1、 Execution standards:
Meets the requirements of industry standard HJ/T70-2001.
2、 Technical principle:
Add a known amount of potassium dichromate solution and mercury sulfate solution to the water sample, and use silver sulfate as a catalyst in a strong acid medium. After boiling and refluxing for 2 hours, use 1,10-phenanthroline as an indicator to titrate the unreduced potassium dichromate in the water sample with ferrous ammonium sulfate. The apparent COD is calculated by converting the amount of ferrous ammonium sulfate consumed to the mass concentration of oxygen consumed. Export the chlorine gas formed by the oxidized chloride ions in the water sample that have not been complexed, absorb it with sodium hydroxide solution, add potassium iodide, and adjust the pH to about 3-2 with sulfuric acid,
Using starch as an indicator, titrate with a standard solution of sodium thiosulfate. The amount of sodium thiosulfate consumed is converted to the mass concentration of oxygen consumed, which is the chloride ion correction value. The difference between the apparent COD and the chloride ion correction value is the true COD of the measured water sample.
3、 Application scope:
1. Suitable for the determination of chemical oxygen demand (COD) in high chloride wastewater with chloride ion content less than 20000mg/L.
2. Widely used for water quality testing in industries such as oil fields, coastal refineries, oil depots, chlor alkali plants, deep-sea wastewater discharge, sewage treatment plants, monitoring stations, environmental protection bureaus, third-party testing, petrochemicals, steel mills, power plants, healthcare, universities, and production-oriented enterprises (including food mills, paper mills, printing and dyeing factories, etc.); Suitable for detecting high chlorine water quality in surface water, groundwater, industrial wastewater, domestic sewage, tap water, etc.
4、 Technical parameters:
1. Anti chlorine interference: 20000mg/l
2. Measurement range: 0-1000mg/l can be directly measured, 1000-10000mg/l needs to be diluted before measurement.
3. Flow range: 5-40ml/min adjustable
4. Dissolving time: 2 hours (instrument 0-999min can be set arbitrarily)
5. Measurement error: Potassium hydrogen phthalate standard solution (500mg/L), RSD ≤ 5.0%
Industrial organic wastewater (500mg/L), RSD ≤ 8.0%
6. Batch digestion sample quantity: 5 samples (standard conical flask digestion).
7. Environmental temperature: 5-45 ℃, otherwise it will affect the temperature stability.
8. Power supply and power consumption: AC220V； 1.3kw
5、 Functional features:
1. The results of nitrogen treatment on high chlorine samples were better than those without nitrogen treatment, which meets industry standards.
2. Using microcomputer technology for timed control of the heating electric furnace, the heating panel is corrosion-resistant and has good insulation properties.
3. The burr reflux tube, combined with the built-in fan, ensures good boiling cooling effect and ensures experimental accuracy.
4. Users can adjust the heating power according to the actual voltage situation to ensure the boiling effect during heating.
5. It has an automatic stop function when needed, truly achieving unmanned operation.
6. Energy saving, water-saving, safe and reliable, can save thousands of yuan in water and electricity bills every year.
6、 Configuration List:
1. 1 high chlorine digestion machine host (with built-in fan)
2. 6 burr reflux pipes
3. 6 specialized heating and digestion bottles
4. 1 power cord
5. Export 4 pipes
6. 4 pipelines
7. 4 silicone wires
8. One power cord, one certificate of conformity, one warranty card, and one instruction manual.