|Ultima descărcare din IBN:|
| SM ISO690:2012|
SANDU, Maria; LUPASCU, Tudor; TARITA, Anatol; TURCAN, Sergiu; MOSANU, Elena. Determination of nitrate in water in the presence of NO2-, SiO32-, NH4+, urea and surface active substances. In: Physical Methods in Coordination and Supramolecular Chemistry. XVIII, 8-9 octombrie 2015, Chişinău. Chisinau, Republic of Moldova: 2015, p. 132.
|Physical Methods in Coordination and Supramolecular Chemistry
Conferința ""Physical Methods in Coordination and Supramolecular Chemistry"" |
Chişinău, Moldova, 8-9 octombrie 2015
The problem of nitrate monitoring in waters intended for human consumption (drinking water, water for foods preparation, etc.) is in attention of specialized institutions . Nitrification in natural waters has mandatory stage the appearance of nitrite content of which in surface waters in Moldova ranges from 0-0.4 mg/dm3 to tens of mg/dm3 in small rivers water downstream of sewage discharges, insufficiently treated in biopurification plants. This study relates to determination of nitrate in presence of compounds that are present in surface and underground waters: NO2 -, SiO3 2-, NH4 + ions, urea and cationic and anionic surface active substances (SAS Ct and SAS An) in the base of developed method for determining nitrate in presence of nitrite in water including the removal of nitrite with sulphaminic acid, the nitrate ion reduction to nitrite using a reducing mixture that contains Na2SO4 and zinc dust in ratio of 100:5 and determining the nitrite with the Griess reagent . In the study it was established that 0,1-10 mg/dm3 of NO3 - in the presence of 20 mg/dm3 NO2 - can be determined in the presence of 1,5 mg/dm3 SAS An and 18 mg/dm3 SiO3 2- (fig. 1). Cationic active substance doesn’t influence process of about 150 mg/dm3; urea and NH4 + ions – more than 1000 mg/dm3.figureFigure 1. The absorbance of the solutions containing 20 mg/dm3 of NO2 -, 3 mg of sulphaminic acid, SAS An and Ct (2 mg/dm3 NO3 -), SiO3 2- ions (1 mg/dm3 NO3 -) in the conditions of NO3 - ions determination.