CN205958507U - Coulometric titration COD test instrument - Google Patents
Coulometric titration COD test instrument Download PDFInfo
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- CN205958507U CN205958507U CN201620732532.9U CN201620732532U CN205958507U CN 205958507 U CN205958507 U CN 205958507U CN 201620732532 U CN201620732532 U CN 201620732532U CN 205958507 U CN205958507 U CN 205958507U
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- 238000005443 coulometric titration Methods 0.000 title claims abstract description 10
- 238000012360 testing method Methods 0.000 title abstract description 12
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 32
- 238000003756 stirring Methods 0.000 claims abstract description 17
- 239000007788 liquid Substances 0.000 claims abstract description 16
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 16
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 10
- 238000001514 detection method Methods 0.000 claims description 9
- 230000005611 electricity Effects 0.000 claims description 5
- 238000000465 moulding Methods 0.000 claims 1
- 238000000034 method Methods 0.000 description 26
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 description 25
- 239000000523 sample Substances 0.000 description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 18
- 239000012286 potassium permanganate Substances 0.000 description 10
- 238000004448 titration Methods 0.000 description 8
- 239000003795 chemical substances by application Substances 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 239000011651 chromium Substances 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- DOBUSJIVSSJEDA-UHFFFAOYSA-L 1,3-dioxa-2$l^{6}-thia-4-mercuracyclobutane 2,2-dioxide Chemical compound [Hg+2].[O-]S([O-])(=O)=O DOBUSJIVSSJEDA-UHFFFAOYSA-L 0.000 description 4
- 241000370738 Chlorion Species 0.000 description 4
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 4
- 230000029087 digestion Effects 0.000 description 4
- 229940074994 mercuric sulfate Drugs 0.000 description 4
- 229910000372 mercury(II) sulfate Inorganic materials 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000012216 screening Methods 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 3
- 239000010842 industrial wastewater Substances 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- 229940032330 sulfuric acid Drugs 0.000 description 3
- 239000002352 surface water Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000003929 acidic solution Substances 0.000 description 2
- 229940037003 alum Drugs 0.000 description 2
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 description 2
- 229940010552 ammonium molybdate Drugs 0.000 description 2
- 235000018660 ammonium molybdate Nutrition 0.000 description 2
- 239000011609 ammonium molybdate Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000003426 co-catalyst Substances 0.000 description 2
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 2
- 238000003411 electrode reaction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 2
- 150000002730 mercury Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 description 2
- 229910052939 potassium sulfate Inorganic materials 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 description 2
- 230000001988 toxicity Effects 0.000 description 2
- 231100000419 toxicity Toxicity 0.000 description 2
- QLOKJRIVRGCVIM-UHFFFAOYSA-N 1-[(4-methylsulfanylphenyl)methyl]piperazine Chemical compound C1=CC(SC)=CC=C1CN1CCNCC1 QLOKJRIVRGCVIM-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- ZXRRHFSTAFVGOC-UHFFFAOYSA-N [AlH3].[K] Chemical compound [AlH3].[K] ZXRRHFSTAFVGOC-UHFFFAOYSA-N 0.000 description 1
- ZLXPLDLEBORRPT-UHFFFAOYSA-M [NH4+].[Fe+].[O-]S([O-])(=O)=O Chemical compound [NH4+].[Fe+].[O-]S([O-])(=O)=O ZLXPLDLEBORRPT-UHFFFAOYSA-M 0.000 description 1
- 238000000184 acid digestion Methods 0.000 description 1
- 239000012491 analyte Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000012496 blank sample Substances 0.000 description 1
- 239000012490 blank solution Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- BFGKITSFLPAWGI-UHFFFAOYSA-N chromium(3+) Chemical compound [Cr+3] BFGKITSFLPAWGI-UHFFFAOYSA-N 0.000 description 1
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 1
- 238000004737 colorimetric analysis Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000003869 coulometry Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005518 electrochemistry Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- CIWXFRVOSDNDJZ-UHFFFAOYSA-L ferroin Chemical compound [Fe+2].[O-]S([O-])(=O)=O.C1=CN=C2C3=NC=CC=C3C=CC2=C1.C1=CN=C2C3=NC=CC=C3C=CC2=C1.C1=CN=C2C3=NC=CC=C3C=CC2=C1 CIWXFRVOSDNDJZ-UHFFFAOYSA-L 0.000 description 1
- 229910001448 ferrous ion Inorganic materials 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 230000002045 lasting effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- VZJXLUXABSAHBN-UHFFFAOYSA-N mercury;sulfuric acid Chemical compound [Hg].OS(O)(=O)=O VZJXLUXABSAHBN-UHFFFAOYSA-N 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 238000006213 oxygenation reaction Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000012488 sample solution Substances 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- ZNCPFRVNHGOPAG-UHFFFAOYSA-L sodium oxalate Chemical compound [Na+].[Na+].[O-]C(=O)C([O-])=O ZNCPFRVNHGOPAG-UHFFFAOYSA-L 0.000 description 1
- 229940039790 sodium oxalate Drugs 0.000 description 1
- 238000002798 spectrophotometry method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
The utility model discloses a coulometric titration COD test instrument, COD test instrument including electrolytic bath (1) that can hold liquid, be arranged in stirring agitator motor (2) of electrolytic bath (1) liquid, platinum working electrode (4) that are arranged in detecting platinum indicator electrode (3) of electrolytic bath (1) intermediate -current and are used for electrolysis electrolytic bath (1) liquid. The utility model discloses a COD test instrument can portably survey COD fast.
Description
Technical field
The utility model the utility model belongs to field of water quality detection, is mainly concerned with surface water, underground water, life dirt
COD (COD) content detection in water, industrial wastewater is and in particular to a kind of coulometric titration COD tester.
Background technology
In existing water, chemical oxygen demand measurement common method is had and is urged based on bichromate potassium dichromate feedback method and sealing
Change resolution method (also known as spectra photometric method) and the permanganimetric method based on permanganate.
Potassium dichromate feedback method measures COD of sewage, is mainly used in the higher waste water of concentration, principle is in strongly acidic solution
In, accurately add excessive potassium bichromate standard liquid, be heated to reflux, by the reducing substances (mainly organic matter) in water sample
Oxidation, excessive potassium bichromate is given instruction agent with ferroin, with iron ammonium sulfate standard liquid residual titration.According to the weight being consumed
Potassium chromate solution amount calculates the amount that reducing substances in water sample consumes oxygen.Potassium dichromate feedback method due to oxidation completely, measures knot
Fruit is more accurate.But relative minute is long, heating process needs 2 hours about, and reagent dosage is big, complex operation, measures
During the mercuric sulfate used there is stronger toxicity, the operation of experimenter is required very high, and mercury salt, silver salt can cause
Secondary pollution.Need lasting backflow cooling water in experimentation, do not have reflux condensation mode water this method of scene cannot apply.
Additionally, scientific worker finds:There is larger error when measuring chloride ion-containing waste water in the National Standard Method of COD, even if using sulfuric acid
Mercury makees screening agent to eliminate the impact of chlorion, when the mass concentration of chlorion in waste water is more than 2g/L, still can make COD
Measure and produce error, especially low to COD value water sample.It is even as high as when the mass concentration of chlorion in waste water is more than 2g/L
10～20g/L, and when COD value is low, potassium dichromate method measures COD and seems unable to do what one wishes, reason is Chloride Ion In Water and digestion
Agent, catalyst reaction, make measurement result produce relatively large deviation.
Sealed catalysis digestion method is in classical potassium bichromate --- add co-catalyst alum and molybdenum in Sulfuric-Acid Digestion system
Sour ammonium.Because digestion process is carried out under closing pressurized conditions, therefore shorten digestion time.Spectrophotometry for Determination is adopted after clearing up
Determine COD.Concrete operation step is as follows：In strongly acidic solution, sample is in potassium dichromate oxidation agent and co-catalyst sulphur
(if containing chlorion in sample, need to add screening agent mercuric sulfate) under sour aluminium potassium and ammonium molybdate effect, in 165 DEG C of Sealing-off Catalytics
Clear up sample 10min, potassium bichromate is reduced to trivalent chromium by Organic substance in water, measure trivalent chromium content at wavelength 610nm,
Afterwards the mass concentration consuming oxygen is conversed according to the amount of trivalent chromic ion.This method replaces sulfuric acid with alum and ammonium molybdate
Silver, makes expense reduce.But there is still a need for using screening agent mercuric sulfate in experiment, after colorimetric, chromium waste liquid containing sexavalence also needs to concentrate
Process.If produce error when measuring the chromic content at 610nm with colorimetric method simultaneously, the survey of COD also can be directly influenced
Value.
Permanganimetric method refers in acid condition, because potassium permanganate has very strong oxidisability, to tested water
It is quantitatively adding liquor potassic permanganate, water sample is cleared up in then heating, in the aqueous solution, most organic pollutions are all oxidized in sample.
Add quantitative and excessive Na2C2O4The excessive potassium permanganate of reduction, is finally returned with potassium permanganate standard titration solution again and drips excessively
Sodium oxalate to blush be terminal, thus calculate the oxygen demand of water sample.Compare dichromate titration, permanganimetric method master
Surface water to be used for and river water, operating process is more simple, it also avoid hexavalent chromium and the secondary dirt of mercury salt, silver salt
Dye.But relatively for chromium method, oxygenation efficiency is relatively low, it is mainly used in testing low content water sample, be not suitable for that industrial wastewater is contour to be contained
Amount water sample.
Utility model content
The purpose of this utility model is to provide a kind of coulometric titration COD tester, COD tester of the present utility model
Device being capable of fast and convenient mensure COD.
For achieving the above object, the utility model provides a kind of coulometric titration COD tester, described COD tester
Including the electrolytic cell of liquid can be accommodated, for stirring the stirring motor of liquid in electrolytic cell, for detecting electric current in electrolytic cell
Platinum indicator electrode and the platinum working electrode for liquid in electrolytic bath.
Preferably, described COD tester also includes microcontroller and constant-current source circuit, and described microcontroller includes electric current
Detector unit includes timing module, switch control module, stirring motor control module and current detection module, described current detecting
Unit is electrically connected with described platinum indicator electrode, and described switch control module is electrically connected with described constant-current source circuit, described constant-current source
Circuit is electrically connected with described platinum working electrode, and described stirring motor control module is connected with described stirring motor.Microcontroller, perseverance
Current source circuit, timing module, switch control module, stirring motor control module and current detection module are people in the art
Known to member.
The utility model has the advantage that：
COD tester of the present utility model is easy and simple to handle, and volume is light and handy, and sensitivity is high, to operating personnel's level requirement
Relatively low.
Brief description
Fig. 1 is a kind of structural representation of specific embodiment of the utility model tester.
Specific embodiment
Detailed description below is used for the utility model is described, but is not limited to scope of the present utility model.
As shown in figure 1, the utility model provides a kind of coulometric titration COD tester, described COD tester includes can
Accommodate electrolytic cell 1, stirring motor 2, the platinum for detecting electric current in electrolytic cell 1 for stirring liquid in electrolytic cell 1 of liquid
Indicator electrode 3 and the platinum working electrode 4 for liquid in electrolytic bath 1；Described COD tester also includes microcontroller 5
With constant-current source circuit 6, described microcontroller 5 include current detecting unit 5 include timing module 7, switch control module 8, stirring
Motor control module 9 and current detection module 10, described current detecting unit 5 is electrically connected with described platinum indicator electrode 3, described opens
Close control module 8 to electrically connect with described constant-current source circuit 6, described constant-current source circuit 6 is electrically connected with described platinum working electrode 4, institute
State stirring motor control module 9 to be connected with described stirring motor 2.
The COD tester that the utility model provides provides one kind easy and simple to handle, and volume is light and handy, and sensitivity is high, to operation
Proficiency requires relatively low portable COD detection scheme.The method that this instrument adopts electrochemistry, using the detection of high integration
IC, substantially reduces the volume of instrument itself, simplifies experimental procedure.Only liquid to be detected need to be put into beaker, after starting instrument
Can select to be tested with potassium permanganate or potassium bichromate and corresponding range, be then placed in reagent and indicate behaviour according to instrument
Make just conveniently can to carry out COD test, thus decreasing the requirement to testing staff's professional knowledge.
COD tester basic functional principle of the present utility model is：
Constant-current source coulometry：It is electrolysed under the condition of constant current, the electricity being produced by electrode reaction is raw " titrant "
React with measured matter, electrochemically (or chemical indicator) determines the terminal of " titration ".Pass through during measurement electrolysis
Electricity, further according to Faraday's law calculate reactive material amount.
The general frame of electrolysis system, as shown in figure 1, right side is the electrolysis section of system, during test, first adds in beaker
Enter excessive dilute sulfuric acid, so that reaction is carried out in acid condition.After adding testing sample, add quantitative Fe2(SO4)3And quantitation
And the potassium bichromate (if potassium permanganate rule also needs, with electric furnace, solution is carried out 5 minutes clear up) of excess.Instrument works
When, the fixed current that working electrode gives 24mA is electrolysed to solution.
Now, there is reduction reaction in working electrode negative electrode：Fe3++e→Fe2+
Then there is oxidation reaction in corresponding anode：
Cr2O7 2-+6Fe2++14H+=2Cr3++6Fe3++ 7H2O (potassium dichromate method)
MnO4 -+5Fe2++8H+=Mn2++5Fe3++ 4H2O (permanganimetric method)
Now, the ferrous iron that the excessive portion of the potassium bichromate for oxidation sample or potassium permanganate can progressively be produced by negative electrode
Ion titrates, and when not reaching titration emphasis, has no Fe in solution2+With Fe3+Reversible electricity is to presence, electrodeless on indicator electrode
Reaction, therefore do not have electric current to pass through in instruction loop.When drop reaction is complete, the Fe of excess2+With Fe3+Due to indicator electrode it
Between added 1.00V constant voltage voltage, produce redox reaction on two indicator electrodes respectively, therefore in End point indication loop
Electric current is had to flow through at once, the change of AD sample detecting to analog quantity, judge to reach titration end-point, stop in time, working electrode stops
Only it is electrolysed.Now, MCU records the time T of electrolytic process needs, and constant Faradaic current I size is it is known that according to faraday
Second law and potassium bichromate reactive chemistry equation can obtain：
6FeSO4+K2Cr2O7+7H2SO4=K2SO4+Cr2(SO4)3+3Fe2(SO4)3+7H2O
-------(1)
M=(1/F) * (A/Z) * Q=(Q/96487) * (A/Z) --- ----(2)
Can be obtained by (1) (2) two formula：
Corresponding potassium permanganate：
10FeSO4+2KMnO4+8H2SO4=K2SO4+5Fe2(SO4)3+2MnSO4+8H2O
-------(3)
Can be obtained by (2) (3) two formula：
I：Constant-current source Faradaic current, A；
T：Electrolysis total time, s；
96487：Faraday constant, C/mol；
8000：Oxygen element molal weight, mg/mol；
V0：Sample solution volume, L；
Test out the value under space state with the blank solution without sample, then use sample test sample value, you can calculate
The value of COD (mg/L).
Compared with existing laboratory experiment method, the beneficial effect of coulometric titration COD tester of the present utility model is：
Portability is strong：Equipment instrument is little, is powered by 220V power supply, electrode and experimental bench is dismantled and assembled carries.
Simple to operate：Loaded down with trivial details experimental procedure and larger chemical levels that contrast traditional means of experiment is related to, instrument
Experimental implementation is greatly simplified, decreases the use of the higher screening agent of the toxicity such as mercuric sulfate, will to the professional of experimenter
Ask reduction.Apparatus preparation high definition color screen LED human-computer interaction interface, the process being capable of Real-time Feedback experiment (includes indicator current big
Little, electrolysis time etc.).
Measurement range is wide：Instrument combines two methods of potassium permanganate and potassium bichromate, meets and knows clearly from low concentration to height
Concentration, from the measurement demand (0.5mg/L to 800mg/L) of surface water, river water to sanitary sewage and industrial wastewater.
High precision：In 0.1mg/L, repeatability is 10% to accuracy of instrument, and the degree of accuracy is less than 10%.
High analyte efficiency：Instrument can complete water sample analysis in 5～10 minutes measures (traditional potassium bichromate backflow
Method only heat be accomplished by 2 hours).
Data processing is simple：Instrument supports data and the preservation of time and printing, maintains easily experimental data.
Next illustrate the embodiment of this instrument.
The utility model coulometric titration COD tester is mainly direct-current switch power supply, LED LCDs, a set of instruction
Platinum electrode, a set of spiral platinum electrolysis electrode, MCU, high-precision AD change-over circuit, voltage follower circuit etc. form.This programme with
220V civil power is as the power supply of whole system, and provides the confession of system components module with Switching Power Supply and AC-DC change-over circuit
Electricity.Judge the terminal of titration process by the real-time sampling that MCU controls high-precision AD change-over circuit electric current between indicator electrode.
Electrolysis electrode be then by be electrolysed ferric sulfate negative electrode produce the potassium permanganate of ferrous ion overtitration or potassium bichromate Lai
Indirectly calculate the amount of the titration potassium bichromate that consumes of reductive pollutants or potassium permanganate.Thus, after reaction is reached home,
Obtained the time of electrolysis by MCU, in the case of known Faradaic current and blank sample COD value, calculate actual testing sample
COD value.Finally by LED LCDs, data is presented to man-machine interaction machine interface, thus preserving further and printing
Experimental data.
Although, above with general explanation and specific embodiment, detailed description is made to the utility model,
On the basis of the utility model, it can be made some modifications or improvements, this is apparent to those skilled in the art
's.Therefore, these modifications or improvements on the basis of without departing from the utility model spirit, belonging to the utility model will
Seek the scope of protection.
Claims (2)
1. a kind of coulometric titration COD tester is it is characterised in that described COD tester includes accommodating the electrolysis of liquid
Pond (1), the platinum instruction electricity being used for stirring the stirring motor (2) of liquid in electrolytic cell (1), being used for detecting electric current in electrolytic cell (1)
Pole (3) and the platinum working electrode (4) for liquid in electrolytic bath (1).
2. COD tester according to claim 1 is it is characterised in that described COD tester also includes microcontroller
(5) and constant-current source circuit (6), described microcontroller (5) includes timing module (7), switch control module (8), stirring motor control
Molding block (9) and current detection module (10), described current detection module (10) is electrically connected with described platinum indicator electrode (3), institute
State switch control module (8) to electrically connect with described constant-current source circuit (6), described constant-current source circuit (6) and described platinum working electrode
(4) electrically connect, described stirring motor control module (9) is connected with described stirring motor (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620732532.9U CN205958507U (en) | 2016-07-09 | 2016-07-09 | Coulometric titration COD test instrument |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620732532.9U CN205958507U (en) | 2016-07-09 | 2016-07-09 | Coulometric titration COD test instrument |
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| Publication Number | Publication Date |
|---|---|
| CN205958507U true CN205958507U (en) | 2017-02-15 |
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ID=57970395
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| CN201620732532.9U Expired - Fee Related CN205958507U (en) | 2016-07-09 | 2016-07-09 | Coulometric titration COD test instrument |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109521077A (en) * | 2018-11-13 | 2019-03-26 | 国电南瑞科技股份有限公司 | A kind of two-wave interpretation formula online Analysis Apparatus of Permanganate Index titration end-point instruction device |
-
2016
- 2016-07-09 CN CN201620732532.9U patent/CN205958507U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109521077A (en) * | 2018-11-13 | 2019-03-26 | 国电南瑞科技股份有限公司 | A kind of two-wave interpretation formula online Analysis Apparatus of Permanganate Index titration end-point instruction device |
| WO2020098361A1 (en) * | 2018-11-13 | 2020-05-22 | 国电南瑞科技股份有限公司 | Titration end point indicating device for permanganate index on-line analyzer of double platinum electrode type |
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