Measurement method for dissolved oxygen content in oxygen rich water bodies
At room temperature and pressure, the dissolved oxygen content in water is generally 6-10mg/L. Due to certain reasons, the dissolved oxygen content in certain water bodies can significantly increase, leading to rich oxidation of the water. The dissolved oxygen content can reach over 20mg/L. For example, rivers and lakes contain a large amount of aquatic plants. When the weather is sunny, the oxygen released by the photosynthesis of aquatic plants can lead to water oxidation; Some water also experiences a significant increase in dissolved oxygen concentration due to aeration or the use of pressurized dissolved oxygen measures. Common examples include aeration tanks and oxygen rich beverages.
There are various methods for measuring dissolved oxygen, among which two methods are commonly used to determine the dissolved oxygen in oxygen rich water bodies:
Iodometric method: Manganese sulfate and alkaline potassium iodide are added to the water sample. Dissolved oxygen in the water oxidizes low valent manganese to high valent manganese, forming a brown precipitate of tetravalent manganese hydroxide. After adding acid, the hydroxide precipitates and dissolves, and reacts with iodine ions to release free iodine. Using starch as an indicator, the dissolved oxygen content is calculated based on the consumption of the titration solution by titrating the released iodine with sodium thiosulfate standard solution.
Electrode method: using a coated dissolved oxygen electrode or a fluorescent dissolved oxygen electrode to measure dissolution
Dissolved oxygen content
Compared to the iodometric method, the electrode method has a simpler, more convenient, and more accurate testing process. However, the effective range of commonly used dissolved oxygen meters in the market is mostly 0-20mg/L, which is powerless for measuring oxygen rich water bodies with dissolved oxygen content greater than 20mg/L. After exploration, the technical R&D personnel of Thundermagnetic have successfully expanded the effective range of the instrument from conventional 0-20mg/L to a higher range, thus solving the problem of detecting high concentration of dissolved oxygen in oxygen rich environments.
