On-line monitoring and early warning instrument for disinfection by-products in drinking water chlorination disinfection

Abstract

The present application belongs to the field of online water quality monitoring, and particularly relates to an online monitoring and early warning instrument for disinfection by-products in drinking water chlorination disinfection. The instrument comprises a shell, a flow path system and an electronic control system. The flow path system comprises a flow path switching module and a UV absorbance monitoring module arranged in sequence. The flow path switching module comprises water inlet flow path I and water inlet flow path II connected with water inlet and water outlet of a water chlorination disinfection process treatment unit respectively, and further comprises a solenoid valve for switching the water inlet flow path I and the water inlet flow path II. The electronic control system comprises a control circuit mainboard for reading and calculating the absolute value ΔUVA of the difference between the UV absorbance under stable state of the water inlet flow path I and the water inlet flow path II. The present application realizes online monitoring and early warning of the concentration of disinfection by-products generated in the chlorination disinfection process by monitoring the absorbance of water samples before and after disinfection through the UV absorbance monitoring module, and according to the linear relationship between the absorbance difference and the disinfection by-products.

Description

Technical Field

[0001] This invention belongs to the field of online water quality monitoring and early warning, specifically relating to an online monitoring and early warning instrument for disinfection byproducts in drinking water chlorination disinfection. Background Technology

[0002] Chlorination disinfection of drinking water is an important method for controlling waterborne infectious diseases, but active chlorine (HOCl / OCl) is problematic. - While inactivating pathogenic microorganisms such as bacteria and viruses, disinfectants also react with dissolved natural organic matter in water to generate toxic halogenated disinfection byproducts. Among these, trihalomethanes and haloacetic acids are the two disinfection byproducts with the highest detection rates and largest quantities, mainly generated via HOCl / OCl reactions. - These substances react with dissolved organic matter in water, especially those with electron-donating groups, through electrophilic substitution to form trichloroacetic acid and trichloroacetic acid. my country's newly promulgated "Standards for Drinking Water Quality" (GB5749-2022) has upgraded dichloroacetic acid and trichloroacetic acid from unconventional to conventional indicators, with maximum limits of 50 μg / L and 100 μg / L, respectively. The "Standard Examination Methods for Drinking Water" (GB / T5750) primarily relies on high-end instruments such as gas chromatography, gas chromatography-mass spectrometry, ion chromatography, and liquid chromatography-mass spectrometry for the detection of trihalomethanes and haloacetic acids, enabling accurate quantitative analysis. However, due to the lag in laboratory testing, rapid monitoring, early warning, and control of disinfection byproducts generated during drinking water chlorination disinfection processes are difficult. In particular, for smaller rural drinking water treatment facilities, adequate analytical testing conditions are lacking, resulting in long periods of regular sampling and monitoring. Therefore, it is necessary to develop a simple, rapid, and efficient online monitoring and early warning device for disinfection byproducts.

[0003] The concentration of disinfection byproducts is related to the composition and concentration of disinfection byproduct precursors (mainly dissolved organic matter). Therefore, monitoring changes in the concentration or properties of dissolved organic matter can be used to monitor and provide early warning of disinfection byproduct indicators, such as total organic carbon concentration, ultraviolet absorption, and fluorescence signal intensity. Among these, ultraviolet absorption spectroscopy has advantages such as speed, sensitivity, and simplicity, making it more suitable for providing online feedback signals for the automated control of water treatment systems and facilitating online monitoring of dissolved organic matter. Numerous studies have shown that the concentration of disinfection byproducts during chlorination disinfection processes has a good linear relationship with the difference in ultraviolet absorbance between the influent and effluent water.

[0004] However, there is currently a lack of online monitoring and early warning devices for disinfection byproducts based on ultraviolet absorbance. The main problems and difficulties are as follows:

[0005] (1) Traditional ultraviolet absorbers or ultraviolet spectrophotometers use mercury lamps, deuterium lamps or pulsed xenon lamps as light sources, which have problems such as large size, high cost, high power consumption and long warm-up time, and especially require expensive and complex spectroscopic structures.

[0006] (2) The concentration of dissolved organic matter in drinking water is low and the change in ultraviolet absorbance before and after chlorination is small. During the use of ultraviolet spectrophotometer, the ultraviolet absorbance will drift due to light intensity attenuation and light window contamination, making it difficult to accurately predict the formation potential of disinfection byproducts.

[0007] (3) Due to the low concentration of dissolved organic matter in drinking water, a long optical path design is required to improve detection sensitivity, while the presence of tiny bubbles in the flow path will seriously interfere with accuracy.

[0008] (4) A certain amount of residual active chlorine (HOCl / OCl) remains in the effluent from the chlorination disinfection process. - ), active chlorine has a strong absorption of ultraviolet light in the 200-350 nm range, which interferes with the calculation of the difference in ultraviolet absorbance between influent and effluent water. Summary of the Invention

[0009] The purpose of this invention is to provide an online monitoring and early warning instrument for disinfection byproducts in drinking water chlorination disinfection processes.

[0010] The technical solution to achieve the purpose of this invention is: an online monitoring and early warning device for disinfection byproducts in drinking water chlorination disinfection, comprising a shell, a flow path system and an electronic control system;

[0011] The flow path system includes a flow path switching module and an ultraviolet absorbance monitoring module arranged in sequence. The flow path switching module includes an inlet flow path I and an inlet flow path II that are respectively connected to the inlet and outlet of the drinking water chlorination disinfection process unit, and also includes a solenoid valve for switching between inlet flow path I and inlet flow path II.

[0012] The electronic control system includes a mainboard of control circuits for reading and calculating the absolute value ΔUVA of the difference between the ultraviolet absorbance in the steady state of inlet flow path I and inlet flow path II, respectively.

[0013] Furthermore, the housing includes a front housing, a partition, and a rear housing;

[0014] The electronic control system is fixed on the front casing, the flow path system is fixed on the rear casing, and a partition is set between the front and rear casings to achieve isolation between water and electricity.

[0015] Furthermore, the front shell consists of an upper panel and a lower panel, which are connected by magnetic attraction or snap-fit.

[0016] The outer casing also includes a mounting plate, which is fixed to the wall, and the rear outer casing is attached to the mounting plate.

[0017] Furthermore, the ultraviolet absorbance monitoring module includes a quartz flow cell, and ultraviolet light-emitting diodes and photodiodes disposed on both sides of the quartz flow cell;

[0018] The center wavelength of the ultraviolet light-emitting diode is 255±5 nm, 265±5 nm or 275±5 nm; the optical path of the quartz flow cell is 2 cm to 10 cm.

[0019] Furthermore, it also includes an ultraviolet irradiation dechlorination module or a degassing and defoaming module set between the flow path switching module and the ultraviolet absorbance monitoring module, or an ultraviolet irradiation dechlorination module and a degassing and defoaming module connected in sequence.

[0020] Furthermore, the ultraviolet irradiation dechlorination module includes an L-shaped flow path cavity, a quartz light window, and an ultraviolet light source;

[0021] The quartz light window separates the ultraviolet light source from the liquid in the flow path. The ultraviolet light source is a light-emitting diode with a center wavelength of 290±5nm.

[0022] Furthermore, the degassing and defoaming module includes a miniature vacuum pump, a check valve, a negative pressure sensor, a sealed housing, a through-wall connector, and a hydrophobic and breathable AF2400 Teflon hose.

[0023] The AF2400 Teflon hose is located inside the sealed housing and is connected to the external flow path hose through a through-wall connector. The miniature vacuum pump is connected to the check valve, negative pressure sensor and sealed housing in sequence through the gas hose, so that negative pressure is generated inside the sealed housing to achieve degassing and defoaming.

[0024] Furthermore, the modules are connected to each other via hoses and connectors.

[0025] Furthermore, the electronic control system includes an AC-DC power supply module, a control circuit motherboard, a display screen, a wireless communication module, a soft start switch, and a main power switch.

[0026] The main control circuit board controls and processes data for the flow path switching module and the ultraviolet absorbance monitoring module, respectively, and enables human-computer interaction through the display screen and data communication with the host computer via wireless or wired communication.

[0027] Furthermore, the microcontroller on the control circuit motherboard uses the Core M101C chip.

[0028] Furthermore, the microcontroller includes an RS485 communication circuit, an Output Array output control circuit, a display connection circuit, a SIM card wireless communication and SD card and data storage circuit, a button circuit, a USB circuit, and a DC-DC conversion circuit.

[0029] The RS485 communication circuit includes two links: one connects the UV absorbance monitoring module to the microcontroller for data acquisition, and the other connects the microcontroller to the wireless communication module to upload data to the IoT cloud platform. The Output Array control circuit controls the solenoid valve through relay components to switch between the inlet flow paths. The microcontroller reads and calculates the absolute value ΔUVA of the difference between the UV absorbance measured by the UV absorbance monitoring module under stable conditions in inlet flow path I and inlet flow path II. Based on the linear relationship between ΔUVA and the concentration of disinfection byproducts, the data is displayed and controlled on the screen through the display connection circuit. The AC-DC power supply module converts 220V AC to 12V DC, and the DC-DC conversion circuit converts the 12V DC to the required voltage to match the voltage requirements of different modules.

[0030] Compared with the prior art, the significant advantages of this invention are:

[0031] This invention uses an ultraviolet absorbance monitoring module to monitor the absorbance of water samples before and after disinfection in real time. Based on the linear relationship between the absorbance difference and disinfection byproducts such as haloacetic acid or trihalomethanes, it achieves online monitoring and early warning of the concentration of disinfection byproducts generated in the chlorination disinfection process. This invention achieves accurate online monitoring, has a simple structure, and can be produced industrially.

[0032] This invention can add an ultraviolet irradiation dechlorination module or a degassing and defoaming module, or both in series, between the flow path switching module and the ultraviolet absorbance monitoring module as needed, thereby realizing online real-time monitoring of different treatment processes and having a wide range of applications. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the outer shell structure of the online monitoring and early warning instrument of the present invention; wherein (a) is a schematic diagram of the overall explosion of the outer shell, and (b) is a schematic diagram of the front outer shell.

[0034] Figure 2 This is a schematic diagram of the flow path switching module of the online monitoring and early warning instrument of the present invention.

[0035] Figure 3 This is a schematic diagram of the ultraviolet irradiation dechlorination module of the online monitoring and early warning instrument of the present invention.

[0036] Figure 4 This is a schematic diagram of the degassing and defoaming module of the online monitoring and early warning instrument of the present invention.

[0037] Figure 5 This is a schematic diagram of the ultraviolet absorbance monitoring module of the online monitoring and early warning instrument of the present invention.

[0038] Figure 6 This is a schematic diagram of the electronic control system structure of the online monitoring and early warning instrument of the present invention.

[0039] Figure 7 This is a schematic diagram of the control motherboard circuit for the online monitoring and early warning instrument of the present invention.

[0040] Figure 8 This is a schematic diagram of the control power supply circuit for the online monitoring and early warning instrument of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 11-Front housing, 12-Baffle plate, 13-Rear housing, 11-1-Upper panel, 11-2-Lower panel, 21-Flow path switching module, 21-1-Solenoid valve, 21-2-Inlet water flow path, 22-UV irradiation dechlorination module, 22-1-L-shaped flow path cavity, 22-2-Quartz light window, 22-3-UV light source, 23-Degassing and defoaming module, 23-1-Miniature vacuum pump, 23-2-Check valve, 23-3-Negative pressure sensor, 23-4-Sealed housing, 23-5-Through-wall connector, 23 -6 Teflon hose, 23-7 External flow path hose, 24 UV absorbance monitoring module, 24-1 UV light emission diode, 24-2 photodiode, 24-3 quartz flow cell, 31 AC-DC power supply module, 32 Control circuit main board, 33 Display screen, 34 Wireless communication module, 35 Soft start switch, 36 Main power switch, 40 Microcontroller, 41 RS485 communication circuit, 42 Output control circuit, 43 Display connection circuit, 44 SIM card wireless communication and SD card and data storage circuit, 45 Button circuit, 46 USB circuit, 47 DC-DC conversion circuit. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings.

[0044] like Figure 1-8 As shown, an online monitoring and early warning instrument for disinfection byproducts in drinking water chlorination disinfection process includes a shell, a flow path system, and an electronic control system. The flow path system includes a flow path switching module 21 and an ultraviolet absorbance monitoring module 24, which are connected sequentially via hoses and connectors. The electronic control system includes an AC-DC power supply module 31, a control circuit motherboard 32, and a display screen 33. The control circuit motherboard 32 controls and processes data from the flow path switching module 21 and the ultraviolet absorbance monitoring module 24, and enables human-computer interaction and data communication with a host computer via wireless or wired communication through the display screen 33.

[0045] The flow path switching module 21 achieves alternating switching between inlet flow path I and inlet flow path II through solenoid valve 21-1. Inlet flow path I and inlet flow path II are respectively connected to the inlet and outlet of the drinking water chlorination disinfection process unit.

[0046] The ultraviolet absorbance monitoring module 24 includes an ultraviolet light-emitting diode 24-1, a photodiode 24-2, and a quartz flow cell 24-3; the center wavelength of the ultraviolet light-emitting diode 24-1 is 255±5 nm, 265±5 nm, or 275±5 nm; the ultraviolet light-emitting diode 24-1 and the photodiode 24-2 are located on both sides of the quartz flow cell 24-3, with an optical path of 2 cm to 10 cm.

[0047] The control circuit motherboard 32 reads and calculates the absolute value ΔUVA of the difference between the ultraviolet absorbance in the stable state of the water inlet flow path I and the water inlet flow path II, and predicts the concentration of disinfection by-products based on the linear relationship between ΔUVA and the concentration of disinfection by-products.

[0048] The flow path system also includes an ultraviolet irradiation dechlorination module 22, located between the flow path switching module 21 and the ultraviolet absorbance monitoring module 24.

[0049] The ultraviolet irradiation dechlorination module 22 includes an L-shaped flow path cavity 22-1, a quartz light window 22-2, and an ultraviolet light source 22-3. The quartz light window 22-2 separates the ultraviolet light source 22-3 from the flow path liquid. The ultraviolet light source 22-3 is a light-emitting diode with a center wavelength of 290±5 nm.

[0050] The flow path system also includes a degassing and defoaming module 23, which is located between the flow path switching module 21 and the ultraviolet absorbance monitoring module 24.

[0051] The degassing and defoaming module 23 includes a miniature vacuum pump 23-1, a check valve 23-2, a negative pressure sensor 23-3, a sealed housing 23-4, a through-wall connector 23-5, and a hydrophobic and breathable AF2400 Teflon hose 23-6. The AF2400 Teflon hose 23-6 is located inside the sealed housing 23-4 and is connected to an external flow path hose 23-7 through the through-wall connector 23-5. The miniature vacuum pump 23-1 is connected to the check valve 23-2, the negative pressure sensor 23-3, and the sealed housing 23-4 in sequence through the gas hose, so that a negative pressure is generated inside the sealed housing 23-4. As a result, the tiny bubbles contained in the liquid inside the AF2400 Teflon hose 23-6 diffuse to the outside of the hose under the action of negative pressure and are extracted and emptied by the miniature vacuum pump 23-1. The electronic control system controls the miniature vacuum pump 23-1 by pulse width modulation based on the difference between the negative pressure value monitored by the negative pressure sensor 23-3 and the set negative pressure value.

[0052] Example 1

[0053] During the chlorination disinfection process in drinking water, active chlorine (HOCl / OCl) -Besides inactivating pathogenic microorganisms, chlorine readily undergoes complex chemical reactions with dissolved organic matter in water. In particular, its aromatic chemical structures (such as phenol and benzoic acid) readily react with active chlorine through oxidation and substitution reactions, generating a series of halogenated disinfection byproducts, such as trihalomethanes and haloacetic acids, accompanied by a decrease in ultraviolet absorbance. Numerous studies have shown a significant linear correlation between the change in ultraviolet absorbance of dissolved organic matter (ΔUVA) and the concentration of disinfection byproducts in chlorination disinfection processes. Therefore, online monitoring and early warning of disinfection byproducts can be achieved by monitoring the difference in ultraviolet absorbance (ΔUVA) of water samples before and after disinfection.

[0054] This embodiment provides an online monitoring and early warning device for disinfection byproducts in drinking water chlorination disinfection process. The device includes a shell, a flow path system, and an electronic control system.

[0055] The outer casing includes a front outer casing 11, a partition 12 and a rear outer casing 13. The electronic control system is fixed on the front outer casing 11, and the flow path system is fixed on the rear outer casing 13. The partition (12) in the middle realizes the isolation between water and electricity. The front outer casing 11 is divided into an upper panel 11-1 and a lower panel 11-2, which are connected by magnetic attraction or buckle to facilitate disassembly and maintenance. The water quality monitoring and early warning instrument is fixed by fixing the fixing plate 14 to the wall, and then hanging the rear outer casing 13 on the fixing plate 14.

[0056] The flow path system includes a flow path switching module 21 and an ultraviolet absorbance monitoring module 24, and the modules are connected in sequence through hoses and connectors;

[0057] The flow path switching module 21 achieves alternating switching between inlet flow path I and inlet flow path II through two solenoid valves 21-1. Inlet flow path I and inlet flow path II are respectively connected to the inlet and outlet of the drinking water chlorination disinfection process unit.

[0058] The ultraviolet absorbance monitoring module 24 includes an ultraviolet light-emitting diode 24-1, a photodiode 24-2, and a quartz flow cell 24-3; the center wavelength of the ultraviolet light-emitting diode is 254 nm; the ultraviolet light-emitting diode 24-1 and the photodiode 24-2 are located on both sides of the quartz flow cell 24-3, and the optical path length of the quartz flow cell is 2 cm.

[0059] The electronic control system includes an AC-DC power supply module 31, a control circuit motherboard 32, a display screen 33, a wireless communication module 34, a soft-start switch 35, and a main power switch 36. The microcontroller 40 on the control circuit motherboard 32 uses a Core M101C chip, and its pin assignments and peripheral auxiliary circuit design are as follows: Figure 7 As shown, it includes an RS485 communication circuit 41, an Output Array control circuit 42, a display connection circuit 43, a SIM card wireless communication and SD card and data storage circuit 44, a button circuit 45, a USB circuit 46, and a DC-DC conversion circuit 47. The RS485 communication circuit 41 includes two links: one connects the UV absorbance monitoring module 24 to the microcontroller 40 for data acquisition, and the other connects the microcontroller 40 to the wireless communication module 34 to upload data to the IoT cloud platform. The Output Array control circuit 42 controls the solenoid valve 21-1 via relay components to switch between flow paths. The microcontroller 40 reads and calculates the absolute value ΔUVA of the difference between the UV absorbance measured by the UV absorbance monitoring module 24 under stable conditions in inlet flow path I and inlet flow path II. Based on the linear relationship between ΔUVA and the concentration of disinfection byproducts, the data is displayed and controlled on the screen 33 via the display connection circuit 43. The AC-DC power supply module 31 converts 220V AC to 12V DC. The DC-DC conversion circuit 47 further converts the 12V DC to voltages of 1.8V, 3.3V, 4V, and 5V to match the voltage requirements of different modules, such as... Figure 8 As shown.

[0060] Example 2

[0061] The difference between this embodiment and Embodiment 1 is that:

[0062] An online monitoring and early warning instrument for disinfection byproducts in drinking water chlorination disinfection process, wherein the flow path system further includes an ultraviolet irradiation dechlorination module 22, located between the flow path switching module 21 and the ultraviolet absorbance monitoring module 24.

[0063] The ultraviolet irradiation dechlorination module 22 includes an L-shaped flow path cavity 22-1, a quartz light window 22-2, and an ultraviolet light source 22-3. The quartz light window 22-2 separates the ultraviolet light source 22-3 from the flow path liquid. The ultraviolet light source 22-3 is a light-emitting diode with a center wavelength of 290±5 nm, and its switching is controlled by the output array control circuit 42.

[0064] The ultraviolet absorbance monitoring module 24 uses a 265 nm ultraviolet light-emitting diode; the optical path length of the quartz flow cell is 5 cm.

[0065] Example 3

[0066] The difference between this embodiment and Embodiment 1 is that:

[0067] An online monitoring and early warning instrument for disinfection byproducts in drinking water chlorination disinfection process, wherein the flow path system 2 further includes a degassing and defoaming module 23, which is located between the flow path switching module 21 and the ultraviolet absorbance monitoring module 24.

[0068] The degassing and defoaming module includes a miniature vacuum pump 23-1, a check valve 23-2, a negative pressure sensor 23-3, a sealed housing 23-4, a through-wall connector 23-5, and a hydrophobic and breathable AF2400 Teflon hose 23-6. The AF2400 Teflon hose is located inside the sealed housing and is connected to an external flow path hose 23-7 via the through-wall connector. The miniature vacuum pump 23-1 is connected to the check valve, the negative pressure sensor, and the sealed housing in sequence via the gas hose, creating a negative pressure inside the sealed housing. As a result, the tiny bubbles contained in the liquid inside the AF2400 Teflon hose diffuse to the outside of the hose under the action of negative pressure and are extracted and emptied by the miniature vacuum pump. The OutputArray control circuit 42 controls the miniature vacuum pump using pulse width modulation (PWM) based on the difference between the negative pressure value monitored by the negative pressure sensor 23-3 and the set negative pressure value.

[0069] The ultraviolet absorbance monitoring module 24 uses a 275 nm ultraviolet light-emitting diode; the optical path length of the quartz flow cell is 10 cm.

[0070] Example 4

[0071] The difference between this embodiment and embodiment 3 is that:

[0072] An online monitoring and early warning instrument for disinfection byproducts in drinking water chlorination disinfection process, wherein the flow path system includes a flow path switching module 21 → an ultraviolet irradiation dechlorination module 22 → a degassing and defoaming module 23 → an ultraviolet absorbance monitoring module 24, and the modules are connected sequentially as needed.

Claims

1. An online monitoring and early warning device for disinfection byproducts in drinking water chlorination disinfection, characterized in that, This includes the housing, flow path system, and electronic control system; The flow path system includes a flow path switching module, an ultraviolet irradiation dechlorination module, a degassing and defoaming module, and an ultraviolet absorbance monitoring module connected in sequence; The flow path switching module includes inlet flow path I and inlet flow path II, which are respectively connected to the inlet and outlet of the drinking water chlorination disinfection process unit, and a solenoid valve for switching the inlet flow path I and inlet flow path II. The ultraviolet irradiation dechlorination module includes an L-shaped flow path cavity, a quartz light window, and an ultraviolet light source. The quartz light window separates the ultraviolet light source from the flow path liquid, and the ultraviolet light source is a light-emitting diode with a center wavelength of 290±5 nm. The degassing and defoaming module includes a miniature vacuum pump, a check valve, a negative pressure sensor, a sealed housing, a through-wall connector, and a hydrophobic and breathable AF2400 Teflon hose. The AF2400 Teflon hose is located inside the sealed housing and is connected to an external flow path hose through the through-wall connector. The miniature vacuum pump is connected to the check valve, the negative pressure sensor, and the sealed housing in sequence through the gas hose, so as to generate negative pressure inside the sealed housing and achieve degassing and defoaming. The ultraviolet absorbance monitoring module includes a quartz flow cell and ultraviolet light-emitting diodes and photodiodes arranged on both sides of the quartz flow cell. The center wavelength of the ultraviolet light-emitting diodes is 255±5 nm, 265±5 nm or 275±5 nm, and the optical path of the quartz flow cell is 2 cm to 10 cm. The electronic control system includes a control circuit main board, which is used to read and calculate the absolute value ΔUVA of the difference between the ultraviolet absorbance in the steady state of the inlet water flow path I and the inlet water flow path II, and realize online monitoring and early warning based on the linear relationship between ΔUVA and the concentration of disinfection by-products. The electronic control system controls the miniature vacuum pump by using pulse width modulation to measure the difference between the negative pressure value monitored by the negative pressure sensor and the set negative pressure value.

2. The online monitoring and early warning device according to claim 1, characterized in that, The housing includes a front housing, a partition, and a rear housing; The electronic control system is fixed on the front shell, the flow path system is fixed on the rear shell, and the partition is set between the front and rear shells to achieve isolation between water and electricity; The front cover consists of an upper panel and a lower panel, which are connected by magnetic attraction or snap-fit. The outer casing also includes a mounting plate, which is fixed to the wall, and the rear outer casing is attached to the mounting plate.

3. The online monitoring and early warning device according to claim 2, characterized in that, The modules are connected by hoses and connectors.

4. The online monitoring and early warning device according to claim 3, characterized in that, The electronic control system includes an AC-DC power supply module, a control circuit motherboard, a display screen, a wireless communication module, a soft start switch, and a main power switch. The main control circuit board controls and processes data for the flow path switching module and the ultraviolet absorbance monitoring module, respectively, and enables human-computer interaction through the display screen and data communication with the host computer via wireless or wired communication.

5. The online monitoring and early warning device according to claim 4, characterized in that, The microcontroller on the control circuit motherboard uses the Core M101C chip.

6. The online monitoring and early warning device according to claim 5, characterized in that, The microcontroller includes an RS485 communication circuit, an Output Array output control circuit, a display connection circuit, a SIM card wireless communication and SD card and data storage circuit, a button circuit, a USB circuit, and a DC-DC conversion circuit. The RS485 communication circuit includes two links: one connects the UV absorbance monitoring module to the microcontroller for data acquisition, and the other connects the microcontroller to the wireless communication module to upload data to the IoT cloud platform. The Output Array control circuit controls the solenoid valve through relay components to switch between the inlet flow paths. The microcontroller reads and calculates the absolute value ΔUVA of the difference between the UV absorbance measured by the UV absorbance monitoring module under stable conditions in inlet flow path I and inlet flow path II. Based on the linear relationship between ΔUVA and the concentration of disinfection byproducts, the data is displayed and controlled on the screen through the display connection circuit. The AC-DC power supply module converts 220V AC to 12V DC, and the DC-DC conversion circuit converts the 12V DC to the required voltage to match the voltage requirements of different modules.

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