Spatio-temporal variation of nitrate and nitrite levels in groundwater samples from Romania

This study investigated spatial and temporal distribution of nitrate and nitrite contaminants in groundwater from different geographical regions in Romania, with a special emphasis on a descriptive statistical analysis of data, namely determination of seasonal indices (dry season and wet season) and with establishing the standard units for the 24 of groundwater sources. Nitrate and nitrite concentrations were monitored in 24 groundwater sources during the period January 2016 - February 2020 for several areas in Romania. The obtained data matrix showed that the maximum values of nitrate concentrations in different areas of Romania were the following: in the northeastern part of Romania the maximum nitrate concentration was 8.03 mg/L, in the south-eastern part of Romania, the maximum nitrate concentration was 6.37 mg/L, and in the western part towards the center of the country, following the evaluation, a maximum of nitrate concentrations of 3.55 mg/L was determined. Nitrite concentration values were <0.5 mg/L in all investigated geographical areas. The obtained data shows small changes in water quality during the monitored period, which leads to the conclusion that there were no significant problems with nitrate and nitrite groundwater contamination. Groundwater indices allow an adequate control of water pollution, and a rigorous management of groundwater sources.