JP2982429B2 - Culture solution sterilizer for hydroponics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a culture solution sterilizer for hydroponics.

[0002]

2. Description of the Related Art Hydroponics does not use soil, but supplies nutrients directly to plants using a culture solution. Therefore, there is no soil slimming and continuous cropping failure observed in soil cultivation. In addition, the cultivation of vegetables and flowers by hydroponic cultivation has recently been activated since there is no dirt due to the adhesion of soil. In the case of soil cultivation, fungicides are generally used to prevent plant infectious diseases and pests. However, in the case of hydroponic cultivation, use is permitted and no fungicide is available. As a sterilization method, heat sterilization or ultraviolet irradiation sterilization of a culture solution is performed.

[0003]

Among the methods for sterilizing a culture solution, sterilization by heating requires the use of a heat-sterilized culture solution that has been cooled again, requiring a long sterilization time.
Thermophilic pathogenic bacteria have the disadvantage of a low bactericidal effect.
Ultraviolet sterilization, which sterilizes the culture solution by irradiating it with ultraviolet light, can provide a high sterilization effect in a short time. However, by irradiating ultraviolet light, nitrogen, phosphate, potassium, magnesium, zinc, manganese, etc. Although the concentration of most of the components does not substantially change, the chelate iron in the culture broth decomposes and precipitates, and the concentration of the chelate iron in the culture broth decreases. For this reason, a cultivated plant may cause iron deficiency, impair the production of chlorophyll, and cause yellowing of leaves.
Furthermore, although there is no biocide that has been approved and released at present, even if a biocide is approved and released in the future, the biocide inherently possesses depending on the frequency and amount of use of the biocide. It is necessary to pay sufficient attention to the effects on the cultivated plants themselves due to the residual and accumulation of toxic substances, and the effects on humans and animals that have eaten the cultivated plants, and it is difficult to cultivate truly clean plants.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a culture solution sterilizer for hydroponics that suppresses a decrease in the concentration of chelated iron in the culture solution due to ultraviolet irradiation.

[0005]

In order to achieve this object, the hydroponic culture solution sterilizing apparatus of the present invention has the following means.

(1) Ultraviolet irradiation tank and ultraviolet provided in the ultraviolet irradiation tank as a chelate iron concentration sensor
It consists of a line intensity detector and a chelate iron concentration controller, sterilizes the culture solution in an ultraviolet irradiation tank, and adjusts and maintains the chelate iron concentration of the culture solution within a certain range .

(2) The certain range is from 100% to 7
0%.

(3) adjusting the concentration of chelated iron in the culture solution,
As a holding means, a chelate iron solution is supplied from a chelate iron solution tank according to a control signal from a chelate iron concentration controller.

(4) It comprises an ultraviolet irradiation tank, a chelate iron concentration sensor and a chelate iron supply device, which sterilizes the culture solution in the ultraviolet irradiation tank and supplies a chelate iron solution according to the time of ultraviolet irradiation. is there.

[0010]

With this configuration, the culture solution sterilizing apparatus for hydroponics according to the present invention is configured such that the culture solution stored in the culture solution tank is sent out by a circulation pump, filtered by a filtration device, and then flows into an ultraviolet irradiation tank. The culture solution is sterilized by irradiation with ultraviolet light having a main wavelength of 254 nm, sent to a hydroponic bed and supplied to plants. The chelate iron concentration sensor provided on the side of the ultraviolet irradiation tank detects the chelate iron concentration in the culture solution, and when the chelate iron concentration becomes 70% or less of the initial value, the chelate iron concentration control device operates a relay. The chelate iron supply pump is operated to supply the chelate iron solution from the chelate iron solution tank into the culture solution of the hydroponic bed, thereby suppressing a decrease in the concentration of the chelate iron in the culture solution.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a culture solution sterilizer for hydroponics according to an embodiment of the present invention. In FIG. 1, the culture solution stored in the culture solution tank 1 is sent out by a circulation pump 2 and filtered by a filtration device 3 and then flows into an ultraviolet irradiation tank 4 where the culture solution is irradiated by ultraviolet light having a main wavelength of 254 nm. It is sterilized, sent to the hydroponic bed 9 and supplied to the plant 10. The chelate iron concentration sensor 11 provided on the side of the ultraviolet irradiation tank 4 detects the chelate iron concentration in the culture solution, and the
% Or less, the chelate iron concentration control device 5 operates the relay 6 to operate the chelate iron supply pump 8, and supplies the chelate iron solution from the chelate iron solution tank 7 into the culture solution of the hydroponic bed 9; Suppress the decrease in the concentration of chelated iron in the culture solution.

In FIG. 2, a flowing water inlet 13 is provided on a lower side surface of an ultraviolet irradiation tank (hereinafter referred to as a tank) 12, and a flowing water outlet 14 is provided on an upper side surface opposite thereto. Inside the tank 12, a single-tube type double tube running water germicidal lamp 16 is provided via an inner lid 15. On the side surface of the tank 12, an ultraviolet intensity detector 17 having sensitivity to ultraviolet light of 254 nm is provided. In addition, running water germicidal lamp 1
Reference numeral 6 denotes a lighting device 19 connected via a socket 18, and an outer lid 20 is provided as a protective cover for the socket 18 of the running water germicidal lamp. The inner lid 15 and the outer lid 20 can be detached by tightening screws 21 and 22, respectively, so that the maintenance, inspection, replacement of the running water germicidal lamp 16, and cleaning of the tank 12 can be easily performed.

As shown in FIG. 3, the running water germicidal lamp 16 has a light emitting tube 23 and a waterproof outer tube 2 made of ultraviolet transmitting glass.
4, a base 25, and a base 26.
6 can be easily fixed to and removed from the inner lid 15 of the running water germicidal lamp 16 in FIG. The base 25 is of a single base type so that the running water germicidal lamp 16 can be easily attached and detached.

In FIG. 4, when the blinking switch 28 is turned on or off, the running water sterilization lamp 16 shown in FIG. 2 is turned on or off, and the state is displayed on a lighting pilot lamp 29 which indicates whether or not it is turned on. An earth leakage breaker 30 is provided for safety.

The operation of the chelate iron concentration control device will be described with reference to FIG. The chelate iron concentration sensor 11 detects the chelate iron concentration in the culture solution. When the chelate iron concentration in the culture solution becomes 70% or less of the initial concentration, the chelate iron concentration control device 5 activates the relay 6 to chelate. The iron supply pump 8 is operated to supply the chelated iron solution from the chelated iron solution tank 7 into the culture solution in the hydroponic bed 9. The chelated iron concentration sensor 11 is constituted by an ultraviolet intensity detector provided on a side surface of the ultraviolet irradiation tank 4.

The components of the chelated iron in the composition in the culture broth are decomposed and precipitated by the irradiation of ultraviolet rays. Therefore, if the culture broth is continuously irradiated with the ultraviolet rays, the chelate iron components decrease. on the other hand,
Chelated iron has the property of absorbing and attenuating ultraviolet light,
When the culture solution is irradiated with ultraviolet rays, the ultraviolet transmittance in the culture solution changes depending on the concentration of chelate iron in the culture solution. From these facts, the ultraviolet transmittance in the culture solution changes as the chelate iron component decreases due to the ultraviolet irradiation. The relationship shown in FIG. 5 exists between the concentration of chelated iron in the culture solution and the ultraviolet transmittance when ultraviolet light is passed through the culture solution by a thickness of 10 cm. An ultraviolet intensity detector 17 is installed in the ultraviolet irradiation tank 12 in FIG.
By determining the degree of attenuation of the ultraviolet light irradiated from the culture solution by the culture solution, the chelate iron concentration in the culture solution can be known from the relationship in FIG. As described above, based on the signal of the chelated iron concentration sensor composed of the ultraviolet intensity detector 17,
The chelate iron concentration control device 5 judges the chelate iron concentration in the culture solution, and when the chelate iron concentration in the culture solution becomes 70% of the initial concentration, the chelate iron is supplied to the culture solution of the hydroponic cultivation bed 9 and cultured. Suppresses the decrease in the concentration of chelated iron in the liquid.

The running water germicidal lamp 16 has an ultraviolet output of 1.7.
W, lamp power 13W, double tube running water germicidal lamp 8 shown in FIG.
Using a lamp, 35 liters of the culture solution was put into the ultraviolet irradiation tank 12 shown in FIG. (Fusarium oxyspor
um Schlechtendahlf.sp.cucumerinum Owen) was inoculated at 1.0 × 10 ⁴ cells / ml, stirred for 10 minutes, and then irradiated with ultraviolet light having a main wavelength of 254 nm. After stirring, a culture solution was collected from the center of the ultraviolet irradiation tank 4, and the bactericidal effect against tomato bacterial wilt was measured by a dilution plate method, and the bactericidal effect against cucumber wilt was measured by a conidiospore germination assay. The results are shown in (Table 1) and (Table 2).

[0018]

[Table 1]

[0019]

[Table 2]

From these results, it was found that when eight double-tube running water sterilizing lamps having an ultraviolet output of 1.7 W and a lamp power of 13 W were used, 35 liters of the culture broth was used for 10 liters of tomato bacterial wilt as an indicator of general bacteria. It is understood that 35 liters of the culture solution can be sterilized in about 60 seconds when the cucumber wilt fungus is taken as an indicator bacterium of the filamentous fungi within seconds.

The change in the concentration of chelated iron in the culture solution due to the irradiation with ultraviolet light was measured by using a running water germicidal lamp with an ultraviolet output of 1.7.
W, using a double tube running water germicidal lamp of 13W of lamp power 13W,
35 liters of the culture solution was put into the ultraviolet irradiation tank 4 and the culture solution was irradiated with ultraviolet light, and then the sample was irradiated for 10, 20, 30, 40, 5
After elapse of each of the predetermined time periods of 0 minute and 60 minutes, the culture solution is collected, and changes in the concentration of chelated iron are shown in FIG. pH
Is 7.0, the chelate iron concentration becomes 6 after 60 minutes.
It shows a decrease of more than 0%, and when the pH of the culture solution is high, the decrease in the concentration of chelated iron is large. When the pH is 5.0, the decrease in the chelate iron concentration after a lapse of 60 minutes is about 20%. When the pH of the culture is known, the concentration of chelated iron in the culture depends on the irradiation time.
As an alternative to the chelate iron concentration sensor and the chelate iron concentration control device in the above embodiment, it is also possible to use a chelate iron concentration control device for supplying the culture solution with chelate iron according to the ultraviolet irradiation time.

[0022]

As is apparent from the above description of the embodiment, according to the culture solution sterilizing apparatus for hydroponic cultivation of the present invention, the culture solution for hydroponic cultivation is sterilized by ultraviolet irradiation, By detecting the chelate iron concentration, it is possible to suppress the decrease in the chelate iron concentration in the culture solution, without causing iron deficiency in the cultivated plant, and furthermore, residual toxic substances that may occur when a fungicide is used. It is possible to cultivate a clean plant which has no adverse effect on the cultivated plant itself and the human and livestock that have eaten the cultivated plant due to the accumulation.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing the concept of a running water sterilizer for hydroponics according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a detailed configuration of the ultraviolet irradiation tank.

FIG. 3 is a sectional view showing a detailed configuration of the running water germicidal lamp.

FIG. 4 is a perspective view showing the configuration of the lighting device.

FIG. 5 is a graph showing the relationship between the concentration of chelated iron in a culture solution and the transmittance of ultraviolet light in the culture solution.

FIG. 6 is a graph showing the relationship between the concentration of chelated iron in the culture solution and the irradiation time of ultraviolet light.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Culture solution tank 2 Circulation pump 4 Ultraviolet irradiation tank 5 Chelate iron concentration control device 7 Chelate iron solution tank 8 Chelate iron supply pump 9 Hydroponics bed 10 Plant 11 Chelate iron concentration sensor 17 Ultraviolet intensity detector

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) A01G 31/00 601

Claims (2)

(57) [Claims] 1. An ultraviolet irradiation tank, an ultraviolet intensity detection device provided in said ultraviolet irradiation tank as a chelate iron concentration sensor.
Vessel , and a device for controlling the concentration of chelate iron, while sterilizing the culture solution by irradiating ultraviolet rays, automatically adjusting the concentration of chelate iron in the culture solution to a certain range , and having a configuration for maintaining hydroponics. Culture solution sterilizer. 2. The certain range is from 100% to 70% of the initial.
The culture liquid sterilizing apparatus for hydroponics according to claim 1, wherein: