Device for indicating photosynthesis efficiency by using plant microbial fuel cell

Abstract

The utility model discloses a device for indicating photosynthesis efficiency by utilizing a plant microbial fuel cell. The device comprises an anode, a cathode, an external resistor and an electric signal collector, the anode is buried in plant planting soil and clings to a plant root system; the cathode is laid in the overlying water on the surface layer of the soil; the anode and the cathode are connected with the external resistor through wires, and the external resistor is connected with the electric signal collector through a wire. According to the utility model, the root exudates are used for providing organic matters for soil rhizosphere microorganisms, and the anode is laid close to the plant root system, so that the root exudates can be decomposed by electrogenesis bacteria to the greatest extent and converted into electric energy, thereby constructing a microbial fuel cell for indicating photosynthesis efficiency. The photosynthesis efficiency of plants is indicated through electric signals, and the change of the photosynthesis efficiency of the plants can be directly, simply and continuously observed.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of microbial fuel cell, concretely relates to a device for indicating photosynthesis efficiency by plant microbial fuel cell. BACKGROUND

[0002] Photosynthesis efficiency refers to the rate of photosynthesis of plants in a certain time, and understanding and measuring photosynthesis efficiency is of great significance for studying plant growth, agricultural production and carbon cycle of ecological system. Common methods for indicating or measuring photosynthesis efficiency of plants mainly include oxygen release method, carbon dioxide absorption method, isotope labeling method, photosynthesis pigment content determination method, leaf area index (LAI) method and the like. Among them, the oxygen release method can only measure net photosynthesis, and needs a closed system, and is not suitable for all plants; the carbon dioxide absorption method and the isotope labeling method are expensive in equipment and complex in experiment; the photosynthesis pigment content determination method needs destructive sampling and cannot be continuously monitored; the leaf area index (LAI) method needs a large amount of data collection and calculation, and is limited to vegetation types. The existing methods cannot be detected in real time and simply.

[0003] Plant microbial fuel cell (PMFC) is a technology that introduces plants into a microbial fuel cell (MFC) system, and the rhizosphere exudates of plants after photosynthesis directly serve as an electron donor for electrode microorganisms, so that sustainable electric energy can be generated. The efficiency of plant photosynthesis directly affects the secretion of plant root exudates, which provides nutrition and energy for rhizosphere microorganisms, thereby affecting the number and activity of electricity-producing microorganisms in the rhizosphere microorganisms, and indirectly affecting the electricity production efficiency of microbial fuel cells, that is, the voltage of PMFC can be used to indicate the photosynthesis efficiency of plants, therefore, the inventors design to use plant microbial fuel cell to indicate photosynthesis efficiency. SUMMARY

[0004] The utility model aims at providing a device for indicating photosynthesis efficiency by plant microbial fuel cell, which comprises an anode, a cathode, an external resistance and an electric signal collector.

[0005] The anode is buried in the soil where plants are planted and closely contacts the plant roots; the cathode is laid in the overlying water of the soil surface layer; the anode and the cathode are connected with the external resistance through wires, and the external resistance is connected with the electric signal collector through wires.

[0006] Further, the device further comprises a display screen, which is connected with the electric signal collector through wires. The electric signal data collected by the electric signal collector can be directly transmitted to the display screen for display.

[0007] Furthermore, the anode is made of stainless steel, titanium, carbon cloth, carbon felt or carbon brush.

[0008] Furthermore, the cathode is made of platinum, stainless steel, titanium, carbon cloth or carbon felt.

[0009] In the present invention, in order to prevent electronic components from malfunctioning due to moisture, the external resistor and the electrical signal collector need to be installed above the overlying water surface; in order for the cathode to fully react with the dissolved oxygen in the water, the cathode needs to be laid on the overlying water surface, close to the air.

[0010] This utility model utilizes root exudates to provide organic matter for rhizosphere microorganisms in the soil. Placing the anode close to the plant roots maximizes the decomposition of the root exudates by electrogenic bacteria and their conversion into electricity, thereby constructing a microbial fuel cell to indicate photosynthesis efficiency. This utility model uses electrical signals to indicate plant photosynthesis efficiency, allowing for intuitive and simple continuous observation of changes in plant photosynthesis efficiency. Beneficial effects

[0011] 1. Since the utility model uses root secretions to provide organic matter for soil rhizosphere microorganisms, plants that can form a symbiotic relationship with rhizosphere microorganisms, such as aquatic plants, mosses, wetland plants, and land plants that are resistant to flooding, can be used to build plant microbial fuel cells. The device has a wide range of applicability to different plant species.

[0012] 2. The raw material purchase cost is low, and the device does not require additional maintenance after it is built. It is easy to operate and can monitor the photosynthesis efficiency in real time through continuous changes in signal voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the device for indicating photosynthesis efficiency of the present invention, wherein 1 is the anode, 2 is the cathode, 3 is the external resistor, 4 is the electrical signal collector, 5 is the display screen, 6 is the container, and 7 is the lamp. DETAILED DESCRIPTION

[0014] like Figure 1 As shown, the present invention provides a device for indicating photosynthesis efficiency using a plant microbial fuel cell, comprising an anode 1, a cathode 2, an external resistor 3, and an electrical signal collector 4. The anode 1 is buried in the soil where the plant is grown, close to the plant roots; the cathode 2 is laid in the overlying water on the soil surface, close to the air; the anode 1 and cathode 2 are connected to the external resistor 3 via a wire, forming a plant microbial fuel cell; the external resistor 3 is connected to the electrical signal collector 4 via a wire, and the electrical signal collector 4 is used to collect the current or voltage signal generated by the plant microbial fuel cell. Furthermore, the device can also include a display screen 5, which is connected to the electrical signal collector 4 via a wire. The electrical signal data collected by the electrical signal collector 4 can be directly transmitted to the display screen 5 for display.

[0015] The preferred embodiments of the present application will be described in detail below with reference to the embodiments. It should be understood that the following embodiments are given only for the purpose of illustration and are not intended to limit the scope of the present application. Those skilled in the art can make various modifications and replacements to the present application without departing from the spirit and principles of the present application.

[0016] The experimental methods used in the following examples are conventional methods unless otherwise specified.

[0017] The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified. Example 1

[0018] A device for indicating photosynthetic efficiency using a plant microbial fuel cell (hereinafter referred to as "device") was built in the laboratory. The device used a cylindrical glass container 6 with a diameter of 15 cm and a height of 50 cm. 8 cm of soil was first filled into the bottom of the container 6, a circular carbon felt with a diameter of 14 cm was buried as an anode 1, and then 2 cm of soil was filled. 10 branches of fortune bamboo were placed in, and 5 L of tap water was added to the lower end of the leaves. The anode 1 and the cathode 2 were connected in series with a 20000 Ω external resistance 3, and the voltage across the external resistance 3 was collected in real time by an electric signal collector 4 and transmitted to a display 5. In order to control the light intensity, a lamp 7 was fixedly arranged on the container 6 to provide continuous light for plant growth.

[0019] After domesticating the electricity-producing microorganisms for one week using the built "device", the electricity-producing voltage of the cell stabilized in the range of 480-490 mV. The leaves of the "device" were irradiated with a lamp, and the light intensity was artificially increased to improve the photosynthetic efficiency. The cell voltage steadily increased within two days of irradiation, reaching 545-550 mV on the second day. With the increase of photosynthetic efficiency, the cell voltage also gradually increased. The change in photosynthetic efficiency was continuously and real-time observed through the rise of the electricity-producing voltage, and the indication of photosynthetic efficiency was realized.

Claims

1. An apparatus for indicating photosynthetic efficiency using a plant microbial fuel cell, characterized by, It comprises an anode (1), a cathode (2), an external resistance (3), an electric signal collector (4); The anode (1) is buried in the soil where plants are planted and is close to the root system of the plants; the cathode (2) is laid in the overlying water of the surface layer of the soil; the anode (1) and the cathode (2) are connected with the external resistance through wires, and the external resistance (3) is connected with the electric signal collector (4) through wires.

2. The apparatus of claim 1, wherein, The device further comprises a display screen (5) connected with the electric signal collector through wires.

3. The apparatus of claim 1 or 2, wherein, The material of the anode (1) is stainless steel, titanium, carbon cloth, carbon felt or carbon brush.

4. The apparatus of claim 1 or 2, wherein, The material of the cathode (2) is platinum, stainless steel, titanium, carbon cloth or carbon felt.

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