Abstract:

There are factors to cause the pollution of surface and wastewater, which contains N and P components. Eutrophication was always caused by high concentrations of these factors. Exact calculation of the pollution of nitrogen and phosphorus in water depends on the content of total nitrogen and phosphorus including organic and inorganic compounds of nitrogen and phosphorus. In this article, we mention to the content of the total N, P determination in water of the To Lich river. This method is based on the transformation of phosphorus forms into orthophosphate. Then, orthophosphate concentration was determined by spectrophotometer method. All nitrogen forms were also transformed into NH4+ by an appropriate oxidation ‐ reduction in base, followed by distillation and absorption in an acid receiver bottle. The obtained NH4+ content is further determined by spectrophotometer method using Nessler as a reactor. The results obtained within 3 years on the concentration of N and P in water of the To Lich River indicated that they are so higher than the 1995 Vietnamese standard, proved that the water in this river is seriously polluted.