Heavy metals are some of the environmental pollutants that have a serious impact on the environment. The analysis of hydromacrophytes growing in small rivers of the south of Kazakhstan with different contents of heavy metal salts revealed that the morphometric indicators of the same plant species differ significantly, depending on the level of total mineralization of the aquatic environment in different rivers of the Turkestan region. It has been established that two plant species can be used to bioindicate the content of lead ions in the aquatic environment: Azolla caroliniana Willd. and Veronica beccabunga L., which must be introduced into the tested aqueous solutions in the amount of 1.0 kg/m 3 and 1.5-2.0 kg/m 3 , respectively, to fully cover the water column at different depths. The first morphological changes in plants, in the form of destruction of the structure of chloroplasts along the edges of unfolded leaves in A. caroliniana Willd. and slight withering of the lower underwater leaves in V. beccabunga L.

The article presents the results of a botanical analysis of water systems in the south of Kazakhstan. Hydromacrophytic vegetation of the reservoir reflects its hydrological and thermal regime and can characterize the features of its chemical composition, trophic status, age (as a stage of development). In some cases, phytocenosis and some types of macrophytes can be used as bioindicators, for example, in clean water, as well as to determine the degree and nature of anthropogenic impacts. Metals, metal compounds and toxins cause disturbances in many metabolic processes in plants. As a result, the highly toxic nature of their ions selectively affects the species composition of the phytocenosis. In Shymkent, almost a unique system of treatment facilities has been operating for about 20 years, during this time, resistant species adapted to the environment were selected, and a plant cenosis consisting of dominant species was formed. In this regard, a floristic study was carried out in the canals around the treatment plant, adapted to climatic conditions and pollutants. As a result of the study, the species composition and the number of plant communities decreased due to the toxic concentration of water. It is clearly seen that Cerathophyllum demersum, Lemna minor, L. trisulca, Phragmites australis, Scirpus lacustris, Epilobium adnatum were identified as effective phytomeliorants, significantly reducing the content of the main pollutants in urban wastewater. In addition, algae have been found to be indicators of pollution. Highly effective organic fertilizers can be obtained from the used vascular plants and algae. In general, these data showed that the optimal consortium of wastewater treatment plants at low temperatures should be formed from different ecological groups of plants: coastal, floating and inhabiting the aquatic environment. In addition, among these plants were found sedimentary hornbeam, campfire fish, southern reed, lake reed and a related cypress.