University of Guilan Caspian Journal of Environmental Sciences 1735-3033 24 2 2026 04 01 Purification of river waters using plant bioindicators 485 493 9634 10.22124/cjes.2026.9634 EN Rosa Zhumakhanova M.Auezov South Kazakhstan University, Shymkent City, Higher School of Science and Pedagogy, Department of Biology and Geography, Kazakhstan Gulnar Kylyshbayeva Central Asian Innovation University, Department of Chemistry, Biology and Ecology, Shymkent, Kazakhstan Aidos Mussabekov M.Auezov South Kazakhstan University, Shymkent City, Higher School of Science and Pedagogy, Department of Biology and Geography, Kazakhstan Gulnar Adyrbekova M.Auezov South Kazakhstan University, Shymkent City, Higher School of Science and Pedagogy, Department of Biology and Geography, Kazakhstan Nyshangul Abduraimova M.Auezov South Kazakhstan University, Shymkent City, Higher School of Science and Pedagogy, Department of Biology and Geography, Kazakhstan Akmaral Berdaliyeva Central Asian Innovation University, Department of Chemistry, Biology and Ecology, Shymkent, Kazakhstan Gulnar Kemelbekova M.Auezov South Kazakhstan University, Shymkent City, Higher School of Science and Pedagogy, Department of Biology and Geography, Kazakhstan Gulmira Yessentureyeva Zhanibekov University, Department of biology, Faculty of Natural Sciences, Shymkent., Kazakhstan Journal Article 2026 05 23 This article discusses modern methods of river water purification using plant bioindicators, based on a field study conducted in the Almaty region and the lower Ili River of Kazakhstan between May and September 2025. We collected water, sediment, and plant samples from three river sections with different pollution levels (clean, moderate, and heavily polluted). Five aquatic and coastal plant species were examined: Phragmites australis, Typha angustifolia, Potamogeton nodosus, Ranunculus aquatilis, and Iris pseudacorus. The results show that P. nodosus (river pondweed) is the most effective accumulator, with bioconcentration factors (BCF) of 1.26 for lead and 1.85 for zinc at the polluted site, exceeding the hyperaccumulator threshold of 1.0. The same species removed 57–68% of dissolved heavy metals from water passing through dense stands. Visible symptoms (root blackening, leaf chlorosis, and stunted growth) correlated strongly with sediment metal levels (Spearman’s ρ = 0.91), enabling rapid visual bioindication without laboratory equipment. T. angustifolia showed moderate accumulation (BCF up to 0.78), while Phragmites and Iris contributed mainly to stabilisation. The strong correlation between sediment and plant root metal concentrations (r > 0.95) confirms that plants can serve as reliable sentinels. The study demonstrates the dual role of aquatic and coastal plants in reducing pollution, accumulating heavy metals and biogenic elements, and restoring the ecological state of aquatic ecosystems. The use of phytobioindication allows simultaneous monitoring and biological purification of water bodies. We recommend planting and protecting P. nodosus in polluted river reaches, harvesting biomass annually, and training local communities to recognise visible bioindicator signs. These low‑cost, sustainable methods are particularly suitable for Kazakhstan’s continental climate and limited laboratory infrastructure.

https://cjes.guilan.ac.ir/article_9634_616dc44a1649c9db49227d849bd6b15f.pdf