CN105928822B

CN105928822B - Online automatic BOD monitoring system and using method thereof

Info

Publication number: CN105928822B
Application number: CN201610504153.9A
Authority: CN
Inventors: 丁雄; 张琳琳; 彭文姣; 李安强; 徐岩
Original assignee: Lihero Technology Hunan Co ltd
Current assignee: Lihero Technology Hunan Co ltd
Priority date: 2016-06-30
Filing date: 2016-06-30
Publication date: 2020-08-28
Anticipated expiration: 2036-06-30
Also published as: CN105928822A

Abstract

The invention discloses a BOD on-line automatic monitoring system, which comprises: a nutritive salt and strain quantifying device, a quantitative mixing aeration device, a distributing device, a culturing device and a data collecting device; the devices are connected in sequence. The invention realizes the full-automatic processing steps, thereby greatly reducing the working intensity of experimenters; the number of the sample bottles is enough to be tested every day within 7 days, the replacement period of the sample bottles is one week, and the maintenance amount is reduced; the strain is stored in an environment of 4 ℃ and is continuously used, so that the parallelism is increased, and the workload is reduced; and the detection time of the online system is not limited by other factors.

Description

Online automatic BOD monitoring system and using method thereof

Technical Field

The invention relates to the technical field of water quality analysis, in particular to an online automatic BOD monitoring system and a using method thereof.

Background

BOD (biochemical oxygen demand) can reflect the degree of pollution of the sewage by organic matter, and the more organic matter contained in the sewage, the more oxygen consumption, the higher the BOD value, and vice versa. Therefore, it is one of the most important parameters in the index of the sewage quality. Although the BOD measurement needs a long time and the data updating is not timely, the BOD index has comprehensiveness, which comprehensively reflects the total amount of organic matters, and the simulation, which simulates the self-purification of the water body, so that the BOD measurement is difficult to replace by other indexes.

The principle of measuring BOD by a pressure difference method is as follows: in a closed system, when the microorganism in the sample to be tested performs aerobic biochemical reaction, the microorganism in the water body consumes the dissolved oxygen in the water body and releases CO₂Gas, by CO₂Absorption of CO by absorbent₂The pressure value in the closed system can be differentiated, the differential value is in direct proportion to the BOD of the water body, and the BOD value is converted by detecting the pressure differential value before and after the pressure in the closed system. At present, most of domestic BOD detection instruments are laboratory instruments, only one part of the laboratory instruments manufactured by a pressure difference method is available, and online temporary shortage is achieved. Therefore, there is a need to develop an automatic online BOD monitoring system.

Disclosure of Invention

Technical problem to be solved

The invention provides an online BOD automatic monitoring system and a using method thereof, aiming at solving the technical problem of how to automatically monitor BOD online.

(II) technical scheme

In order to solve the above technical problems, the present invention provides an online automatic BOD (biochemical oxygen demand) monitoring system, comprising: a nutritive salt and strain quantifying device, a quantitative mixing aeration device, a distributing device, a culturing device and a data collecting device; the devices are connected in sequence.

Preferably, the nutrient salt and strain quantifying device is provided with two storage bottle bodies with the lower stirring nutrient salt and strain, the storage bottle bodies are stored at the low temperature of 4 ℃, the nutrient salt and the strain are extracted through a power part, the nutrient salt and the strain are quantified through a liquid metering device, and then the nutrient salt and the strain are pushed into a designated position through the power part.

Preferably, the liquid metering device comprises a liquid level pipe and a liquid level detection device, a valve is arranged in the middle of the pipeline, and nutrient salt and strains can be directionally extracted or pushed out through valve switching; the power part is a peristaltic pump or a plunger pump.

Preferably, the quantitative mixing aeration device is provided with a liquid level detection device which is provided with a sample introduction and air inlet hole, a nutrient salt and bacteria inlet hole, an air extraction hole and an air extraction pump body. Can realize the functions of mixing the sample with nutrient salt and strains and aerating and oxygenating.

Preferably, the sample introduction and air inlet hole is positioned at the lower end of the device and is a multi-purpose hole with the purpose of switching channels by using a valve, the sample introduction hole is opened to control the valve channel during sample introduction, and a sample is extracted through the pump body to enter the device; during aeration, the sample introduction and air inlet control valve channel is opened to enable gas to flow from the lower part to the upper part, and the aeration rate is controlled by controlling the extraction speed and time of the pump body.

The sample introduction and air inlet hole is positioned at the lower end of the device and is a multi-purpose hole with the function of switching channels by using a valve, the sample introduction hole is opened to control the valve channel during sample introduction, and a sample is extracted by the power part to enter; when in aeration, the aeration hole control valve channel is opened to enable the gas to flow from the lower part to the upper part, and the aeration quantity is controlled by controlling the extraction speed and time of the pump body.

Preferably, the distribution device is a device which is formed by connecting a plurality of valve arrays with a plurality of channels and independently controls each channel, the left side and the right side of the device are provided with a plurality of channels which are arranged by parallel valves, when samples are distributed, the valve body can be controlled to open and close so that the samples enter any valve channel on the left side and the right side, the lower end of the device is provided with an air inlet hole controlled by a valve, and the upper end of the device is connected with a sample introduction and air inlet hole of the quantitative mixing aeration device.

Preferably, the culture device is a sealed culture bottle with a pressure sensor, a sample inlet pipe and a non-return device, and the device is arranged on a bottle cover or a bottle body; when the bottle cap is sealed, the pressure sensor reads the air pressure in the bottle in real time, and the non-return device ensures that positive pressure does not occur during sample injection, so as to maintain the air pressure in the bottle to be stable; the inner stopper of the bottle cap is provided with a device for placing alkali particles absorbing CO2 and plays a sealing role when the bottle cap is screwed down.

Preferably, the data acquisition device acquires the pressure sensor data of each culture bottle in real time, obtains the pressure value at each time, converts the pressure value into the BOD value through software and displays the BOD value on the display screen.

The invention also provides a method for carrying out BOD online automatic monitoring by using the BOD online automatic monitoring system, which comprises the following steps:

the method comprises the following steps: automatic sample introduction process: switching the valve 14 into a water sample, starting the pump 2 for pumping, pumping the water sample into the liquid level pipe 2, and quantitatively and accurately closing the valve 14 and the pump body through a quantitative device; the blank test is carried out when the sample injection of the valve body is switched to be distilled water, the standard sample test is carried out when the sample injection of the valve body is switched to be the standard sample, and other steps are consistent;

step two: the reagent adding process comprises the following steps: a switching valve 1 and a valve 2, wherein nutrient salt and strains are pumped into the liquid level pipe 1 by the pump 2 for quantification, and then the switching valve 2 is pumped into the liquid level pipe 2 by the pump 2;

step three: aeration mixing process: all valve channels are closed, the pump 2 is started to pump air outwards, meanwhile, the air pipeline of the switching valve 3 is in a channel state, the air is pumped into the liquid level pipe 2 continuously to achieve the aim of aeration, and the sample, the nutrient salt and the strains can be mixed uniformly;

step four: and (3) quantitative distribution process: after aeration is finished, the valve 3 and the pump 1 are closed, the closing sequence of the multi-way valve and the valve connected with the bottle body is controlled, the pump 1 is started to blow air into the liquid level pipe 2, the sample is pushed into the target culture bottle, and the non-return device on the cover of the culture bottle can prevent the bottle from generating positive pressure so that the sample can smoothly enter the bottle; increasing the sample adding amount, and repeating the steps from the first step to the fourth step for multiple times to achieve the required volume;

step five: and (3) constant-temperature culture process: culturing the device in a dark room environment at 20 ℃, and continuously stirring and culturing the culture bottle with a stirring device below;

step six: and (3) detection process: and detecting the pressure change condition at any time, uploading the pressure change condition through a software computing module, and displaying the BOD value on a screen.

Preferably, the pump is a peristaltic pump or a plunger pump; the valve is a two-way valve, a three-way valve, an electromagnetic valve or a three-way electromagnetic valve.

(III) advantageous effects

In the prior art, the BOD pretreatment steps are various, the pretreatment steps are fully automatically realized, and the working intensity of experimenters is greatly reduced; the number of the sample bottles is enough to be tested every day within 7 days, and the sample bottles can be replaced once a week when replaced, so that the maintenance amount is reduced; the strain is stored in an environment of 4 ℃ for continuous use, so that the parallelism is increased, and the workload is reduced; the detection time of the online system is not limited by other factors.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of the overall structure of the BOD online automatic monitoring system of the present invention;

FIG. 2 is a schematic view of the overall flow of the BOD online automatic monitoring system of the present invention;

FIG. 3 is a schematic diagram of the process for BOD analysis using the present invention BOD on-line automatic monitoring system.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The invention relates to a BOD automatic on-line monitoring system, which realizes a series of actions of full-automatic sample introduction, reagent mixing, aeration, quantitative distribution and the like of a BOD sample by controlling a plurality of valve bodies and pump bodies to work in a linkage manner, and finally drives the BOD sample into a sample bottle for culture and detection, and reads a pressure value from time to time through a pressure sensor to convert the BOD value, thereby achieving the purpose of BOD on-line.

The invention is further illustrated by the following examples. The raw materials and components used in the present invention are commercially available conventional raw materials and components unless otherwise specified.

Example 1

Referring to fig. 1-2, the BOD online automatic monitoring system of the present invention is composed as follows: a nutritive salt and strain quantifying device, a quantitative mixing aeration device, a distributing device, a culturing device and a data collecting device; the devices are connected in sequence. Nutritive salt and bacterial quantitative device: comprises two storage bottle bodies with underlying stirred nutrient salt and strains, the storage bottle bodies are stored at the low temperature of 4 ℃, a three-way valve is arranged in the middle of a connecting pipeline of the nutrient salt and the strains, the pipeline channel can be switched to any one of the nutrient salt or the strains by switching the three-way valve,

the nutritive salt or the strain is extracted by the pump body, the volume is measured by the liquid metering device, and then the nutritive salt or the strain is pushed to a specified position by the pump body. The liquid metering device comprises a liquid level pipe and a liquid level detection device. Quantitative aeration device: is a device for quantifying the volume of a water sample and realizing the functions of mixing and aerating the water sample, nutritive salt and strains, the water sample is pumped into a liquid level pipe by a pump body and is metered by a liquid level metering deviceAnd (3) pumping nutrient salt and strains into the water sample, pumping air through the pump body, and aerating the air from the lower part to the upper part so as to uniformly mix the water sample, the nutrient salt and the strains. A distribution device: after the water sample, nutrient salt and strain are mixed and aerated, air is pushed back to the liquid level pipe by the pump body to form positive pressure, the water sample can be pushed into the distribution device, the distribution device consists of a plurality of electromagnetic valves and a plurality of channels, the opening and the closing of each channel are independently controlled by the electromagnetic valves, each channel is connected with the sample bottle, and the water sample can reach any specified sample bottle through the switching of the electromagnetic valves. A culture device: when the sample enters the sample bottle, the non-return device on the sample bottle can discharge the air in the bottle to keep the balance of the air pressure in the bottle and the external air pressure, the non-return device has the characteristic of only being out but not in, negative pressure can be generated in the bottle in the sample culture process, the non-return device can ensure that the air cannot enter the bottle, the sealing property of the bottle body is kept, and meanwhile, the sample bottle is internally provided with a gas absorbing device for absorbing CO₂The sample bottle is used for culturing under the condition of protecting from light at the temperature of 20 ℃. A data acquisition device: the pressure sensor on the sample bottle detects the pressure value in the uploading bottle in real time, and the BOD value is converted by calculation software and displayed on the display screen.

Example 2

Referring to fig. 3, the BOD analysis process using the BOD online automatic monitoring system of the present invention is as follows: starting a test flow, and carrying out a sample introduction process: switching the valve 14 and the valve 4 to an opening state, simultaneously starting the pump 1 to work, pumping a sample into the liquid level pipe 2 through the pump body 1, finally determining the liquid level through a liquid level detection device beside the liquid level pipe 2 to achieve the purpose of quantification, then closing the pump 1, the valve 14 and the valve 4, and temporarily storing the sample in the liquid level pipe 2; the process of adding salt and bacteria comprises the following steps: the channel of the switching valve 1 can achieve the purpose of extracting nutrient salt or strains, the channel of the switching valve 2 can pump the nutrient salt or the strains into the liquid level pipe 2, or pump the nutrient salt or the strains into the liquid level pipe 2 from the liquid level pipe 1, pump the nutrient salt or the strains into the liquid level pipe 1 through the pump 2, and push the strains or the nutrient salt into the liquid level pipe 2 after the quantification is carried out through the liquid level detection device; and (3) a mixed aeration process: after the water sample, the nutrient salt and the strains are all pumped into the liquid level pipe 2, opening the valve 3 and simultaneously opening the pump 1, pumping air through the pump 1, aerating and mixing the water sample, the nutrient salt and the strains for a period of time, and then closing the pump 1 and the valve 3 to finish the aeration process; and (3) quantitative distribution process: the working state of the pump 1 is opposite to that during aeration, air is blown into the liquid level pipe 2, the switching valves 5-8 and the valves 9-12 are in an open state, meanwhile, the switching valves 15-18 and the valves 20-23 are matched with each other in an open state, so that a mixed sample can reach any sample bottle or blank bottle, the sample can be pushed into the sample bottle according to the specified sequence of software in actual measurement, the sample can be added into the sample bottle for multiple times by repeating the previous steps to reach the volume required by the specified experiment, after the sample addition is finished, the valve opened during sample introduction is switched to be in a closed state, and the constant temperature culture process can be started; and (3) constant-temperature culture process: potassium hydroxide particles capable of absorbing CO2 are placed in the inner plug of the sample bottle, an air conditioner is arranged in the whole instrument, the internal environment temperature can be controlled to be 20 ℃, the sample is cultured in the sample bottle at the constant temperature of 20 ℃ for 5 days, the stirring speed at the bottom needs to be constant and uninterrupted during culture, the sample is consumed by strains to generate CO2, and the CO2 is absorbed by the potassium hydroxide particles, so that the pressure in the bottle is reduced; in the detection process, the pressure in the bottle is detected in real time through the pressure sensor on the bottle cap of the sample bottle and is uploaded to a computer, the BOD value can be automatically converted by calculation software, the numbers and the graphs are displayed on a screen in real time, and the data are stored in the computer and can be inquired.

The above embodiments are merely illustrative of the present invention and are not to be construed as limiting the invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications or equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and the technical solution of the present invention is covered by the claims of the present invention.

Claims

1. A method for BOD online automatic monitoring by using a BOD online automatic monitoring system is characterized in that the BOD online automatic monitoring system comprises: a nutritive salt and strain quantifying device, a quantitative mixing aeration device, a distributing device, a culturing device and a data collecting device; the devices are connected in sequence;

the nutrient salt and strain quantifying device comprises a second pump, a first liquid level pipe, a first storage bottle filled with nutrient salt, a second storage bottle filled with strains, a first valve and a second valve; the second pump is connected with the first interface of the first liquid level pipe, the second interface of the first liquid level pipe is connected with the first interface of the second valve, the second interface of the second valve is connected with the first interface of the first valve, the second interface of the first valve is connected with the first storage bottle, and the third interface of the first valve is connected with the second storage bottle;

the quantitative mixing aeration device comprises a first pump and a second liquid level pipe, the first pump is connected with an air suction hole of the second liquid level pipe, and a nutrient salt inlet hole and a strain hole of the second liquid level pipe are connected with a third interface of the second valve; the sample introduction and air inlet of the second liquid level pipe are connected with the upper end of the distribution device;

the distribution device is communicated with the atmosphere through a third valve; the distribution device is connected to a first interface of a fourteenth valve through a fourth valve, a second interface of the fourteenth valve is used for accessing a standard sample, and a third interface of the fourteenth valve is used for accessing a water sample; the distribution device is connected to a first interface of a nineteenth valve through a tenth valve, a second interface of the nineteenth valve is used for introducing distilled water, and a third interface of the nineteenth valve is used for discharging waste liquid;

the culture device comprises a plurality of sample bottles and blank bottles which correspond to the sample bottles one by one; the distribution device also comprises a three-way valve and a two-way valve which are in one-to-one correspondence with the sample bottles, the sample bottles and the blank bottles are respectively connected with a first interface and a second interface of the three-way valve, and the two-way valve is connected with a third interface of the three-way valve;

the liquid level detection device is used for detecting the liquid levels of the first liquid level pipe and the second liquid level pipe;

the method comprises the following steps:

the method comprises the following steps: automatic sample introduction process: switching the fourteenth valve into a water sample, switching the fourth valve into an open state, starting the first pump for pumping, pumping the water sample into the second liquid level pipe, quantitatively and accurately detecting the water sample by the liquid level detection device, and then closing the fourteenth valve, the fourth valve and the first pump; switching the nineteenth valve to sample distilled water for blank test, switching the fourteenth valve to sample standard sample for standard sample test, and keeping the other steps consistent;

step two: the reagent adding process comprises the following steps: switching the first valve and the second valve, pumping nutrient salt and strains into the first liquid level pipe by using the second pump for quantification, switching the second valve, and pumping the nutrient salt and the strains into the second liquid level pipe by using the second pump;

step three: aeration mixing process: closing the first valve, the second valve, the fourth valve, the tenth valve and the two-way valves, starting the first pump to draw air outwards, switching an air pipeline of the third valve to be in a passage state, continuously pumping the air into the second liquid level pipe to achieve the aim of aeration, and uniformly mixing the sample, the nutritive salt and the strains;

step four: and (3) quantitative distribution process: after aeration is finished, closing the third valve and the first pump, controlling the closing sequence of the two-way valve and the three-way valve, starting the first pump to start to blow air into the second liquid level pipe, and pushing the aerated and mixed sample, nutritive salt and strain into the sample bottle; the non-return device on the bottle cap of the sample bottle is used for preventing the sample bottle from generating positive pressure, so that the sample, nutritive salt and strains after aeration mixing can smoothly enter; increasing the sample adding amount and repeating the steps from the first step to the fourth step for multiple times to reach the required volume;

step five: and (3) constant-temperature culture process: placing the sample bottles in a dark room environment at 20 ℃ for culturing, wherein a stirring device is arranged below each sample bottle for continuous stirring culture;

step six: and (3) detection process: and detecting the pressure change condition in real time, uploading the pressure change condition through a software computing module, and displaying the BOD value on a screen.

2. The method of on-line automatic BOD monitoring of claim 1, wherein the first pump is a peristaltic pump or a plunger pump and the second pump is a peristaltic pump or a plunger pump.

3. The method for on-line automatic monitoring of BOD of claim 1, wherein the bottom of the first storage bottle and the bottom of the second storage bottle are both provided with stirring members, and the first storage bottle and the second storage bottle are both maintained at a low temperature of 4 ℃.

4. A method for BOD online automatic monitoring according to claim 1, characterized in that the aeration amount is controlled by controlling the pumping speed and time of the first pump when aerating.

5. The method for BOD online automatic monitoring of claim 1, wherein the sample vial comprises a pressure sensor and an inlet tube, the pressure sensor and the inlet tube being mounted on a cap of the sample vial; when the bottle cap of the sample bottle is sealed, the pressure sensor reads the air pressure in the sample bottle in real time; the bottle cap inner plug of the sample bottle is provided with a device for absorbing CO₂And plays a sealing role when the bottle cap of the sample bottle is screwed down.

6. The method for on-line automatic BOD monitoring as claimed in claim 5, wherein the data acquisition device acquires data of each pressure sensor in real time, obtains pressure values at each time, converts the pressure values into BOD values through software, and displays the BOD values on a display screen.