Nitrate in drinking water: A major polluting component of groundwater in gulf region aquifers, south of Togo

Abstract

Hydrochemical investigations of groundwater have been carried out on objectives of evaluating groundwater quality. Groundwater quality contaminations have emerged in many geographical areas due to natural environmental processes and human intervention in the geosystems. Geochemical evaluation of nitrate contaminated groundwater in Gulf region was investigated. Results showed that most of the samples contained high concentrations of nitrate. More than 70% of samples in central area contained high concentration of nitrate. Furthermore, results show that nitrate has a negative relationship with calcium and sodium, whereas relationship with magnesium, potassium, alkalinity, sulphate, chloride and electrical conductivity (EC) are positive. Factor analysis was used to identify key parameters that described the groundwater quality. Two factors were extracted as follows: Factor 1 explained 60% of the total variance, reflected the importance of the intrusion of salt water into the groundwater and factor 2 explained 35% of the total variance, and reflected impact of human activities and acid-rain recharge of the aquifers in the area. The geochemical modeling reveals that the high nitrate groundwater behaves like two kinds of the mechanism of hydrogeochemical evolution, namely the intervention of human activities, and the evaporation effect of the shallow groundwater.

Physicochemical quality of groundwater in suburban area - Impact of uncontrolled landfill in the district of Kitidjan in Agoe-Nyvé- Togo

“…Water pollution arising from the presence of foreign substances (organic, inorganic, bacteriological or radiological) which tends to degrade the quality of water has became an issue of serious concern. There is the general perception that water from boreholes are good for drinking and general household utilisation [5] . Unfortunately, many of the ground waters in the coastal aquifer are suffering from seawater intrusion by over-abstraction and water quality degradation due to urbanization and agricultural activities.…”

Assessment of hydrological factors affecting shallow groundwater chemistry in the most urbanized area of the coastal sedimentary basin of Togo

“…Runoff from these environments is drained into natural storm basins, some developed as artificial storm pools and con-nected to the lagoon system (MPT-Togo, 2013;Ayah et al, 2015). All these features constitute potential sources of high contamination of the Continental Terminal shallow aquifer, the primary and overexploited resource for drinking water in Lomé (Alfa-Sika Mande et al, 2012;Gnazou et al, 2017). In addition to formal exploitation by the Togolese Water Company (TdE) which cannot cover the population's needs, the past decade has witnessed a proliferation of informal private boreholes.…”

Physicochemical and Microbiological Quality of Shallow Groundwater in Lomé, Togo

“…The primary water security and public health concerns in urban sub-Saharan Africa, particularly in the coastal cities of the Gulf of Guinea, are the chemical and microbial contaminations of shallow groundwater evidenced by high contents of nitrate, heavy metals, fecal coliforms, and fecal Streptococci in boreholes and dug wells water samples (Erah, Akujieze, & Oteze, 2002;Takem et al, 2010;Gibrilla et al, 2011;Mande et al, 2012;Totin et al, 2013;Affum et al, 2015;Soncy et al, 2015). In-situ sanitation facilities, mainly pit latrines and septic tanks, are considered the dominant cause of microbiological contamination and a significant cause of nutrient loading to water sources (Lapworth et al, 2017).…”

“…Groundwater in coastal areas can also evidence an accentuated salinization due to seawater's influence (Akouvi et al, 2008;Olufemi, 2010;Mohamed et al, 2020). (Mande et al, 2012;Soncy et al, 2015;Gnazou et al, 2017). In addition to formal groundwater exploitation by the Togolese Water Company (TdE), the past decades have witnessed a proliferation of informal private boreholes (MEAHV, 2010).…”