A STUDY OF THE EFFECTIVENESS OF MICROALGAE IN REMOVING HEAVY METALS FROM WASTEWATER FROM MECHANICAL ENGINEERING PLANTS

This review article examines modern research on the problem of wastewater pollution from machine-building enterprises with heavy metals and the possibilities of their biological purification using microalgae. The main sources of industrial wastewater formation, their chemical composition and approximate maximum permissible concentrations of pollutants are analyzed. The limitations of traditional physico-chemical cleaning methods are considered. The work describes in detail the mechanisms of bioremediation involving microalgae, including the processes of biosorption, bioaccumulation and complexation.
Data on Chlorella vulgaris biological characteristics, resistance to contamination, and high efficiency of heavy metal removal under various conditions are presented. A comparison of the effectiveness of different types of microalgae is presented. The advantages and limitations of microalgae purification in terms of environmental safety, economic feasibility and resistance to changing environmental conditions are analyzed.
In conclusion, the use of Chlorella vulgaris for environmentally safe and cost-effective wastewater treatment from heavy metals is considered promising, and the need for further research in this area is emphasized.

1. Alloway B.J. Heavy Metals in Soils: Trace Metals and Metalloids in Soils and Their Bioavailability. - Dordrecht: Springer, 2013. - 614 p. - https://doi.org/10.1007/978-94-007-4470-7

2. Tchounwou P.B., Yedjou C.G., Patlolla A.K., Sutton D.J. Heavy Metals Toxicity and the Environment // EXS. - 2012. - Vol. 101. - P. 133-164. - https://doi.org/10.1007/978-3-7643-8340-4_6

3. Qasem N.A.A., Mohammed R.H., Lawal D.U. Removal of Heavy Metal Ions from Wastewater: A Comprehensive and Critical Review // npj Clean Water. - 2021. - Vol. 4. - Article 36. - https://doi.org/10.1038/s41545-021-00127-0

4. Mahlangu D., Mphahlele K., De Paola F., Mthombeni N.H. Microalgae-Mediated Biosorption for Effective Heavy Metals Removal from Wastewater: A Review // Water. - 2024. - Vol. 16, No. 5. - Article 718. - https://doi.org/10.3390/w16050718

5. Metal Processing Wastewater Components // Almawatech. - URL: https://www.almawatech.com/en/waste-water/metal-processing/ (accessed: 20.02.26).

6. Sources of Heavy Metals in Industrial Wastewater // Almawatech. - URL: https://www.almawatech.com/en/waste-water/heavy-metals/ (accessed: 22.02.26).

7. Classification of Wastewater Components // Industrial and Other Types of Wastewater. - ISSN 1728-8975. - URL: https://rmebrk.kz/journals/703/25946.pdf (accessed: 04.03.26).

8. Heavy Metals in Fresh Waters of Kazakhstan and Methodological Approaches. - URL: https://ks.dku.kz/documents/67/7._Heavy_Metals_in_Fresh_Waters_of_Kazakhstan_and_Methodological_Approaches_RUS.pdf (accessed: 11.03.26).

9. Leong Y.K., Chang J.-S. Bioremediation of Heavy Metals Using Microalgae: Recent Advances and Mechanisms // Bioresource Technology. - 2020. - Vol. 303. - Article 122886. - https://doi.org/10.1016/j.biortech.2020.122886

10. Al-Jabri H., Das P., Khan S., Thaher M., AbdulQuadir M. Treatment of Wastewaters by Microalgae and the Potential Applications of the Produced Biomass: A Review // Water. - 2021. - Vol. 13, No. 1. - Article 27. - https://doi.org/10.3390/w13010027

11. Xu K., Du M., Yao R., Luo J., Chen Z., Li C., Lei A., Wang J. Microalgae-Mediated Heavy Metal Removal in Wastewater Treatment: Mechanisms, Influencing Factors, and Novel Techniques // Algal Research. - 2024. - Vol. 82. - Article 103645. - https://doi.org/10.1016/j.algal.2024.103645

12. Yang X.-Y., Wei Y.-X., Su Y.-Q., Zhang Z.-W., Tang X.-Y., Chen Y.-E., Yuan M., Yuan S. The Strategies Microalgae Adopt to Counteract the Toxic Effect of Heavy Metals // Microorganisms. - 2025. - Vol. 13, No. 5. - Article 989. - https://doi.org/10.3390/microorganisms13050989

13. Mahlangu D., Mphahlele K., De Paola F., Mthombeni N.H. Microalgae-Mediated Biosorption for Effective Heavy Metals Removal from Wastewater: A Review // Water. - 2024. - Vol. 16, No. 5. - Article 718. - https://doi.org/10.3390/w16050718

14. Aslam A., Kanwal F., Javied S. et al. Microbial Biosorption: A Sustainable Approach for Metal Removal and Environmental Remediation // International Journal of Environmental Science and Technology. - 2025. - Vol. 22. - P. 13245-13276. - https://doi.org/10.1007/s13762-025-06611-1

15. Xiao X., Li W., Jin M., Zhang L., Qin L., Geng W. Responses and Tolerance Mechanisms of Microalgae to Heavy Metal Stress: A Review // Marine Environmental Research. - 2023. - Vol. 183. - Article 105805. - https://doi.org/10.1016/j.marenvres.2022.105805

16. Zaitsev V.V., Petryakov V.V., Zaitseva L.M., Makhimova Zh.N. Influence of Nutrient Medium on Morphological Features and Cell Viability of Microalgae Chlorella vulgaris Beijer // Samara Scientific Bulletin. - 2022. - Vol. 11, No. 2. - P. 52-56. - https://doi.org/10.55355/snv2022112107

17. Microalgae Chlorella vulgaris. - URL: https://bioaa.info/index.php/186-2010-01-28-12-03-56 (accessed: 02.04.26).

18. Kyratzopoulou E., Kyzaki N., Malletzidou L., Nerantzis E., Kazakis N.A. The Efficiency of Chlorella vulgaris in Heavy Metal Removal: A Comparative Study of Mono- and Multi-Component Metal Systems // Clean Technologies. - 2025. - Vol. 7, No. 2. - Article 35. - https://doi.org/10.3390/cleantechnol7020035

19. Kireeva N.A., Kabirov T.R., Dubovik I.E. Complex Biotesting of Oil-Contaminated Soils // Theoretical and Applied Ecology. - 2007. - No. 1. - P. 65-69. - https://doi.org/10.25750/1995-4301-2007-1-041-45

20. Kyratzopoulou E., Kyzaki N., Malletzidou L., Nerantzis E., Kazakis N.A. The Efficiency of Chlorella vulgaris in Heavy Metal Removal: A Comparative Study of Mono- and Multi-Component Metal Systems // Clean Technologies. - 2025. - Vol. 7, No. 2. - Article 35. - https://doi.org/10.3390/cleantechnol7020035

21. Reda M. Heavy Metals Removal by Using Chlorella vulgaris Microalgae/Zinc Oxide Nanocomposite for Wastewater Treatment in Menyet El-Nasr, Egypt // Biochemistry Letters. - 2023. - Vol. 19, No. 1. - P. 27-36. - https://doi.org/10.21608/blj.2023.294659

22. Mosleh Y., Mofeed J., Heham S., Nafea E.S. Eco-Friendly Biosorption of Heavy Metals by Chlorella vulgaris: A Green Solution for Wastewater Remediation // Egyptian Journal of Aquatic Biology and Fisheries. - 2025. - https://doi.org/10.21608/ejabf.2025.433979

23. Mahlangu D., Mphahlele K., De Paola F., Mthombeni N.H. Microalgae-Mediated Biosorption for Effective Heavy Metals Removal from Wastewater: A Review // Water. - 2024. - Vol. 16, No. 5. - Article 718. - https://doi.org/10.3390/w16050718

24. Yang X.-Y., Wei Y.-X., Su Y.-Q., Zhang Z.-W., Tang X.-Y., Chen Y.-E., Yuan M., Yuan S. The Strategies Microalgae Adopt to Counteract the Toxic Effect of Heavy Metals // Microorganisms. - 2025. - Vol. 13, No. 5. - Article 989. - https://doi.org/10.3390/microorganisms13050989

25. Pradana A.B., Buchori L., Pratama W.D., Pratiwi W.Z., Hadiyanto. Immobilized Algae for Heavy Metals Remediation in Textile Wastewater // Journal of Emerging Science and Engineering. - 2023. - Vol. 1, No. 2. - P. 51-56. - https://doi.org/10.61435/jese.2023.10

26. Karpov M.V., Naumova O.V., Zhizdyuk A.A., Malysheva A.A. Prospects for the Use of Cultivated Chlorella Algae in Additional Treatment and Disinfection of Wastewater at Treatment Facilities // Agrarian Scientific Journal. - 2023. - No. 1. - P. 150-154. - https://doi.org/10.28983/asj.y2023i1pp150-154