Geochemical evaluation of groundwater and suitability of groundwater quality for irrigation purpose in an agricultural region of South India

• Published in: Applied water science 2022-06, Vol.12 (6), p.1-13, Article 142
• Main Authors: Gugulothu, Sakram, Subbarao, N., Das, Rashmirekha, Dhakate, Ratnakar
• Format: Article
• Language: English
• Subjects: Agricultural region; Anthropogenic factors; Aquatic Pollution; Aquifers; Bicarbonates; Calcite; Calcium; Calcium ions; Carbonates; Cations; Comparative Law; Crop growth; Dissolved solids; Earth and Environmental Science; Earth Sciences; Electrical conductivity; Electrical resistivity; Evaluation; Evaporation; Fluorides; Geochemistry; Groundwater; Groundwater chemistry; Groundwater quality; Gypsum; Halite; Human influences; Hydrogeology; Industrial and Production Engineering; International & Foreign Law; Ion exchange; Irrigation; Magnesium; Minerals; Nanotechnology; Original Article; Potassium; Private International Law; Quality assessment; Rural environments; Saturation; Silicate minerals; Silicates; Sodium; Sodium carbonate; Sustainable development; Waste Water Technology; Water Industry/Water Technologies; Water Management; Water Pollution Control; Water quality; Water sampling; Weathering
• ISSN: 2190-5487; 2190-5495
• DOI: 10.1007/s13201-022-01583-w

The objective of the present study was to evaluate the geochemical processes controlling the groundwater chemistry and also to assess the groundwater quality suitability criteria for irrigation purposes. An agricultural region of Telangana, South India, was selected for the present study. A total of 100 groundwater samples were collected and estimated for pH, electrical conductivity (EC), total dissolved solids (TDS), calcium (Ca 2+ ), magnesium (Mg 2+ ), sodium (Na + ), potassium (K + ), bicarbonate ( HCO 3 - ), chloride (Cl − ), sulfate ( SO 4 2 - ), nitrate ( NO 3 - ), and fluoride (F − ). The groundwater was characterized by mostly alkaline conditions with a dominance of Na + and HCO 3 - ions, indicating the prevailing conditions of weathering and dissolution of silicate minerals. The various geochemical signatures such as Na + vs Cl − , Ca 2+  + Mg 2+ vs HCO 3 - , Ca 2+  + Mg 2+ vs HCO 3 -  +  SO 4 2 - , HCO 3 - vs Cl −  +  SO 4 2 - , Ca 2+  + Mg 2+ vs total cations, and Ca 2+  + Mg 2+ vs Na +  + K + and the saturation indices with respect to calcite, halite, and gypsum suggest obviously the dominant conditions of carbonate weathering associated with the reverse ion exchange and evaporation processes as the geogenic factors. The linear trend of TDS vs NO 3 -  + Cl − / HCO 3 - clearly  specifies the influence of non-geogenic sources on the aquifer system. These are the important contributors to the variation in the groundwater chemistry. However, the impact of the geogenic source is masking the influence of the anthropogenic source in some areas of the present study region. According to the salinity vs sodium adsorption ratio, residual sodium carbonate, magnesium ratio, and Kelly ratio, 99.9%, 7.06%, 63.07%, and 51.27% of the total study region come under the unsuitable categories for irrigation purposes, respectively. Therefore, the findings of this study recommended some site-specific appropriate management strategies for the safe supply of groundwater for proper crop growth and consequently for sustainable development of the rural environment.