Hidrogeoquímica das águas subterrâneas no município de Lençóis, Bahia, Brasil

Resumen

This study aimed to point out the hydrogeochemistry groundwater in the municipality of Lençóis, State of Bahia, to classify them according to the content and types of dissolved salts. To this, twenty sampling points were listed in the groundwater in aquifers formed by metasediments, detritical covers and limestones, with the purpose of analyze the following parameters: electrical conductivity, temperature, pH, turbidity, total dissolved solids, HCO₃, PO₄, SO₄, Cl^-, NO₃, Na⁺, K⁺, Ca²⁺, Mg²⁺, Fe³⁺, Mn⁴⁺, Sr²⁺ and Ba²⁺. The results showed that the groundwater in the municipality of Lençóis are distributed into two zones with different hydrogeochemistry, one of the largest controlled by geological clastic metasedimentary rocks typologies (sandstones, quartzites, conglomeratics, detritical covers) where the process of water-rock interaction allows occur little quantity salt water, slightly acidic, sweet, soft and predominantly sulfated sodic. The other zone is controlled by chemical metasedimentary rocks (limestones) as well as bicarbonates, where they occur hard water, slightly alkaline, sweets and sulfated calcic and mixed. The levels of metals and elements nitrate, phosphate and sulfate presented themselves generally at low concentrations, with some deviations detected in points of the urban area.