperature of the drainage returned through the return channel 28 is high), the temperature passes through the bypass channel 31. By controlling the drainage flow rate adjustment valve 32 so as to reduce the drainage flow rate, the temperature of the drainage returned through the return water channel 28 can be lowered. On the other hand, when the temperature detected by the temperature detecting means 33 is higher than a preset reference temperature (when the temperature of the drainage returned through the return water channel 28 is low), the temperature passes through the bypass water channel 31. By controlling the drainage flow rate adjustment valve 32 so as to increase the drainage flow rate, the temperature of the drainage returned through the return water channel 28 can be raised. In this way, by adjusting the amount of waste water that passes through the bypass water channel 31, the temperature of the waste water that is refluxed to the enzymatic decomposition treatment tank 2 can be controlled to 35 to 40 ° C. suitable for enzymatic decomposition.

  As mentioned above, the waste water temperature in the enzyme decomposition treatment tank 2 is lowered by returning the heat-recovered waste water to the enzyme decomposition treatment tank 2. On the other hand, in order to efficiently recover the heat, It is desirable to send the waste water in the decomposition treatment tank 2 to the cooling side heat exchanger 12 at a temperature as high as possible. Therefore, in this embodiment, as shown in FIG. 2, the waste water is returned from the first tank 2 </ b> A into which the warm waste water from the production facility (drainage source) flows and the cooling side heat exchanger 12. The second tank 2B is divided so that feed water having a high drainage temperature and reflux (return) water having a lowered drainage temperature are not mixed directly. Further, the water inlet 27a through which the feed water channel 27 takes the waste water from the first tank 2A of the enzyme decomposition treatment tank 2 is provided in the vicinity of the drain inlet 29a into which the waste water from the production facility (drainage source) flows. The waste water flowing in from 29a is sent to the cooling side heat exchanger 12 in a high temperature state so that heat can be efficiently recovered. As a result, in this embodiment, 85-90 degreeC high temperature water can be produced | generated and supplied to a production process.

  In addition, since the amylase in the enzyme injection device 9 is put into the first tank 2A of the enzyme decomposition treatment tank 2, the wastewater sent from the enzyme decomposition treatment tank 2 to the cooling side heat exchanger 12 is subjected to the enzyme decomposition treatment. Is included. For this reason, the starch viscosity in waste water can be reduced compared with the case where waste water which has not been subjected to enzymatic decomposition treatment is sent as it is. Thereby, between the plates of the cooling side heat exchanger 12, in the piping of the feed water passage 27 and the return water passage 28, and further in the foreign matter removing device 25, the drainage flow rate is reduced and the drainage is clogged. It is possible to prevent the performance of the foreign matter removing device 25 from being lowered. In particular, even if the temperature of the wastewater recovered by the cooling-side heat exchanger 12 decreases, the increase in starch viscosity in the wastewater can be suppressed, so the flow of wastewater in the cooling-side heat exchanger 12 and the return water channel 28. Can be improved.

  In addition, when the swirl type is used as the foreign matter removing device 25 as in the present embodiment, the swirl flow rate is increased by reducing the viscosity of the waste water, and the separation / discharge performance of the waste in the waste water is improved. As a result, an operation failure due to inflow or retention of foreign matter in the warm drainage storage tank 21 or the cooling side heat exchanger 12 provided on the downstream side (for example, malfunction of the water level switch in the warm drainage storage tank 21 or poor monitoring of the level meter). , Performance deterioration of the cooling side heat exchanger 12) can be avoided. Moreover, since the decomposition | disassembly of the starch in the waste_water | drain in the foreign material removal apparatus 25, the warm waste water storage tank 21, the cooling side heat exchanger 12, the feed water channel 27, and the return water channel 28 is accelerated | stimulated, generation | occurrence | production of mold | fungi in these inside can also be suppressed.

  The dividing wall 2c that divides the enzyme decomposition treatment tank 2 into the first tank 2A and the second tank 2B does not reach the ceiling of the enzyme decomposition treatment tank 2, and is spaced apart from the ceiling. Yes. Usually, the drainage water storage amount in the first tank 2A and the second tank 2B is managed so that the water surface comes to a position lower than the upper end of the dividing wall 2c, but is constant between the dividing wall 2c and the ceiling. When the interval is increased, the wastewater in the first tank 2A is temporarily divided into the dividing wall 2c when the inflow of hot wastewater from the production facility suddenly increases or the water supply stops due to the heat pump being stopped for a short time. Over to the second tank 2B. Thereby, it can avoid that the waste_water | drain in the 1st tank 2A overflows to the exterior of the enzyme decomposition processing tank 2, and it becomes possible to perform the smooth operation of waste water treatment.

  As described above, according to the present invention, the heat exchanger, the feed water channel, and the return channel are supplied by sending the waste water whose viscosity is reduced by enzymatic decomposition in the enzymatic decomposition treatment tank to the (cooling side) heat exchanger. It is possible to prevent a decrease in the flow rate of drainage and clogging of drainage in waterways and the like, and it is possible to maintain the performance of heat exchangers and pipes well over a long period of time. Moreover, by returning the wastewater collected by the heat exchanger to the enzymatic decomposition treatment tank, the temperature of the wastewater in the enzymatic decomposition treatment tank can be adjusted to a temperature range in which the enzymatic decomposition treatment is easily activated. Thereby, since the viscosity fall of the waste_water | drain sent to a heat exchanger is accelerated | stimulated, the further performance improvement, such as a heat exchanger, can be anticipated. Moreover, with the improvement of the performance of the heat exchanger and the like, the temperature of the waste water in the enzymatic decomposition treatment tank can be reliably adjusted. Thus, according to the present invention, the wastewater in the enzymatic decomposition treatment tank is sent to the heat exchanger and recirculated to the enzymatic decomposition treatment tank, thereby improving the performance of the heat exchanger and the like in the enzymatic decomposition treatment tank. The activation of the enzymatic decomposition treatment can be realized, and further improvement of the wastewater treatment performance by these synergistic effects can be expected. In addition, according to the present invention, it is possible to maintain long-term performance such as piping and heat exchangers and promote wastewater treatment efficiency without taking a large facility measure.

  Moreover, in the waste water treatment apparatus provided with the aerobic treatment tank as in the above-described embodiment, the waste water treatment time in the subsequent aerobic treatment tank can be shortened by performing the enzyme decomposition treatment in the enzyme decomposition treatment tank. At the same time, energy saving of aeration power can be expected.

  In addition, in the case of operation for 24 hours such as in a noodle factory, it is necessary to limit the production amount according to the performance of the wastewater treatment device. In particular, by applying the present invention to such a wastewater treatment device, Since the treatment efficiency is improved and the wastewater treatment time can be shortened, an increase in production volume can be expected. In addition, in the case of newly installing the wastewater treatment apparatus can be made slim.

  It should be noted that the present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. , And includes all equivalents and equivalents of those expressed by the claims and expressed in the claims.

DESCRIPTION OF SYMBOLS 1 Waste water treatment equipment 2 Enzymatic decomposition processing tank 3 Aerobic processing tank 8 Heat pump system 11 Heat pump 12 Cooling side heat exchanger 13 Heating side heat exchanger 27 Feed water channel 27a Water intake 28 Return water channel 29a Drain inlet 30 Drain temperature adjustment means

Claims (6)

An enzymatic decomposition treatment tank for enzymatic decomposition of organic matter in the waste water;
A heat exchanger that recovers heat from the waste water;
A feed channel for sending waste water in the enzymatic decomposition treatment tank to the heat exchanger;
A waste water treatment apparatus comprising: a return water channel for returning waste water heat-recovered by the heat exchanger to the enzymatic decomposition treatment tank.   The wastewater treatment apparatus according to claim 1, wherein wastewater is returned from the heat exchanger to the enzymatic decomposition treatment tank so that the temperature of the wastewater in the enzymatic decomposition treatment tank falls within a temperature range suitable for enzymatic decomposition. .   The waste water treatment apparatus according to claim 2, further comprising a waste water temperature adjusting means for adjusting a temperature of the waste water returned to the enzymatic decomposition treatment tank. Dividing the enzymatic decomposition treatment tank, and preventing the waste water having a high temperature and the waste water having a lowered temperature in the heat exchanger from being mixed,
4. The water supply port according to claim 1, wherein a water intake port through which the feed water channel takes water from the enzymatic decomposition treatment tank is provided in the vicinity of a drainage inlet through which wastewater flows from a drainage source to the enzymatic decomposition treatment tank. Wastewater treatment equipment.   The wastewater treatment apparatus according to any one of claims 1 to 4, further comprising an aerobic treatment tank that aerobically treats the wastewater that has been enzymatically decomposed in the enzyme decomposition treatment tank. Enzymatic decomposition treatment of organic matter in the wastewater in the enzymatic decomposition treatment tank,
Sending wastewater in the enzymatic decomposition treatment tank to a heat exchanger and recovering heat from the wastewater,
A wastewater treatment method characterized by returning the heat-recovered wastewater to the enzymatic decomposition treatment.

Images