Uncertainty of ammonium nitrogen determination in wastewater

摘要

The measurement uncertainty of result of ammonium nitrogen determination in wastewater was evaluated. Ammonium was determined using distillation and titration method (ISO 5664). The major sources of uncertainty of the result of measurement were identified: preparation of the sample, preparation of the reagents, titration and overall repeatability of the procedure. Identification and evaluation of uncertainty sources was followed by combined uncertainty calculations. The results show that the major sources of uncertainty arose from repeatability and volumetric steps, thus leading to the conclusion what is the target operation for reducing the measurement uncertainty of this determination.