Pyrite denitrification biofilter, sewage treatment device and sewage treatment equipment

Abstract

The utility model discloses a pyrite denitrification biofilter, sewage treatment device and sewage treatment equipment, the pyrite denitrification biofilter comprises a filter body, a filler layer is arranged in the middle of the filter body, a water inlet cavity is arranged in the filter body and below the filler layer, and a water outlet cavity is arranged in the filter body and below the filler layer. A water outlet cavity is formed in the filter body and located above the filler layer, a raw water inlet, a backwashing water inlet, a backwashing air inlet and a dosing port which are communicated with the interior of the water inlet cavity are formed in the lower end of the filter body, and an opening is formed in the upper end of the filter body or an exhaust hole is formed in the upper end of the filter body; a clear water outlet and a backwashing wastewater outlet which are communicated with the water outlet cavity are formed in the upper end of the filter tank body, so that raw water can be purified, and the filter tank body can be subjected to backwashing treatment.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and in particular relates to a pyrite denitrification biological filter, a sewage treatment device and sewage treatment equipment. Background Art

[0002] At present, various types of sewage treatment equipment usually need to conduct small-scale tests and pilot-scale simulations on their treatment processes before construction. At present, small-scale tests are mostly completed in the laboratory after sampling, while pilot-scale tests require on-site use of pilot-scale equipment for small-scale treatment. At present, most pilot-scale equipment uses a single reactor to treat sewage. When optimizing sewage treatment conditions, it is necessary to conduct multiple tests in succession, and it is impossible to conduct multiple groups of tests at the same time. Therefore, the test takes a long time and has low efficiency. Tests under different conditions are easily interfered by various factors, such as raw water concentration and different temperatures during sewage treatment, which will cause errors in the test. For example, the treatment process of the sewage deep treatment tank disclosed in document number CN117430296A "Sewage Deep Treatment Tank Based on Pyrite Filler and Skid-Mounted Sewage Purification Assembly" needs to be piloted before finalization, but there is currently a lack of similar pilot-scale equipment. Utility Model Content

[0003] In order to solve the above technical problems, one of the purposes of the utility model is to provide a pyrite denitrification biofilter which has a simple structure, can treat sewage, and also has a backwashing function.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is as follows: a pyrite denitrification biological filter, comprising a filter body, a pyrite-based filling material layer is arranged in the middle of the filter body, a water inlet cavity is located below the filling material layer in the filter body, a water outlet cavity is located above the filling material layer in the filter body, a raw water inlet, a backwash water inlet, a backwash air inlet and a dosing port connected to the water inlet cavity are arranged at the lower end of the filter body, the upper end of the filter body is open or provided with an exhaust hole, and the upper end of the filter body is provided with a clean water outlet and a backwash wastewater outlet connected to the water outlet cavity.

[0005] The beneficial effect of the above technical solution is that raw water is introduced into the pyrite denitrification biological filter through the water inlet chamber, and the raw water enters the water outlet chamber after flowing from bottom to top through the packing material layer for treatment, and is finally discharged through the clean water outlet, wherein the raw water is purified after being treated by the packing material layer, and after the pyrite denitrification biological filter has been running for a period of time, clean water and air can be introduced into the water inlet chamber through the backwash water inlet and the backwash air inlet to generate a large number of boiling bubbles in the filter body, thereby flushing and decontaminating the packing material layer, and the sewage finally entering the water outlet chamber is discharged through the flushing wastewater outlet.

[0006] The above technical solution also provides an overflow trough in the middle of the water outlet cavity, the notch of the overflow trough faces upward, and the clean water outlet and the backwash wastewater outlet are both extended inwardly to communicate with the inside of the overflow trough.

[0007] The beneficial effect of the above technical solution is that the water on the upper surface of the water outlet cavity overflows into the overflow trough and then is discharged, which can avoid single-point water outlet of the clean water outlet, and the provision of the overflow trough can make the water discharged from the clean water outlet more homogeneous.

[0008] The filling material layer in the above technical solution includes a filter brick layer, a porous filter plate and a pyrite-based filter material layer stacked in sequence from bottom to top.

[0009] The beneficial effect of the above technical solution is that the porous filter plate and the filter brick layer can filter the granular residue in the raw water, and the filter material layer can attach microorganisms to react with nitrate ions and phosphate ions in the sewage to achieve nitrogen and phosphorus removal.

[0010] The above technical solution also has two water quality detectors, and the detection probes of the two water quality detectors are respectively located in the water inlet cavity and the water outlet cavity.

[0011] The beneficial effect of the above technical solution is that: in this way, the water quality in the water inlet chamber and the water outlet chamber can be tested respectively by two water quality detectors to determine the water quality treatment efficiency.

[0012] The second purpose of the utility model is to provide a sewage treatment device which has a simple structure, can treat sewage, and also has a backwashing function.

[0013] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is as follows: a sewage treatment device, comprising a raw water tank, a clean water tank, a backwash fan, a backwash water pump, a dosing tank, a dosing pump and the pyrite denitrification biofilter as described above, the raw water tank is connected to the raw water inlet, a first valve is arranged at the raw water inlet, the air outlet of the backwash fan is connected to the backwash air inlet, a second valve is arranged at the backwash air inlet, the clean water tank has a drain, a third valve is arranged at the drain, and the clean water outlet is connected to the backwash air inlet. The inlet of the backwash pump is connected to the clean water tank, a fourth valve is arranged at the clean water outlet, the water inlet of the backwash pump is connected to the clean water tank, the water outlet of the backwash pump is connected to the backwash water inlet, a fifth valve is arranged at the backwash water inlet, the backwash wastewater discharge outlet is connected to the raw water tank, and a sixth valve is arranged at the backwash wastewater discharge outlet, the liquid inlet of the dosing pump is connected to the dosing tank, the liquid outlet of the dosing pump is connected to the dosing port, and a seventh valve is arranged at the dosing port.

[0014] The beneficial effect of the above technical solution is that when the pyrite denitrification biological filter is in operation, raw water is supplied from the raw water tank to the water inlet chamber, and the reagent is added into the water inlet chamber from the dosing tank via the dosing pump. At this time, the raw water and the reagent are mixed evenly, wherein the reagent can be a carbon source and / or a nitrogen source, which is beneficial to the growth and reproduction of microorganisms.

[0015] The above technical solution also includes a raw water supply pump, and the raw water tank is connected to the raw water inlet through the raw water supply pump.

[0016] The beneficial effect of the above technical solution is that the raw water in the raw water pool is pumped into the water inlet chamber through the raw water supply pump.

[0017] In the above technical solution, the backwash fan is located above the pyrite denitrification biological filter, or the air outlet of the backwash fan is connected to the backwash air inlet through an n-shaped pipe, and the upper end of the n-shaped pipe is higher than the upper end of the pyrite denitrification biological filter.

[0018] The beneficial effect of the above technical solution is that it can prevent the raw water in the water inlet chamber from flowing back into the backwash fan.

[0019] In the above technical solution, the pyrite denitrification biofilter, the dosing tank and the dosing pump are provided in plurality, and the plurality of pyrite denitrification biofilters, the plurality of dosing tanks and the plurality of dosing pumps correspond to each other one by one.

[0020] The beneficial effect of the above technical solution is that: in this way, multiple pyrite denitrification biological filters can simultaneously treat sewage, and at this time the sewage treatment device can be subjected to pilot comparative tests.

[0021] The third purpose of the utility model is to provide a sewage treatment device which is convenient for transportation, can treat sewage, and also has a backwashing function.

[0022] In order to achieve the above-mentioned purpose, the technical solution of the utility model is as follows: sewage treatment equipment includes a box body and the sewage treatment device as described above, and the sewage treatment device is arranged in the box body.

[0023] The beneficial effect of the above technical solution is that by arranging the sewage treatment device in the box, the transportation of the entire sewage treatment equipment is more convenient.

[0024] The above technical solution also includes a photovoltaic power station arranged at the upper end of the box, and the photovoltaic power station is used to supply power to the sewage treatment device.

[0025] The beneficial effect of the above technical solution is that it enables the sewage treatment equipment to achieve self-sufficiency in electrical energy, and is especially adaptable to the needs of operations in remote environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a cross-sectional view of the pyrite denitrification biological filter described in Example 1 of the utility model;

[0027] Figure 2 It is a cross-sectional view of the pyrite denitrification biological filter tank described in Example 1 of the utility model at a vertical angle;

[0028] Figure 3 This is a vertical view of one side of the sewage treatment device described in Example 2 of the utility model;

[0029] Figure 4 This is a vertical view of the other side of the sewage treatment device described in Example 2 of the utility model;

[0030] Figure 5 This is a simplified structural diagram of the sewage treatment device described in Example 2 of the utility model;

[0031] Figure 6 It is a vertical view of the sewage treatment device when a plurality of pyrite denitrification biological filters are provided in Example 2 of the utility model;

[0032] Figure 7 This is a schematic structural diagram of a sewage treatment device described in Example 3 of the utility model when one side of the box body is cut away.

[0033] In the figure: 1 sewage treatment device; 11 pyrite denitrification biological filter; 111 filter body; 1111 water inlet chamber; 11111 raw water inlet; 11112 backwash water inlet; 11113 backwash air inlet; 11114 dosing port; 1112 water outlet chamber; 11121 clean water outlet; 11122 backwash wastewater outlet; 112 filling material layer; 1121 filter brick layer; 1122 porous filter plate; 1123 filter material layer; 113 overflow tank; 114 water quality Detector; 115 observation window; 12 raw water tank; 121 raw water inlet; 13 clean water tank; 131 drain outlet; 14 backwash fan; 141 n-shaped pipe; 15 backwash water pump; 16 dosing tank; 161 dosing pump; 17 raw water supply pump; 18 controller; 191 first valve; 192 second valve; 193 third valve; 194 fourth valve; 195 fifth valve; 196 sixth valve; 197 seventh valve; 198 eighth valve; 2 cabinet; 3 photovoltaic power station. DETAILED DESCRIPTION

[0034] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. According to the following description and claims, the advantages and features of the present invention will be more clearly described. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0035] Example 1

[0036] like Figure 1 and Figure 2 As shown, this embodiment provides a pyrite denitrification biological filter, including a filter body 111, a pyrite-based filling material layer 112 is arranged in the middle of the filter body 111, a water inlet chamber 1111 is located below the filling material layer 112 in the filter body 111, and a water outlet chamber 1112 is located above the filling material layer 112 in the filter body 111, and a raw water inlet 11111, a backwash water inlet 11112, a backwash air inlet 11113 and a dosing port 11114 connected to the water inlet chamber 1111 are arranged at the lower end of the filter body 111, and the upper end of the filter body 111 is open or provided with an exhaust hole (preferably, the filter body is directly a trough body, the notch of which faces upward, and the notch of which faces upward). Directly used for exhaust), the upper end of the filter body 111 is provided with a clean water outlet 11121 and a backwash wastewater outlet 11122 which are connected to the water outlet chamber 1112, the pyrite denitrification biological filter is introduced with raw water through the water inlet chamber, and the raw water enters the water outlet chamber after being treated by the filling material layer from bottom to top, and is finally discharged through the clean water outlet, wherein the raw water will be purified after being treated by the filling material layer, and after the pyrite denitrification biological filter has been running for a period of time, clean water and air can be introduced into the water inlet chamber through the backwash water inlet and the backwash air inlet to generate a large number of boiling bubbles in the filter body, thereby flushing and decontaminating the filling material layer, and the sewage finally entering the water outlet chamber is discharged through the flushing wastewater outlet.

[0037] The above technical solution also provides an overflow trough 113 in the middle of the water outlet chamber 1112, the notch of the overflow trough 113 faces upward, and the clean water outlet 11121 and the backwash waste water outlet 11122 are both extended inward to communicate with the interior of the overflow trough 113, so that the water on the upper surface of the water outlet chamber overflows into the overflow trough and then is discharged, which can avoid single-point water discharge from the clean water outlet, and the provision of the overflow trough can improve the homogeneity of the water discharged from the clean water outlet.

[0038] The filling material layer 112 in the above technical solution includes a filter brick layer 1121, a porous filter plate 1122 and a pyrite-based filter material layer 1123 stacked in sequence from bottom to top. The porous filter plate and the filter brick layer can filter the granular residue in the raw water, and the filter material layer can attach microorganisms to react with nitrate ions and phosphate ions in the sewage to achieve denitrification and phosphorus removal, wherein the filter material layer is a pyrite-based granular filler (such as pyrite sand particles).

[0039] The above technical solution also has two water quality detectors 114, and the detection probes of the two water quality detectors 114 are respectively located in the water inlet chamber 1111 and the water outlet chamber 1112. In this way, the water quality in the water inlet chamber and the water outlet chamber can be detected by the two water quality detectors to determine the water quality treatment efficiency.

[0040] Compared with the document number CN117430296A "Sewage deep treatment tank based on pyrite filler and skid-mounted sewage purification assembly", the pyrite denitrification biological filter described in this embodiment has the raw water flowing from bottom to top. At this time, the raw water is first filtered through the filter brick layer 1121 and the porous filter plate 1122 to remove granular residue and then purified through the filter material layer. This can avoid the appearance of a large amount of solid residue in the filter material layer and affect the purification effect of the filter material layer.

[0041] In this embodiment, the thickness of the filter material layer can be 1-2m, and a hollow support frame can be set in the water inlet cavity in this embodiment (but a hollow plate is horizontally set in the filter tank body, and the filling material layer is set on the hollow plate). In this way, the filling material layer 112 can be lifted up by the support frame in the middle of the filter tank body 111, and the structure of the support frame is not elaborated here.

[0042] Preferably, an observation window may be provided on the side wall of the filter tank body in this embodiment, and a transparent tempered glass may be provided at the corresponding position of the observation window for sealing, so that the treatment of the raw water in the filter tank body through the filling material layer can be observed through the observation window.

[0043] Example 2

[0044] like Figure 3-Figure 5As shown, the present embodiment provides a sewage treatment device, including a raw water tank 12, a clean water tank 13, a backwash fan 14, a backwash water pump 15, a dosing tank 16, a dosing pump 161 and the pyrite denitrification biological filter 11 as described in Example 1, the raw water tank 12 is connected to the raw water inlet 11111, a first valve 191 is provided at the raw water inlet 11111, the air outlet of the backwash fan 14 is connected to the backwash air inlet 11113, a second valve 192 is provided at the backwash air inlet 11113, the clean water tank 13 has a drain 131, a third valve 193 is provided at the drain 131, and the clean water outlet 11121 is connected to the clean water tank 13, a fourth valve 194 is provided at the clean water outlet 11121, and the water inlet of the backwash water pump 15 is connected to the The clean water tank 13 is connected, the water outlet of the backwash water pump 15 is connected to the backwash water inlet 11112, the backwash water inlet 11112 is provided with a fifth valve 195, the backwash wastewater outlet 11122 is connected to the raw water tank 12, and the backwash wastewater outlet 11122 is provided with a sixth valve 196, the liquid inlet of the dosing pump 161 is connected to the dosing tank 16, the liquid outlet of the dosing pump 161 is connected to the dosing port 11114, and the dosing port 11114 is provided with a seventh valve 197, so that when the pyrite denitrification biological filter is in operation, raw water is supplied from the raw water tank to the water inlet chamber, and the agent is added to the water inlet chamber from the dosing tank through the dosing pump. At this time, the raw water and the agent are mixed, wherein the agent can be a carbon source and / or a nitrogen source, which is beneficial to the growth and reproduction of microorganisms.

[0045] The above technical solution also includes a raw water supply pump 17. The raw water tank 12 is connected to the raw water inlet 11111 through the raw water supply pump 17, so that the raw water in the raw water tank is pumped into the water inlet cavity through the raw water supply pump.

[0046] In the above technical solution, the backwash fan 14 is located above the pyrite denitrification biological filter 11, or the air outlet of the backwash fan 14 is connected to the backwash air inlet 11113 through an n-shaped tube 141, and the upper end of the n-shaped tube 141 is higher than the upper end of the pyrite denitrification biological filter 11, so that the raw water in the water inlet chamber can be prevented from flowing back into the backwash fan.

[0047] like Figure 6 As shown, the pyrite denitrification biological filter 11, the dosing tank 16 and the dosing pump 161 in the above technical solution are provided in plurality, and the plurality of pyrite denitrification biological filters 11, the plurality of dosing tanks 16 and the plurality of dosing pumps 161 correspond to each other one by one, so that the plurality of pyrite denitrification biological filters can treat sewage at the same time, and the sewage treatment device can carry out pilot comparative tests at this time.

[0048] The filter tank body described in the present embodiment can be miniaturized. In this case, a plurality of the filter tank bodies can be matched so that the sewage treatment device can be used to conduct pilot comparative tests on raw water. For example, the materials of the filter layers in each filter tank body are different to compare the water purification effects of various filter layer materials. The water purification effects of different filling thicknesses of the same filter material can also be compared. The water purification effects of different particle sizes of the same filter material can also be compared. Of course, the raw water purification effects can also be compared by adding different agents, etc. At this time, multiple groups of tests can be conducted simultaneously to improve the test efficiency.

[0049] Preferably, the number of the pyrite denitrification biological filter 11, the dosing tank 16 and the dosing pump 161 described in this embodiment is consistent, and 2-8 can be set, preferably 4-6.

[0050] In this embodiment, the first valve 191, the second valve 192, the fourth valve 194, the fifth valve 195, the sixth valve 196 and the seventh valve 197 can all be electric valves, especially the first valve 191 can be an electric flow valve, which can adjust its opening and closing degree, and a controller can also be set. The backwash fan, backwash water pump, dosing pump, raw water supply pump, first valve 191, second valve 192, fourth valve 194, fifth valve 195, sixth valve 196 and seventh valve 197 are all electrically connected to the controller, which can improve the intelligence level of the entire sewage treatment device. In this embodiment, the controller can be a PLC controller.

[0051] In this embodiment, the raw water pool 12 further has a raw water inlet 121, which is connected to the sewage discharge network, and an eighth valve 198 is provided at the raw water inlet. Both the eighth valve 198 and the third valve 193 can be manual valves.

[0052] Example 3

[0053] like Figure 7 As shown, this embodiment provides a sewage treatment equipment, including a box body 2 and a sewage treatment device 1 as described in Example 2, wherein the sewage treatment device 1 is arranged in the box body 2. By arranging the sewage treatment device 1 in the box body 2, the transportation of the entire sewage treatment equipment is made more convenient.

[0054] The above technical solution also includes a photovoltaic power station 3 arranged at the upper end of the box body 2, and the photovoltaic power station 3 is used to supply power to the sewage treatment device 1, so that the sewage treatment equipment can achieve self-sufficiency in electricity, especially can adapt to the operation needs in remote environments (the box body in this embodiment can be similar to a container-like structure, which can be provided with components such as a door and a ventilation window). Preferably, the raw water inlet 121 and the drain outlet 131 both pass through the outside of the box body 2, and the eighth valve 198 and the third valve 193 are also located outside the box body.

[0055] This embodiment is a sewage treatment equipment for pilot test treatment based on document number CN117430296A "Deep sewage treatment tank based on pyrite filler and skid-mounted sewage purification assembly", which can test and compare various factors affecting the raw water treatment efficiency. For the principles of raw water purification treatment in this embodiment that are not described in detail, please refer to the contents recorded in CN117430296A "Deep sewage treatment tank based on pyrite filler and skid-mounted sewage purification assembly".

[0056] In this embodiment, the controller is arranged in the box body near the door thereof (the controller has a human-computer interaction interface), which facilitates setting operations.

[0057] The above description is only a preferred embodiment of the utility model and does not limit the utility model in any form. Any ordinary technician in the industry can smoothly implement the utility model as shown in the drawings of the specification and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the utility model using the technical content disclosed above are all equivalent embodiments of the utility model. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the utility model are still within the protection scope of the technical solution of the utility model.

Claims

1. Pyrite denitrification biofilter, characterized in that: The invention comprises a filter body (111), wherein a pyrite-based filling material layer (112) is arranged in the middle of the filter body (111), a water inlet cavity (1111) is located below the filling material layer (112) in the filter body (111), a water outlet cavity (1112) is located above the filling material layer (112) in the filter body (111), and a water outlet cavity (1112) is arranged at the lower end of the filter body (111) and connected to the water inlet cavity (1111). The filter tank body (111) comprises a raw water inlet (11111), a backwash water inlet (11112), a backwash air inlet (11113) and a dosing port (11114) connected to the water outlet cavity (1112); the upper end of the filter tank body (111) is open or provided with an exhaust hole; the upper end of the filter tank body (111) is provided with a clean water outlet (11121) and a backwash wastewater outlet (11122) connected to the water outlet cavity (1112).

2. The pyrite denitrification biofilter according to claim 1, characterized in that: An overflow trough (113) is also provided in the middle of the water outlet chamber (1112), the notch of the overflow trough (113) faces upward, and the clean water outlet (11121) and the backwash wastewater outlet (11122) are both extended inwardly to communicate with the interior of the overflow trough (113).

3. The pyrite denitrification biofilter according to claim 1, characterized in that: The filling material layer (112) comprises a filter brick layer (1121), a porous filter plate (1122) and a pyrite-based filter material layer (1123) which are stacked in sequence from bottom to top.

4. The pyrite denitrification biofilter according to any one of claims 1 to 3, characterized in that: It also has two water quality detectors (114), and the detection probes of the two water quality detectors (114) are respectively located in the water inlet chamber (1111) and the water outlet chamber (1112).

5. A sewage treatment device, characterized in that: The invention comprises a raw water tank (12), a clean water tank (13), a backwash fan (14), a backwash water pump (15), a dosing tank (16), a dosing pump (161) and a pyrite denitrification biofilter (11) according to any one of claims 1 to 4, wherein the raw water tank (12) is connected to the raw water inlet (11111), a first valve (191) is provided at the raw water inlet (11111), an air outlet of the backwash fan (14) is connected to the backwash air inlet (11113), a second valve (192) is provided at the backwash air inlet (11113), the clean water tank (13) has a drain outlet (131), a third valve (193) is provided at the drain outlet (131), and the clean water outlet (11121) is connected to the clean water tank (13). The backwashing tank (13) and the backwashing tank (12) are connected to each other, a fourth valve (194) is provided at the clean water outlet (11121), a water inlet of the backwashing water pump (15) is connected to the clean water tank (13), a water outlet of the backwashing water pump (15) is connected to the backwashing water inlet (11112), a fifth valve (195) is provided at the backwashing water inlet (11112), the backwashing wastewater outlet (11122) is connected to the raw water tank (12), and a sixth valve (196) is provided at the backwashing wastewater outlet (11122), a liquid inlet of the dosing pump (161) is connected to the dosing tank (16), a liquid outlet of the dosing pump (161) is connected to the dosing port (11114), and a seventh valve (197) is provided at the dosing port (11114).

6. The sewage treatment device according to claim 5, characterized in that: It also includes a raw water supply pump (17), and the raw water tank (12) and the raw water inlet (11111) are connected through the raw water supply pump (17).

7. The sewage treatment device according to claim 5, characterized in that: The backwash fan (14) is located above the pyrite denitrification biological filter (11), or the air outlet of the backwash fan (14) is connected to the backwash air inlet (11113) through an n-shaped pipe (141), and the upper end of the n-shaped pipe (141) is higher than the upper end of the pyrite denitrification biological filter (11).

8. The sewage treatment device according to any one of claims 5 to 7, characterized in that: The pyrite denitrification biofilter (11), the dosing tank (16) and the dosing pump (161) are provided in plurality, and the plurality of pyrite denitrification biofilters (11), the plurality of dosing tanks (16) and the plurality of dosing pumps (161) correspond to each other one by one.

9. Sewage treatment equipment, characterized in that, It comprises a housing (2) and a sewage treatment device (1) according to any one of claims 4 to 8, wherein the sewage treatment device (1) is arranged in the housing (2).

10. The sewage treatment equipment according to claim 9, characterized in that: It also comprises a photovoltaic power station (3) arranged at the upper end of the box body (2), and the photovoltaic power station (3) is used to supply power to the sewage treatment device (1).

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