A method suitable for the determination of ammonia nitrogen content in water bodies with different salinities

Abstract

The invention provides a determination method applicable to ammonia-nitrogen content in water bodies with different salinities, and relates to determination of pollutants in environment water bodies. The determination method comprises the following steps: filtering a water sample to be detected; after diluting and making the volume constant, adding a trisodium citrate water solution, a sodium o-phenylphenolate water solution, a high-alkali sodium dichloroisocyanurate water solution and a sodium nitroferricyanide water solution in sequence; sufficiently and uniformly mixing to realize coloration; selecting a blank matrix water sample with the salinity which is the same as or is similar to that of the sample to be detected, so as to prepare ammonia-nitrogen standard solutions with different concentration gradients; treating the ammonia-nitrogen standard solutions in a manner of treating the sample; determining light absorption values of the ammonia-nitrogen standard solutions at a fixed wavelength part by utilizing a spectrophotometer, and drawing a working curve; determining the colored water sample to be detected, and calculating to obtain uncorrected ammonia-nitrogen concentration of the sample; correcting and calculating the ammonia-nitrogen concentration by utilizing a salinity equation and dilution times, so as to obtain actual ammonia-nitrogen concentration of the water sample to be detected. The water sample is odorless and stable, and can be colored at room temperature; the determination method has the advantages of simple operation, good repeatability and high sensitivity, and can be used for determining the ammonia-nitrogen content in the water bodies with the different salinities.

Description

technical field

[0001] The invention relates to the measurement of pollutants in environmental water bodies, in particular to a method for measuring ammonia nitrogen content in water bodies with different salinities. Background technique

[0002] Ammonia nitrogen refers to the free ammonia (NH 3 ) and ammonium ions (NH 4 + ) in the form of nitrogen. Ammonia nitrogen in natural environmental water mainly comes from the decomposition products of nitrogen-containing organic matter in domestic sewage by microorganisms, some industrial sewage and farmland drainage. The non-ionic ammonia in ammonia nitrogen is extremely toxic to aquatic organisms, and the high content of total ammonia nitrogen can easily cause eutrophication of water bodies. At present, ammonia nitrogen, as the main excessive pollutant, occurs frequently in the seven major water systems, and ammonia nitrogen pollution has become a nationwide pollution problem. In water quality analysis, the determination of a...

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