Water Practice and Technology (Apr 2024)

Hydrogeochemical characterization of groundwater in mountainous catchment and its suitability for drinking purposes in Irob, Tigray, Northern Ethiopia

  • Haile Tadelle Abadi,
  • Tewodros Alemayehu,
  • Berihu Abadi Berhe

DOI
https://doi.org/10.2166/wpt.2024.067
Journal volume & issue
Vol. 19, no. 4
pp. 1495 – 1512

Abstract

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The primary source of drinking water in Ethiopia's semi-arid mountainous regions is groundwater. The present study aims to assess the hydrogeochemical characteristics of low-grade basement rocks dominated by mountainous catchments. Moreover, it examines the suitability of the groundwater quality for drinking purposes in Irob, Tigray, northern Ethiopia. However, relatively little is known about the water chemistry and groundwater quality of the resources in the area. Fifteen samples of groundwater were collected and examined for ions according to standard procedures. The outcomes were assessed against the World Health Organization (WHO) drinking water quality criteria. To identify the source of dissolved ions and the process involved, graphic interpretations were applied. The results show that Ca–Mg–SO4–HCO3 and Ca–SO4–HCO3 were the dominant water types. Gibbs plots and ionic ratios reveal that silicate weathering, carbonate dissolution and ion exchange control water chemistry. Furthermore, the findings reveal that 60, 80, 46.67, 46.67, 60, 6.67, 60 and 53.33% of samples are above the safe limits of the WHO for hardness, alkalinity, total dissolved solids, electrical conductivity, calcium (Ca2+), potassium (K+), bicarbonate (HCO3-) and sulfate (SO42-), respectively. Consequently, the groundwater quality assessment demonstrates that the water sources in lower parts of the catchment are unsuitable for drinking. HIGHLIGHTS The study area is a mountainous and geologically complex setting.; Groundwater is the main source for drinking in semi-arid regions.; Dissolution, silicate weathering and ion exchange processes are responsible water quality.; Anthropogenic processes also control the water chemistry.; The groundwater chemistry is changing from Ca–Mg–SO4–HCO3 in the mountainous area to Ca–Na–HCO3–SO4 in the flat areas.;

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