1 Subject matter and scope of application
This standard specifies the ozone concentration of ozone generator, production and power consumption measurement and calculation methods.
Applicable to the measurement of ozone generator with electricity as energy source.
2 Terminology
Specific energy consumption
Electricity consumed by the equipment to produce a unit weight of finished product.
3 ozone generator ozone concentration, production, power consumption measurement and calculation methods
3.1 ozone concentration
3.1.1 Summary of the principle of the method: ozone (O3) is a strong oxidant, and potassium iodide (KI) aqueous solution can be free of iodine, at the end of the sampling and the acidification of the solution, the solution is acidified with 0.1000mol/L sodium thiosulfate (Na2S2O3) standard. Na2S2O3) standard solution and starch solution as an indicator for the free iodine into the titration, according to the consumption of sodium thiosulfate standard solution to calculate the amount of ozone. The reaction formula is:
O3+2KI+H2O--O2+I2+2KOH(1)
I2+2Na2S2O3---2NaI+Na2S4O6(2)
3.1.2 Reagents
3.1.2.1 Potassium iodide (KI) solution (20%): dissolve 200g of potassium iodide (analytically pure) in 1000mL of boiled and cooled distilled water and store in a brown bottle in the refrigerator for at least one day before use. This solution 1.00mL contains 0.20g of potassium iodide.
3.1.2.2 (1 + 5) sulfuric acid (H2SO4) solution: measure concentrated sulfuric acid (p = 1.84; analytically pure) dissolved in 5 times the volume of distilled water.
3.1.2.3 C (Na2S2O3-5H2O) = 0.1000mol / L sodium thiosulfate standard solution; use an analytical balance to accurately weigh 24.817g of sodium thiosulfate (Na2S2O3-5H2O; analytically pure) with a newly boiled and cooled distilled water to dissolve in a 1000mL volumetric flask. Or weigh 25g of sodium thiosulfate (Na2S2O3-5H2O; analytically pure) dissolved in 1000mL of freshly boiled and cooled distilled water, the concentration of sodium thiosulfate in this solution is about 0.1mol/L. Add 0.2g of sodium carbonate (Na2S0O3) or 5mL of trichloromethane (CHCL3); calibrate, adjust the concentration to 0.1000mol/L, and store it in a brown bottle. If the storage time is too long, it needs to be recalibrated before use (see Appendix A for calibration method).
3.1.2.4 Starch solution; weigh 1g of soluble starch, with cold water into a suspension slurry, and then add about 80mL of boiling water, stirring while adding, dilute to 100mL; boil for a few minutes and then leave to settle overnight, take the supernatant to use, such as the need for a longer period of time to save can be added to 1.25g of salicylic acid or 0.4g of zinc chloride.
3.1.3 Test apparatus, equipment and its requirements
3.1.3.1 Triangular wash bottle (absorption bottle) 500mL.
3.1.3.2 Burette 50mL, preferably with precision burette.
3.1.3.3 Wet gas flow meter capacity 5L.
3.1.3.4 Measuring cylinder 20mL 500mL each.
3.1.3.5 Graduated pipette (pipette) 10mL.
3.1.3.6 Volumetric flask 1000mL.
3.1.3.7 Polyethylene or PVC hose for ozone-containing gases. Rubber hoses must not be used.
3.1.4 Experimental procedures and methods: Measure 20mL of potassium iodide solution (3.1.2.1), poured into the 500mL absorption bottle, and then add 350mL of distilled water, to be ozone generator operation is stable after the ozonation of the gas outlet in the ozonation of the sample, the first pass through the absorption bottle (3.1.3.1) to the absorption of ozone, and then through the wet gas flow meter (3.1.3) on the gas. 3.3) on the gas measurement, gas through the amount of 2000mL (time control in about 4min), stop sampling immediately after adding 5mL (1 + 5) sulfuric acid solution (3.1.2.2) (so that the pH value dropped to below 2.0) and shaking well, let stand for 5min. 0.1000mol / L sodium thiosulfate standard deep solution (3.1.2.3) titration, to be a light yellow when adding starch solution. Add a few drops (about 1mL) of starch solution (3.1.2.4) when the solution is light yellow, and continue to titrate carefully and rapidly until the color disappears. Record the amount of sodium thiosulfate standard solution.
3.1.5 Calculation of ozone concentration
Co3=ANa×B×2400/V0(mg/L) (3)
The formula: Co3 - ozone concentration, mg/L;
ANa- -Sodium thiosulfate standard solution dosage, mL;
B - sodium thiosulfate standard solution concentration, mol/L;
V0 - ozonized gas sampling volume, mL;
Ozone concentration, mg/L;
Ozone concentration, mg/L;
Ozone concentration, mg/L;
Ozone concentration, mg/L. p>
When ozone concentration is greater than or equal to 3mg/L, the precision of this test result is within ±1%.
3.2 Ozone yield
3.2.1 Summary of the principle of the method: the ozone concentration value and the value of the total amount of gas into the ozone generator is the product of the yield.
3.2.2 Equipment, instruments and their requirements
3.2.2.1 Pressure gauge 1.5
3.2.2.2 Gas rotameter industrial grade
3.2.3 Corrective calculations of the gas flow rate: flowmeter use of the temperature and pressure of the gas being measured, often different from the flowmeter calibration of the scale. Therefore, the use of readings when the flow rate display value, often not flow through the flow meter gas is a true reflection, must be corrected. The formula is as follows:
QN = (PsTN/PNTs)1/2-Qs (m3/h or L/h) (4)
Where: QN - the standard state, the actual flow of gas, m3/h or L/h;
Qs - the measurement (test) state, the actual flow of gas, m3/h or L/h;
Qs - the measurement (test) state, the actual flow of gas, m3/h or L/h. - measurement (test) state, the gas in the meter display flow, m3 / h or L / h;
Ps - measurement (test) state, the pressure of the gas, Pa;
TN- - absolute temperature at the time of calibration of the instrument, (273.15+20)K;
Ts - temperature of the gas in the state of measurement (test), K;
PN - absolute pressure at the time of calibration of the instrument (one standard atmosphere) When the absolute pressure (a standard atmospheric pressure 1.01325 × 105Pa).
3.2.4 Calculation of ozone yield
Do3=Co3-QN (g or mg) (5)
In Do3 - ozone yield, g or mg.
3.3 Electricity Consumption
3.3.1 Summary of the method principle: ozone generator The ratio of the measured electrical power consumption to the unit ozone production is the electrical consumption.
3.3.2 Equipment, instruments and their requirements.
3.3.2.1 Voltmeter (voltmeter) 0.5.
3.3.2.2 Ammeter (ammeter) class 0.5.
3.3.2.3 Power meter (wattmeter) class 0.5.
3.3.2.4 Static high voltage meter class 1.5.
3.3.2.5 Power meter class 2.0.
3.3.3 Calculation of power consumption: power meter (wattmeter) (3.3.2.3) measured values or electricity meter (3.3.2.5) unit of time to record the cumulative value of the ozone production per unit of time is the ratio of the consumption of electricity, the formula is as follows:
P=W/Do3 (W-h/g-O3 or kW-h/kg-O3) (6) or
P=AH/Do3(W-h/g-O3 or kW-h/kg-O3) (7)
Where P - ozone unit electricity consumption, W-h/g-O3 or kW-h/kg-O3;
W - Electric power, W or kW;
AH--Accumulated value per unit time hour of the meter, kW-h.
Appendix A Calibration of sodium thiosulfate standard solution (Supplementary)
This appendix lists two methods of calibrating sodium thiosulfate standard solution, which are used equivalently in the calibration of sodium thiosulfate standard solution. In the calibration of sodium thiosulfate standard solution, equivalent use.
A1 Method 1
A1.1 Reagents
A1.1.1 Potassium iodide (KI), analytically pure.
A1.1.2 C(1/6K2Cr2O7)=0.1000mol/L potassium dichromate standard solution: use an analytical balance to accurately weigh the potassium dichromate 4.9032g dried at 105~110oC for 2h and cooled in a silica gel desiccator for more than 30min, and dissolve it in a 1000mL volumetric flask and shake well.
A1.2 Test apparatus, equipment and its requirements
A1.2.1 Iodine measuring flask 250mL;
A1.2.2 Weighing tube 10.00mL;
A1.3 Methods, steps: weighing 1g of potassium iodide (A1.1.1) placed in a 250mL iodine measuring flask (A1.2.1), and adding 100mL Distilled water, pipette (A1.2.2) into 10.00mL, 0.1000mol / L potassium dichromate standard solution (A1.1.2), add 5mL (1 + 5) sulfuric acid solution (3.1.2.2), let stand for 5min. to be calibrated with sodium thiosulfate standard solution (3.1.2.3) titration, wait until the solution becomes light yellow, add about 1mL starch solution (3.1.2.4), continue titration until the blue color fades, record the amount. The concentration of sodium thiosulfate standard solution is:
N1=N2V/V1(mol/L)(A1)
Where N1--Sodium thiosulfate standard solution concentration, mol/L;
N2- -concentration of potassium dichromate standard solution, 0.1000 mol/L;
V1 - consumption of sodium thiosulfate solution, mL;
V2 - volume of potassium dichromate standard solution taken, mL;
V2 - volume of potassium dichromate standard solution taken, mL;
Equation Volume of potassium dichromate standard solution taken, mL;
A2 Method II
A2.1 Reagents
A2.1.1 Potassium iodate (KIO3).
A2.1.2 Acetic acid (CH3COOH).
A2.2 Methods and steps: use analytical balance to accurately weigh 0.15g in 105 ~ 110oC drying 1h, and placed in a silica gel dryer cooled for more than 30min of potassium iodate (A2.1.1) 2 copies, respectively, into 250mL iodine measuring flasks (A1.2.1), each bottle, each add 100mL of distilled water, so that the potassium iodate is dissolved, and then each added 3g Potassium iodide (A1.1.1) and 10mL acetic acid (A2.1.2), shake well, let stand in the dark for 5min, titrate with sodium thiosulfate solution (3.1.2.3) to be calibrated, to be a light yellow solution, add about 1mL of starch solution (3.1.2.4), and continue to titrate until just so the blue color fades, and record the amount. The concentration of sodium thiosulfate standard solution is:
B=W/ V×214.00/6000=W/ V×0.03567 (mol/L) (A2)
In the formula B--concentration of sodium thiosulfate standard solution, mol/L;
W -- weight of potassium iodate, g;
V -- consumption of sodium thiosulfate standard solution, mL.
The difference between the results of two parallel samples shall not be more than 2%.
Appendix B Quality of Measurement (Reference Pieces)
This appendix is a description of quality of measurement issues.
B1 chemical analysis
B1.1 General rules: this standard on chemical analysis of the general rules (nouns, terminology, selection of glass instruments and washing, etc.) with reference to GB5750 "standard test of drinking water," "the first general principles, 1 general rules" of the relevant content.
B1.2 solution quality: In addition to the quality of reagents, other factors affecting the quality of the solution and the avoidance of the elephant and prevention methods in accordance with relevant regulations.
Note: See "water and wastewater monitoring and analysis" (Third Edition) "six chemical reagents and test solution preparation (E) the quality of the test solution" of the relevant content.
B1.3 solution representation
B1.3.1 Concentration: this standard, the concentration refers to the quantitative concentration (molar concentration) which is expressed as follows:
C(B)=a mol/L
The formula C - concentration symbols;
(B) - the basic unit of matter;
(B) - the basic unit of matter;
a - concentration value;
mol/L - unit.
B1.3.2 (a + b) solution: a solution mixed in the proportion of a certain volume "a" represents the volume of solute, "b" represents the volume of solvent.
B1.3.3 solution (a%): customary weight percent concentration, in chemical analysis often refers to the mass of solute a (weight) and the ratio of the volume of solution (m/V), is an inaccurate representation of this standard in parentheses "a%" is just a customary mark. The method of expression used in this standard is: this solution 1.00mL contains a gram of a substance, a refers to a substance mass (weight) number.
B2 Instruments, meters
B2.1 balance, electrical instrumentation, flow and pressure instruments should be regularly calibrated, calibrated.
B2.2 Electrical instrumentation verification and calibration should be carried out in accordance with relevant state regulations and procedures, verification and calibration should be carried out in the state-authorized electrical instrumentation verification and calibration units, and has been verified and calibrated instrumentation to issue a certificate.
B2.3 Flow and pressure instruments shall be tested and calibrated in accordance with the relevant state regulations and procedures.
B2.4 The calibration of the capacity of glass measuring instruments should be carried out in accordance with the relevant national regulations and procedures, which can be found in the "Water and Wastewater Monitoring and Analysis Act" (Third Edition) "five capacity calibration of measuring instruments".
B3 Measurement results and data processing
B3.1 Measurement results and data processing refer to GB5750 "First General, 3 water quality test results and data processing" of the relevant content.
Additional Notes
This standard construction standards institute.
This standard by the Chinese people **** and the State Ministry of Construction of urban water treatment equipment standard technical focal point unit of China Municipal Engineering North China Design Institute focal point management.
This standard by Tsinghua University Department of Environmental Engineering (editor-in-chief), Tsinghua University equipment and instrumentation factory, Beijing Yuyuantan environmental protection equipment factory, Jiangsu Taixing environmental protection equipment factory is responsible for drafting.
The main drafter of this standard: Liu Liqun.