CN106092805A - A kind of mass method chemical oxygen demand measuring method - Google Patents
A kind of mass method chemical oxygen demand measuring method Download PDFInfo
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- CN106092805A CN106092805A CN201610385610.7A CN201610385610A CN106092805A CN 106092805 A CN106092805 A CN 106092805A CN 201610385610 A CN201610385610 A CN 201610385610A CN 106092805 A CN106092805 A CN 106092805A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/78—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour
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Abstract
A kind of mass method chemical oxygen demand measuring method, comprises the following steps: quality m of weighing container1；In weighing container, add water sample to be measured, weigh quality m of water sample+container2, data are manipulated by unit and are automatically entered in data acquisition storage computing unit, and show on the display unit；In weighing container, add oxidant, weigh quality m of container+water sample+oxidant3, then in container, add a certain amount of catalyst；Heating is cleared up, and makes oxidant fully react with the Organic substance in water sample；Mixed liquor after heating is cleared up adds the spirit of indicator ferrous iron；Titrate mixed liquor with Ferrous ammonium sulfate, shown the terminal determining titration by the color of ferrous spirit.Calculate CODcrValue.The present invention can avoid measuring the personal error that link produces, sampling, compounding medicine accurate measurement, measures accurately and reliably, easy to operate.
Description
Technical field
The present invention relates to field of measuring technique, particularly relate to a kind of mass method chemical oxygen demand measuring method.
Background technology
Water chemical oxygen demand (CODcr) it is one of the main monitoring index of environment water quality standard promulgated of China, its reflection
The degree that water body is polluted by reducing substances.Owing to Organic substance is main reductive pollutants, so hydrochemistry is aerobic
Figureofmerit can be the basic aggregative indicator of water quality monitoring as the Comprehensive Criteria of measurement water quality degree polluted by organic matter.At present
The main method of China's COD determination has two kinds, titrimetry and spectrophotography.Titrimetry i.e. dichromate titration, the party
Method oxygenation efficiency is high, and repeatability is good, accurately and reliably, becomes universally recognized standard method.But this standard method still exists
Weak point: all can produce personal error in compounding medicine process, various range estimation metering link, reagent dosage is big, operation inconvenience,
It is difficult to high-volume quickly measure；Though spectrophotography can bear high-volume and quickly measure, but it is very accurate to require that water sample measures,
Easily producing personal error measuring water sample link, be indirectly by optical method measurement owing to measuring, the performance impact of instrument is accurate
Exactness is the biggest.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of personal error avoiding measuring link generation, sampling, medicine
Product preparation accurate measurement, measures accurately and reliably, easy to operate, the mass method chemical oxygen demand measurement side that can quickly measure in high volume
Method.
The technical scheme is that
A kind of mass method chemical oxygen demand measuring method, by being calculated by weighing unit, operation control unit, data acquisition storage
The mass method chemical oxygen demand measurement system of unit, display unit composition realizes measuring, and its measuring method comprises the following steps:
Weighing container quality, is placed on quality m of weighing container on the object stage of weighing unit by container1,These data are passed through
Operation control unit is automatically entered in data acquisition storage computing unit, and shows on the display unit；
In weighing container, add water sample to be measured, weighed quality m of water sample+container by weighing unit2, these data are passed through
Operation control unit is automatically entered in data acquisition storage computing unit；
In weighing container, add oxidant, weighed quality m of container+water sample+oxidant by weighing unit3, this number
It is automatically entered in data acquisition storage computing unit according to being manipulated by unit, then in container, adds a certain amount of catalysis
Agent (silver sulfate+sulphuric acid)；
Heating is cleared up, and the mixed liquor (water sample+oxidant+catalyst) in container is carried out heating and clears up, make oxidant and water
Organic substance in sample fully reacts；
Mixed liquor after heating is cleared up adds the spirit of indicator ferrous iron and adds proper amount of clear water；
With the mixed liquor in Ferrous ammonium sulfate titration vessel, shown the terminal determining titration by the color of ferrous spirit.
Weight m by the Ferrous ammonium sulfate+container before weighing unit metering titration4 , these data are manipulated by
Unit is automatically entered in data acquisition storage computing unit；After being titrated to terminal, remaining Ferrous ammonium sulfate adds the weight of container
m5, these data are manipulated by unit and are automatically entered in data acquisition storage computing unit；The water sample every time measured wraps
Include a blank sample and a known CODcrThe water sample of value.
COD is calculated by following computing formulacrValue:
CODcr=K·p 1 (m 3 -m 2 -m 1 )/49.03-p 2 (m 4 -m 5 )/392.1 ..①
(m2-m1)
Wherein:
CODcrThe COD (mg/l) of water sample
P1Potassium bichromate solution mass concentration (%), for datum, is manipulated by unit and is input to data acquisition storage meter
Calculate unit.
P2L ferrous ammonium sulfate solution mass concentration, need to be through CODcrTitration data when=0 carries out calibrated and calculated
The molecular weight of 49.03 1/6 potassium dichromates
392.1 Ferrous ammonium sulfate molecular weight
According to formula by blank sample (CODcr=0), P is calculated2.Again by known CODcrWater sample calculate K value, then with public
1. formula calculates the COD of water sample to be measuredcrValue.
Above-mentioned catalyst is silver sulfate+sulphuric acid
Above-mentioned oxidant is potassium dichromate.
The present invention can avoid measuring the personal error that link produces, sampling, compounding medicine accurate measurement, measures and accurately may be used
Lean on, easy to operate.
The present invention compares with known technology.
The most conventional CODcrMethod of testing divides two big classes: 1, according to the titrimetry of National Standard Method, is by manually estimating meter
Measuring device tool (burette, pipet, volumetric measurement utensil etc.) metering water sample, oxidant and the volume number of Ferrous ammonium sulfate, then lead to
Cross formula and calculate CODcrValue.2, spectrophotography: be by different CODcrValue water sample react with oxidant after mixed liquor color
Difference and measured by spectrophotometric and calculate CODcrValue, their difference is as follows.
| Method | Error produces link | Operation complexity | Result essence Exactness |
| Titrimetry | Compounding medicine process, various range estimation metering link all can produce personal error. | Requiring that operator's maneuver is very skilled, each step requires accurately. | ±4% |
| Light splitting light Degree method | Requiring that water sample measures accurately, is easily generated personal error, measuring because being indirectly by optical method, instrument The performance impact accuracy of device is the biggest. | Operating procedure is less, but each step requires accurate measurement. | ±15% |
| This method | Any link is not had to require the continuous data of fixed precision so that all metering links all will not be produced Raw personal error. | Operation requires simple, does not has any link to produce personal error, entirely by metering units (5) precision determining measuring accuracy. | ± 0.37% |
Accompanying drawing explanation
Fig. 1 is that the present invention measures CODcrThe system composition diagram of value.
Detailed description of the invention
A kind of mass method chemical oxygen demand measuring method, by being deposited by weighing unit 3, operation control unit 5, data acquisition
Storage computing unit 4, the mass method chemical oxygen demand flowmeter of display unit 6 composition realize measuring, and its measuring method includes following
Step: weighing container, is placed on quality m of weighing container 1 on the object stage 2 of weighing unit 3 by container 11,These data are by behaviour
Make control unit 5 to be automatically entered in data acquisition storage computing unit 4, and show on display unit 6；To weighing container 1
Middle addition water sample to be measured, weighs quality m of water sample+container by weighing unit 32, these data are manipulated by unit 5 certainly
Move and be input in data acquisition storage computing unit 4；Oxidant potassium dichromate is added, by weighing unit 3 in weighing container 1
Weigh quality m of container+water sample+oxidant3, these data are manipulated by unit 5 and are automatically entered into data acquisition storage
In computing unit 4, then in container 1, add a certain amount of catalyst sulfuric acid silver+sulphuric acid；Heating is cleared up, by the mixing in container
Liquid (water sample+oxidant+catalyst) carries out heating and clears up, and makes oxidant fully react with the Organic substance in water sample, the side of heating
Formula is water-bath, microwave, thermostatic drying chamber, baking box, special clears up instrument etc.；Mixed liquor after heating is cleared up adds indicator sub-
Ferrum spirit also adds proper amount of clear water；With the mixed liquor in Ferrous ammonium sulfate titration vessel, show by the color of ferrous spirit and determine droplet
Fixed terminal.
Weight m by the Ferrous ammonium sulfate+container before weighing unit 3 metering titration4These data are manipulated by list
Unit 5 is automatically entered in data acquisition storage computing unit 4.After being titrated to terminal, remaining Ferrous ammonium sulfate adds the weight of container
m5, these data are manipulated by unit 5 and are automatically entered in data acquisition storage computing unit 4.
The water sample every time measured includes a blank sample and a known CODcrThe water sample of value.
COD is calculated by following computational methodscrValue.
CODcrValue=K M/m
Wherein: K coefficient
M aoxidizes the molal quantity of the consumed potassium dichromate of Organic substance in a certain amount of water sample
The quality of m water sample, m=m2-m1
M=mk/49.03-mf/392.1 mkQuality m of the potassium dichromate usedk=P1(m3-m2-m1)
mfThe weight of the ferrous sulfate ammonia that titration residual gravity Neutral potassium chromate is consumed
mf=P2(m4-m5)
CODcr=K·p 1 (m 3 -m 2 -m 1 )/49.03-p 2 (m 4 -m 5 )/392.1 ①
(m2-m1)
Wherein:
CODcrThe COD (mg/l) of water sample.
P1Potassium bichromate solution quality solubility (%), for datum, is manipulated by unit 5 and inputs data acquisition and deposit
Storage computing unit 4.
P2L ferrous ammonium sulfate solution mass concentration, need to be through CODcrTitration data when=0 carries out calibrated and calculated.
The molecular weight of 49.03 1/6 potassium dichromates.
392.1 Ferrous ammonium sulfate molecular weight.
According to formula (1) by blank sample (CODcr=0), P is calculated2.Again by known CODcrWater sample calculate K value,
Use formula againCalculate the COD of water sample to be measuredcrValue.
Process calculated above is to be automatically performed by the calculation procedure in input data acquisition storage computing unit 4.
Measuring CODcrIn equipment and method of testing, computational methods disclosed in this invention, formula and principle, all in protection
Within the scope of.
Claims (3)
1. a mass method chemical oxygen demand measuring method, by by weighing unit, operation control unit, data acquisition storage meter
Calculate unit, the mass method chemical oxygen demand flowmeter of display unit composition realizes measuring, it is characterised in that under measuring method includes
Row step:
Weighing container, is placed on quality m of weighing container on the object stage of weighing unit by container1,These data are controlled by operation
Unit processed is automatically entered in data acquisition storage computing unit, and shows on the display unit；
In weighing container, add water sample to be measured, weighed quality m of water sample+container by weighing unit2, these data are passed through
Operation control unit is automatically entered in data acquisition storage computing unit；
In weighing container, add oxidant, weighed quality m of container+water sample+oxidant by weighing unit3, these data
It is manipulated by unit to be automatically entered in data acquisition storage computing unit, then in container, adds a certain amount of catalysis
Agent；
Heating is cleared up, and the mixed liquor (water sample+oxidant+catalyst) in container is carried out heating and clears up, make oxidant and water sample
In Organic substance fully react；
Mixed liquor after heating is cleared up adds the spirit of indicator ferrous iron and adds proper amount of clear water；
With the mixed liquor in Ferrous ammonium sulfate titration vessel, shown the terminal determining titration by the color of ferrous spirit.
Weight m by the Ferrous ammonium sulfate+container before weighing unit metering titration4 , these data are manipulated by unit
It is automatically entered in data acquisition storage computing unit；After being titrated to terminal, remaining Ferrous ammonium sulfate adds weight m of container5,
These data are manipulated by unit and are automatically entered in data acquisition storage computing unit；The water sample every time measured includes one
Individual blank sample and a known CODcrThe water sample of value；
COD is calculated by following computing formulacrValue:
CODcr=K·p 1 (m 3 -m 2 -m 1 )/49.03-p 2 (m 4 -m 5 )/392.1
(m2-m1)
Wherein:
CODcrThe COD (mg/l) of water sample
P1Potassium bichromate solution mass concentration (%), for datum, is manipulated by unit input data acquisition storage and calculates
Unit obtains
P2L ferrous ammonium sulfate solution mass concentration, need to be through CODcrTitration data when=0 carries out calibrated and calculated
The molecular weight of 49.03 1/6 potassium dichromates
392.1 Ferrous ammonium sulfate molecular weight
According to formula by blank sample (CODcr=0), P is calculated2, then by known CODcrWater sample calculate K value, then with public
Formula calculates the COD of water sample to be measuredcrValue.
A kind of mass method chemical oxygen demand measuring method the most according to claim 1, it is characterised in that described catalyst
For silver sulfate+sulphuric acid.
A kind of mass method chemical oxygen demand measuring method the most according to claim 1, it is characterised in that described oxidant
For potassium dichromate.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201610385610.7A CN106092805A (en) | 2016-06-03 | 2016-06-03 | A kind of mass method chemical oxygen demand measuring method |
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| CN201610385610.7A CN106092805A (en) | 2016-06-03 | 2016-06-03 | A kind of mass method chemical oxygen demand measuring method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108956496A (en) * | 2018-07-11 | 2018-12-07 | 东盛科兴环保科技河北有限公司 | A kind of multi-wavelength detection method of rapid-digestion COD |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1049909A (en) * | 1989-08-31 | 1991-03-13 | 卡伯特公司 | The iodine number of gravimetric determination carbon black |
| CN203414376U (en) * | 2013-09-11 | 2014-01-29 | 张贵珍 | Device for measuring water content through chemical method |
| CN103728292A (en) * | 2012-10-10 | 2014-04-16 | 肖泸燕 | Method for testing chemical oxygen demand of degradable water-soluble polymer |
| JP2015049180A (en) * | 2013-09-03 | 2015-03-16 | 株式会社堀場製作所 | Water quality analysis system and water quality analysis method |
| CN104792648A (en) * | 2015-04-23 | 2015-07-22 | 江苏省沙钢钢铁研究院有限公司 | Method for determining contents of aluminum and iron in steel grit aluminum through combination of weighing method and titration method |
| CN105548160A (en) * | 2015-12-10 | 2016-05-04 | 苏州国环环境检测有限公司 | Method for testing chemical oxygen demand of water sample through bichromate method |
-
2016
- 2016-06-03 CN CN201610385610.7A patent/CN106092805A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1049909A (en) * | 1989-08-31 | 1991-03-13 | 卡伯特公司 | The iodine number of gravimetric determination carbon black |
| CN103728292A (en) * | 2012-10-10 | 2014-04-16 | 肖泸燕 | Method for testing chemical oxygen demand of degradable water-soluble polymer |
| JP2015049180A (en) * | 2013-09-03 | 2015-03-16 | 株式会社堀場製作所 | Water quality analysis system and water quality analysis method |
| CN203414376U (en) * | 2013-09-11 | 2014-01-29 | 张贵珍 | Device for measuring water content through chemical method |
| CN104792648A (en) * | 2015-04-23 | 2015-07-22 | 江苏省沙钢钢铁研究院有限公司 | Method for determining contents of aluminum and iron in steel grit aluminum through combination of weighing method and titration method |
| CN105548160A (en) * | 2015-12-10 | 2016-05-04 | 苏州国环环境检测有限公司 | Method for testing chemical oxygen demand of water sample through bichromate method |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108956496A (en) * | 2018-07-11 | 2018-12-07 | 东盛科兴环保科技河北有限公司 | A kind of multi-wavelength detection method of rapid-digestion COD |
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Application publication date: 20161109 |