Seasonal Assessment of Nitrate, Nitrite, and Heavy Metals Pollution in Groundwater of Ardabil Aquifer, Iran

Abstract

One of the most important resources for drinking water is groundwater. Recently, the quality of groundwater has been endangered due to several reasons, including human activities, vast agricultural activities, and the discharge of industrial wastewater containing nitrogen (N) and heavy metals. For this study we investigated the values of NO 3 , NO 2 , and some heavy metals and analyzed the groundwater of the Ardabil Aquifer area in wet and dry seasons. For this purpose we evaluated 76 wells in the study area. In order to analyze the results we used World Health Organization (WHO), U.S. Environmental Protection Agency (EPA), and Institute of Standard and Industrial Research of Iran (ISIRI) standards. The results indicated that, according to WHO and ISIRI, 10.5% of wells and, according to the EPA, 69.7% of wells have NO 3 above the standard level in the wet season, but in the dry season, according to WHO and ISIRI,29% and, according to the EPA, 80.6% of the wells have NO 3 above the permissible level. However, according to all standards, NO 2 values are less than the permissible level for drinking consumption. In terms of evaluation criteria of the simultaneous presence of NO 3 and NO 2 in drinking water (K), 29% of wells in the dry season and 13.15% of wells in the wet season have NO 3 and NO 2 problems. In order to find an appropriate interpolation method and zoning parameter of NO 3 and NO 2 , different interpolation methods were evaluated and Kriging method with the lowest error was chosen for zoning the parameters. According to zoning maps, in the wet season the Namin and south Ardabil areas, which have the most drinking water wells, contain values of NO 3 above the permissible levels, whereas the values of NO 3 are at the mediocre level in the dry season. In addition to NO 3 and NO 2 analysis, the evaluation of heavy metals pollution indices in the aquifer include: heavy metal pollution index (HPI), heavy metal evaluation index (HEI), and contamination degree (C d ). Generally, according to the EPA, in terms of NO 3 and NO 2 pollution, Ardabil aquifer is in an undesirable condition, and according to WHO and ISIRI standards, this area has a mediocre level of undesirable condition. According to HPI and C d indices, most parts are in a high class of heavy metal pollution, as well.

Assessing Pollution Risk in Ardabil Aquifer Groundwater of Iran with Arsenic and Nitrate Using the SINTACS Model

“…Nitrate is essential for producing crops, the source of which is nitrogen in the soil or nitrogen fertilizers [22]. Nitrogen pollution in groundwater is one of the most important factors in reducing water quality [8].…”

“…Nitrate is a very important agricultural fertilizer and is advantageous in terms of its sustainability and non-loss of nitrogen in the atmosphere. Nitrate is obtained from the oxidation of nitrogenous compounds that becomes nitrite in the human body and causes methemoglobinemia [8].…”

Physicochemical characteristics and heavy metals of groundwater during the wet and dry seasons at the Lafarge cement factory environment, Sagamu, Ogun State, Nigeria

“…Studies on the physicochemical characteristics of groundwater and heavy metals have been carried out in Africa (Amoako et al, 2011; Beatrice et al, 2019; Boateng et al, 2019), Asia (Bhagure & Mirgane, 2011; Lou et al, 2017; Nagendrappa et al, 2010; Rezaverdinejad & Rahimi, 2017; Selvam, 2017; Shakerkhatibi et al, 2019; Shyamala et al, 2008; Wang et al, 2022; Zhai et al, 2022), Europe (Algül & Beyhan, 2020; Dippong et al, 2022; Stamatis et al, 2001; Zanchi et al, 2022), North America (de León‐Gómez et al, 2020), and South America (Custodio et al, 2021; Gimenez et al, 2013; Rupias et al, 2021). Many scholars including Adejuwon and Mbuk (2011) and Alabi et al (2013) based their studies on the physicochemical characteristics of groundwater water in Nigeria.…”

Impact of the industrial activity on groundwater quality (case of study: El-Kalitoussa Region Northeast Algeria)

“…The transfer time of pollutants from the surface of the soil to the groundwater and then within the aquifer can be long: they depend on the hydrogeological context and the hydrological situations (retention capacities of the various materials crossed, speed of flow of the groundwater, beat of the groundwater) (Riser-Roberts, 1992). Furthermore, wastewater is often loaded with pollutants, sometimes toxic, which present an enormous danger for the environment, in this case for the groundwater if they are not collected and drained (Attoui et al, 2016;Rezaverdinejad, Rahimi, 2017;Prasad et al, 2014). The objective of this study, is the determination of the impact of some heavy metals on the quality of water resources generated by the discharges of some industrial units in the region of El-Kalitoussa, relying on the analytical results of some metallic trace elements.…”