Application of Ammonia Nitrogen Analyzer in Monitoring of Wastewater Discharge

Ammonia nitrogen in water refers to the compound ammonia in the form of ammonia (NH3) or ammonium (NH4+) ions. Ammonia nitrogen is one of the most harmful forms of various types of nitrogen, and it is a sign of water pollution, and its harm to the aquatic environment is manifested in many aspects. Like COD, ammonia nitrogen is also the main oxygen-consuming pollutant in the water body. The oxidation and decomposition of ammonia nitrogen consume dissolved oxygen in the water, making the water body black and smelly. The non-ionic ammonia in the ammonia nitrogen is the main factor causing the toxicity of aquatic organisms, and it is more toxic to aquatic organisms, and its toxicity is dozens of times greater than that of an ammonium salt. In the case of sufficient oxygen, ammonia nitrogen can be oxidized by microorganisms to nitrite nitrogen and then decomposed into nitrate nitrogen. Nitrite nitrogen combines with protein to form nitrosamines, which have carcinogenic and teratogenic effects.

At present, the commonly used methods for monitoring ammonia nitrogen in water quality at home and abroad include distillation-neutralization titration and Nessler's reagent method. The distillation-neutralization titration method has the characteristics of simple operation and is time-consuming. If the sample contains urea, volatile amines will cause high results. Nessler's reagent method is a commonly used method in the analysis of ammonia nitrogen, which has the advantages of simplicity, speed, accuracy, and so on. The traditional Nessler's reagent method has complicated pre-processing, is time-consuming, and is not conducive to the determination of a large number of samples. With the importance of environmental monitoring and the increase in workload, the use of fast, effective, and highly accurate instrument methods to determine water quality ammonia nitrogen has attracted more and more attention.

Through experimental analysis, the following conclusions are obtained:

1. The automatic ammonia nitrogen analyzer can meet the requirements of environmental standards and machinery industry standards in terms of curve linearity, detection limit, precision, and accuracy.

2. Distillation-neutralization method to determine water quality ammonia nitrogen takes about 40 minutes, and the instrument method only needs 10 minutes to complete the sample determination. If the sample ammonia nitrogen content is higher than the linear range of the curve, the automatic ammonia nitrogen analyzer can automatically dilute. The instrument method has the characteristics of simple, fast, and accurate determination of water quality ammonia nitrogen, which can greatly reduce the labor intensity of the operators.

3. The Nessler's reagent used in the automatic ammonia nitrogen analyzer only runs in the closed pipeline of the instrument, which reduces the harm of mercury to the human body in the experimental operation, and can be widely used in daily environmental monitoring work.