CN117607082B - Method for measuring concentration of each oxidant in mixed solution of peroxymonosulfate and free chlorine based on iodometry and application of method - Google Patents
Method for measuring concentration of each oxidant in mixed solution of peroxymonosulfate and free chlorine based on iodometry and application of method Download PDFInfo
- Publication number
- CN117607082B CN117607082B CN202311671932.4A CN202311671932A CN117607082B CN 117607082 B CN117607082 B CN 117607082B CN 202311671932 A CN202311671932 A CN 202311671932A CN 117607082 B CN117607082 B CN 117607082B
- Authority
- CN
- China
- Prior art keywords
- free chlorine
- concentration
- absorbance
- peroxomonosulfate
- measuring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000000460 chlorine Substances 0.000 title claims abstract description 172
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 title claims abstract description 147
- 229910052801 chlorine Inorganic materials 0.000 title claims abstract description 143
- 238000000034 method Methods 0.000 title claims abstract description 53
- 239000011259 mixed solution Substances 0.000 title claims abstract description 32
- FHHJDRFHHWUPDG-UHFFFAOYSA-L peroxysulfate(2-) Chemical compound [O-]OS([O-])(=O)=O FHHJDRFHHWUPDG-UHFFFAOYSA-L 0.000 title claims abstract description 32
- 239000007800 oxidant agent Substances 0.000 title claims abstract description 31
- 230000001590 oxidative effect Effects 0.000 title claims abstract description 28
- 239000000243 solution Substances 0.000 claims abstract description 91
- 238000002835 absorbance Methods 0.000 claims abstract description 64
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 claims abstract description 44
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 claims description 147
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 96
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 48
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 48
- 238000006243 chemical reaction Methods 0.000 claims description 43
- 239000007788 liquid Substances 0.000 claims description 34
- 150000003839 salts Chemical class 0.000 claims description 27
- 230000010355 oscillation Effects 0.000 claims description 19
- 238000007865 diluting Methods 0.000 claims description 17
- 239000005708 Sodium hypochlorite Substances 0.000 claims description 11
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 3
- 238000005259 measurement Methods 0.000 abstract description 3
- 230000000873 masking effect Effects 0.000 abstract 1
- 239000012295 chemical reaction liquid Substances 0.000 description 8
- -1 iodine ions Chemical class 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910052740 iodine Inorganic materials 0.000 description 4
- 239000011630 iodine Substances 0.000 description 4
- 238000004088 simulation Methods 0.000 description 3
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 2
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000012085 test solution Substances 0.000 description 2
- JNOZGFXJZQXOSU-UHFFFAOYSA-N 1-chloro-2-methylpropan-2-ol Chemical compound CC(C)(O)CCl JNOZGFXJZQXOSU-UHFFFAOYSA-N 0.000 description 1
- QNGVNLMMEQUVQK-UHFFFAOYSA-N 4-n,4-n-diethylbenzene-1,4-diamine Chemical compound CCN(CC)C1=CC=C(N)C=C1 QNGVNLMMEQUVQK-UHFFFAOYSA-N 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 230000026045 iodination Effects 0.000 description 1
- 238000006192 iodination reaction Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- 238000005375 photometry Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000002798 spectrophotometry method Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
Classifications
-
- 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
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/33—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using ultraviolet light
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Plasma & Fusion (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
Abstract
The invention provides a method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometry and application thereof, and relates to the technical field of oxidant concentration measurement. The invention is based on an iodometric method, and three standard curves are drawn by combining the masking effect of tert-butyl alcohol on free chlorine: and (3) obtaining a calculation formula of the concentration of the peroxymonosulfate and the free chlorine by using a standard curve. And then measuring the absorbance of the diluted solution to be measured, and combining a calculation formula to obtain the concentration of the peroxymonosulfate and the concentration of the free chlorine, thereby solving the problem that the concentration of each oxidant can not be measured when the peroxymonosulfate and the free chlorine coexist in the same system in the prior art.
Description
Technical Field
The invention relates to the technical field of oxidant concentration measurement, in particular to a method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometry and application thereof.
Background
Advanced oxidation techniques based on Peroxomonosulphate (PMS), free chlorine, are widely used in drinking water and wastewater treatment processes. By activating PMS, free chlorine or both synergistically in the system, oxidative free radicals can be generated to effectively oxidatively degrade organic pollutants. The detection method of PMS concentration in the report research is mainly a traditional iodometric method, and the standard detection method of free chlorine in water is mainly a photometry method, namely a spectrophotometry method for detecting N, N-diethyl-1, 4-phenylenediamine (HJ 586-2010) of free chlorine and total chlorine in water. All of the above methods can only measure the concentration of a single oxidizing agent in a system, but cannot measure the concentration of each oxidizing agent when PMS and free chlorine coexist in the same system. Therefore, how to establish a convenient and accurate method for determining the concentration of each oxidant in a PMS, free chlorine mixed solution is a problem to be solved by those skilled in the art.
Disclosure of Invention
The invention aims to provide a method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometry and application thereof, so as to solve the problem that the concentration of each oxidant in the mixed solution of peroxymonosulfate and free chlorine can not be measured simultaneously in the prior art.
In order to achieve the above object, the present invention provides the following technical solutions:
The invention provides a method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometry, which comprises the following steps:
Preparing free chlorine solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-free chlorine concentration standard curve y 1＝a1x+b1;
Preparing peroxomonosulfate solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 2＝a2x+b2;
Preparing mixed solutions of peroxomonosulfate and free chlorine with different concentrations and equal volumes, adding tertiary butanol, then adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 4＝a4x+b4;
diluting the liquid to be measured by N times, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, and measuring the absorbance of the liquid to be measured by an ultraviolet spectrophotometer and recording the absorbance as A PMS+Free chlorine;
Taking a liquid to be detected, adding tertiary butanol, diluting to N times of the volume of the liquid to be detected, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, and measuring the absorbance of the liquid to be detected by an ultraviolet spectrophotometer and recording the absorbance as A PMS+Free chlorine+TBA;
Wherein, the concentration of the peroxymonosulfate is as follows: c peroxomonosulfate salt ＝N×(APMS+Free chlorine+TBA-b4)/a4, in mmol/L;
The concentration of free chlorine in Cl 2 is: c free chlorine ＝N×(A free chlorine -b1)/a1, unit is mu mol/L;
A free chlorine ＝APMS+Free chlorine-A peroxomonosulfate salt ,A peroxomonosulfate salt ＝a2×C peroxomonosulfate salt /N+b2。
Preferably, the drawing method of the standard curve y 1＝a1x+b1 is as follows: sodium hypochlorite solution is used for simulating free chlorine solution, free chlorine solutions with different concentrations and equal volumes are prepared, sodium bicarbonate and potassium iodide are added for oscillation reaction, an ultraviolet spectrophotometer is used for measuring absorbance of the reaction solution, and an absorbance-free chlorine concentration standard curve y 1＝a1x+b1 is drawn.
Preferably, the drawing method of the standard curve y 2＝a2x+b2 is as follows: preparing peroxomonosulfate solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, performing oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 2＝a2x+b2.
Preferably, the drawing method of the standard curve y 4＝a4x+b4 is as follows: preparing peroxomonosulfate and free chlorine solutions with different concentrations and equal volumes, adding tert-butanol, uniformly mixing, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 4＝a4x+b4.
Preferably, in the drawing method of the standard curve y 4＝a4x+b4, the volume ratio of the tertiary butanol to the mixed solution containing peroxymonosulfate and free chlorine is 0.8-2: 10.
Preferably, when preparing different solutions, the time of the shaking reaction after adding sodium bicarbonate and potassium iodide is independently 15-20 min.
Preferably, the absorbance is the absorbance of the solution at a wavelength of 352 nm.
Preferably, when different solutions are prepared, the concentration of potassium iodide in a system after adding sodium bicarbonate and potassium iodide is not less than 0.60mol/L independently, and the concentration of sodium bicarbonate is not less than 0.119mol/L independently.
Preferably, the volume ratio of the addition amount of the tertiary butanol in the liquid to be measured to the solution after the liquid to be measured is diluted by N times is 0.8-2: 10.
The invention also provides an application of the method for measuring the concentration of each oxidant in the mixed solution containing the peroxymonosulfate and the free chlorine based on the iodometry.
The invention has at least the following beneficial effects:
1) The iodination method is that iodine ions react with oxidant under certain conditions to generate equivalent iodine simple substance, the iodine simple substance and excessive iodine ions continue to react in half to generate equivalent I 3 －, then an ultraviolet spectrophotometer is used for detecting the absorbance of the reaction liquid at 352nm, and the concentration of the oxidant in the system can be obtained by combining the drawn standard curve and calculating according to a formula.
2) The Tertiary Butyl Alcohol (TBA) is added into the liquid to be detected, so that free chlorine in the system can be masked without affecting the reaction of iodide ions and PMS, and the concentration of PMS in the liquid to be detected can be determined, thereby further determining the corresponding concentration of free chlorine and PMS in the liquid to be detected through the addition relation.
Drawings
FIG. 1 is a graph of absorbance versus free chlorine concentration standard;
FIG. 2 is a graph of absorbance versus peroxomonosulfate concentration standard;
FIG. 3 is a graph of absorbance versus peroxymonosulfate concentration standard curve for a peroxymonosulfate/free chlorine system and a peroxymonosulfate/free chloro-t-butanol system;
FIG. 4 is a graph showing the absorbance of the free chlorine test solution before and after t-butanol addition;
FIG. 5 is a bar graph of the measured values and theoretical values of the concentration of peroxymonosulfate and free chlorine in the sample to be tested.
Detailed Description
The invention provides a method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometry, which comprises the following steps:
Preparing free chlorine solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-free chlorine concentration standard curve y 1＝a1x+b1;
Preparing peroxomonosulfate solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 2＝a2x+b2;
Preparing mixed solutions of peroxomonosulfate and free chlorine with different concentrations and equal volumes, adding tertiary butanol, then adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 4＝a4x+b4;
Diluting the liquid to be measured by N times, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, and measuring the absorbance of the liquid to be measured by an ultraviolet spectrophotometer and recording the absorbance as A PMS+Freechlorine;
Taking a liquid to be detected, adding tertiary butanol, diluting to N times of the volume of the liquid to be detected, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, and measuring the absorbance of the liquid to be detected by an ultraviolet spectrophotometer and recording the absorbance as A PMS+Free chlorine+TBA;
Wherein, the concentration of the peroxymonosulfate is as follows: c peroxomonosulfate salt ＝N×(APMS+Free chlorine+TBA-b4)/a4, in mmol/L;
The concentration of free chlorine in Cl 2 is: c free chlorine ＝N×(A free chlorine -b1)/a1, unit is mu mol/L;
A free chlorine ＝APMS+Free chlorine-A peroxomonosulfate salt ,A peroxomonosulfate salt ＝a2×C peroxomonosulfate salt /N+b2。
In the invention, the method also comprises the steps of preparing mixed solutions of peroxomonosulfate and free chlorine in different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 3＝a3x+b3.
It can be demonstrated by standard curves y 3 and y 4 that t-butanol masks free chlorine in the mixed system of free chlorine and peroxomonosulfate, but does not affect the determination of peroxomonosulfate concentration.
In the present invention, the oxidizing agents include peroxomonosulfate and free chlorine.
In the invention, the drawing method of the standard curve y 1＝a1x+b1 is as follows: sodium hypochlorite solution is used for simulating free chlorine solution, free chlorine solutions with different concentrations and equal volumes are prepared, sodium bicarbonate and potassium iodide are added for oscillation reaction, an ultraviolet spectrophotometer is used for measuring absorbance of the reaction solution, and an absorbance-free chlorine concentration standard curve y 1＝a1x+b1 is drawn.
In the method for preparing the free chlorine solution with different concentrations and equal volumes, the free chlorine solution is simulated by sodium hypochlorite solution, the free chlorine solution with the concentration of 0 mu mol/L, 6.2059 mu mol/L, 12.4118 mu mol/L, 18.6178 mu mol/L, 24.8237 mu mol/L and 31.0296 mu mol/L is prepared by preparing the Cl 2, and the free chlorine solution with different concentrations and equal volumes is obtained by respectively diluting the sodium hypochlorite solution with different concentrations by 5 times.
In the invention, the preparation method of the free chlorine solution comprises the steps of preparing sodium hypochlorite solution with a certain concentration, and then measuring the accurate concentration of the free chlorine by adopting a HACH free chlorine reagent pack.
In the invention, the drawing method of the standard curve y 2＝a2x+b2 is as follows: preparing peroxomonosulfate solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, performing oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 2＝a2x+b2.
In the invention, the concentration gradient of the peroxomonosulfate solution with different concentrations and equal volumes is 0mmol/L, 0.01mmol/L, 0.02mmol/L, 0.03mmol/L, 0.04mmol/L and 0.05mmol/L.
In the invention, the preparation method of the peroxomonosulfate solution with different concentrations and equal volumes comprises the following steps: preparing a PMS concentrated solution with concentration gradients of 0mmol/L, 0.2mmol/L, 0.4mmol/L, 0.6mmol/L, 0.8mmol/L and 1.0 mmol/L; and respectively adding water into equal volumes of PMS concentrated solutions with different concentrations to dilute the PMS concentrated solutions by 20 times to obtain peroxomonosulfate solutions with different concentrations and equal volumes.
In the invention, the drawing method of the standard curve y 3＝a3x+b3 is as follows: preparing peroxomonosulfate and free chlorine solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, performing oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 3＝a3x+b3.
In the invention, the concentration gradient of the peroxomonosulfate with different concentrations and equal volumes and the peroxomonosulfate of the free chlorine solution is 0mmol/L, 0.01mmol/L, 0.02mmol/L, 0.03mmol/L, 0.04mmol/L and 0.05mmol/L; the concentration of free chlorine was 14.10. Mu. Mol/L.
In the invention, the drawing method of the standard curve y 4＝a4x+b4 is as follows: preparing peroxomonosulfate and free chlorine solutions with different concentrations and equal volumes, adding tert-butanol, uniformly mixing, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 4＝a4x+b4.
In the drawing method of the standard curve y 4＝a4x+b4, the volume ratio of the tertiary butanol to the mixed solution containing peroxymonosulfate and free chlorine is 0.8-2: 10, preferably 1.0 to 1.8:10, more preferably 1.2 to 1.6:10, more preferably 1.4 to 1.5:10.
In the invention, the concentration gradient of the peroxomonosulfate with different concentrations and equal volumes and the peroxomonosulfate of the free chlorine solution in the drawing process of the standard curve y 4＝a4x+b4 is 0mmol/L, 0.01mmol/L, 0.02mmol/L, 0.03mmol/L, 0.04mmol/L and 0.05mmol/L; the concentration of free chlorine was 14.10. Mu. Mol/L.
In the invention, when each standard curve is drawn, the time of the oscillation reaction after adding sodium bicarbonate and potassium iodide is independently 15-20 min.
In the present invention, the configuration of the different solutions includes configuration of a solution for measuring a standard curve and a solution to be measured.
In the present invention, the absorbance is the absorbance of the solution at a wavelength of 352 nm.
In the invention, when different solutions are prepared, the concentration of potassium iodide in a system after adding sodium bicarbonate and potassium iodide is more than or equal to 0.60mol/L, preferably 0.60-3.0 mol/L, more preferably 0.80-2.5 mol/L, still more preferably 1.0-2.0 mol/L, and more preferably 1.2-1.5 mol/L; the concentration of sodium bicarbonate is independently not less than 0.119mol/L, preferably 0.15 to 1.50mol/L, more preferably 0.20 to 1.0mol/L, still more preferably 0.25 to 0.8mol/L, and still more preferably 0.30 to 0.50mol/L.
In the invention, the potassium iodide needs to be excessive, and after the potassium iodide reacts with an oxidant to generate I 2, excessive iodide ions react with I 2 to generate I 3 -, so that the characteristic absorbance is detected; sodium bicarbonate serves the primary function of buffering and stabilizing the pH of the solution.
In the present invention, the configuration of the different solutions includes configuration of a solution for measuring a standard curve and a solution to be measured.
In the invention, the volume ratio of the addition amount of the tertiary butanol in the liquid to be tested to the solution after the liquid to be tested is diluted by N times is 0.8-2: 10, preferably 1.0 to 1.8:10, more preferably 1.2 to 1.6:10, more preferably 1.4 to 1.5:10.
In the invention, the method for measuring A PMS+Free chlorine comprises the following steps: taking a certain volume of liquid to be measured, diluting N times, adding sodium bicarbonate and potassium iodide, shaking uniformly, vibrating and reacting for 15-20 min, and measuring the absorbance of the reaction liquid at 352nm by using an ultraviolet spectrophotometer, and recording as A PMS+Free chlorine.
In the invention, the method for measuring A PMS+Free chlorine+TBA comprises the following steps: taking a certain volume of liquid to be measured, adding tertiary butanol, diluting to N times of the volume of the liquid to be measured, shaking uniformly, standing for 15-30 seconds, adding sodium bicarbonate and potassium iodide, shaking uniformly, vibrating for 15-20 minutes, measuring the absorbance of the reaction liquid at 352nm by using an ultraviolet spectrophotometer, and recording as A PMS+Free chlorine+TBA.
In the present invention, the above-mentioned N is not less than 1 and not more than 30, preferably not less than 5 and not more than 25, more preferably not less than 10 and not more than 20, still more preferably not less than 10 and not more than 15.
In the present invention, the concentration of the free chlorine is calculated as Cl 2.
The invention also provides an application of the method for measuring the concentration of each oxidant in the mixed solution containing the peroxymonosulfate and the free chlorine based on the iodometry.
The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.
Example 1
1) Simulating a free chlorine solution by using a sodium hypochlorite solution, preparing a sodium hypochlorite solution with a certain concentration, taking 10mL of the solution, using a Hach free chlorine reagent package, measuring the characteristic absorbance at a wavelength of 530nm by using an ultraviolet spectrophotometer, and determining that the accurate free chlorine concentration (calculated by Cl 2) of the sodium hypochlorite solution is 2.2mg/L as Cl 2 (namely 31.0296 mu mol/L as Cl 2); diluting to obtain six sodium hypochlorite solutions with concentration gradients of 0μmol/L as Cl2、6.2059μmol/L as Cl2、12.4118μmol/L as Cl2、18.6178μmol/L as Cl2、24.8237μmol/L as Cl2、31.0296μmol/L as Cl2 and determined concentration gradients; 2mL of sodium hypochlorite solution with determined concentration gradient is taken and diluted to 10mL by adding water to obtain six free chlorine solutions with concentration gradient 0μmol/L as Cl2、1.2412μmol/L as Cl2、2.4824μmol/L as Cl2、3.7236μmol/L as Cl2、4.9647μmol/L as Cl2、6.2059μmol/L as Cl2, then 0.1g of sodium bicarbonate and 1g of potassium iodide are added, shaking is carried out, shake reaction is carried out for 20min to obtain six reaction solutions, absorbance of the reaction solution at 352nm is measured by using an ultraviolet spectrophotometer, an absorbance-free chlorine concentration standard curve at 352nm is drawn, as shown in figure 1, and a linear equation of y 1＝0.0444x－0.00148,a1＝0.0444,b1 = -0.00148 is obtained by fitting;
2) Preparing PMS concentrated solutions with the concentration of 0mmol/L, 0.2mmol/L, 0.4mmol/L, 0.6mmol/L, 0.8mmol/L and 1.0mmol/L respectively, diluting the concentrated solutions by 20 times by 0.5mL to obtain PMS solutions with the concentration of 0mmol/L, 0.01mmol/L, 0.02mmol/L, 0.03mmol/L, 0.04mmol/L and 0.05mmol/L respectively, adding 0.1g sodium bicarbonate and 1g potassium iodide, shaking uniformly, vibrating for 20min, measuring the absorbance of the reaction solution at 352nm by using an ultraviolet spectrophotometer, and drawing an absorbance-PMS concentration standard curve at 352nm, wherein a linear equation is obtained by fitting as shown in a graph 2, wherein the linear equation is y 2＝24.334x+0.00303,a2＝24.334,b2 = 0.00303;
3) Preparing mixed solutions with PMS concentration gradients of 0mmol/L, 0.2mmol/L, 0.4mmol/L, 0.6mmol/L, 0.8mmol/L and 1.0mmol/L and free chlorine concentration of 14 mu mol/L as Cl 2 (namely 1mg/L as Cl 2), respectively taking 0.5mL, adding water to dilute to 10mL, adding 0.1g sodium bicarbonate and 1g potassium iodide, shaking uniformly, vibrating and reacting for 20min, measuring the absorbance of the reaction solution at 352nm by using an ultraviolet spectrophotometer, drawing a standard curve of the absorbance-PMS concentration at 352nm, and fitting to obtain a linear equation of y 3＝23.750x+0.0398,a3＝23.750,b3 =0.0398 as shown in fig. 3;
4) Preparing mixed solutions consistent with the step 3), taking 0.5mL of each mixed solution, adding 1mL of tertiary butanol, shaking uniformly, standing for 15-30 s (as shown in figures 3 and 4, tertiary butanol can react with free chlorine in a system and does not influence the reaction of iodide ions and PMS, so that the existence of free chlorine in the system can be masked by tertiary butanol), adding water to dilute to 10mL, adding 0.1g of sodium bicarbonate and 1g of potassium iodide, shaking uniformly, performing shaking reaction for 20min, measuring the absorbance of a reaction solution at 352nm by using an ultraviolet spectrophotometer, drawing a standard curve of the absorbance-PMS concentration at 352nm, and fitting to obtain a linear equation of y 4＝23.184x－0.0418,a4＝23.184,b4 = -0.0418 as shown in figure 3;
5) Taking 0.5mL of a liquid to be detected (the liquid to be detected is a prepared simulation solution containing PMS 0mmol/L and free chlorine 14 mu mol/L as Cl 2), adding 0.1g of sodium bicarbonate and 1g of potassium iodide, diluting to 10mL, shaking uniformly, carrying out shaking reaction for 20min, and measuring the absorbance A PMS+Free chlorine = 0.07567 of the reaction liquid at 352nm by using an ultraviolet spectrophotometer;
6) Taking 0.5mL of the solution to be detected, adding 1mL of tertiary butanol, shaking uniformly, standing for 30s, diluting to 10mL, adding sodium bicarbonate and potassium iodide, shaking uniformly, vibrating and reacting for 20min, and measuring the absorbance A PMS+Free chlorine+TBA =0 of the reaction solution at 352nm by using an ultraviolet spectrophotometer;
7) PMS concentration C peroxomonosulfate salt ＝N×(APMS+Free chlorine+TBA-b4)/a4; PMS absorbance a peroxomonosulfate salt ＝a2×C peroxomonosulfate salt /N+b2; free chlorine absorbance a free chlorine ＝APMS+Free chlorine-A peroxomonosulfate salt ; free chlorine concentration C free chlorine ＝N×(A free chlorine -b1)/a1; wherein, the unit of C peroxomonosulfate salt is mmol/L, and the unit of C free chlorine is mu mol/L as Cl 2. The concentration of PMS was calculated according to the above formula to be 0.0361mmol/L and the concentration of free chlorine was 13.625. Mu. Mol/L as Cl 2.
Example 2
The standard curves were drawn as in example 1, steps 1) to 4).
Taking 0.5mL of a liquid to be detected (the liquid to be detected is a prepared simulation solution containing PMS 0.4mmol/L and free chlorine 14 mu mol/L as Cl 2), diluting to 10mL, adding sodium bicarbonate and potassium iodide, shaking uniformly, carrying out oscillation reaction for 20min, and measuring absorbance A PMS+Freechlorine = 0.49767 of the reaction liquid at 352nm by using an ultraviolet spectrophotometer;
Taking 0.5mL of liquid to be detected, adding 1mL of tertiary butanol, shaking uniformly, standing for 30s, diluting to 10mL, adding sodium bicarbonate and potassium iodide, shaking uniformly, vibrating and reacting for 20min, and measuring absorbance A PMS+Freechlorine+TBA = 0.40700 of the reaction liquid at 352nm by using an ultraviolet spectrophotometer;
PMS concentration C peroxomonosulfate salt ＝N×(APMS+Freechlorine+TBA-b4)/a4; PMS absorbance a peroxomonosulfate salt ＝a2×C peroxomonosulfate salt /N+b2; free chlorine absorbance a free chlorine ＝APMS+Freechlorine-A peroxomonosulfate salt ; free chlorine concentration C free chlorine ＝N×(A free chlorine -b1)/a1; wherein, the unit of C peroxomonosulfate salt is mmol/L, and the unit of C free chlorine is mu mol/L as Cl 2. The concentration of PMS was calculated to be 0.387mmol/L and the concentration of free chlorine was calculated to be 11.287. Mu. Mol/L as Cl 2 according to the above formula.
Example 3
The standard curves were drawn as in example 1, steps 1) to 4).
Taking 0.5mL of a liquid to be detected (the liquid to be detected is a prepared simulation solution containing PMS 0.6mmol/L and free chlorine 14 mu mol/L as Cl 2), diluting to 10mL, adding sodium bicarbonate and potassium iodide, shaking uniformly, carrying out oscillation reaction for 20min, and measuring absorbance A PMS+Freechlorine = 0.73133 of the reaction liquid at 352nm by using an ultraviolet spectrophotometer;
Taking 0.5mL of liquid to be detected, adding 1mL of tertiary butanol, shaking uniformly, standing for 30s, diluting to 10mL, adding sodium bicarbonate and potassium iodide, shaking uniformly, vibrating and reacting for 20min, and measuring absorbance A PMS+Freechlorine+TBA = 0.62567 of the reaction liquid at 352nm by using an ultraviolet spectrophotometer;
PMS concentration C peroxomonosulfate salt ＝N×(APMS+Freechlorine+TBA-b4)/a4; PMS absorbance a peroxomonosulfate salt ＝a2×C peroxomonosulfate salt /N+b2; free chlorine absorbance a free chlorine ＝APMS+Freechlorine-A peroxomonosulfate salt ; free chlorine concentration C free chlorine ＝N×(A free chlorine -b1)/a1; wherein, the unit of C peroxomonosulfate salt is mmol/L, and the unit of C free chlorine is mu mol/L as Cl 2. The concentration of PMS was calculated according to the above formula to be 0.576mmol/L and the concentration of free chlorine was 13.154. Mu. Mol/L as Cl 2.
The results of comparing the theoretical values and measured values of the concentrations of PMS and free chlorine in the three test solutions of examples 1 to 3 are shown in FIG. 5, and it can be considered that the measured values of the concentrations of PMS and free chlorine are actual values, which means that the measurement of the concentrations of PMS and free chlorine are not interfered with each other under the test conditions of the present method. In summary, when the concentration of each oxidant in the mixed solution of PMS and free chlorine is measured based on the iodometry, the interference of the free chlorine can be effectively shielded by adding tertiary butanol, and the reaction of iodide ions and PMS is not influenced, so that the concentration of PMS and free chlorine in the liquid to be measured can be measured simultaneously through the steps of the method.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (10)
1. A method for determining the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometric method, comprising the steps of:
Preparing free chlorine solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-free chlorine concentration standard curve y 1＝a1x+b1;
Preparing peroxomonosulfate solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 2＝a2x+b2;
Preparing mixed solutions of peroxomonosulfate and free chlorine with different concentrations and equal volumes, adding tertiary butanol, then adding sodium bicarbonate and potassium iodide, measuring absorbance, and drawing an absorbance-peroxomonosulfate concentration standard curve y 4＝a4x+b4;
diluting the liquid to be measured by N times, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, and measuring the absorbance of the liquid to be measured by an ultraviolet spectrophotometer and recording the absorbance as A PMS+Free chlorine;
Taking a liquid to be detected, adding tertiary butanol, diluting to N times of the volume of the liquid to be detected, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, and measuring the absorbance of the liquid to be detected by an ultraviolet spectrophotometer and recording the absorbance as A PMS+Free chlorine+TBA;
Wherein, the concentration of the peroxymonosulfate is as follows: c peroxomonosulfate salt ＝N×(APMS+Free chlorine+TBA-b4)/a4, in mmol/L;
The concentration of free chlorine in Cl 2 is: c free chlorine ＝N×(A free chlorine -b1)/a1, unit is mu mol/L;
A free chlorine ＝APMS+Free chlorine-A peroxomonosulfate salt ,A peroxomonosulfate salt ＝a2×C peroxomonosulfate salt /N+b2。
2. The method for determining the concentration of each oxidant in the mixed solution of peroxymonosulfate and free chlorine based on the iodometry according to claim 1, wherein the standard curve y 1＝a1x+b1 is drawn by the following method: sodium hypochlorite solution is used for simulating free chlorine solution, free chlorine solutions with different concentrations and equal volumes are prepared, sodium bicarbonate and potassium iodide are added for oscillation reaction, an ultraviolet spectrophotometer is used for measuring absorbance of the reaction solution, and an absorbance-free chlorine concentration standard curve y 1＝a1x+b1 is drawn.
3. The method for determining the concentration of each oxidant in the mixed solution of peroxymonosulfate and free chlorine based on the iodometry according to claim 2, wherein the standard curve y 2＝a2x+b2 is drawn by the following method: preparing peroxomonosulfate solutions with different concentrations and equal volumes, adding sodium bicarbonate and potassium iodide, performing oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 2＝a2x+b2.
4. A method for determining the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on an iodometric method according to claim 2 or 3, wherein the standard curve y 4＝a4x+b4 is drawn by the following method: preparing peroxomonosulfate and free chlorine solutions with different concentrations and equal volumes, adding tert-butanol, uniformly mixing, then adding sodium bicarbonate and potassium iodide, carrying out oscillation reaction, measuring the absorbance of the reaction solution by an ultraviolet spectrophotometer, and drawing an absorbance-peroxomonosulfate concentration standard curve y 4＝a4x+b4.
5. The method for measuring the concentration of each oxidant in the mixed solution of peroxymonosulfate and free chlorine based on the iodometry according to claim 4, wherein the volume ratio of the tertiary butanol to the mixed solution containing peroxymonosulfate and free chlorine in the drawing method of the standard curve y 4＝a4x+b4 is 0.8-2: 10.
6. The method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on the iodometric method according to claim 5, wherein the time of the shaking reaction after adding sodium bicarbonate and potassium iodide is independently 15 to 20 minutes when preparing different solutions.
7. The method for measuring the concentration of each oxidant in a mixed solution of peroxymonosulfate and free chlorine based on the iodometry according to claim 6, wherein the absorbance is the absorbance of the solution at a wavelength of 352 nm.
8. The method for measuring the concentration of each oxidant in the mixed solution of peroxymonosulfate and free chlorine based on the iodometry according to claim 7, wherein when different solutions are prepared, the concentration of potassium iodide in a system after adding sodium bicarbonate and potassium iodide is independently not less than 0.60mol/L, and the concentration of sodium bicarbonate is independently not less than 0.119mol/L.
9. The method for determining the concentration of each oxidant in the mixed solution of peroxymonosulfate and free chlorine based on the iodometry according to claim 8, wherein the volume ratio of the added amount of tertiary butanol in the solution to be tested to the solution to be tested diluted by N times is 0.8-2: 10.
10. Use of a method according to any one of claims 1 to 9 for measuring the concentration of each oxidizing agent in a mixed solution containing peroxomonosulfate and free chlorine based on the iodometry method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311671932.4A CN117607082B (en) | 2023-12-07 | 2023-12-07 | Method for measuring concentration of each oxidant in mixed solution of peroxymonosulfate and free chlorine based on iodometry and application of method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311671932.4A CN117607082B (en) | 2023-12-07 | 2023-12-07 | Method for measuring concentration of each oxidant in mixed solution of peroxymonosulfate and free chlorine based on iodometry and application of method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117607082A CN117607082A (en) | 2024-02-27 |
| CN117607082B true CN117607082B (en) | 2024-05-17 |
Family
ID=89946140
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311671932.4A Active CN117607082B (en) | 2023-12-07 | 2023-12-07 | Method for measuring concentration of each oxidant in mixed solution of peroxymonosulfate and free chlorine based on iodometry and application of method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117607082B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109612951A (en) * | 2018-11-13 | 2019-04-12 | 上海仪电科学仪器股份有限公司 | For detecting chlorine residue in water/total chlorine detection agent and preparation method thereof and detection method |
| CN110632250A (en) * | 2019-11-13 | 2019-12-31 | 东北农业大学 | Method for determining concentrations of peroxides in mixed solutions of peroxomonosulfate, peroxodisulfate and hydrogen peroxide based on iodometry |
| CN113415870A (en) * | 2021-06-11 | 2021-09-21 | 中国地质大学（北京） | Method and kit for removing vanadium citrate in water environment and application |
-
2023
- 2023-12-07 CN CN202311671932.4A patent/CN117607082B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109612951A (en) * | 2018-11-13 | 2019-04-12 | 上海仪电科学仪器股份有限公司 | For detecting chlorine residue in water/total chlorine detection agent and preparation method thereof and detection method |
| CN110632250A (en) * | 2019-11-13 | 2019-12-31 | 东北农业大学 | Method for determining concentrations of peroxides in mixed solutions of peroxomonosulfate, peroxodisulfate and hydrogen peroxide based on iodometry |
| CN113415870A (en) * | 2021-06-11 | 2021-09-21 | 中国地质大学（北京） | Method and kit for removing vanadium citrate in water environment and application |
Non-Patent Citations (1)
| Title |
|---|
| Simultaneous Determination of PMS, PDS, and H2O2 Concentrations with Multi-Step Iodometry;Jiang, X.等;water;20230610;第15卷;1-14 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117607082A (en) | 2024-02-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Buck et al. | Recommended procedures for calibration of ion-selective electrodes (Technical Report) | |
| Chen | Spectrophotometric determination f microquantities of chlorate, chlorite, hypochlorite, and chloride in perchlorate | |
| Xiao et al. | Simultaneous spectrophotometric determination of peracetic acid and the coexistent hydrogen peroxide using potassium iodide as the indicator | |
| Buechsenstein et al. | SO2 determination by aeration-oxidation: a comparison with Ripper | |
| CN109612951A (en) | For detecting chlorine residue in water/total chlorine detection agent and preparation method thereof and detection method | |
| CN110987918A (en) | Detection reagent and rapid detection method for total nitrogen in water | |
| CN111458329B (en) | Total chlorine and residual chlorine analysis method | |
| CN117607082B (en) | Method for measuring concentration of each oxidant in mixed solution of peroxymonosulfate and free chlorine based on iodometry and application of method | |
| CN116256355A (en) | On-line measurement, calibration and quality control method for total chlorine of residual chlorine | |
| JP4944740B2 (en) | Chlorite ion measurement method | |
| CN109061041A (en) | The measuring method of the COD of waste water | |
| Sollo Jr et al. | Colorimetric methods for bromine | |
| Miller et al. | Automated iodometric method for determination of trace chlorate ion using flow injection analysis | |
| CN103336089A (en) | Simple calibrating method of sodium thiosulfate standard solution | |
| CN114354594A (en) | Method for measuring ammonium nitrogen, nitrate nitrogen, nitrite nitrogen and total dissolved nitrogen in sample | |
| KR101346660B1 (en) | Potassium ion concentration measuring method and the measuring kit using thereof | |
| JP3997265B2 (en) | Hydrogen peroxide concentration measuring reagent and method for measuring hydrogen peroxide concentration using the same | |
| CN112964654A (en) | Method for determining content of ammonia nitrogen in chlorine-containing wastewater and application thereof | |
| TWI636006B (en) | Capturing and concentration measuring methods of chlorine dioxide gas and chlorine dioxide gas scavenger | |
| CN110749696A (en) | Method for detecting residual persulfate in environmental remediation engineering | |
| Saad et al. | Sequential flow injection determination of chlorine species using a triiodide-selective electrode detector | |
| CN110579449A (en) | Method and reagent for detecting bromate in water | |
| JPH0715468B2 (en) | Halogen determination method | |
| Olenin et al. | Sols of silver nanoparticles as analytical reagents for the determination of active chlorine in water samples by spectrophotometry and photometric titration | |
| WO2024007482A1 (en) | Solid reagent for detection of ammonia nitrogen and detection method therefor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |