Accumulation, Distribution, and Transformation of Heavy Metals in the Dried Bottom Soils of the Aral Sea

Jabbarov, Zafarjon; Abdrakhmanov, Tokhtasin; Abdullaev, Shokhrukh; Makhammadiev, Samad; Nomozov, Urol; Imomov, Otamurod; Makhkamova, Dilafruz

doi:10.21608/ejss.2025.369277.2070

Accumulation, Distribution, and Transformation of Heavy Metals in the Dried Bottom Soils of the Aral Sea

Document Type : Original Article

Authors

¹ National University of Uzbekistan, Tashkent, 100174, Uzbekistan

² Tashkent branch of the Samarkand state university veterinary medicine of livestock and biotechnologies, Chilanzar, 35a, Uzbekistan

10.21608/ejss.2025.369277.2070

Abstract

The article examines the quantity, accumulation, and distribution of elements in the soil and sediments formed on the dried-up bottom of the Aral Sea, which began drying up in 1960. It was determined that not all soils in the eastern part of the dried-up seabed are equally contaminated with heavy metals. However, the scientific analysis confirms the localized accumulation of certain heavy metals at specific points, while their distribution patterns have also been identified. The study area was divided into three regions: I region - the coastal areas of the Aral Sea that have been dry for 50 years. II region - soils formed due to wind-driven sand accumulation, which have been dry for 30 years. III region - located in the northern region, characterized by high salt content and dry for 25 years. The results show that in II region, the Clarke concentration coefficient (CCC) of all elements is below 1. However, the heavy metals V, Co, Mn, Mo, Cd, Cu, and Zn in I region and III have a CCC value above 1, indicating higher accumulation in these areas. The Clarke scattering coefficient (Ks), however, follows a different pattern. Heavy metals are more widely distributed in regions II and III, particularly Ni, Mn, Co, Cu, Cr, and Zn. In the initially dried-up areas, the dispersion coefficient, or Clarke concentration, remains below 1. The sequential ranking of elements by Clarke concentration in the eastern part of the dried-up Aral Sea bottom is as follows: Cd (56.46) - Cu (15.8) - Mo (9.91) - Zn (9.82) - Co (1.81) - V (1.21) - Mn (1.0) - Cr (0.81) - Ni (0.69). This indicates that these elements have a high accumulation in the soil.

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