Hydrogeochemistry

Groundwater (GW) though vastly important resource for man, however, it may not meet the standards because it contains dissolved constituents coming from natural sources. Obviously, as stated by Hiscock (2005), the chemical and biochemical interactions between groundwater and the geological materials of soils and rocks through which water flows as well as by the chemistry of incoming water, provide a wide variety of dissolved inorganic and organic constituents. Likewise, water contains dissolved salts, dissociated into cations (positively charged ions) and anions (negatively charged ions). The most common dissolved cations are sodium (Na+), calcium (Ca2+), magnesium (Mg2+), and potassium (K+). The most common anions are chloride (Cl-), bicarbonate (HCO3-), and sulfate (SO42-) (Mazor, 2004; Khadri & Pande, 2015).

GW quality variation is a function of physical and chemical constituents in an area influenced by geological and anthropogenic activities (Srinivasamoorthy et al., 2014). Hydro-geochemistry that constitutes the other issues deals with processes such as dissolution, precipitation, absorption and desorption, ion exchange reactions and the residence time along the flow path which controls the chemical composition of GW, which alter GW quality (Kazemi & Mohammadi, 2012). As there is an increasing interest in environmental issues, hydro-geochemistry is very necessary from viewpoint of environmental impact assessment (Šráček & Zeman, 2004).

Understanding the principal processes that control GW chemistry is either crucial, in terms of sustainable management of GW resources, or scientifically challenging. Research and knowledge of hydro-geochemistry and evolution of GW can disclose the present situation of GW and the interacting mechanism between GW and environment and is essential to determine the origin of chemical composition of GW. Moreover, it is as vital as its quality since it is the key factor to determine its suitability for drinking, domestic, engineering, agricultural, and industrial aspects (Subramani, Elango & Damodarasamy, 2005).