Authors: Adilov Sobit Uktamovich, Gulomov Gofir Komil o‘g‘li, Umirzoqov Jamshid Mirzayevich, Umirov Ismoil Eshonqulovich
Abstract: This study presents a hydrochemical characterization of groundwater from four wells (Chanishbay yakka quduq, Kupet turar joy, Nissan uy oldi, and Beknazar quduq) within the Central Kyzylkum desert ecosystem, Uzbekistan, focusing on major cations (Ca²⁺, Mg²⁺, Na⁺, K⁺), a set of regulated trace elements (Cu, Cr, Fe, Cd), and the Sodium Adsorption Ratio (SAR). Samples were collected on 30 April 2026 and analysed by Flame Atomic Absorption Spectrometry (FAAS) at an accredited laboratory (Workshop No. 081, order No. 23764). Results were compared against World Health Organization (WHO) drinking-water guidelines and the United States Salinity Laboratory (USSL) SAR classification. The hydrochemical facies at all sites were sodium-dominant (Na⁺ > Ca²⁺ > Mg²⁺ > K⁺), and sodium concentrations exceeded the WHO palatability threshold (200 mg/L) at every site. Calculated SAR values ranged from 4.9 (low hazard, S1) to 55.8 (very high hazard, S4), indicating a substantial sodium/salinity hazard should these waters be used for irrigation. Concentrations of the regulated heavy metals (Cu, Cr, Cd) were below the detection limit at all sites. The findings underline the need for expanded hydrochemical monitoring of groundwater in arid desert ecosystems such as Central Kyzylkum.
