TWI384217B - Measurement method and system of water quality - Google Patents

Description

Method and system for measuring suspended solids concentration and chemical oxygen demand

The invention relates to a method and a system for measuring water quality, and in particular to a method and a system for measuring the concentration of suspended solids and chemical oxygen demand.

The wastewater treatment system is a system consisting of a processing unit, pipelines, mechanical equipment, and civil structures. The purpose is to enable the treated discharge water to meet the “regulated emission standards”, thereby protecting the water body and the environment. In wastewater treatment systems, wastewater is passed through a wastewater treatment program for the removal of contaminants. In order to ensure that the discharged wastewater meets the regulatory emission standards, water quality measurements must be taken during or after the wastewater treatment process.

In the measurement of water quality, the chemical oxygen demand (COD) and the concentration of suspended solids (SS) of the water are usually measured. The chemical method for measuring the chemical oxygen demand of water is generally based on the Potassium bichromate method. The potassium dichromate method requires additional chemicals, which increases the cost and the test time is too long to provide water quality information immediately.

In addition, the chemical oxygen demand and suspended solids concentration of the general water body are measured by the standard test method or infrared light measurement method of the environmental inspection, and the absorbance is analyzed by a single wavelength, wherein the chemical oxygen demand is measured by ultraviolet light. The suspended solids concentration is measured by infrared light. However, the absorbance of a single wavelength The analysis is not applicable to the measurement of the particle size of wastewater and suspended solids of various characteristics.

The invention provides a method for measuring the concentration of suspended solids and chemical oxygen demand, which can simultaneously measure the chemical oxygen demand and the suspended solid concentration of the water body.

The invention provides a measuring system for suspended solids concentration and chemical oxygen demand, which has a blank correction function.

One embodiment of the present invention provides a method for measuring the concentration of suspended solids and chemical oxygen demand, which is suitable for measuring the water quality of a water body by using a light source and a spectrophotometer. The light source is adapted to emit a beam of light. The beam penetrates the body of water and is then passed to a spectrophotometer with a range of wavelengths. The measurement method of the suspended solid concentration and the chemical oxygen demand includes the following steps: (a) scanning a wavelength analysis range in the wavelength range by using a spectrophotometer to obtain an optical spectrum data; (b) qualitatively analyzing the water body according to the optical spectrum data. a suspended solids concentration and a chemical oxygen demand; (c) quantitative analysis of suspended solids concentration based on optical spectrum data and qualitative analysis of suspended solids concentrations; and (d) qualitative analysis of chemical oxygen demand based on optical spectral data And quantitative analysis of suspended solids concentration results quantitative analysis of chemical oxygen demand.

In an embodiment of the invention, the wavelength analysis range includes the wavelength of visible light and the wavelength of ultraviolet light.

In one embodiment of the invention, the optical spectral data includes a plurality of data that exhibits a plurality of absorbances of the water body relative to a plurality of wavelengths of the light beam. The method for measuring the concentration of suspended solids and the chemical oxygen demand further comprises the following steps before step (b): (a1) selecting a light absorption And (a2) deleting data in which the absorbance of water in the optical spectrum data falls outside the range of absorbance analysis, and the data in the range of absorbance analysis is used in step (b), step (c) and step (d) .

In an embodiment of the invention, the absorbance analysis range is from an absorbance lower limit value to an absorbance upper limit value, wherein the absorbance upper limit value is greater than the absorbance lower limit value.

In an embodiment of the present invention, step (c) selects a suspended solid wavelength analysis range for analysis to obtain a estimated suspended solid concentration and a plurality of first estimated absorbances calculated therefrom, and the step ( d) A chemical oxygen demand wavelength analysis range is selected for analysis to obtain a predicted chemical oxygen demand and a plurality of third estimated absorbances calculated therefrom, and the water quality measurement method further comprises the following steps: E1) adding these first estimated absorbances to the corresponding third estimated absorbances to obtain a plurality of total estimated absorbances; (e2) calculating the total estimated absorbances and the absorbances in the corresponding optical spectrum data a plurality of absorbance differences; and (e3) determining whether the absorbance differences fall within an error tolerance, and if not, repeating steps (a1), (a2), (b), and (steps) c), step (d), step (e1) and step (e2) until the absorbance differences fall within the error tolerance, wherein the range of analysis of the suspended solid wavelength selected each time step (c) is performed is not Same, and the selected one is taken each time step (d) is performed The range of wavelength analysis of the oxygen demand is different.

In one embodiment of the invention, step (b) includes comparing the optical spectral data to a spectral database to estimate possible absorption components. The optical spectrum data may include a plurality of data indicating that the plurality of absorbances of the water body are relatively The relationship between multiple wavelengths of the beam. Step (b) may further comprise estimating, by at least one peak of absorbance of the absorbing component in the optical spectrum data, a first estimated suspended solids concentration and a first estimated chemical oxygen demand.

In one embodiment of the invention, the body of water has a plurality of absorbing components and the optical spectrum data has a plurality of major absorption peaks. Estimating the first estimated chemical oxygen demand and the first estimated suspended solid concentration includes the following steps: (b1) selecting a wavelength of a main absorption peak; (b2) using the absorbance corresponding to the wavelength of the main absorption peak and a main absorption peak Calculating a temporary estimated concentration by an absorption coefficient of the corresponding absorption component, wherein the temporarily estimated concentration is a temporary estimated chemical oxygen demand or a temporary estimated suspended solid concentration; (b3) is temporarily pushed Estimating the concentration and the absorption coefficient to calculate a plurality of estimated absorbances corresponding to the wavelengths of the other main absorption peaks; (b4) subtracting the estimated absorbances from the absorbances corresponding to the main absorption peaks in the optical spectrum data to obtain a plurality of absorbance differences; (b5) determining whether the absorbance differences are greater than zero, and if not, repeating steps (b1), (b2), (b3), and (b4) until all of the absorbances The difference is greater than zero, wherein the wavelength of the main absorption peak selected at each step (b1) is different; and (b6) the temporary estimation of the concentration as the first estimated suspended solid concentration or the first estimation chemistry Oxygen.

In an embodiment of the present invention, when the step (b1), the step (b2), the step (b3), and the step (b4) are repeatedly performed, the wavelength of the main absorption peak selected in the step (b1) is repeated each time. The wavelength corresponding to the smallest of these absorbance differences at the last step (b4).

In one embodiment of the invention, the body of water has a plurality of absorbing components, and the optical spectral data includes a plurality of data indicative of a plurality of absorbances of the body of water relative to a plurality of wavelengths of the beam. In addition, step (c) may comprise: (c1) selecting a suspended solid wavelength analysis range according to the spectral database; (c2) selecting a first test wavelength within the suspended solid wavelength analysis range; (c3) using the first test wavelength The absorbance is calculated from a first absorption coefficient of the absorption component corresponding to the first test wavelength to calculate a temporarily estimated suspended solid concentration; (c4) the first test wavelength is calculated by temporarily estimating the suspended solid concentration and the first absorption coefficient. a plurality of first estimated absorbances corresponding to the wavelength range of the suspended solids; (c5) subtracting the first estimated absorbances from the absorbances corresponding to the optical spectrum data to obtain a plurality of first absorbance differences (c6) determining whether the first absorbance differences are greater than zero, and if not, repeating steps (c2), (c3), (c4), and (c5) until all of the first absorbances The difference is greater than zero, wherein the first test wavelength selected each time step (c2) is performed is different; and (c7) is to temporarily estimate the suspended solids concentration as a second estimated suspended solids concentration. In addition, the suspended solids wavelength analysis range may include the wavelength of visible light.

In an embodiment of the present invention, when step (c2), step (c3), step (c4), and step (c5) are repeated, the first test wavelength selected when step (c2) is repeated each time is The wavelength corresponding to the smallest of the first absorbance differences at the time of the previous step (c5).

In an embodiment of the present invention, the step (d) comprises: (d1) selecting a chemical oxygen demand wavelength analysis range according to the spectral database; (d2) estimating the suspended solid concentration and the corresponding absorption coefficient by the second Deriving its chemical aerobic a plurality of second estimated absorbances within a range of wavelength analysis, and subtracting the second estimated absorbances from the plurality of absorbances within the range of the chemical oxygen demand wavelength analysis in the optical spectrum data to obtain a plurality of corrected absorbances Absorbance; (d3) selecting a second test wavelength within the range of chemical oxygen demand wavelength analysis; (d4) utilizing a corrected absorbance corresponding to the second test wavelength and a second absorption of the absorption component corresponding to the second test wavelength The coefficient calculates a temporary estimated chemical oxygen demand; (d5) calculates the chemical oxygen demand and the second absorption coefficient by temporarily estimating the chemical oxygen demand wavelength analysis range other than the second test wavelength Estimating the absorbance by three; (d6) subtracting the corrected absorbances from the third estimated absorbances respectively to obtain a plurality of second absorbance differences; (d7) determining whether the second absorbance differences are greater than Zero, if no, repeat step (d3), step (d4), step (d5), and step (d6) until all of the second absorbance differences are greater than zero, each time step (d3) is performed Selected second The test wavelengths are different; and (d8) temporarily estimates the chemical oxygen demand as a second estimated chemical oxygen demand. In addition, the chemical oxygen demand wavelength analysis range may include the wavelength of ultraviolet light.

In an embodiment of the present invention, when step (d3), step (d4), step (d5), and step (d6) are repeated, the second test wavelength selected when step (d3) is repeated each time is The wavelength corresponding to the smallest of the second absorbance differences at the last step (d6).

One embodiment of the present invention provides a measurement system for suspended solids concentration and chemical oxygen demand, which includes a light source, a spectrophotometer, a blank water sample tank, and a water sample tank to be tested. The light source is adapted to emit a beam of light. The spectrophotometer is disposed on the transmission path of the light beam. Blank water sample tank suitable for cutting or cutting The path of the beam from the source and the spectrophotometer. When the blank water sample slot cuts into the transmission path of the beam, the beam will penetrate the blank water sample slot. The water sample tank to be tested is adapted to cut into or cut off the transmission path of the light beam between the light source and the spectrophotometer. When the water sample groove to be tested is cut into the transmission path of the light beam, the light beam will penetrate the water sample groove to be tested.

In an embodiment of the invention, the blank water sample trough is adapted to receive a clear water. The water sample tank to be tested is suitable for accommodating a water body to be tested or a clear water. The measurement system of the suspended solid concentration and the chemical oxygen demand may further include a water inlet pipe and a water body output pipe. The water inlet pipe is connected to the water sample tank to be tested. The water body output pipe is connected to the water sample tank to be tested. The water body to be tested or the clean water is suitable to flow into the water sample tank to be tested via the water body inlet pipe, and flow out of the water sample tank to be tested via the water body output pipe.

In an embodiment of the invention, the measurement system for suspended solids concentration and chemical oxygen demand further comprises a first optical fiber and a second optical fiber. One end of the first fiber is located next to the light source, and the other end is located next to the blank water sample tank or the water sample tank to be tested. One end of the second fiber is located beside the spectrophotometer, and the other end is located beside the blank water sample tank or the water sample tank to be tested. The light beam is adapted to pass along the first optical fiber and the second optical fiber to the spectrophotometer, and the blank water sample tank and the water sample tank to be tested are adapted to be cut between the other end of the first optical fiber and the other end of the second optical fiber.

In an embodiment of the invention, the measurement system of the suspended solids concentration and the chemical oxygen demand further comprises an actuator connected to the blank water sample tank and the water sample tank to be driven to drive the blank water sample tank and to be tested. The water sample trough cuts or cuts off the transmission path of the beam.

In one embodiment of the present invention, at a point in time, only the blank water sample tank and the water sample tank to be tested are in the transmission path of the light beam.

In the method for measuring the concentration of suspended solids and the chemical oxygen demand in an embodiment of the present invention, since the spectrophotometer can scan within a wavelength analysis range, the measurement method of the suspended solid concentration and the chemical oxygen demand can be simultaneously performed. Measure the suspended solids concentration and chemical oxygen demand of the water. In the measurement system of the suspended solids concentration and the chemical oxygen demand in an embodiment of the present invention, since the blank water sample tank is used, the measurement system of the suspended solid concentration and the chemical oxygen demand has the function of blank correction, Improve the accuracy of the measurement.

The above described features and advantages of the present invention will be more apparent from the following description.

1 is a flow chart of a method for measuring suspended solids concentration and chemical oxygen demand according to an embodiment of the present invention. Referring to FIG. 1 , the measurement method of the suspended solid concentration and the chemical oxygen demand in the embodiment is suitable for measuring the water quality of a water body by using a light source and a spectrophotometer. The water body is, for example, waste water, treated water or other suitable water body to be tested. The light source is adapted to emit a beam of light. The beam penetrates the water and is passed to the spectrophotometer. The light beam has a wavelength range, which in the present embodiment covers, for example, the wavelength of all visible light and the wavelength of part of the ultraviolet light. The measurement method of the suspended solid concentration and the chemical oxygen demand includes the following steps.

First, step S100 is performed, which is to use a spectrophotometer to scan one wavelength analysis range in the wavelength range of the light beam to obtain an optical spectrum data. In this embodiment, the wavelength analysis range includes the wavelength of visible light and the wavelength of ultraviolet light. Specifically, the wavelength analysis range is, for example, from 190 nm to 500 nm. In addition, in this embodiment, the optical spectrum data includes many Data showing the relationship of multiple absorbances of a water body with respect to multiple wavelengths of a beam in the wavelength analysis range.

Next, in this embodiment, step S110 may be performed, which is to select an absorbance analysis range. In the present embodiment, the absorbance analysis range is from an absorbance lower limit value to an absorbance upper limit value, wherein the absorbance upper limit value is greater than the absorbance lower limit value. Data with an absorbance greater than the upper limit of the absorbance can be considered to exceed the detection limit, and data with an absorbance less than the lower limit of the absorbance can be regarded as noise.

Then, in this embodiment, step S120 may be performed to determine whether the absorbance in the optical spectrum data falls within the absorbance analysis range. If not, the subsequent step S130 is performed; if YES, the step S130 is skipped and the subsequent step S200 is directly performed. Step S130 is to delete data in which the absorbance of the water in the optical spectrum data falls outside the range of the absorbance analysis, that is, the data exceeding the detection limit and the data which can be regarded as noise are deleted, and the data in the range of the absorbance analysis is provided for the subsequent steps. S200, step S300, and step S400 are used.

2 is a detailed flow chart of step S200 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG. Referring to FIG. 1 and FIG. 2, the next step of the method for measuring the concentration of suspended solids and the chemical oxygen demand in the present embodiment is to perform step S200, which is a qualitative analysis of the suspended solid concentration and a chemical of a water body according to optical spectrum data. oxygen demand. In this embodiment, step S200 includes step S210, which is a comparison optical spectrum data and a spectral database to estimate possible absorption components, wherein the spectral data library includes suspended solid concentration and chemical oxygen demand. Which wavelength is the characteristic wavelength? And the absorption coefficient of suspended solids concentration and chemical oxygen demand at their respective wavelengths. In addition, in this embodiment, step S200 further includes estimating, by the at least one main absorption peak of the absorption component in the optical spectrum data, a first estimated suspended solid concentration and a first estimated chemical oxygen demand. Specifically, in the embodiment, the water body has a plurality of absorption components, and the optical spectrum data has a plurality of main absorption peaks, and after performing step S210, the step S200 further includes the following steps.

First, step S220 is performed, which is to select a wavelength of a main absorption peak. Next, step S230 is performed to calculate a temporary estimated concentration by using the absorbance corresponding to the wavelength of the main absorption peak and an absorption coefficient of the absorption component corresponding to the main absorption peak, wherein the temporarily estimated concentration is, for example, a temporary Estimate chemical oxygen demand or a temporary estimate of suspended solids concentration. For example, the absorbance corresponding to the wavelength of the main absorption peak is, for example, _Ir1 , and the absorption coefficient of the absorption component corresponding to the main absorption peak at the wavelength λ ₁ where the main absorption peak is located is, for example, ε(λ ₁ ). That is, the absorption coefficient is a function of a change in relative wavelength, and the concentration C _t =I _r1 /ε(λ ₁ ) is temporarily estimated. Thereafter, step S240 is performed, which is a plurality of estimated absorbances calculated from the temporarily estimated concentration and the absorption coefficient corresponding to the wavelengths of the other main absorption peaks. For example, the wavelengths of other main absorption peaks are λ ₂ , λ ₃ , ..., and λ _n , and the multiple estimated absorbances I _e2 , I _e3 , ..., and I _en corresponding to the wavelengths of these main absorption peaks may be _expressed by the following formula Sub-calculation: I _e2 = C _t . ε(λ ₂ ); I _e3 =C _t . ε(λ ₃ );...; and I _en =C _t ·ε(λ _n ), where n is a positive integer.

Then, step S250 is performed to subtract the absorbance corresponding to the main absorption peak of the estimated absorption peak in the optical spectrum data to obtain a plurality of absorbance difference values. For example, in the optical spectrum data, the actual absorbances corresponding to the wavelengths λ ₂ , λ ₃ , ..., and λ _n are _{Ir 2} , I _r3 , ..., and I _rn , respectively, and the absorbance difference D ₂ corresponding thereto, D ₃ , ..., and D _n can be calculated by the following equation: D ₂ = I _{e2 -} I _r2 ; D ₃ = I _{e3 -} I _r3 ; ...; and D _n = I _{en -} I _rn .

Then, step S260 is performed to determine whether the absorbance differences are all greater than zero. If not, the process proceeds to step S220; if the answer is YES, the subsequent step S270 is performed. In other words, if these absorbance differences are not all greater than zero, steps S220 through S260 may be repeated one or more times until the absorbance differences are greater than zero before proceeding to the next step S270. Further, the wavelengths of the main absorption peaks selected each time the step S220 is performed are different. In this embodiment, the wavelength of the main absorption peak selected when the step S220 is repeated each time is the wavelength corresponding to the smallest of the absorbance differences when the step S250 is performed last time, that is, the negative absorbance difference is absolute. The wavelength corresponding to the largest value. In addition, step 270 is to use the temporary estimated concentration obtained in step S230 as the first estimated suspended solid concentration or the first estimated chemical oxygen demand. If the step S230 is repeated multiple times, the step S230 is performed last time. Temporary estimate of concentration One estimate of the suspended solids concentration or the first estimated chemical oxygen demand.

3 is a detailed flow chart of step S300 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG. Referring to FIG. 1 and FIG. 3, in the present embodiment, after step S200 is ended (that is, after step S270 is ended), the next step is to perform step S300. Step S300 quantitatively analyzes the suspended solids concentration based on the optical spectrum data and the qualitative analysis of the suspended solids concentration. In the embodiment, step S300 includes the following steps. First, step S310 is performed, which is to select a suspended solid wavelength analysis range according to the spectral database. In this embodiment, the selected wavelength range of suspended solids analysis includes the wavelength of visible light, for example, from 450 nm to 500 nm. Next, step S320 is performed, which is to select a first test wavelength within the analysis range of the suspended solid wavelength. Then, step S330 is performed to calculate a temporary estimated suspended solid concentration by using a first absorption coefficient of the absorbance corresponding to the first test wavelength and the absorption component corresponding to the first test wavelength. In this embodiment, the calculation manner of step S330 is similar to the calculation manner of step S230. In other words, the first absorption coefficient is also a function of a wavelength, and the absorbance corresponding to the first test wavelength is divided by the first absorption coefficient to temporarily estimate the suspended solids concentration.

Then, step S340 is performed, which is to calculate a plurality of first estimated absorbances corresponding to the suspended solid wavelength analysis range except the first test wavelength by temporarily estimating the suspended solid concentration and the first absorption coefficient. In this embodiment, the calculation method of step S340 is to obtain the first estimated absorbance by multiplying the wavelengths other than the first test wavelength in the suspended solid wavelength analysis range by the first absorption coefficient.

Thereafter, step S350 is performed to subtract the absorbances corresponding to the optical spectral data from the first estimated absorbances to obtain a plurality of first absorbance differences. In other words, the first estimated absorbance corresponding to the same wavelength is subtracted from the absorbance in the optical spectral data.

Next, step S360 is performed to determine whether the first absorbance differences are all greater than zero. If not, the process proceeds to step S320; if YES, the subsequent step S370 is performed. In other words, if the first absorbance differences are not all greater than zero, steps S320 through S360 may be repeated one or more times until the first absorbances are greater than zero, and the subsequent step S370 is performed. In addition, the first test wavelength selected each time step S320 is performed is different. In this embodiment, the first test wavelength selected when the step S320 is repeated each time is the wavelength corresponding to the smallest of the first absorbance differences when the step S350 is performed last time, that is, the negative first absorbance difference. The wavelength corresponding to the largest absolute value of the value.

Furthermore, step S370 is to temporarily estimate the suspended solids concentration obtained in step S330 as a second estimated suspended solids concentration. If the step S330 is repeated a plurality of times, the temporary estimated suspended solid concentration obtained in the last step S330 is used as the second estimated suspended solid concentration.

4 is a detailed flow chart of step S400 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG. 1. Referring to FIG. 1 and FIG. 4, in the present embodiment, after step S300 is ended (that is, after step S370 is ended), the next step is to perform step S400. Step S400 quantitatively analyzes the chemical oxygen demand based on the optical spectrum data, the qualitative analysis of the chemical oxygen demand, and the quantitative analysis of the suspended solids concentration. In this embodiment, step S400 includes The following steps. First, step S410 is performed, which is to select a chemical oxygen demand wavelength analysis range according to the spectral database. In this embodiment, the selected chemical oxygen demand wavelength analysis range includes the wavelength of the ultraviolet light, for example, from 250 nm to 300 nm. Then, step S420 is performed, which is derived from the second estimated suspended solid concentration obtained by step S370 (shown in FIG. 3) and the corresponding first absorption coefficient thereof, and is calculated within the chemical oxygen demand wavelength analysis range. The plurality of second estimated absorbances are, for example, multiplying the second estimated suspended solids concentration by the first absorption coefficient to obtain a second estimated absorbance. Next, the second estimated absorbances are subtracted from the plurality of absorbances falling within the range of the chemical oxygen demand wavelength analysis in the optical spectrum data to obtain a plurality of corrected absorbances. In other words, the absorbance in the optical spectral data corresponding to the same wavelength is subtracted from the second estimated absorbance.

Thereafter, step S430 is performed, which is to select a second test wavelength within the range of chemical oxygen demand wavelength analysis. Then, step S440 is performed to calculate a temporary estimated chemical oxygen demand by using the corrected absorbance corresponding to the second test wavelength and a second absorption coefficient of the absorption component corresponding to the second test wavelength. In this embodiment, the calculation manner of step S440 is similar to the calculation manner of step S330. In other words, the second absorption coefficient is also a function of a wavelength, and the corrected absorbance corresponding to the second test wavelength divided by the second absorption coefficient is a temporary estimation of the chemical oxygen demand.

Then, step S450 is performed, which is to calculate a plurality of third estimated absorbances corresponding to the chemical oxygen demand wavelength analysis range except for the second test wavelength by temporarily estimating the chemical oxygen demand and the second absorption coefficient. In this embodiment, the calculation method of step S450 is to analyze the wavelength of the chemical oxygen demand. These third estimated absorbances are obtained by multiplying the wavelengths other than the second test wavelength by the second absorption coefficient.

Thereafter, step S460 is performed to subtract the corrected absorbances from the third estimated absorbances to obtain a plurality of second absorbance differences. In other words, the third estimated absorbance corresponding to the same wavelength is subtracted from the corrected absorbance.

Next, step S470 is performed to determine whether the second absorbance differences are all greater than zero. If not, step S430 is re-executed; if YES, then step S480 follows. In other words, if the second absorbance differences are not all greater than zero, steps S430 through S470 may be repeated one or more times until the second absorbance differences are greater than zero, and the subsequent step S480 is performed. In addition, the second test wavelength selected each time step S430 is performed is different. In this embodiment, the second test wavelength selected when the step S430 is repeated each time is the wavelength corresponding to the smallest of the second absorbance differences when the step S460 is performed last time, that is, the negative second absorbance difference. The wavelength corresponding to the largest absolute value of the value.

Furthermore, step S480 is a second estimated chemical oxygen demand as the second estimated chemical oxygen demand obtained in step S440. If the step S440 is repeated a plurality of times, the temporary estimated chemical oxygen demand obtained by the last step S440 is used as the second estimated chemical oxygen demand.

FIG. 5 is a detailed flow chart of step S500 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG. Referring to FIG. 1 and FIG. 5, in the present embodiment, the next step after the end of step S400 (that is, after the end of step S480 of FIG. 4) is step S500. Step S500 is a step by judgment Whether the difference between the absorbance estimated by S300 and step S400 and the absorbance in the optical spectrum data falls within a margin of error. If not, proceed to step S110; if yes, the measurement ends, and the second estimated suspended solid concentration and the second estimated chemical oxygen demand obtained in steps S300 and S400 are the same as the embodiment. The measured results of the method for measuring the concentration of suspended solids and chemical oxygen demand. If the step S300 and the step S400 are repeated, the measurement result is the second estimated suspended solid concentration and the second estimated chemical oxygen demand obtained by performing the last step S300 and the step S400.

In the embodiment, step S500 includes the following steps. First, step S510 is performed, which is to add the first estimated absorbances obtained in step S300 to those obtained in step S400 corresponding thereto, that is, to correspond to the first push of the same wavelength. The estimated absorbance is added to the third estimated absorbance to obtain a plurality of total estimated absorbances. Then, step S520 is performed, which is to calculate a plurality of absorbance differences between the total estimated absorbance and the absorbance in the optical spectrum data corresponding thereto, for example, subtracting the absorbance in the optical spectrum data from the total estimated absorbance corresponding to the same wavelength. To get the difference in absorbance. Next, step S530 is performed to determine whether the absorbance differences in step S520 fall within a margin of error. If no, step S110 is performed again; if YES, the method for measuring the suspended solids concentration and the chemical oxygen demand of the present embodiment is completed. When the absorbance in step S520 does not fall within the error tolerance, steps S110 to S500 may be repeated one to many times until the absorbance difference in step S520 falls within the error tolerance, and the measurement is completed. The wavelength range of the suspended solids selected in each step S310 (shown in FIG. 3) is not the same. Similarly, the range of chemical oxygen demand wavelength analysis selected when performing step S410 (shown in FIG. 4) is different.

In the method for measuring the concentration of suspended solids and the chemical oxygen demand in the present embodiment, since the spectrophotometer can scan within a wavelength analysis range, that is, multi-wavelength measurement, the suspended solid concentration and the chemical oxygen demand are The measurement method can simultaneously measure the suspended solid concentration and chemical oxygen demand of the water body, and can improve the measured concentration of suspended solids and the accuracy of chemical oxygen demand. In addition, the multi-wavelength measurement of this embodiment can also be applied to the measurement of different suspended solid particle sizes. Furthermore, the optical spectrum data obtained in this embodiment can be used as an application for water quality fingerprint identification and other related water quality monitoring. In addition, since the measurement method of the suspended solid concentration and the chemical oxygen demand in the present embodiment is an optical measurement method, the measurement reaction time is short and the stability is high, and it can be applied to an immediate monitoring system for water quality. The water quality monitoring system can perform all the steps of Figure 1 at intervals to complete a measurement. In this way, when the water quality begins to mutate, it can be discovered immediately, and necessary measures are taken to achieve the effect of real-time monitoring.

6A is a top view of a measurement system for suspended solids concentration and chemical oxygen demand according to an embodiment of the present invention, and FIG. 6B is a front view of the measurement system for suspended solids concentration and chemical oxygen demand of FIG. 6A, and FIG. 6C is a top plan view of the measurement system of FIG. 6A in another state. Referring to FIG. 6A to FIG. 6C, the measurement system 100 for suspended solids concentration and chemical oxygen demand of the present embodiment can be used to perform the above measurement method of suspended solid concentration and chemical oxygen demand or other applicable suspended solid concentration and chemistry. The method of measuring oxygen demand. The measurement system 100 for suspended solids concentration and chemical oxygen demand includes a The light source 110, a spectrophotometer 120, a blank water sample tank 130, and a water sample tank 140 to be tested. Light source 110 is adapted to emit a beam of light 112. In the present embodiment, the light beam 112 emitted by the light source 110 has a wavelength range, which is, for example, a wavelength covering all visible light and a part of ultraviolet light.

The spectrophotometer 120 is disposed on the transmission path of the light beam 112. The blank water sample tank 130 is adapted to cut into or cut away from the transmission path of the light beam 112 between the light source 110 and the spectrophotometer 120, and the water sample tank 140 to be tested is also adapted to be cut or cut between the light source 110 and the spectrophotometer 120. The path of the beam 112. In the present embodiment, the measurement system 100 for suspended solids concentration and chemical oxygen demand further includes a first optical fiber 150 and a second optical fiber 160. A first end 152 of the first optical fiber 150 is located beside the light source 110, and a second end 154 of the first optical fiber 150 is located beside the blank water sample tank 130 or the water sample tank 140 to be tested. A third end 162 of the second optical fiber 160 is located beside the spectrophotometer 120, and a fourth end 164 of the second optical fiber 160 is located beside the blank water sample tank 130 or the water sample tank 140 to be tested. The light beam 112 is adapted to be transmitted to the spectrophotometer along the first optical fiber 150 and the second optical fiber 160, and the blank water sample tank 130 and the water sample tank 140 to be tested are adapted to be cut into the second end 154 and the second end of the first optical fiber 150. Between the fourth ends 164 of the optical fibers 160. Moreover, in the present embodiment, the light beam 112 is transmitted by the first optical fiber 150 and the second optical fiber 160, and the light source 110 and the spectrophotometer 120 can be integrated in an optical measuring device 50.

In the present embodiment, at a point in time, only the blank water sample tank 130 and the water sample tank 140 to be tested enter the transmission path of the light beam 112. In other words, when the blank water sample tank 130 cuts into the transmission path of the light beam 112, it is to be tested. The water sample tank 140 cuts off the transmission path of the light beam 112, as shown in FIG. 6A; and when the water sample tank 140 to be tested cuts into the transmission path of the light beam 112, the blank water sample groove 130 cuts off the transmission path of the light beam 112. The state shown in Figure 6C.

In addition, in the present embodiment, the measurement system 100 for suspended solids concentration and chemical oxygen demand further includes an actuator 170 connected to the blank water sample tank 130 and the water sample tank 140 to be driven to drive the blank water sample tank. 130 and the water sample tank 140 to be tested cut or cut away from the transmission path of the beam 112. Specifically, the actuator 170 is, for example, a motor that is coupled to the blank water sample tank 130 and the water sample tank 140 to be tested and driven by the gear set 172 and the transmission belt 174 (as shown in FIG. 6B). In addition, the actuator 170 can be electrically connected to a control panel 180, and the user can cut the blank water sample tank 130 and the water sample tank 140 to be tested into or away from the transmission path of the light beam 112 through the control panel 180.

In the present embodiment, the blank water sample tank 130 is adapted to accommodate a clean water, for example, deionized water. When the blank water sample tank 130 cuts into the transmission path of the light beam 112, the light beam 112 penetrates the blank water sample tank 130 and the clear water contained therein, and is transmitted to the spectrophotometer 120. In this way, the measurement system 100 for the suspended solids concentration and the chemical oxygen demand of the present embodiment can perform blank correction. In addition, in the embodiment, the water sample tank 140 to be tested is adapted to accommodate a water body to be tested, and the water body to be tested is, for example, waste water, treated water or other suitable water body to be tested. When the water sample tank 140 to be tested cuts into the transmission path of the light beam 112, the light beam 112 penetrates the water sample tank 140 to be tested and the water body to be tested therein, and is transmitted to the spectrophotometer 120. In this way, the measurement system 100 for the suspended solids concentration and the chemical oxygen demand of the present embodiment is It can measure the water quality of the water to be tested.

In the present embodiment, the measurement system 100 for suspended solids concentration and chemical oxygen demand further includes a water body input pipe 192 (as shown in FIG. 6B) and a water body output pipe 194. The water inlet pipe 192 is in communication with the water sample tank 140 to be tested. The water body output pipe 194 is in communication with the water sample tank 140 to be tested. The water body to be tested is adapted to flow into the water sample tank 140 to be tested via the water body inlet pipe 192, and flows out of the water sample tank 140 to be tested via the water body output pipe 194. For example, the measurement system 100 for suspended solids concentration and chemical oxygen demand can feed the water to be tested into the water inlet pipe 192 by a pump (not shown), and continue to flow into the water sample tank to be tested. 140 for measurement. When the equivalent measurement is completed, the water to be tested can be sent to the water body output pipe 194 by the pump, and the water body to be tested flows out of the water sample tank 140 to be tested.

In the present embodiment, the water sample tank 140 to be tested is also suitable for accommodating fresh water, and the clean water is, for example, deionized water. In addition, the fresh water is adapted to flow into the water sample tank 140 to be tested via the water body inlet pipe 192, and flows out of the water sample tank 140 to be tested via the water body output pipe 194. In addition, the measuring system 100 for the suspended solids concentration and the chemical oxygen demand can control the water to be tested or the clean water to flow into the water sample tank 140 to be tested by a valve (not shown), wherein the valve is, for example, a controllable solenoid valve. The measuring system 100 for the suspended solids concentration and the chemical oxygen demand of the present embodiment can alternately flow the water to be tested and the clean water into the water sample tank 140 to be tested, so that the water quality of the water to be tested can be continuously sampled and continuously measured. Since the water to be tested is finished once per quantity, the clean water will flow into the water sample tank 140 to be tested to clean the water sample tank to be tested, so that the data of the water body to be tested adjacent to the two measurements will not interfere with each other. In this embodiment, the valve and the pump can be controlled by the control unit, and the control unit is an example. Such as a computer. With the automatic control of the computer, the measurement system 100 for suspended solids concentration and chemical oxygen demand can instantly measure water quality. When the water quality changes, the measures can be taken immediately to achieve the effect of real-time monitoring.

In summary, in the method for measuring the concentration of suspended solids and the chemical oxygen demand in the embodiment of the present invention, since the spectrophotometer can scan within a wavelength analysis range, that is, multi-wavelength measurement, suspended solids Concentration and chemical oxygen demand measurement methods can simultaneously measure the suspended solids concentration and chemical oxygen demand of water, and can improve the accuracy of measured suspended solids concentration and chemical oxygen demand. In addition, multi-wavelength measurements can also be applied to measurements of different suspended solid particle sizes. Furthermore, the optical spectrum data obtained by the embodiments of the present invention can be used as water quality fingerprint identification and other related water quality monitoring applications.

In the measurement system of the suspended solids concentration and the chemical oxygen demand in the embodiment of the present invention, since the blank water sample tank is used, the measurement system of the suspended solid concentration and the chemical oxygen demand has a blank correction function to enhance The accuracy of the measurement. In addition, the measurement system and method for the suspended solids concentration and the chemical oxygen demand of the embodiment of the present invention can measure the water quality once every time interval, so that when the water quality begins to mutate, the water quality can be immediately detected, and necessary measures are taken. To achieve the effect of real-time monitoring.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

50‧‧‧Optical measuring device

100‧‧‧Measurement system for suspended solids concentration and chemical oxygen demand

110‧‧‧Light source

112‧‧‧ Beam

120‧‧‧Spectrophotometer

130‧‧‧White water sample tank

140‧‧‧ water sample tank to be tested

150‧‧‧First fiber

152‧‧‧ first end

154‧‧‧ second end

160‧‧‧second fiber

162‧‧‧ third end

164‧‧‧ fourth end

170‧‧‧Actuator

172‧‧‧ Gear Set

174‧‧‧Drive belt

180‧‧‧Control panel

192‧‧‧ water body input pipe

194‧‧‧Water body output tube

S100, S110, S120, S130, S200, S210, S220, S230, S240, S250, S260, S270, S300, S310, S320, S330, S340, S350, S360, S370, S400, S410, S420, S430, S440, S450, S460, S470, S480, S500, S510, S520, S530‧‧ steps

1 is a flow chart of a method for measuring suspended solids concentration and chemical oxygen demand according to an embodiment of the present invention.

2 is a detailed flow chart of step S200 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG.

3 is a detailed flow chart of step S300 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG.

4 is a detailed flow chart of step S400 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG. 1.

FIG. 5 is a detailed flow chart of step S500 in the method for measuring the suspended solids concentration and the chemical oxygen demand of FIG.

6A is a top plan view of a measurement system for suspended solids concentration and chemical oxygen demand according to an embodiment of the present invention.

Figure 6B is a front elevational view of the measurement system for the suspended solids concentration and chemical oxygen demand of Figure 6A.

Figure 6C is a top plan view of the measurement system of the suspended solids concentration and chemical oxygen demand of Figure 6A in another state.

S100, S110, S120, S130, S200, S300, S400, S500‧‧‧ steps

Claims (22)

A method for measuring a concentration of suspended solids and a chemical oxygen demand is suitable for measuring the water quality of a water body by using a light source and a spectrophotometer, the light source being adapted to emit a light beam that penetrates the water body and then transmits to the water body The spectrophotometer, the light beam has a wavelength range, and the method for measuring the suspended solid concentration and the chemical oxygen demand includes: (a) scanning the wavelength analysis range of the wavelength range by using the spectrophotometer to obtain an optical Spectral data; (b) qualitative analysis of suspended solids concentration and a chemical oxygen demand of the water body according to the optical spectrum data; (c) quantitative analysis of the suspended solid concentration according to the optical spectrum data and qualitative analysis of the suspended solids concentration And (d) quantitatively analyzing the chemical oxygen demand based on the optical spectrum data, the qualitative analysis of the chemical oxygen demand, and the quantitative analysis of the suspended solids concentration. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 1 wherein the wavelength analysis range includes a wavelength of visible light and a wavelength of ultraviolet light. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 1, wherein the optical spectral data includes a plurality of data, the data indicating a plurality of absorbances of the water body relative to the plurality of light beams The relationship between the wavelength of the suspended solids and the chemical oxygen demand is further included before step (b): (a1) selecting an absorbance analysis range; (a2) deleting data in the optical spectrum data whose absorbance falls outside the absorbance analysis range, and data in the absorbance analysis range is used in the steps (b), (c) and (d). The method for measuring the concentration of suspended solids and the chemical oxygen demand as described in claim 3, wherein the absorbance analysis range is from an absorbance lower limit value to an absorbance upper limit value, wherein the absorbance upper limit value is greater than the The lower limit of absorbance. A method for measuring the concentration of suspended solids and chemical oxygen demand as described in claim 3, wherein step (c) selects a wavelength range of suspended solids for analysis to obtain a predicted concentration of suspended solids and Calculating a plurality of first estimated absorbances, and step (d) selecting a chemical oxygen demand wavelength analysis range for analysis to obtain a predicted chemical oxygen demand and a plurality of thirds calculated therefrom Estimating the absorbance, and the method for measuring the water quality further comprises: (e1) adding the first estimated absorbances to the corresponding third estimated absorbances to obtain a plurality of total estimated absorbances; (e2) calculating The total estimated absorbance and a plurality of absorbance differences corresponding to the absorbance in the optical spectrum data; and (e3) determining whether the absorbance differences fall within a margin of error, and if not, repeating Carrying out step (a1), step (a2), step (b), step (c), step (d), step (e1) and step (e2) until the absorbance differences fall within the error tolerance , wherein the suspended solid wavelength analysis sample selected each time step (c) is performed They are not the same, and the wavelength of the COD analysis of step (d), each time the selected range is not the same. A method for measuring the concentration of suspended solids and chemical oxygen demand as described in claim 1 wherein step (b) includes comparing the optical spectrum data with a spectral database to estimate possible absorption components. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 6 wherein the optical spectral data comprises a plurality of data, the data indicating a plurality of absorbances of the water body relative to the plurality of light beams In relation to the wavelength, step (b) further comprises estimating, by the at least one main absorption peak of the absorption component in the optical spectrum data, a first estimated suspended solid concentration and a first estimated chemical oxygen demand of the water body. . A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 7 wherein the water body has a plurality of absorption components, and the optical spectrum data has a plurality of main absorption peaks, and the first push is estimated Estimating the chemical oxygen demand and the first estimated suspended solids concentration comprises: (b1) selecting the wavelength of the main absorption peak; (b2) the absorbance corresponding to the wavelength of the main absorption peak and the main absorption peak Corresponding the absorption coefficient of the absorbing component to calculate a temporary estimated concentration, wherein the temporary estimated concentration is a temporary estimated chemical oxygen demand or a temporary estimated suspended solid concentration; (b3) from the temporary estimation a concentration and the absorption coefficient calculate a plurality of estimated absorbances corresponding to wavelengths of the other main absorption peaks; (b4) subtracting the estimated absorbances from the other main absorption peaks corresponding to the optical spectrum data The absorbances in the plurality of absorbance differences to obtain a plurality of absorbance differences; (b5) determining whether the absorbance differences are greater than zero, and if not, then Repeating step (b1), step (b2), step (b3), and step (b4) until all of the absorbance differences are greater than zero, wherein the main absorption peak selected each time step (b1) is performed The wavelength is not the same; and (b6) using the temporary estimated concentration as the first estimated suspended solids concentration or the first estimated chemical oxygen demand. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 8 wherein when step (b1), step (b2), step (b3), and step (b4) are repeated, each time The wavelength of the main absorption peak selected when the step (b1) is repeated is the wavelength corresponding to the smallest of the absorbance differences when the step (b4) is performed last time. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 1, wherein the water body has a plurality of absorption components, and the optical spectrum data includes a plurality of data, the data indicating a plurality of the water bodies The relationship between the absorbance and the plurality of wavelengths of the light beam, and the step (c) comprises: (c1) selecting a suspended solid wavelength analysis range according to the spectral database; (c2) selecting a first within the suspended solid wavelength analysis range. Testing the wavelength; (c3) calculating a temporarily estimated suspended solids concentration by using the absorbance corresponding to the first test wavelength and a first absorption coefficient of the absorption component corresponding to the first test wavelength; (c4) by the temporary Estimating the suspended solid concentration and the first absorption coefficient to calculate a plurality of first estimated absorbances corresponding to the suspended solid wavelength analysis range except the first test wavelength; (c5) subtracting the first estimated absorbances from the absorbances corresponding to the optical spectrum data to obtain a plurality of first absorbance difference values; (c6) determining whether the first absorbance differences are all More than zero, if not, repeat step (c2), step (c3), step (c4) and step (c5) until all of the first absorbance differences are greater than zero, wherein each step (c2) The first test wavelength selected at the time is not the same; and (c7) using the temporary estimated suspended solids concentration as a second estimated suspended solids concentration. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 10, wherein when step (c2), step (c3), step (c4), and step (c5) are repeated, each time The first test wavelength selected when the step (c2) is repeated is the wavelength corresponding to the smallest of the first absorbance differences when the step (c5) is performed last time. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 10, wherein the suspended solids wavelength analysis range includes a wavelength of visible light. The method for measuring the concentration of suspended solids and the chemical oxygen demand described in claim 10, wherein the step (d) comprises: (d1) selecting a chemical oxygen demand wavelength analysis range according to the spectral database; (d2) Deriving a plurality of second estimated absorbances within the chemical oxygen demand wavelength analysis range from the second estimated suspended solid concentration and its corresponding absorption coefficient, and dropping the optical spectrum data in the chemical The plurality of absorbances within the range of the oxygen demand wavelength are correspondingly subtracted from the second estimated absorbances, Obtaining a plurality of corrected absorbances; (d3) selecting a second test wavelength within the chemical oxygen demand wavelength analysis range; (d4) utilizing the corrected absorbance corresponding to the second test wavelength and the second test wavelength Calculating a temporary estimated chemical oxygen demand by a second absorption coefficient of the corresponding absorption component; (d5) calculating, in addition to the second test wavelength, the temporary estimated chemical oxygen demand and the second absorption coefficient a plurality of third estimated absorbances corresponding to the chemical oxygen demand wavelength analysis range; (d6) subtracting the corrected absorbances corresponding to the third estimated absorbances respectively to obtain a plurality of second absorbances a difference; (d7) determining whether the second absorbance differences are greater than zero, and if not, repeating steps (d3), (d4), (d5), and (d6) until all of the The second absorbance difference is greater than zero, wherein the second test wavelength selected each time step (d3) is performed is different; and (d8) the temporary estimated chemical oxygen demand is used as a second estimated chemical requirement Oxygen content. A method for measuring a suspended solids concentration and a chemical oxygen demand as described in claim 13 wherein when step (d3), step (d4), step (d5), and step (d6) are repeated, each time The second test wavelength selected when the step (d3) is repeated is the wavelength corresponding to the smallest of the second absorbance differences when the step (d6) is performed last time. The method for measuring the concentration of suspended solids and the chemical oxygen demand described in claim 13 of the patent application scope, wherein the chemical oxygen demand wavelength analysis range includes Including the wavelength of ultraviolet light. A measuring system for suspended solids concentration and chemical oxygen demand, comprising: a light source adapted to emit a light beam; a spectrophotometer disposed on the transmission path of the light beam; a blank water sample groove adapted to cut or cut a path of the light beam from the light source and the spectrophotometer, when the blank water sample slot cuts into the transmission path of the light beam, the light beam penetrates the blank water sample slot; and a water sample tank to be tested, The light beam is adapted to cut into or out of the light source and the transmission path of the light beam between the light source and the spectrophotometer. When the water sample groove to be tested cuts into the transmission path of the light beam, the light beam penetrates the water sample groove to be tested. A measuring system for suspended solids concentration and chemical oxygen demand as described in claim 16 wherein the blank water sample tank is adapted to receive a clean water. The measuring system of the suspended solids concentration and the chemical oxygen demand described in claim 16 , wherein the water sample tank to be tested is adapted to accommodate a water body to be tested or a clear water. The measuring system for the suspended solids concentration and the chemical oxygen demand described in claim 18, further comprising: a water inlet pipe connected to the water sample tank to be tested; and a water body output pipe, and the to be tested The water sample tank is connected, wherein the water body to be tested or the water is suitable to flow into the water sample tank to be tested via the water body inlet pipe, and flow out the water sample tank to be tested through the water body output pipe. The measurement system for suspended solids concentration and chemical oxygen demand as described in claim 16 of the patent application includes: a first optical fiber, one end of the first optical fiber is located beside the light source, and the other end is located beside the blank water sample tank or the water sample tank to be tested; and a second optical fiber, one end of the second optical fiber is located at the spectrophotometer Next to the meter, the other end is located next to the blank water sample tank or the water sample tank to be tested, wherein the light beam is adapted to be transmitted to the spectrophotometer along the first optical fiber and the second optical fiber, and the blank water sample tank And the water sample tank to be tested is adapted to be cut between the other end of the first optical fiber and the other end of the second optical fiber. The measuring system for the suspended solids concentration and the chemical oxygen demand described in claim 16 further includes an actuator connected to the blank water sample tank and the water sample tank to drive the blank water. The sample tank and the water sample tank to be tested cut into or cut off the transmission path of the light beam. A measuring system for suspended solids concentration and chemical oxygen demand as described in claim 16 wherein, at a point in time, the blank water sample tank and the water sample tank to be tested are only included in the light beam. Pass the path.