Investigation of Hydrogeochemical Characteristics and Groundwater Quality of Hoz–e–Soltan Lake, Qom, Iran

In this research, the groundwater quality of Hoz–e–Soltan Lake and its catchment was studied for drinking, domestic and irrigation uses according to different parameters. This Lake with 195 km² catchment area is located 85 km of southwest of Tehran–Qom highway. In order to investigate groundwater quality characteristics in the study area, 34 data from water of well belong to 2008 selected to processing and interpretation. The data was edited and processed to determine groundwater quality parameters such as Magnesium Absorption Ratio (MAR), Sodium Solution Percent (SSP), Residual Sodium Bicarbonate (RSBC), Permeability Index (PI), Kelly Ratio (KR) and Sodium Absorption Ratio (SAR), Electric Conductivity (EC), Na⁺, K⁺, Mg²⁺, Ca²⁺, SO₄^2–, Cl^–, HCO₃^–. Based on Piper diagram and cations and anions abundance order, the groundwater type of the study area is currently classified as Na⁺–Cl^––SO₄^2–. On the basis of Schoeller diagram, amounts of Na⁺, Cl^–, SO₄^2–, Total Hardness (TH) and Total Dissolved Solid (TDS) are higher than permissible limit and therefore, the water is unsuitable for drinking and domestic uses. The average pH values of the groundwater equal to 8, indicating alkaline nature of groundwater. Total hardness average of samples equal to 806.8, shows that the Hoz–e–Soltan groundwater was not suitable for drinking, domestic and irrigation uses. Sodium Content (Na %) average equal to 67.1, groundwater resources of the study area was belongs to the suspicious class. As a result, high salinity, SAR, TH, TDS, EC and Na% in most water samples have restricted the water quality for drinking, domestic and irrigation uses