Investigation On The Influence Factors To Determinate The Content Of Ammonia Nitrogen In The Sewage With Nessler’s Reagent By Colorimetric Method

Determining the status of nitrogen compounds in water is helpful in assessing water pollution and’automatic depuration’. Because of its simplicity, high accuracy, and extensive application. Nessler’s reagent method is adopted to determine ammonia nitrogen content in water. In this research, Nessler’s regent was used for the preparation of the standard curve of ammonia nitrogen, and its accuracy and precision were confirmed. Moreover, the influence of different experimental factors on the determination of nitrogen compounds was investigated.This spectrophotometric method was used to determine ammonia nitrogen in sewage, and the corresponding standard curve was formulated with a correlation coefficient of0.99999. The standard curve was examined and a high accuracy (relative error=0.00) and good precision (RSD<5%) was confirmed.Many experimental factors tend to influence the determination of ammonia nitrogen in water, i.e., coloration time, pH value, temperature and settling time, and they were tested by using the Nessler’s reagent spectrophotometric method. In this research, two kinds of different ammonia nitrogen concentrations in varying experimental conditions were tested and the result indicated that the reaction time of sample was unsuitably long, and the longer the time was, the higher the content of ammonia nitrogen was. Therefore, the absorbance of water sample should be determined as fast as possible in an effort to obtain an accurate, reliable experimental result. The coloration time should be set at10-30min. pH value of water sample was at6-8, and reaction temperature was at25℃.