Sewage sludge microbial flora concentration detection device and detection method

Abstract

The invention provides a sewage sludge microbial flora concentration detection device and detection method, and relates to the technical field of sewage detection, and the detection device comprises a light-shielding box body, a light-transmitting container, a detection assembly, a moving mechanism and a processor; the light-transmitting container is arranged in the light-proof box body, and a sewage sample can be introduced and a fluorescent agent can be added. The detection assembly comprises a light splitting detection module and a fluorescence detection module; the light splitting detection module calculates the total biomass by measuring a transmission light signal; and the fluorescence detection module marks the active flora by capturing a fluorescence signal with a specific wavelength. The moving mechanism drives the detection assembly to move in the axial direction of the container, and multi-point detection is achieved. And the processor controls the moving mechanism, cooperatively analyzes transmission light and fluorescence data, establishes a quantitative relationship between the total biomass and a viable organism signal, and finally calculates the concentration of the active microorganisms. According to the device, through data fusion of light splitting and fluorescence detection, the problem that live bacteria and dead bacteria cannot be distinguished by a traditional method is solved, and accurate determination of the concentration of the active flora is realized.

Description

Technical Field

[0001] The present application relates to the technical field of sewage detection, and in particular to a device and method for detecting the concentration of microbial flora in sewage sludge. Background Art

[0002] Biological treatment is widely used in wastewater treatment due to its mature and stable technology and lower operating costs compared to physical or chemical treatment. Biological treatment relies on the metabolic activity of microorganisms to remove pollutants such as organic matter, ammonia nitrogen, and total phosphorus from wastewater. Therefore, the effectiveness of microbial growth directly determines the removal efficiency of wastewater pollutants.

[0003] During operation, conventional indicators for monitoring microorganisms in wastewater mainly include the sludge settling ratio SV30, MLSS, or MLVSS. These indicators are mainly appearance indicators and are easily interfered with by suspended matter and inorganic components in the water. The measurement results can only be used as a reference and cannot accurately reflect the concentration of microbial flora in activated sludge. Currently, the main methods for measuring microbial flora concentration are plate count method, ATP method, and spectrophotometry. Among them, the plate count method has the highest measurement accuracy, but the test cycle is long, usually requiring 2-3 days to obtain results. The ATP method is currently still in the laboratory offline detection stage.

[0004] Spectrophotometry, which measures the absorbance of a sample at a specific wavelength (OD) to assess microbial concentration, has fundamental limitations. This method cannot distinguish between the optical signals of live and dead bacteria, leading to significant deviations from the true live bacterial concentration. Because live and dead bacteria produce similar absorbance signals at 590 nm, OD values cannot accurately reflect the number of metabolically active microorganisms.

[0005] Experimental data show that although a sterilized dead bacterial suspension completely loses metabolic activity, its OD value can still deviate by up to ±15% from that of a live bacterial culture. This signal overlap leads to systematic errors in the results of spectrophotometry alone. This limitation is particularly prominent in wastewater treatment scenarios where precise activity monitoring is required.

[0006] Existing technologies attempt to distinguish live from dead bacteria using a fixed coefficient correction, but this method cannot adapt to the dynamic changes in the live / dead ratio in different samples. Furthermore, as the sludge ages, the dead bacteria ratio increases, further amplifying the detection error of spectrophotometry. This fundamental technical flaw significantly limits the application of spectrophotometry for microbial activity detection. Application Contents

[0007] In view of this, the present application proposes a sewage sludge microbial flora concentration detection device and detection method to solve the problem that the existing spectroscopic detection technology cannot distinguish the difference in signals between live and dead bacteria, resulting in errors in the detection of sewage sludge microbial flora concentration.

[0008] The technical solution of this application is achieved as follows: In one aspect, the present application provides a device for detecting the concentration of microbial flora in sewage sludge, comprising: Light-proof box; The light-transmitting container is arranged in the light-proof box, and is provided with a liquid inlet and a feeding port. The liquid inlet is used to pass the sewage sample, and the feeding port is used to add the fluorescent agent; The detection assembly includes a spectroscopic detection module and a fluorescence detection module. The spectroscopic detection module has a spectroscopic light source and a spectroscopic receiver arranged opposite to each other along a first radial direction. The spectroscopic light source is used to emit a detection beam toward the light-transmitting container, and the spectroscopic receiver is used to receive a transmitted light signal. The fluorescence detection module has a fluorescence light source and a fluorescence receiver arranged opposite to each other along a second radial direction. The fluorescence light source is used to emit an excitation beam toward the light-transmitting container, and a filter assembly is provided in front of the fluorescence receiver for receiving and filtering a fluorescence signal of a specific wavelength. The first radial direction and the second radial direction do not overlap. The moving mechanism is arranged in the light-proof box and is used to drive the detection component to move along the axial direction of the light-transmitting container; The processor is electrically connected to the spectroscopic receiver, the fluorescence receiver, and the moving mechanism, and is configured to control the moving mechanism to enable the detection component to perform detection at multiple axial positions, calculate the total biomass data of the sample based on the transmitted light signal, calculate the active bacterial colony marker data based on the fluorescence signal, and calculate the concentration data of the active microorganisms based on the total biomass data and the active bacterial colony fluorescent marker data.

[0009] On the basis of the above technical solution, preferably, the spectroscopic detection module further includes a first collimating lens provided in the light-emitting direction of the spectroscopic light source and a first focusing lens provided in the light-incident direction of the spectroscopic receiver; The fluorescence detection module further includes: A second focusing lens is provided in the light emitting direction of the fluorescent light source; and a collecting lens and a second collimating lens are provided in the light incident direction of the fluorescent receiver, and the two lenses are coaxially arranged and spaced apart; The filter assembly includes a 520nm bandpass filter and a 620nm bandpass filter, which are used to detect the fluorescence signals of live bacteria and dead bacteria respectively.

[0010] On the basis of the above technical solution, preferably, the spectroscopic detection module further includes a first light source light shield and a first receiving light shield, the first light source light shield covers the light path between the spectroscopic light source and the first collimating lens, and the first receiving light shield covers the light path between the first focusing lens and the spectroscopic receiver; The fluorescence detection module further includes a second light source shading cover and a second receiving shading cover. The second light source shading cover covers the light path between the fluorescent light source and the second focusing lens. The second receiving shading cover covers the light path between the collecting lens and the fluorescence receiver.

[0011] On the basis of the above technical solution, preferably, the detection component also includes an annular mounting disk, which is coaxially sleeved on the outer wall of the light-transmitting container, the spectroscopic detection module and the fluorescence detection module are fixedly arranged along the circumference of the annular mounting disk, and the driving end of the moving mechanism is connected to the annular mounting disk.

[0012] On the basis of the above technical solution, preferably, a stirring mechanism is further included, and the stirring mechanism includes: The stirring shaft is coaxially arranged in the light-transmitting container, and the side wall of the stirring shaft is provided with at least two symmetrically arranged receiving grooves; The stirring rod has an upper end mounted in the receiving groove via a hinge shaft and can rotate around the hinge shaft; The driving assembly is arranged on the outside of the light-transmitting container and connected to the stirring shaft, and is used to drive the stirring shaft to rotate and move axially; when the stirring shaft rotates, the stirring rod is unfolded from the storage groove under the action of centrifugal force; when the stirring shaft stops rotating, the stirring rod is retracted into the storage groove under the action of gravity.

[0013] On the basis of the above technical solution, preferably, the driving component includes: A mounting bracket is fixedly arranged on the bottom of the light-transmitting container; The limiting plate is fixedly mounted on the mounting bracket and has a through hole at its center; A toothed disc is provided between the limiting plate and the bottom surface of the light-transmitting container. The lower end of the stirring shaft movably passes through the toothed disc and the through hole. A guide groove is provided on the side wall of the stirring shaft along its axial direction. A guide protrusion is provided on the inner wall of the toothed disc to cooperate with the guide groove. A sealing member is provided on the outer side of the stirring shaft, and the sealing member is located between the toothed disc and the light-transmitting container. The rotating motor is fixed on the mounting bracket, and the output end of the rotating motor is engaged with the gear wheel through the main gear; The telescopic element has a fixed end and a telescopic end. The fixed end is fixed to the outside of the light-shielding box, and the telescopic end is rotatably connected to the lower end of the stirring shaft.

[0014] In a second aspect, the present application discloses a method for detecting the concentration of microbial flora in sewage sludge, which uses the sewage sludge microbial flora concentration detection device described in the first aspect, comprising the following steps: S1. Inject the pre-treated sludge sample to be tested into the light-transmitting cavity; S2: Start the spectrophotometric detection module and measure the initial OD value of the sample at 590 nm; S3: Start the fluorescence detection module and measure the background fluorescence intensity at 520nm ; S4: injecting fluorescent agent into the light-transmitting cavity and stirring evenly; S5: Measure the fluorescence intensity at 520 nm again F 520 ; S6: Calculate the viable bacterial concentration according to the formula: , where a is the calibration factor for the standard plate count method.

[0015] On the basis of the above technical solution, preferably, in step S3 Calculated by the following formula: ,in, is the fluorescence intensity at 520 nm before staining, is the fluorescence intensity at 620 nm before staining, is the background value of pure water at 620nm, β is the interference coefficient of dead bacteria, and the calibration value is 0.3-0.5, where To extract the specific signal of dead bacteria / organic matter in the 620nm channel, To convert the 620nm interference signal into the equivalent 520nm interference value proportionally, To deduct the contribution of dead bacteria / organic matter from the total signal at 520 nm to obtain the real live bacteria background signal. On the basis of the above technical solution, preferably, the β The coefficient was calibrated by gradient addition of dead bacteria sludge. The specific steps included: preparing sludge standard samples with dead bacteria proportions of 0%, 20%, 50%, and 80%; measuring the autofluorescence intensity of each standard sample at 520nm / 620nm; fitting β The value minimizes the error in the calculation of viable bacterial concentration.

[0016] On the basis of the above technical solution, preferably, after step S1, an axial multi-point detection step is further included: S11, drive the detection component to move along the axial direction of the light-transmitting container through the moving mechanism, and perform steps S2-S5 at at least three equally spaced positions in sequence, and record the OD at each position respectively. 590 、 F 520 and value; S12, measured at each position F 520 and After taking the arithmetic mean, the average OD 590 The value is substituted into the formula in step S6 to calculate the final viable bacteria concentration.

[0017] Compared with the prior art, this application has the following beneficial effects: (1) The sewage sludge microbial flora concentration detection device disclosed in this application obtains total sample biomass data through a spectrophotometric detection module and uses a fluorescence detection module to specifically identify live bacteria marker signals. The processor establishes a quantitative relationship between the total biomass data and the live bacteria marker signals based on a collaborative analysis of the two, thereby achieving accurate calculation of the active microbial concentration. This technical effect is derived from the inherent correlation between the total biomass benchmark provided by spectrophotometric detection and the live bacteria-specific signal provided by fluorescence detection. Through data fusion processing by the processor, it effectively solves the technical problem that traditional methods cannot distinguish between live and dead bacteria.

[0018] (2) By optimizing the optical structure of the spectroscopic detection module and the fluorescence detection module, the detection accuracy and reliability are significantly improved. The spectroscopic detection module uses the first collimating lens to ensure the incident light beam is parallel, and the first focusing lens is combined to improve the signal-to-noise ratio of the transmitted light signal, making the OD value measurement more stable. The fluorescence detection module forms a uniform excitation spot through the second focusing lens, and at the same time uses a combined optical path of the collecting lens + the second collimating lens to greatly improve the collection efficiency of the fluorescence signal and optimize the incident angle of the light beam to match the optimal working conditions of the filter. The filter assembly (520nm / 620nm bandpass filter) accurately separates the fluorescence signals of live bacteria and dead bacteria, improves the specificity of live bacteria detection, and reduces the interference of dead bacteria.

[0019] (3) By setting the stirring mechanism as a retractable structure, the driving assembly pushes the stirring shaft into the light-transmitting container during the stirring stage, and the hinged stirring rod is expanded by centrifugal force to achieve efficient mixing. After the stirring is completed, the stirring rod is automatically retracted into the storage groove under the action of gravity, so that the stirring shaft can exit the detection area without obstacles. This not only ensures the uniform distribution of the fluorescent dye, but also completely eliminates the obstruction of the light path by the traditional rigid stirring rod, and realizes the interference-free collaborative operation of stirring and mixing and optical detection.

[0020] (4) The drive assembly achieves precise control of the rotation and axial movement of the agitator shaft through an innovative mechanical structure design. The gear disc and the agitator shaft cooperate through a guide groove to ensure stable and reliable power transmission while allowing the agitator shaft to rise and fall freely; the seal effectively prevents sewage leakage, and the telescopic element and the agitator shaft are connected by a rotation to avoid motion interference. This design enables the agitator mechanism to smoothly complete the complete workflow of extending into the agitator and withdrawing to avoid the agitator, which not only ensures the agitation effect, but also ensures that the light path is not disturbed during detection, and the overall operation is stable and reliable.

[0021] (5) This application combines OD value (total biomass) with fluorescence signal (specificity of live bacteria) to useOD 590 As the total biomass benchmark, the fluorescence difference ( ) Extract the live bacteria ratio to avoid interference from dead bacteria. (Contains dead bacteria / organic matter signals) Corrected staining F 520 , significantly improving the specificity of live bacteria detection, through experimental calibration α , adapting to the characteristics of different sludge samples and reducing system errors. By fusing data from spectrophotometry (OD value) and fluorescence (520nm / 620nm dual-channel), the inherent defect of traditional spectrophotometry, which cannot distinguish between live and dead bacteria, is overcome, greatly reducing the error in live bacteria concentration detection.

[0022] (6) Through 620nm signal and β The interference signal of dead bacteria / organic matter at 520 nm is quantified by the synergistic correction of the coefficient. and from F auto520 Deduct from the final This method significantly reduces the error in live bacteria concentration detection and is particularly suitable for complex sludge samples with a high proportion of dead bacteria or containing humic acid, significantly improving the accuracy and universality of the detection method of this embodiment.

[0023] (7) A mobile mechanism is used to drive the detection component to perform measurements at at least three equally spaced positions along the axis of the light-transmitting container. The final viable bacteria concentration is calculated after taking the average of the data at each point. This method effectively eliminates the measurement deviation caused by the uneven axial distribution of the sample, making the test results more representative and reducing the measurement error as much as possible. At the same time, it enhances the system's adaptability to complex samples such as high-concentration samples or samples containing particulate matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 This is a schematic diagram of the three-dimensional structure of the sewage sludge microbial flora concentration detection device disclosed in this application; Figure 2 This is a schematic diagram of the internal structure of the sewage sludge microbial flora concentration detection device disclosed in this application; Figure 3 This is a schematic diagram of the planar structure of the detection assembly disclosed in this application; Figure 4This is a schematic diagram of the first-perspective three-dimensional structure of the sewage sludge microbial flora concentration detection device disclosed in this application after removing the light-shielding box; Figure 5 This is a schematic diagram of the third perspective structure of the sewage sludge microbial flora concentration detection device disclosed in this application after removing the light-shielding box; Figure 6 A schematic diagram of the three-dimensional structure of the stirring mechanism disclosed in this application; Figure 7 A top view of the sewage sludge microbial flora concentration detection device disclosed in this application; Figure 8 for Figure 7 Plane section view at AA in the middle; Figure 9 for Figure 7 Plane section view at the middle BB; Figure 10 for Figure 9 A partial enlarged view of point C in the middle; Reference numerals: 1. Light-proof housing; 2. Light-transmitting container; 21. Liquid inlet; 22. Feeding port; 3. Detection assembly; 30. Ring mounting plate; 31. Spectroscopic detection module; 311. Spectroscopic light source; 312. Spectroscopic receiver; 313. First collimating lens; 314. First focusing lens; 315. First light source light shield; 316. First receiver light shield. 32. Fluorescence detection module; 321. Fluorescence light source; 322. Fluorescence receiver; 323. Second focusing lens; 324. Collecting lens; 325. Second collimating lens; 326. Filter assembly; 327. Second light source light shield; 328. Second receiving light shield; 3261. 520nm bandpass filter; 3262. 620nm bandpass filter; 4. Moving mechanism; 5. Stirring mechanism; 51. Stirring shaft; 511. Storage slot; 512. Guide groove; 52. Stirring rod; 52. Driving assembly; 521. Mounting bracket; 5211. Limiting plate; 5212. Through hole; 522. Toothed disc; 5221. Guide protrusion; 523. Rotating motor; 524. Main gear; 525. Telescopic element; 526. Seal; 527. Linkage; 6. Mounting tube; 7. Fixing frame. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] like Figure 1 As shown, combined Figure 2-10 The embodiment of the present application discloses a device for detecting the concentration of microbial flora in sewage sludge, including a light-proof box 1, a light-transmitting container 2, a detection component 3, a moving mechanism 4 and a processor.

[0028] The light-proof box 1 serves as the installation base of the entire detection device, and provides a closed detection environment to eliminate interference from ambient light, especially interference with the fluorescent signal.

[0029] A light-transmitting container 2 is disposed within the light-proof housing 1 and is used to hold the sewage sludge sample and provide an optical detection window. The light-transmitting container 2 is made of a light-transmitting material with high UV-visible light transmittance, such as quartz glass. In this embodiment, the light-transmitting container 2 is preferably cylindrical, which allows the sewage sludge sample to be evenly dispersed within the container. The light-transmitting container 2 is provided with a liquid inlet 21 for introducing the sewage sample and a feed port 22 for adding a fluorescent dye, such as SYBR Green I.

[0030] The detection assembly 3 comprises a spectroscopic detection module 31 and a fluorescence detection module 32. The spectroscopic detection module 31 comprises a spectroscopic light source 311 and a spectroscopic receiver 312, arranged opposite each other along a first radial direction. The spectroscopic light source 311 is used to transmit a detection beam toward the light-transmitting container 2, and the spectroscopic receiver 312 is used to receive the transmitted light signal. In this embodiment, the wavelength of light emitted by the spectroscopic light source 311 is between 550nm and 650nm, preferably a 590nm LED, to avoid common absorption peaks of sludge, such as the strong absorption of humic acid at 400-500nm. The spectroscopic receiver 312 is a silicon photodiode with a wavelength range of 400nm to 1100nm.

[0031] In this embodiment, the spectroscopic light source 311 emits a detection light beam, which then vertically penetrates the sewage sample in the light-transmitting container 2. The transmitted light is detected by the spectroscopic receiver 312 (silicon photodiode), and the total biomass is calculated according to the Lambert-Beer light absorption law.

[0032] The fluorescence detection module 32 comprises a fluorescence light source 321 and a fluorescence receiver 322, arranged opposite each other along a second radial direction. The fluorescence light source 321 is used to emit an excitation beam toward the light-transmitting container 2, and the fluorescence receiver 322 is used to receive the fluorescence signal. In this embodiment, the fluorescence light source 321 is a 470nm blue-light-emitting LED, matching the optimal excitation wavelength of SYBR Green I. The fluorescence receiver 322 is a photomultiplier tube (PMT) or a high-sensitivity APD. A filter assembly 326 is positioned in front of the fluorescence receiver 322. The filter assembly 326 includes a 520nm bandpass filter 3261 and a 620nm bandpass filter 3262, respectively, for detecting the fluorescence signals of live and dead bacteria.

[0033] 470nm excitation light excites the fluorescent dye, and live bacterial DNA binds to the dye, emitting 520nm fluorescence, while dead bacteria / impurities emit 620nm fluorescence. By separating the signals with dual-wavelength filters, active bacterial marker data can be calculated.

[0034] In this embodiment, the first radial direction and the second radial direction do not overlap, so that the optical paths of the spectroscopic detection module 31 and the fluorescence detection module 32 do not overlap, so that light beams can be emitted into the sample respectively, and then corresponding data can be measured.

[0035] The moving mechanism 4 is disposed within the light-proof housing 1 and is used to drive the detection assembly 3 to move axially along the light-transmitting container 2. With this arrangement, the spectroscopic detection module 31 can be moved axially along the light-transmitting container 2 to detect the total biomass data of sewage samples at different axial locations within the light-transmitting container 2. Correspondingly, the fluorescence detection module 32 can also be moved axially along the light-transmitting container 2 to detect fluorescence signals from sewage samples at different axial locations within the light-transmitting container 2.

[0036] In this example, dead bacteria, organic debris, or free dyes in the sludge sample will spontaneously generate fluorescence (such as a 620 nm signal), which is directly superimposed on the live bacteria-specific signal (520 nm), resulting in a high false positive rate.

[0037] Therefore, before adding fluorescent dye, background signal measurement is required. This test measures the sludge sample's autofluorescence at wavelengths of 520nm and 620nm. This includes dead bacteria / cell debris: background fluorescence (main peak at 620nm) generated by DNA / RNA fragments released from damaged cells; and organic matter such as humic acid: weak fluorescence at 520nm from natural organic matter in the sludge. This background signal measurement is used to correct the data after staining.

[0038] The fluorescence measurement after adding the dye includes the total fluorescence response of the live bacteria signal and the residual background, which includes the live bacteria specific signal: the dye binds to the intact DNA of the live bacteria and emits 520nm fluorescence (intensity F 520 ); Residual background signal: non-specific binding of dead bacteria / organic matter to the dye (still contains 620nm fluorescence).

[0039] By subtracting the background signal from the total fluorescence data, the true live bacteria signal can be obtained.

[0040] During the actual processing process, the spectroscopic light source emits a 590nm beam, and the spectroscopic receiver measures the transmitted light intensity (OD value) at that position; the fluorescent light source excites the sample, and the fluorescent receiver measures the 520nm fluorescence signal and background interference (such as the 620nm signal). The processor directly uses the OD value and fluorescence signal of the current point (520nm minus the background) to calculate the viable bacteria concentration through the pre-calibrated calibration coefficient.

[0041] During the data processing process, this embodiment uses a processor electrically connected to the spectroscopic receiver 312, the fluorescence receiver 322 and the moving mechanism 4. The processor, which is an embedded system or an industrial computer, is configured to control the moving mechanism 4 to enable the detection component 3 to perform detection at multiple axial positions, and can measure data at different positions.

[0042] The total biomass data of the sample is calculated based on the transmitted light signal. The spectrophotometric detection module 31 measures the transmitted light intensity (OD value) of the sample at a wavelength of 590 nm. This signal directly reflects the total biomass concentration of the sample (including live bacteria, dead bacteria and other light-absorbing substances).

[0043] The active bacterial colony marker data is calculated based on the fluorescence signal. Specifically, the fluorescence detection module induces SYBR Green I dye to bind to the live bacterial DNA through 470nm excitation light, emitting a 520nm fluorescence signal ( F 520 ), while detecting the 620nm background signal ( F 背景 ), the live bacteria marker data is calculated by dual wavelength difference: active bacteria marker = , and eliminate the interference of dead bacteria and impurities through background subtraction.

[0044] Based on the total biomass data and the fluorescent labeling data of the active bacterial colony, the concentration data of the active microorganisms is calculated. The concentration of live bacteria can be calculated using the formula: , where a is the calibration factor for the standard plate count method.

[0045] In this embodiment, if F is used directly 520 Calculation, samples with the same live bacteria concentration will have high deviations due to turbidity differences (such as different sludge thickness). High turbidity samples will attenuate the fluorescence intensity (light scattering effect), which needs to be compensated by OD value and calculated by difference. Eliminate the interference of sample matrix autofluorescence and ensure that the detection signal only reflects the specific fluorescence of SYBR Green I dye binding to live bacterial DNA. 590 Contains dead bacteria absorbance, through OD 590 (total biomass) and fluorescence signal (F 520 ) inverse relationship, inverse calculation can suppress its interference, the higher the proportion of dead bacteria, the higher the OD / F 520 The larger the ratio, the more automatic correction is made to the calculation result.

[0046] The sewage sludge microbial flora concentration detection device disclosed in this application uses a spectrophotometric detection module 31 to obtain total sample biomass data, while utilizing a fluorescence detection module 32 to specifically identify live bacteria marker signals. The processor then establishes a quantitative relationship between the total biomass data and the live bacteria marker signals based on a collaborative analysis of the two, thereby accurately calculating the concentration of active microorganisms. This technical advantage stems from the inherent correlation between the total biomass benchmark provided by spectrophotometric detection and the live bacteria-specific signals provided by fluorescence detection. Through data fusion processing by the processor, this effectively addresses the technical issue of traditional methods being unable to distinguish between live and dead bacteria.

[0047] As some embodiments, see the attached Figure 3 and 8 As shown, the spectroscopic detection module 31 further includes a first collimating lens 313 and a first focusing lens 314 .

[0048] The first collimating lens 313 is arranged in the light emitting direction of the spectroscopic light source 311 to convert the divergent light source into a parallel beam, thereby eliminating the OD value measurement error caused by the beam angle difference and ensuring the applicable conditions of the Beer-Lambert law (uniform optical path).

[0049] The first focusing lens 314 is located in the light incident direction of the spectroscopic receiver 312 , and its focal length matches the diameter of the light-transmitting container 2 , focusing the transmitted light onto the detection surface of the spectroscopic receiver 312 to improve the signal-to-noise ratio.

[0050] Refer to the attached Figure 3 and 9 As shown, the fluorescence detection module 32 further includes a second focusing lens 323 , a collecting lens 324 and a second collimating lens 325 .

[0051] The second focusing lens 323 is located in the direction of light emission from the fluorescent light source 321. It is configured as an aspheric lens and is used to form an excitation spot of a certain diameter in the sample area. The collecting lens 324 and the second collimating lens 325 are located in the direction of light incidence from the fluorescence receiver 322, with the second collimating lens 325 being located close to the fluorescence receiver 322. The collecting lens 324 is positioned as close as possible to the sidewall of the light-transmitting container 2 to efficiently focus the scattered fluorescence emitted by the sample, improving signal capture capabilities. The second collimating lens 325 re-collimates the scattered light into a parallel beam, ensuring that the light passes through the subsequent filter assembly 326 at the optimal angle of incidence, thereby avoiding spectral shift caused by oblique incidence.

[0052] Filter assembly 326 includes a 520 nm bandpass filter 3261 and a 620 nm bandpass filter 3262, which are used to detect the fluorescence signals of live and dead bacteria, respectively. Specifically, 520 nm bandpass filter 3261 is used to extract the characteristic fluorescence (main peak at 520 nm) generated by the binding of the fluorescent dye (SYBR Green I) to live bacterial DNA. 620 nm bandpass filter 3262 is used to monitor the interfering fluorescence of dead bacteria and organic matter (for background subtraction).

[0053] By optimizing the optical structures of the spectroscopic detection module 31 and the fluorescence detection module 32, detection accuracy and reliability have been significantly improved. The spectroscopic detection module 31 utilizes a first collimating lens 313 to ensure parallel light beam incidence. Combined with a first focusing lens 314, this lens improves the signal-to-noise ratio of the transmitted light signal, resulting in more stable OD measurement. The fluorescence detection module 32 uses a second focusing lens 323 to form a uniform excitation spot. It also utilizes a combined optical path consisting of a collection lens 324 and a second collimating lens 325, significantly improving fluorescence signal collection efficiency and optimizing the beam incident angle to match the filter's optimal operating conditions. The filter assembly 326 (520nm / 620nm bandpass filter 3262) precisely separates the fluorescence signals of live and dead bacteria, improving the specificity of live bacteria detection and reducing interference from dead bacteria. Through precise optical design, the overall solution achieves highly sensitive and repeatable detection of active microbial concentrations.

[0054] As some embodiments, see the attached Figure 4 、 8 As shown in Figure 9 , the spectroscopic detection module 31 also includes a first light source shield 315 and a first receiving shield 316. The first light source shield 315 covers the optical path between the spectroscopic light source 311 and the first collimating lens 313, eliminating lateral leakage of LED divergent light and blocking ambient light from entering the optical path from the lens edge. The first receiving shield 316 covers the optical path between the first focusing lens 314 and the spectroscopic receiver 312, preventing the transmitted light from being contaminated by ambient light before reaching the detector and suppressing secondary interference from light reflected from the lens surface.

[0055] The fluorescence detection module 32 also includes a second light source shield 327 and a second receiver shield 328. The second light source shield 327 covers the optical path between the fluorescence light source 321 and the second focusing lens 323, ensuring that the excitation light enters the sample only through the predetermined optical path. The second receiver shield 328 covers the optical path between the collection lens 324 and the fluorescence receiver 322, blocking background light interference outside the sample cell and maintaining a dark field detection environment for the filter assembly 326.

[0056] The above-mentioned sunshades are all made of opaque materials.

[0057] In order to achieve synchronous movement of the spectroscopic detection module 31 and the fluorescence detection module 32 along the axial direction of the transparent container 2, the detection component 3 of this embodiment also includes an annular mounting disk 30, which is coaxially sleeved on the outer wall of the transparent container 2, and the spectroscopic detection module 31 and the fluorescence detection module 32 are fixedly arranged along the circumference of the annular mounting disk 30, and the driving end of the moving mechanism 4 is connected to the annular mounting disk 30.

[0058] In this embodiment, the optical paths of the spectroscopic detection module 31 and the fluorescence detection module 32 are perpendicular to each other, so that the components in the spectroscopic detection module 31 and the fluorescence detection module 32 can be evenly distributed on the annular mounting plate 30. At the same time, the optical paths of the spectroscopic detection module 31 and the fluorescence detection module 32 are coplanar. In this way, the spectroscopic detection module 31 and the fluorescence detection module 32 can synchronously detect the sample at the same cross section of the light-transmitting container 2. For example, before the fluorescent dye is added, the spectroscopic detection module 31 and the fluorescence detection module 32 can be triggered alternately for detection, and the alternating time difference is less than 1ms, thereby ensuring the spatial-temporal synchronization of the spectroscopic and fluorescence signals and reducing the calculation error of the live bacteria concentration. For example, before the fluorescent dye is added, the spectroscopic detection module 31 and the fluorescence detection module 32 can be driven by the moving mechanism to synchronously move along the axial direction of the light-transmitting container, and the OD value and the fluorescence value at each axial position of the sewage sample can be measured respectively. F 背景 .

[0059] In this embodiment, the moving mechanism 4 is a screw module, including a motor, a screw and a nut seat. The motor is fixed to the bottom surface of the light-proof box 1, and the output shaft of the motor is vertically upward and connected to the nut seat and the annular mounting plate 30. In this way, the position of the detection component 3 in the axial direction of the light-transmitting container 2 can be efficiently and accurately controlled.

[0060] After adding the fluorescent dye to the light-transmitting container 2, it needs to be stirred to mix thoroughly. Without stirring, the fluorescent dye (such as SYBR Green I) can be unevenly distributed in the sludge, resulting in locally high concentrations and large deviations in test results. Traditional fixed agitators can block the light path, causing OD measurement distortion and scattered fluorescence signals.

[0061] For this purpose, this embodiment shows a stirring mechanism 5. Figure 4-10 As shown, the stirring mechanism 5 includes a stirring shaft 51 , a stirring rod 52 and a driving assembly 52 .

[0062] Among them, the stirring shaft 51 is coaxially arranged in the light-transmitting container 2, and its side wall is provided with at least two symmetrically arranged storage grooves 511. The upper end of the stirring rod 52 is installed in the storage groove 511 through a hinge shaft and can rotate around the hinge shaft. Specifically, when the stirring shaft 51 rotates centrifugally, the upper end of the stirring rod 52 can rotate around the hinge shaft toward the outside of the stirring shaft 51. When there is no centrifugal force, the stirring rod 52 is retracted into the storage groove 511 under the action of gravity.

[0063] In this embodiment, the length and width of the receiving groove are slightly larger than the length and width of the stirring rod 52, so as to ensure that the stirring rod 52 can be easily retracted into the receiving groove 511 under the action of gravity. By setting the depth of the receiving groove to be greater than the thickness of the stirring rod 52, after the stirring rod 52 is retracted into the receiving groove 511, the outer wall of the stirring rod 52 and the outer wall of the stirring shaft 51 are not coaxial, so as to avoid sludge adhering to the receiving groove 511, resulting in the outer wall of the stirring rod 52 protruding from the outside of the receiving groove 511 after the stirring rod 52 is retracted into the receiving groove 511.

[0064] In this embodiment, the driving assembly 52 is disposed outside the light-transmitting container 2 and connected to the stirring shaft 51 to drive the stirring shaft 51 to rotate and move axially. Specifically, the driving assembly 52 is disposed at the bottom of the light-transmitting container 2.

[0065] When stirring is required, the driving component 52 drives the stirring shaft 51 to extend into the interior of the light-transmitting container 2. After the stirring shaft 51 is extended to the appropriate position of the light-transmitting container 2, the driving component 52 drives the stirring shaft 51 to rotate, and the stirring rod 52 is unfolded from the receiving groove 511 under the action of centrifugal force, thereby stirring and mixing the sewage with the added fluorescent dye.

[0066] After stirring is completed, if the stirring rod 52 and the stirring shaft 51 are rigidly connected, the stirring shaft 51 will be blocked by the stirring rod 52, and the stirring shaft 51 cannot be withdrawn by the driving assembly 52. Therefore, in this embodiment, the upper end of the stirring rod 52 is hinged to the stirring shaft 51, and a storage groove 511 is provided on the outside of the stirring shaft 51. After stirring is completed, the stirring rod 52 can be automatically retracted into the storage groove 511 by gravity, preventing the stirring rod 52 from leaking out of the stirring shaft 51 and affecting the withdrawal of the stirring shaft 51 from the light-transmitting container 2.

[0067] The stirring mechanism 5 of this embodiment adopts a retractable design. During the stirring stage, the driving component 52 pushes the stirring shaft 51 into the light-transmitting container 2, and the hinged stirring rod 52 is expanded by centrifugal force to achieve efficient mixing. After the stirring is completed, the stirring rod 52 is automatically retracted into the storage groove 511 under the action of gravity, so that the stirring shaft 51 can exit the detection area without obstacle, which not only ensures the uniform distribution of the fluorescent dye, but also completely eliminates the obstruction of the light path by the traditional rigid stirring rod 52, and realizes the interference-free coordinated operation of stirring and mixing and optical detection.

[0068] In order to realize that the driving assembly 52 can realize both the rotation of the stirring shaft 51 and the linear movement of the stirring shaft 51, this embodiment shows a preferred structural mode of the driving assembly 52. Specifically, the driving assembly 52 includes a mounting bracket 521, a gear plate 522, a rotating motor 523, a main gear 524 and a telescopic element 525.

[0069] Among them, the mounting bracket 521 is fixedly set at the bottom of the light-transmitting container 2, and the mounting bracket 521 is used to position the gear disc 522 and the rotating motor 523. Specifically, a limit plate 5211 is fixedly set on the mounting bracket 521, and the limit plate 5211 is parallel to the bottom surface of the light-transmitting container 2, and there is a gap between the limit plate 5211 and the light-transmitting container 2, which is used to install the gear disc 522. The above-mentioned gap is adapted to the thickness of the gear disc 522, thereby ensuring that after the gear disc 522 is located between the limit plate 5211 and the bottom surface of the light-transmitting container 2, the gear disc 522 will not move axially.

[0070] A through hole 5212 is defined in the limiting plate 5211 for the stirring shaft 51 to pass through. The stirring shaft 51 can move and rotate axially along the through hole 5212 .

[0071] The toothed disc 522 is arranged between the limiting plate 5211 and the bottom surface of the light-transmitting container 2. The lower end of the stirring shaft 51 moves through the toothed disc 522 and the through hole 5212. The side wall of the stirring shaft 51 is provided with a guide groove 512 along its axial direction. The inner wall of the toothed disc 522 is provided with a guide protrusion 5221 that cooperates with the guide groove 512. Due to the cooperation between the guide groove 512 and the wire protrusion, the toothed disc 522 and the stirring shaft 51 cannot rotate relative to each other, and can only achieve overall rotation. At the same time, the stirring shaft 51 can move axially relative to the toothed disc 522.

[0072] Due to the presence of the guide groove 512 on the stirring shaft 51, the sewage inside the light-transmitting container 2 will flow out of the outside of the light-transmitting container 2 along the guide groove 512. Therefore, this embodiment also provides a seal 526 on the outside of the stirring shaft 51. The seal 526 is located between the toothed disc 522 and the light-transmitting container 2. With this arrangement, the seal 526 can seal the bottom surface of the mounting hole of the stirring shaft 51 and the light-transmitting container 2 to prevent sewage from flowing out of the outside of the light-transmitting container 2 along the guide groove 512.

[0073] The rotating motor 523 is fixedly mounted on the mounting bracket 521 , and the output end of the rotating motor 523 is engaged with the toothed disc 522 through the main gear 524 . Thus, the rotating motor 523 drives the main gear 524 to rotate, and the main gear 524 drives the toothed disc 522 to rotate, thereby causing the toothed disc 522 to drive the stirring shaft 51 to rotate.

[0074] The telescopic element 525 has a fixed end and a telescopic end. The fixed end is fixed to the outside of the light-shielding housing 1, and the telescopic end is rotatably connected to the lower end of the stirring shaft 51. With this arrangement, when the stirring shaft 51 needs to be moved, the telescopic element 525 is extended or shortened to drive the stirring shaft 51 in the axial direction of the light-transmitting container 2. Specifically, when the stirring shaft 51 needs to be inserted into the light-transmitting container 2 to perform stirring, the telescopic end of the telescopic element 525 is extended. When the stirring shaft 51 needs to be withdrawn from the light-transmitting container 2, the telescopic end of the telescopic element 525 is shortened.

[0075] During the movement of the stirring shaft 51, since the guide groove 512 and the guide protrusion 5221 cooperate with each other, the stirring shaft 51 can only move axially relative to the toothed disc 522. At this time, the toothed disc 522 is limited between the limiting plate 5211 and the light-transmitting container 2. Therefore, the toothed disc 522 will not move axially. In this embodiment, the end of the stirring shaft 51 cannot be separated from the contact surface between the toothed disc 522 and the limiting plate 5211. This is because there is a sealing member 526 between the top surface of the toothed disc 522 and the bottom surface of the light-transmitting container 2, which can seal the mounting hole on the light-transmitting container 2 to prevent sewage from flowing out of the mounting hole and overflowing to the periphery of the toothed disc 522.

[0076] Since the telescopic end of the telescopic element 525 is rotatably connected to the stirring shaft 51, the stirring shaft 51 can rotate relative to the telescopic end of the telescopic element 525 during rotation, without affecting the rigid movement restriction of the telescopic element 525. In this embodiment, the telescopic element 525 is a pneumatic cylinder, an oil cylinder, or an electric push rod.

[0077] The drive assembly 52 of this embodiment achieves precise control of the rotation and axial movement of the agitator shaft 51 through an innovative mechanical design. The toothed disc 522 and the agitator shaft 51 cooperate through guide grooves, ensuring stable and reliable power transmission while allowing the agitator shaft 51 to rise and fall freely. The seal 526 effectively prevents sewage leakage, and the telescopic element 525 is connected to the agitator shaft 51 through a rotational connection to avoid motion interference. This design enables the agitator mechanism 5 to smoothly complete the entire workflow of extending into the agitator and withdrawing out of the way, ensuring both effective agitation and an uninterrupted optical path during detection, resulting in stable and reliable overall operation.

[0078] As some embodiments, the light-transmitting container 2 is fixed on the inner bottom surface of the light-proof box 1 by means of the mounting tube 6. The bottom of the mounting tube 6 is open. The mounting tube 6 has a cavity of a certain depth. The bottom of the light-proof box 1 is open and corresponds to the opening of the mounting tube 6. The mounting bracket 521, the gear wheel 522, the rotating motor 523 and the active gear are arranged in the cavity of the mounting tube 6, thereby realizing protection of the driving component 52 and preventing the entire driving component 52 from being completely exposed to the outside of the light-proof box 1.

[0079] In addition, in order to realize the installation of the telescopic element 525, the present embodiment also fixes a fixing bracket 7 at the bottom opening of the light-proof box 1, on the one hand, to block the bottom opening of the installation tube 6, and on the other hand, as the installation basis of the telescopic element 525, by arranging the installation tube 6 inside the light-proof box 1, at least a part of the driving component 52 can be hidden inside the light-proof box 1 to avoid being completely exposed at the bottom of the light-proof box 1, which causes the volume of the mechanical components to occupy a larger space at the bottom of the light-proof box 1, while reducing the protection of the driving component 52.

[0080] The present application discloses a method for detecting the concentration of microbial flora in sewage sludge, comprising the following steps: S1. Inject the pre-treated sludge sample into the light-transmitting cavity. The sludge sample is pre-treated (e.g., crushed, filtered, diluted) and then injected into the light-transmitting container to ensure sample uniformity and avoid particulate matter interfering with optical detection.

[0081] S2: Start the spectrophotometric detection module and measure the initial OD of the sample at 590nm 590 The initial OD value was measured at a wavelength of 590 nm, reflecting the total biomass of the sample (including living bacteria, dead bacteria, and non-biological light-absorbing substances).

[0082] S3: Start the fluorescence detection module and measure the background fluorescence intensity at 520nm When no fluorescent dye is added, the autofluorescence intensity at 520 nm is detected. , used for subsequent deduction of interference signals from dead bacteria / organic matter.

[0083] S4: Inject a fluorescent agent into the light-transmitting cavity and stir evenly. Add a fluorescent dye such as SYBR Green I and use the stirring mechanism to stir the fluorescent dye and wastewater to ensure that the fluorescent dye and live bacterial DNA are fully mixed.

[0084] S5: Measure the fluorescence intensity at 520 nm again F 520 Before proceeding to step S5, the stirring shaft needs to be removed from the light-transmitting container to prevent the stirring shaft and stirring rod from affecting the light path. Measure the fluorescence intensity at 520 nm F 520 , at this time, the signal includes live bacteria-specific fluorescence and residual background.

[0085] S6: Calculate the viable bacterial concentration according to the formula: , where a is the calibration factor for the standard plate count method.

[0086] Combine OD value (total biomass) with fluorescence signal (specific for live bacteria) and use OD 590 As the total biomass benchmark, the fluorescence difference ( ) Extract the live bacteria ratio to avoid interference from dead bacteria. (Contains dead bacteria / organic matter signals) Corrected staining F 520 , significantly improving the specificity of live bacteria detection, through experimental calibration α , adapting to the characteristics of different sludge samples and reducing system errors. By fusing data from spectrophotometry (OD value) and fluorescence (520nm / 620nm dual-channel), the inherent defect of traditional spectrophotometry, which cannot distinguish between live and dead bacteria, is overcome, greatly reducing the error in live bacteria concentration detection.

[0087] The above method measures the difference in 520nm fluorescence before and after staining ( ) to calculate the concentration of live bacteria, but unstained sludge samples may produce autofluorescence at 520nm due to dead bacteria, cell debris or organic matter such as humic acid ( F auto520 ), directly as This will lead to an overestimation of the live bacteria signal. Especially when the proportion of dead bacteria in sludge is high, this background subtraction method has significant errors.

[0088] To this end, this embodiment proposes a new Calculation method, specifically, in step S3 Calculated by the following formula: .

[0089] in, It is the fluorescence intensity at 520 nm before staining, which may include fluorescence interference from live bacteria, dead bacteria, and organic matter.

[0090] It is the fluorescence intensity at 620 nm before staining, mainly from dead bacteria and organic debris.

[0091] It is the background value of pure water at 620nm, which is used to deduct instrument noise.

[0092] β is the dead bacteria interference coefficient, with a calibration value of 0.3-0.5, indicating the interference ratio of the 620nm signal to the 520nm channel.

[0093] in, After deducting the instrument background, the specific signal of dead bacteria / organic matter in the 620nm channel is extracted.

[0094] To convert the 620nm interference signal into the equivalent 520nm interference value proportionally, To deduct the contribution of dead bacteria / organic matter from the total signal at 520 nm to obtain the real live bacteria background signal.

[0095] By introducing the dead bacteria-specific signal of the 620 nm channel ( F auto620 ) and interference coefficient β , establish a dynamic correction model, from F auto520 The contribution of dead bacteria can be accurately removed to solve the problem of impure background signal in the above detection methods.

[0096] Through 620nm signal and β The interference signal of dead bacteria / organic matter at 520 nm is quantified by the synergistic correction of the coefficient. and from F auto520 Deduct from the final This method significantly reduces the error in live bacteria concentration detection and is particularly suitable for complex sludge samples with a high proportion of dead bacteria or containing humic acid, significantly improving the accuracy and universality of the detection method of this embodiment.

[0097] This embodiment also discloses the dead bacteria interference coefficient β The specific calibration method includes the following steps: Prepare standard sludge samples with dead bacteria proportions of 0%, 20%, 50%, and 80%; simulate the changes in dead bacteria proportions that may be encountered in actual sewage treatment.

[0098] The autofluorescence intensity of each standard sample at 520 nm / 620 nm can be measured by a fluorescence detection module to measure the unstained fluorescence intensity of each standard sample at 520 nm and 620 nm.

[0099] Fitting β The value minimizes the error in the calculation of viable bacterial concentration. Based on experimental data, adjust β value (0.3-0.5) to minimize the error in the calculation of viable bacterial concentration (e.g., using the least squares fitting method).

[0100] The proportion of dead bacteria in sludge varies greatly between different sewage treatment plants or at different operating stages (e.g. young sludge has fewer dead bacteria, while aged sludge has more dead bacteria). β value, ensuring that the algorithm can adapt to different samples and avoid fixed β Systematic errors caused by the value.

[0101] In the above embodiment, after step S1, an axial multi-point detection step is also included: S11, drive the detection component to move along the axial direction of the light-transmitting container through the moving mechanism, and perform steps S2-S5 at at least three equally spaced positions in sequence, and record the OD at each position respectively. 590 、 F 520 and value; S12, measured at each position F 520 and After taking the arithmetic mean, the average OD 590 The value is substituted into the formula in step S6 to calculate the final viable bacteria concentration.

[0102] The accuracy and reliability of live bacteria concentration measurement have been significantly improved through axial multi-point detection. Its technical effects are mainly reflected in: using a mobile mechanism to drive the detection component to measure at least three equally spaced positions in the axial direction of the light-transmitting container, and taking the average of the data at each point to calculate the final live bacteria concentration. This method effectively eliminates the measurement deviation caused by uneven axial distribution of the sample, makes the test results more representative, and reduces the measurement error as much as possible. At the same time, it enhances the system's adaptability to complex samples such as high concentrations or those containing particulate matter. Through collaborative operation with the stirring mechanism, a fully automated process from sample mixing to multi-point detection is realized, which greatly improves the detection efficiency and the stability of the results, and provides more reliable data support for the precise regulation of sewage treatment processes.

[0103] It is worth noting that in order to adapt to the structural characteristics of the detection device of this embodiment, before adding fluorescent dye, the detection component can be driven by the moving mechanism to perform multi-point testing along the axial direction of the transparent container. In this process, the OD at different positions can be measured. 590 and After the fluorescent dye is added, the spectrophotometer module can be disabled and only the fluorescence detection module can be enabled. At this time, the fluorescence at different positions can be measured. F 520 .

[0104] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A device for detecting the concentration of microbial flora in sewage sludge, characterized in that: include: Light-proof box; The light-transmitting container is arranged in the light-proof box, and is provided with a liquid inlet and a feeding port. The liquid inlet is used to pass the sewage sample, and the feeding port is used to add the fluorescent dye; The detection assembly includes a spectroscopic detection module and a fluorescence detection module. The spectroscopic detection module has a spectroscopic light source and a spectroscopic receiver arranged opposite to each other along a first radial direction. The spectroscopic light source is used to emit a detection beam toward the light-transmitting container, and the spectroscopic receiver is used to receive a transmitted light signal. The fluorescence detection module has a fluorescence light source and a fluorescence receiver arranged opposite to each other along a second radial direction. The fluorescence light source is used to emit an excitation beam toward the light-transmitting container, and a filter assembly is provided in front of the fluorescence receiver for receiving and filtering a fluorescence signal of a specific wavelength. The first radial direction and the second radial direction do not overlap. The moving mechanism is arranged in the light-proof box and is used to drive the detection component to move along the axial direction of the light-transmitting container; The processor is electrically connected to the spectroscopic receiver, the fluorescence receiver, and the moving mechanism, and is configured to control the moving mechanism to enable the detection component to perform detection at multiple axial positions, calculate the total biomass data of the sample based on the transmitted light signal, calculate the active bacterial colony marker data based on the fluorescence signal, and calculate the concentration data of the active microorganisms based on the total biomass data and the active bacterial colony fluorescent marker data.

2. The sewage sludge microbial flora concentration detection device according to claim 1, characterized in that: The spectroscopic detection module further includes a first collimating lens arranged in the light-emitting direction of the spectroscopic light source and a first focusing lens arranged in the light-incident direction of the spectroscopic receiver; The fluorescence detection module further includes a second focusing lens arranged in the light emitting direction of the fluorescence light source; and a collecting lens and a second collimating lens arranged in the light incident direction of the fluorescence receiver, the two lenses being coaxially spaced apart. The filter assembly includes a 520nm bandpass filter and a 620nm bandpass filter, which are used to detect the fluorescence signals of live bacteria and dead bacteria respectively.

3. The sewage sludge microbial flora concentration detection device according to claim 2, characterized in that: The spectroscopic detection module further includes a first light source light shield and a first receiving light shield, wherein the first light source light shield covers the light path between the spectroscopic light source and the first collimating lens, and the first receiving light shield covers the light path between the first focusing lens and the spectroscopic receiver; The fluorescence detection module further includes a second light source shading cover and a second receiving shading cover. The second light source shading cover covers the light path between the fluorescent light source and the second focusing lens. The second receiving shading cover covers the light path between the collecting lens and the fluorescence receiver.

4. The sewage sludge microbial flora concentration detection device according to claim 1, characterized in that The detection assembly also includes an annular mounting disk, which is coaxially sleeved on the outer wall of the light-transmitting container. The spectroscopic detection module and the fluorescence detection module are fixedly arranged along the circumference of the annular mounting disk. The driving end of the moving mechanism is connected to the annular mounting disk.

5. The sewage sludge microbial flora concentration detection device according to claim 1, characterized in that: Also included is a stirring mechanism, the stirring mechanism comprising: The stirring shaft is coaxially arranged in the light-transmitting container, and the side wall of the stirring shaft is provided with at least two symmetrically arranged receiving grooves; The stirring rod has an upper end mounted in the receiving groove via a hinge shaft and can rotate around the hinge shaft; The driving assembly is arranged on the outside of the light-transmitting container and connected to the stirring shaft, and is used to drive the stirring shaft to rotate and move axially; when the stirring shaft rotates, the stirring rod is unfolded from the storage groove under the action of centrifugal force; when the stirring shaft stops rotating, the stirring rod is retracted into the storage groove under the action of gravity.

6. The sewage sludge microbial flora concentration detection device according to claim 5, characterized in that: The drive assembly includes: The mounting bracket is fixedly arranged on the bottom of the light-transmitting container, and a limit plate is fixedly arranged on the mounting bracket, and a through hole is opened on the limit plate; The toothed disc is arranged between the limiting plate and the bottom surface of the light-transmitting container. The lower end of the stirring shaft movably passes through the toothed disc and the through hole. The side wall of the stirring shaft is provided with a guide groove along its axial direction. The inner wall of the toothed disc is provided with a guide protrusion that matches the guide groove. The outer side of the stirring shaft is provided with a seal, which is located between the toothed disc and the light-transmitting container. The rotating motor is fixed on the mounting bracket, and the output end of the rotating motor is engaged with the gear wheel through the main gear; The telescopic element has a fixed end and a telescopic end. The fixed end is fixed to the outside of the light-shielding box, and the telescopic end is rotatably connected to the lower end of the stirring shaft.

7. A method for detecting the concentration of microbial flora in sewage sludge, using the device for detecting the concentration of microbial flora in sewage sludge according to any one of claims 2 to 6, characterized in that: The steps are as follows: S1. Inject the pre-treated sludge sample to be tested into the light-transmitting cavity; S2: Start the spectrophotometric detection module and measure the initial OD of the sample at 590nm 590 value; S3: Start the fluorescence detection module and measure the background fluorescence intensity at 520nm ; S4: injecting fluorescent agent into the light-transmitting cavity and stirring evenly; S5: Measure the fluorescence intensity at 520 nm again F 520 ; S6: Calculate the viable bacterial concentration according to the formula: , where a is the calibration factor for the standard plate count method.

8. The method for detecting the concentration of microbial flora in sewage sludge according to claim 7, wherein: In step S3 Calculated by the following formula: ,in, is the fluorescence intensity at 520 nm before staining, is the fluorescence intensity at 620 nm before staining, is the background value of pure water at 620nm, β is the dead bacteria interference coefficient, and the calibration value is 0.3-0.5, where To extract the specific signal of dead bacteria / organic matter in the 620nm channel, To convert the 620nm interference signal into the equivalent 520nm interference value proportionally, To deduct the contribution of dead bacteria / organic matter from the total signal at 520 nm to obtain the real live bacteria background signal.

9. The method for detecting the concentration of microbial flora in sewage sludge according to claim 8, wherein: described β The coefficient was calibrated by gradient addition of dead bacteria sludge. The specific steps included: preparing sludge standard samples with dead bacteria proportions of 0%, 20%, 50%, and 80%; measuring the autofluorescence intensity of each standard sample at 520nm / 620nm; fitting β The value minimizes the error in the calculation of viable bacterial concentration.

10. The method for detecting the concentration of microbial flora in sewage sludge according to claim 7, wherein: After step S1, an axial multi-point detection step is also included: S11, drive the detection component to move along the axial direction of the light-transmitting container through the moving mechanism, and perform steps S2-S5 at at least three equally spaced positions in sequence, and record the OD at each position respectively. 590 、 F 520 and value; S12, measured at each position F 520 and After taking the arithmetic mean, the average OD 590 The value is substituted into the formula in step S6 to calculate the final viable bacteria concentration.

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