JP4461247B2 - Water quality measuring device - Google Patents

Description

  The present invention relates to a water quality measuring device for measuring water quality such as acid rain.

In recent years, as one of the environmental problems, interest in acid rain has increased, and various apparatuses for measuring the quality of rainwater such as pH and conductivity have been proposed. As a device for measuring the quality of rain water, for example, acid rain automatic measuring machine 600 as shown in FIG. 6 described in Non-Patent Document 1 have been commercialized.

  This automatic acid rain measuring instrument 600 is housed in a front and side 1.5 to 2m case, and has not only the measurement of water quality but also a function as a rain gauge. It consists of a mechanism that measures the quality of water.

  The mechanism for measuring the rainfall includes a water receiving funnel 601 disposed at the upper part of the housing of the automatic acid rain measuring instrument 600 with the water receiving port facing upward, and a predetermined amount disposed below the water receiving funnel 601. It is comprised from a pair of left and right overturning rods 604, 605. The left and right pair of overturning rods 604 and 605 are configured symmetrically across the support shaft 606. The support shaft 606 is directly below the water inlet 601a of the water receiving funnel 601, and the pair of left and right overturning rods 604 and 605 are horizontal. In such a state that the balance of the weights of the pair of left and right overturning rods 604 and 605 is slightly broken, one of the water inlets 601a of the water receiving funnel 601 It is the structure located immediately below.

  With this configuration, when a predetermined amount of rainwater is received by one of the overturning rods 604 and 605 and the amount of received water reaches a predetermined amount, the overturning rods 604 and 605 are positioned at the discharge position around the support shaft 606. The other overturning troughs 605 and 604 are positioned directly below the water inlet 601a of the water receiving funnel 601.

  Therefore, it is possible to measure the rainfall by counting the number of falls of the fall ridges 604 and 605 within a predetermined time.

  Corresponding to the discharge positions of the overturning rods 604, 605, drain tubes 607, 608 are disposed in the case of the automatic acid rain measuring instrument 600, and the rainwater discharged from the drain tubes 607, 608 is The water is guided to the storage cell 614 through a recovery pipe constituting a mechanism for measuring the quality of rainwater. The rainwater stored in the storage cell 614 is measured for physical quantities by a PH sensor, a conductivity sensor, a temperature sensor, and the like, and the measured physical quantities are output to the outside by an amplification control signal converter 611.

In addition, the automatic acid rain measuring instrument 600 covers the water receiving port of the water receiving funnel 601 with a lid 610 when there is no rain, and removes the lid 610 from the water receiving port when the rain sensor 609 detects rain. A funnel opening / closing mechanism, a water receiving funnel 601, an overturning trough 604, 605, and an automatic cleaning mechanism for cleaning the drain tubes 607, 608 are provided.
“Acid Rain Survey Method -Guide to Data Collection, Component Analysis and Data Arrangement”, Gyosei Co., Ltd., June 25, 1993 p. 45

  In order to measure the water quality for each fall overfall, only rainwater discharged from the fall overfalls 604, 605 by one fall of the pair of left and right fall fallouts 604, 605 must be stored in the storage cell 614. I must. However, since the conventional storage cell 614 shown in FIG. 7 has a larger volume than the overturning rods 604 and 605, rainwater discharged by several overturns is stored. Therefore, in the storage cell 614, since the rainwater discharged by each overturning is mixed with each other, the above PH sensor or the like measures the quality of the mixed rainwater. Therefore, even if the quality of rainwater changes every fall, the change in water quality does not appear clearly in the measurement results output from the amplification control signal converter 611.

  Moreover, the acid rain automatic measuring machine 600 is very expensive because it includes a number of complicated and large mechanisms such as a water receiving funnel opening and closing mechanism and an automatic washing mechanism. Since it is necessary to carry out at a point, it is impossible from an economical viewpoint to install an expensive measuring device such as the acid rain automatic measuring machine 600 at a number of points.

  Then, an object of this invention is to provide the water quality measuring apparatus which can measure the water quality of rain water correctly for every 1 meter, and is cheap.

  The water quality measurement device of the present invention causes rainwater to flow into a storage space whose volume is smaller than that of a tip over and measures the quality of rainwater in the storage space. If the volume is smaller than the tip of the fall, when new rainwater flows into the storage space, if the rainwater previously stored is pushed out by the new rainwater and flows out, both the new rainwater and the rainwater previously stored will be It can prevent mixing and storing.

  However, even if the volume of the storage space is smaller than that of the overturning ridge, the rainwater discharged from the overturning ridge does not necessarily push the rainwater that has been stored before from the storage space and flow into the storage space. For example, as shown in FIG. 8, when rainwater discharged from a tumble bag flows into a storage space 814 b in which rainwater is stored, the rainwater that flows in flows out from an outlet 814 c through the surface of the stored rainwater. May end up.

  This occurs because friction force is generated in the bottom and side walls that form the stored rainwater and the storage space 814b, and the stored rainwater is difficult to move.

  Even if the stored rainwater is difficult to move, if the amount of rainwater discharged from the overturned ridge is large, the stored rainwater can be moved with the momentum of the rainwater discharged from the overturned ridge.

  The automatic acid rain measuring instrument 600 shown in FIG. 6 has a capacity of the overturning rods 604 and 605 that receives the rain with a rainfall of 0.5 mm so that the rainfall can be measured in units of 0.5 mm. It is equal to the amount. The water receiving port of the water receiving funnel 601 of the automatic acid rain measuring apparatus 600 has a diameter of 20 cm. When rain of 0.5 mm is received by the water receiving funnel 601, the amount received is 15.7 ml. Therefore, the capacity of the overturning troughs 604 and 605 is 15.7 ml.

  Thus, since the volume of the overturning rods 604 and 605 is as small as 15.7 ml, the rainwater stored from the overturning rods 604 and 605 cannot be moved.

  In the water quality measuring apparatus of the present invention, as shown in FIG. 2, in order to prevent rainwater from flowing out of the storage space 114b through the surface of the stored rainwater, a flow path forming lid is provided on the upper surface of the storage space 114b. The body 116 is provided, and the outlet 114c is provided at the upper end of the storage space 114b and on the side opposite to the inlet 114a through which rainwater that has flowed out from the overturned ridge flows across the storage space 114b.

  When the volume of the storage space is made smaller than the overturning ridge and the outlet is provided at such a position, rainwater discharged from the overturning ridge fills the storage space, partly overflows from the storage space and flows out from the outflow outlet. In order to fill the storage space, the rainwater stored in the storage space comes into contact with the bottom surface of the flow path forming lid that forms the bottom of the storage space and the tray that forms the ceiling of the storage space.

  When new rainwater is discharged from the fall over the storage space filled with rainwater as described above, the new rainwater cannot flow on the surface of the rainwater as shown in FIG. It tries to flow into the storage space while pushing out rainwater. Since rainwater filling the storage space is in contact with the saucer and the flow path forming lid as described above, it is pushed by new rainwater, so that an even frictional force is generated around the rainwater filling the storage space. work. Therefore, when pushed by new rainwater, the entire rainwater filling the storage space is uniformly pushed out and discharged from the outlet.

  As described above, since the volume of the storage space is smaller than that of the overturned trap, the new rainwater pushes out all the rainwater that fills the storage space from the storage space, and further, the storage space together with the rainwater that partially fills the storage space. Spill from.

  As described above, when a fall overfall falls and rainwater is discharged, the rainwater that has been stored in the storage space from before is drained, and only rainwater discharged from the overturn by this fall is stored in the storage space. Is done. Therefore, it is possible to accurately measure the quality of rainwater every 1 km.

  If you use an existing overturning rain gauge for surface meteorological observation installed by the Japan Meteorological Agency, etc. to collect rainwater to measure water quality, just add the storage cell as above to the overturning rain gauge, Simultaneously with rainfall measurement, the quality of rainwater can be measured every 1 km. Of course, even if a storage cell is added, the function of the overturning rain gauge for ground weather observation as a rain gauge is not impaired.

  In addition, if the existing overturning rain gauge for ground weather observation is used in this way, the water quality measuring device can be manufactured at low cost.

  FIG. 1 shows a water quality measuring apparatus 100 of the present embodiment. As shown in FIG. 1, the water quality measuring device 100 includes a toppling gutter type rain gauge A and an acid rain measuring mechanism B provided below the toppling gutter type rain gauge A. The water quality measuring apparatus 100 of the present embodiment uses, as the tipping-up type rain gauge A, a tipping-up type rain gauge for ground weather observation installed by the Japan Meteorological Agency or the like.

  The overturning rain gauge A has basically the same configuration as the mechanism for measuring the rainfall of the automatic acid rain measuring instrument 600 described in the background art section.

  Drain tubes 107 and 108 are provided at the discharge positions of the overturning rods 104 and 105, and the drain tubes 107 and 108 communicate with the water guide means 111 of the acid rain measuring mechanism B. The water guiding means 111 includes a funnel 112 and a recovery pipe 113 connected to the lower side of the funnel 112. The recovery pipe 113 has a smaller inner diameter as it goes downward. To the inlet 114a.

  The measurement cell 114 of the acid rain measurement mechanism B is shown in FIGS. 2 (a) and 2 (b). 2A is a front longitudinal sectional view of the storage cell 114, and FIG. 2B is a sectional view taken along line XX ′ of FIG. 2A.

  As shown in FIG. 2 (a), the storage cell 114 is configured to receive rainwater from the recovery pipe 113 by a receiving tray 115 through an inflow port 114a, and rainwater flowing into the storage cell 114 is It flows out from the outflow port 114c provided in the position facing the said inflow port 114a of the receiving tray 115. FIG.

  The upper surface of the tray 115 is covered with a flow path forming lid body 116, and the lower surface 116a of the flow path forming lid body is configured to be lower than the upper end of the outlet 114c. Various measuring means such as a PH sensor 118a, a temperature sensor 118b, and a conductivity sensor 118c are supported on the body 116, and the sensing portion protrudes into the storage space 114b. Accordingly, the rainwater flowing in from the inlet 114a is guided to the outlet 114c through the storage space 114b sandwiched between the bottom surface of the tray 115 and the lower surface 116a of the flow path forming lid, and Various physical quantities and chemical quantities are measured by the sensors 118a to 118c.

  The volume of the storage space 114b is smaller than the volume of the overturning rods 104 and 105. In other words, since the volume of the overturning dredge type rain gauge for ground meteorological observation installed by the Japan Meteorological Agency etc. is 15.7 ml, the volume of the storage space 114b of this embodiment is about 15.0 ml. ing. The capacity of the overturning cage 104, 105 of the overturning rain gauge for ground weather observation is about 15.7 ml, which is the same as the capacity of the overturning cages 604, 605 of the automatic acid rain measuring instrument 600 is 15.7 ml. That is why.

  The size of the storage space 114b basically depends on the above-mentioned volume, but is determined by the diameters of the other sensors 118a to 118c and the protruding length from the lower surface 116a of the flow path forming lid. .

  For example, when the diameter of each sensor 118a to 118c is 12 mm and the length protruding from the lower surface 116a of the flow path forming lid of each sensor 118a to 118c is 20 mm, the dimension in the direction from the inlet 114a to the outlet 114c is About 50 mm, the dimension in the direction perpendicular to the paper surface of FIG. 2A is about 15 mm, and the dimension between the tray 15 and the lower surface 116 a of the flow path forming lid is about 30 mm. The type of sensor supported by the flow path forming lid 116 is not limited to the PH sensor 118a, the temperature sensor 118b, and the conductivity sensor 118c, and may be a salt sensor, a nitric acid sensor, a sulfuric acid sensor, or the like.

  Rainwater discharged from the overturning rods 104 and 105 to the drain pipes 107 and 108 flows into the storage space 114b from the inflow port 114a through the water guiding means 111 for every overturning rod.

  At this time, if the storage space 114b is already filled with rainwater, the rainwater newly discharged from the overturning rods 104 and 105 flows into the storage space 114b while pushing out rainwater that has already filled the storage space 114b. At this time, as shown in FIG. 2 (b), the rainwater that has newly flown is subjected to the resistance of the bottom surface and the side surface of the tray 115 and the bottom surface 116a of the flow path forming lid, and has been accumulated for a long time. It advances in the direction of the outflow port 114e, pushing out.

  As a result, the rainwater that has flowed in is pushed out from the rainwater that has already accumulated while being evenly diffused into the storage space 114b without flowing through the surface with less resistance as in the prior art. Will be done quickly. Further, as described above, since the storage space 114b is slightly smaller than the volume of the overturning rods 104 and 105, theoretically, only new rainwater discharged from the overturning rods 104 and 105 by one overturning. Is stored in the storage cell 114, so that the quality of rainwater can be measured every time it falls.

  The fall of the overturning rods 104 and 105 is detected by the detection means, and the detection means starts measuring the water quality at the same time as measuring the rainfall amount, and starts the water quality measurement with the measurement sensors 118a to 118c. Output to.

  Note that there is a slight time difference between the discharge of rainwater from the overturning rods 104 and 105 and the storage of rainwater in the storage space 114b. This time difference differs depending on the distance from the overturning rods 104, 105 to the storage space 114b, the shape of the water guiding means 111, and the like.

  When using the water quality measuring device 100 of the present embodiment, such a time difference and the response delay of each sensor 118a-118c are measured in advance, and delayed from when it is notified that the overturning rods 104, 105 are overturned, The water quality at the measurement sensors 118a to 118c is measured. Thus, by measuring the water quality based on the time when the overturning rods 104 and 105 are overturned, the quality of the rainwater can be measured every time the overturning rods 104 and 105 are overturned.

  FIG. 3 is a table and a graph showing experimental results when the storage cell 114 described in the present embodiment is used and when the storage cell 814 shown in FIG. 8 is used.

  In this experiment, in a state where the storage spaces 114 and 814 are filled with the rainwater α, rainwater β having a different water quality from the rainwater α is dropped on the receiving funnel 101, and the number of times the overturning rods 104 and 105 have fallen, The ratio of the rainwater β to the entire rainwater stored in the storage space 114b when there is a fall is measured.

  As apparent from FIG. 3, when the storage cell 114 of the present embodiment is used, when the overturning rods 104 and 105 are overturned at most two times, the rainwater filling the storage space 114b is almost completely replaced with the rainwater β. More than 90% substitution was confirmed in each fall. On the other hand, when the storage cell 814 shown in FIG. 8 is used, in order for the rainwater filling the storage space 114b to become the rainwater β completely, at least seven falls are required, and only about 40% is replaced by one fall. Therefore, when the storage cell 114 of the present embodiment is used, the rainwater stored in the storage space 114b can be easily replaced, so that the quality of the rainwater for each overturn can be measured more accurately.

  In addition, in FIG. 4, PH6.88 rainwater is dropped onto the receiving funnel 101 in the storage space 114b described in the present embodiment, which is filled with PH4.00 rainwater. The number of times and the pH of rainwater in the storage space 114b when each number of falls occurred are shown. As shown in FIG. 4, it was proved that the PH indication value was 6.85 after two falls.

  FIG. 5 shows the experimental results of measuring the response time of the PH sensor in the storage space 114b described in the present embodiment.

  The experimental result 1 in FIG. 5 shows that when the storage space 114b is filled with adjusted tap water adjusted to PH7, 50 ml of adjusted tap water adjusted to PH4 is poured into the water receiving funnel 101 at a time, and then stored. The time required for the rainwater PH in the space 114b to reach 4 is shown. As shown in Experiment Result 1 in FIG. 5, the PH of rainwater in the storage space 114b became 4 within 1 minute.

  Experimental result 2 shows that when 50 ml of adjusted tap water adjusted to PH7 is poured into the receiving funnel 101 at a time in a state where the storage space 114b is filled with adjusted tap water adjusted to PH4, the storage space 114b Indicates the time required for the rainwater pH to reach 7 or 7 ± 0.1.

  As shown in the experimental result 2 of FIG. 5, it took 5 minutes for the rainwater in the storage space 114b to reach PH7, and 1.5 minutes for PH7 ± 0.1. The time required to change from PH7 to PH4 is longer than the time required from PH4 to PH7 because the PH7 solution is pure and contains almost no electrolyte.

  By the way, in the measurement of acid rain, since a deviation of about PH ± 0.1 is allowed, even when it is raining more neutral than rainwater stored in the storage space 114b, it is stored in the storage space 114b. PH measurement can be performed with almost the same accuracy as when acid rain stronger than rainwater falls.

The external view of the water quality measuring apparatus of this invention. The enlarged view of a storage cell. The chart which shows the experimental result of the easiness of replacement of rainwater of storage space. The chart which shows the change of PH of rainwater of a storage space, and electrical conductivity. The table | surface which shows the time required until PH of rainwater of the storage space became PH of rainwater received by the water receiving funnel. The figure of the conventional acid rain automatic measuring machine which measures PH etc. of the conventional acid rain. The figure which shows the conventional storage space. The figure which shows the storage space which added the improvement to the conventional storage space.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Water quality measuring device 101 Receiving funnel 102 Drainer 104, 105 Tumbler 114 Storage cell 114a Inlet 114b Reserving space 114c Outlet 115 Receiving tray 116 Channel formation lid 116a Bottom surface of channel formation lid

Claims (2)

Each time it is filled with rainwater, it falls over, and a pair of overturning traps that discharge the filled rainwater by a predetermined amount, a storage cell that stores the discharged rainwater, and a measurement sensor that measures the quality of the stored rainwater In the equipped water quality measuring device,
The storage cell includes a receiving tray, a flow path forming lid for the receiving tray, a storage space having a smaller volume than the falling tub formed by the bottom surface of the receiving tray and the lower surface of the flow path forming lid, and the falling tub. Water quality comprising: an inflow port for allowing discharged rainwater to flow into the storage space; and an outflow port provided at an upper end of the storage space on the opposite side of the inflow port across the storage space measuring device.   The water quality measuring device according to claim 1, wherein the measurement sensor is a sensor that measures at least one of rainwater pH, salinity, conductivity, nitric acid concentration, sulfuric acid concentration, and temperature.

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