A new technology for reducing and disposing of concentrates from reverse osmosis plants by creating conditions for the crystallization of insoluble salts in the channels of the devices

Precipitation of poorly soluble salts on membranes and discharge of concentrate have always been problems for the development and improvement of reverse osmosis plants. Deposits are also the main reason that prevents increased extraction and reduced discharge of concentrate, since the formation of insoluble salts due to supersaturation negatively affects the membrane performance. The article presents the results of research based on the study of the theory of sedimentation and crystallization, which make it possible to ensure effective control over the formation and growth of crystals. As a result, a new technology has been developed that makes it possible to reduce concentrate consumption by 20-100 times without the formation of deposits of insoluble salts on membranes and without the use of reagents. Calcium carbonate and calcium sulfate are precipitated without the use of a softening reagent due to the creation of supersaturation due to the concentration of source water in the channels of the apparatus. This non-reactive technology has been developed using nanofiltration membranes with low selectivity. The results of experiments are presented, which demonstrate the conditions necessary for the start of the nucleation process in the concentrate stream, and allow us to determine the rates of nucleation and crystal growth. The application of a new technology for desalination of groundwater and marine waters is presented. The technology allows not only to reduce the discharge of concentrate, but also to divide it into a number of concentrated solutions. An economic comparison of the newly developed technology used in groundwater treatment is given.

1. Pervov A. Investigation of Scaling and Inhibition Mechanisms in Reverse Osmosis Spiral Wound Elements. Membranes. 2022;12(9):1-21. https://doi.org/10.3390/membranes12090852.

2. Xiaoqiang Wang, Ruizhu Hu, Jilin Wei, Tinglin Huang, Kaihong Li, Haitao Cheng Experimental Study on Softening High-Calcium Sulfate Reverse Osmosis Concentrate Using Induced Crystallization Method. Water. 2025;17(1):1-16. https://doi.org/10.3390/w17010004.

3. Alrehaili O., Perreault F., Sinha S., Westerhoff P. Increasing Net Water Recovery of Reverse Osmosis with Membrane Distillation Using Natural Thermal Differentials Between Brine and Co-Located Water Sources: Impacts at Large Reclamation Facilities. Water Research. 2020;184:1-8. https://doi.org/10.1016/j.watres.2020.116134.

4. Turek M., Mitko K., Skora P., Dydo P., Jakobik-Kolon A., Warzecha A. et al. Improving the Performance of a Salt Production Plant by Using Nanofiltration as a Pretreatment. Membranes. 2022;12(12):1-11. https://doi.org/10.3390/membranes12121191.

5. Joy M., Boussemaere R. Investigation of Carbon Dioxide for Scale Control in Reverse Osmosis Systems. Journal of Environmental Management. 2025;373:1-15. https://doi.org/10.1016/j.jenvman.2024.123837.

6. Fumio Yokoyama, Mitsutoshi Nakajima, Sosaku Ichikawa Analysis of Calcium Sulfate Scaling Phenomena on Reverse Osmosis Membranes by Scaling-Based Flux Model. Membranes. 2022;12(9):1-20. https://doi.org/10.3390/membranes12090894.

7. Pervov A., Htet Zaw Aung, Spitsov D. Treatment of Mine Water with Reverse Osmosis and Concentrate Processing to Recover Copper and Deposit Calcium Carbonate. Membranes. 2023;13(2):1-20. https://doi.org/10.3390/membranes13020153.

8. Pervov A., Andrianov A. Deposition of Calcium and Magnesium from RO Concentrate By Means Of Seed Crystallization and Production of Softened Water for Technical Purposes. Desalination and Water Treatment. 2018;110:10-18. https://doi.org/10.5004/dwt.2018.21875.

9. García-Trinanes P., Chairopoulou M.A., Campos L.C. Investigating Reverse Osmosis Membrane Fouling and Scaling by Membrane Autopsy of A Bench Scale Device. Environmental Technology. 2022;43(21):3198- 3211. https://doi.org/10.1080/09593330.2021.1918262.

10. Nassr M., Dischinger S.M., Ji Yeon Lee, Gleason K.L., Molins S., Spycher N. et al. Mineral Scale Formation during Crossflow Reverse Osmosis at Constant Flux and Constant Transmembrane Pressure Conditions. Industrial & Engineering Chemistry Research. 2025;64(2):1295-1308. https://doi.org/10.1021/acs.iecr.4c04059.

11. Ahmed M.A., Amin S., Mohamed A.A. Fouling in reverse osmosis membranes: monitoring, characterization, mitigation strategies and future directions. Heliyon. 2023;9(4):1-27. https://doi.org/10.1016/j.heliyon.2023.e14908.

12. Popov K., Oshchepkov M., Pervov A., Golovesov V., Ryabova A., Trukhina M. et al. A Case Study of Calcium Carbonate Crystallization during Reverse Osmosis Water Desalination in Presence of Novel Fluorescent-Tagged Antiscalants. Membranes. 2022;12(2):1-15. https://doi.org/10.3390/membranes12020194.

13. Ramirez-Garcia P., Duran-Olivencia M.A., Kellermeier M., Van Driessche A.E.S. Determining the Operational Window of Green Antiscalants: A Case Study for Calcium Sulfate. Desalination. 2022;544:1-13. https://doi.org/10.1016/j.desal.2022.116128.

14. Kisel A.V. Desalination of Sea Water from the Black, Azov and Caspian Seas Using Membrane Technologies. Vestnik nauki. 2019;3(2):79-94. (In Russ.). EDN: YWLVBR.

15. Jiapeng Li, Yunhuan Chen, Hailong Wang, Xinyue Liu, Yulong Ma, Yongsheng Ren Investigation of the Effect of Phosphonate Antiscalants on the Reverse Osmosis Membranes' Permeation And Desalination Performance in Mine Wastewater Treatment Process. Journal of Water Process Engineering. 2024;68:1-12. https://doi.org/10.1016/j.jwpe.2024.106310.

16. Mosin O.V., Ignatov I. Modern Technologies of Seawater Desalination. Energosberezhenie i vodopodgotovka. 2012;4:13-19. (In Russ.). EDN: NPSEGI.

17. Golovesov V.A. Solutions to Problems Arising from The Use of Reverse Osmosis Units in Drinking Water Supply. In: Yakovlevskie chteniya. Sbornik dokladov XVI Mezhdunarodnoi nauchno-tekhnicheskoi konferentsii, posvyashchennoi pamyati akademika RAN S.V. Yakovleva = Yakovlev Readings. Collection of Reports of The XVI International Scientific and Technical Conference Dedicated to The Memory of Academician of The Russian Academy of Sciences S.V. Yakovlev. 15 March 2021, Moscow. Moscow, 2021. P. 48–55. (In Russ.). EDN: GNRXUA.

18. Al-Anzi B.S., Al-Rashidi A., Abraham L., Fernandes J., Al-Sheikh A., Alhazza A. Brine Management from Desalination Plants for Salt Production Utilizing High Current Density Electrodialysis-Evaporator Hybrid System: A Case Study in Kuwait. Desalination. 2021;498:1-11. https://doi.org/10.1016/j.desal.2020.114760.

19. Pervov A., Xuan Quyet Nguyen Application of Reverse Osmosis and Nanofiltration Techniques at Municipal Drinking Water Facilities. E3S Web of Conferences. 2019;97:1-10. https://doi.org/10.1051/e3sconf/20199706004.

20. Gadalla M.A., Fatah A.A., Elazab H.A. A Novel Renewable Energy Powered Zero Liquid Discharge Scheme for RO Desalination Applications. Case Studies in Chemical and Environmental Engineering. 2023;8:1-6. https://doi.org/10.1016/j.cscee.2023.100407.

21. Popov K.I., Oshchepkov M.S. Current State of the Theory of Action of Scale Inhibitors. In: VIII nauchnoprakticheskaya konferentsiya «Sovremennye tekhnologii vodopodgotovki i zashchi-ty oborudovaniya ot korrozii i nakipeobrazovaniya». Sbornik dokladov VIII nauchno-prakticheskoi konferentsii v ramkakh mezhdunarodnoi vystavki «Khimiya-2019» «Ekspotsentr» na Krasnoi Presne = VIII Scientific and Practical Conference “Modern Technologies of Water Treatment and Protection of Equipment From Corrosion and Scale Formation”. Collection of Reports of The VIII Scientific and Practical Conference within The Framework of The International Exhibition “Chemistry-2019” “Expocentre” on Krasnaya Presnya. 16–17 September 2019, Moscow. Moscow, 2019. P. 5–11. (In Russ.). EDN: XALSQR.

22. El Sayed M.M., Abulnour A.M.G., Tewfik S.R., Sorour M.H., Hani H.A., Shaalan H.F. Reverse Osmosis Membrane Zero Liquid Discharge for Agriculture Drainage Water Desalination: Technical, Economic, and Environmental Assessment. Membranes. 2022;12(10):1-10. https://doi.org/10.3390/membranes12100923.

23. Cappelle M., Walker W.S., Davis T.A. Improving Desalination Recovery Using Zero Discharge Desalination (ZDD): A Process Model for Evaluating Technical Feasibility. Industrial & Engineering Chemistry Research. 2017;56(37):10448-10460. https://doi.org/10.1021/acs.iecr.7b02472.

24. Xianhui Li, Hasson D., Semiat R., Shemer H. Intermediate Concentrate Demineralization Techniques for Enhanced Brackish Water Reverse Osmosis Water Recovery – A Review. Desalination. 2019;466:24-35. https://doi.org/10.1016/j.desal.2019.05.004.

25. Omerspahic M., Al-Jabri H., Amir Siddiqui S., Saadaoui I. Characteristics of Desalination Brine and Its Impacts on Marine Chemistry and Health, With Emphasis on the Persian/Arabian Gulf: A Review. Frontiers in Marine Science. 2022;9:1-12. https://doi.org/10.3389/fmars.2022.845113.

26. Abu Sharkh B., Al-Amoudi A.A., Farooque M., Fellows C.M., Ihm S., Lee S. et al. Seawater Desalination Concentrate – A New Frontier for Sustainable Mining of Valuable Minerals. Clean Water. 2022;5:1-17. https://doi.org/10.1038/s41545-022-00153-6.

27. Murtaza M., Alarifi S.A., Rasm M.Y., Kamal M.S., Mahmoud M., Al-Ajmi M. Single Step Calcium Sulfate Scale Removal at High Temperature Using Tetrapotassium Ethylenediaminetetraacetate with Potassium Carbonate. Scientific Reports. 2022;12:1-18. https://doi.org/10.1038/s41598-022-14385-6.

28. Yan Yan, Tao Yu, Huan Zhang, Jiayu Song, Chengtun Qu, Jinling Li et al. Co-Deposition Mechanisms of Calcium Sulfate and Calcium Carbonate Scale in Produced Water. Crystals. 2021;11(12):1-17. https://doi.org/10.3390/cryst11121494.