The arid zone rivers Amudarya and Syrdarya are located in Central Asia and are subjected to the influx of different kinds of natural and anthropogenic pollutants. The concentrations and speciation of heavy metals, nam...The arid zone rivers Amudarya and Syrdarya are located in Central Asia and are subjected to the influx of different kinds of natural and anthropogenic pollutants. The concentrations and speciation of heavy metals, namely, Hg, Cr, Cd, Co, U, Zn, Sc, Fe, Br, Au, and Sm. in the Amudarya and Syrdarya rivers water in the territory of Uzbekistan were investigated by applying the neutron-activation analysis and through experimental modeling using appropriate radionuclides. The heavy metals speciation in the rivers water was separated in cationic, anionic, and a combination of colloidal and neutral forms. The experimental results showed that heavy metals in the Amudarya and Syrdarya rivers water migrate as a complex set of suspended solids, cationic, anionic, and a combination of colloidal neutral forms. The ratio of neutral and colloidal forms averages approximately 40% for the majority of the investigated heavy metals, and the share of neutral and colloidal forms of heavy metals in the Syrdarya river water is slightly less than in the Amudarya river water （10-20%）, which might be due to discharge of water from agricultural and industry sectors into the river.展开更多
文摘The arid zone rivers Amudarya and Syrdarya are located in Central Asia and are subjected to the influx of different kinds of natural and anthropogenic pollutants. The concentrations and speciation of heavy metals, namely, Hg, Cr, Cd, Co, U, Zn, Sc, Fe, Br, Au, and Sm. in the Amudarya and Syrdarya rivers water in the territory of Uzbekistan were investigated by applying the neutron-activation analysis and through experimental modeling using appropriate radionuclides. The heavy metals speciation in the rivers water was separated in cationic, anionic, and a combination of colloidal and neutral forms. The experimental results showed that heavy metals in the Amudarya and Syrdarya rivers water migrate as a complex set of suspended solids, cationic, anionic, and a combination of colloidal neutral forms. The ratio of neutral and colloidal forms averages approximately 40% for the majority of the investigated heavy metals, and the share of neutral and colloidal forms of heavy metals in the Syrdarya river water is slightly less than in the Amudarya river water （10-20%）, which might be due to discharge of water from agricultural and industry sectors into the river.
