Abstract
The continuing anthropogenic pollution of the Ile River occurs both by transboundary runoff and as a result of discharges of industrial, agricultural, and domestic wastewater on the territory of Kazakhstan. With this amount of pollution, the river’s capacity for self-purification is very limited, and in some cases practically exhausted. Hydrochemical and toxic indicators in the Ile River basin were analyzed based on water sampling from the Chinese–Kazakh border station to 37 km downstream of the hydroelectric power plants (HPPs). Heavy metals were determined by flame AAS methods. The self-purification capacity (SPC) was determined for cadmium by 28–81%, copper 15–66%, zinc 22–37%, and cobalt 5–9% while the nickel self-purification of water did not occur. The SPC was influenced by the Kapshagai reservoir. The identified main regularities of the anthropogenic transformation of water quality and self-purification capacity of the river will help both in solving the problems of river pollution and in the development of necessary measures aimed at the protection of water resources from pollution and depletion.