Control of the ratio of monovalent and bivalent ions in drinking water treatment by nanofiltration method

Introduction. The main problem is discussed that is related to application of reverse osmosis membranes method for quality drinking water production from underground water sources that contain dissolved contaminants dangerous for health such as: fluoride, ammonia, lithium, strontium, arsenic, boron etc. It is also mentioned that reverse osmosis is currently efficiently used for drinking water production. The main goal of the present work was evaluation of the new developed method efficiency and calculation of the operational costs to compare with conventional approach to use reverse osmosis to remove lithium from the ground water. Present article demonstrates results of research aimed at developing a new approach to change the ratio of monovalent and bivalent ions in the permeate of nanofiltration membranes. An example of water with high lithium content that exceeds normative value by 24 times is discussed. The developed technique of ion separation is applied and experimental results are demonstrated, thus providing low lithium concentration in product water with increased calcium and TDS by 5 times as compared to the conventional use of reverse osmosis membranes. Operational costs are evaluated and compared with conventionally used approach to produce drinking quality water from ground water.

Materials and methods. A series of experiments were conducted to remove lithium from ground water and to demonstrate the efficiency of the new developed method of ion separation. Experimental results of permeate and concentrate separation are presented compared to reverse osmosis that provided the increase of calcium and TDS values in the product water by 4–5 times compared to permeate produced by reverse osmosis membranes. The economical evaluation of the main technical parameters of the developed method involved calculation of the required membrane area and the number of membrane elements at each stage, calcium carbonate scaling rates and reagent consumption to prevent scaling as well as the amounts of concentrate discharges into the sewer.

Results. Experimental dependencies of the efficiency of different dissolved contaminants removal from the ground water using different types of membranes depending on the recovery values were obtained. Experimentally obtained results confirmed the possibility to increase the calcium concentration and TDS values of the product water by 4–5 times leaving the lithium concentration at the same level. A flow diagram of the developed process is demonstrated based on experimentally obtained results. The increase of product water TDS facilitates the further reduction of concentrate flow rate and operational costs. Design characteristics to calculate operational costs for two options (conventional and proposed) are presented. Economical comparison was performed using results of calculations of membrane surface area on each stage of membrane treatment, scaling rates, reagent consumption, concentrate discharges.

Conclusions. Application of reverse osmosis for removal of monovalent contaminants (such as: lithium, ammonia, boron) from ground water results, in reduction of TDS values that requires additional costs to provide permeate conditioning. Operation of reverse osmosis facilities also is distinguished by scaling problems that also requires additional operational costs to prevent and remove scale deposits. In this paper, a new approach is proposed to apply nanofiltration membranes using double stage treatment and separate monovalent and bivalent ions and increase calcium and TDS content in product water leaving the lithium content at the extreme level. The use of developed method enables to reduce operational costs due to lower membrane replacement costs, reagent consumption for scale prevention and concentrate discharges.

1. Suratt W.B., Andrews D.R., Pujals V.J., Richards S.A. Design considerations for major membrane treatment facility for groundwater. Desalination. 2000; 131(1-3):37-46. DOI: 10.1016/S0011-9164(00)90004-3

2. Spitsov D., Aung H.Z., Pervov A. The sel- ection of efficient antiscalant for RO facility, control of its quality and evaluation of the economical efficiency of its application. Membranes. 2023; 13(1):85. DOI: 10.3390/membranes 13010085

3. Watson B.M., Hornburg C.D. Low-energy membrane nanofiltration for removal of color, organics and hardness from drinking water supplies. Desalination. 1989; 72(1-2):11-22. DOI: 10.1016/0011-9164(89)80024-4

4. Lopes C.N., Petrus J.C.C., Riella H.G. Color and COD retention by nanofiltration membranes. Desalination. 2005; 172(1):77-83. DOI: 10.1016/j.desal.2004.07.030

5. Al-Qadami E., Ahsan A., Mustafa Z., Abdurrasheed S., Yusof K.W., Shah S.M.H. Nanofiltration membrane technology and its applications in surface water treatment : a review. Journal of Desalination and Water Purification. 2020; 18:3-9.

6. Tian J., Zhao X., Gao S., Wanng X., Zhang R. Progress in research and application of Nanofiltration (NF) technology for brackish water treatment. Membranes. 2021; 11(9):662. DOI: 10.3390/membranes11090662

7. Guo H., Li X., Yang W., Yao Z., Mei Y., Peng L.F. et al. Nanofiltration for drinking water treatment : a review. Frontiers of Chemical Science and Engineering. 2021; 16(5):681-698. DOI: 10.1007/s11705-021-2103-5

8. Li S., Wang X., Guo Y., Hu J., Lin S., Tu Y. et al. Recent advances on cellulose-based nanofiltration membranes and their applications in drinking water purification : a review. Journal of Cleaner Production. 2022; 333:130171. DOI: 10.1016/j.jclepro.2021.130171

9. Jamaly S., Darwish N.N., Ahmed I., Hasan S.W. A short review on reverse osmosis pretreatment technologies. Desalination. 2014; 354:30-38. DOI: 10.1016/j.desal.2014.09.017

10. Goh P.S., Lau W.J., Othman M.H.D., Ismail A.F. Membrane fouling in desalination and its mitigation strategies. Desalination. 2018; 425:130-155. DOI: 10.1016/j.desal.2017.10.018

11. Jiang S., Li Y., Ladewig B.P. A review of reverse osmosis membrane fouling and control strategies. Science of The Total Environment. 2017; 595:567-583. DOI: 10.1016/j.scitotenv.2017.03.235

12. Xu W., Liu D., He L., Zhao Z. A comprehensive membrane process for preparing lithium carbonate from high Mg/Li brine. Membranes. 2020; 10(12):371. DOI: 10.3390/membranes10120371

13. Li X., Mo Y., Qing W., Shao S., Tang C.Y., Li J. Membrane-based technologies for lithium recovery from water lithium resources : a review. Journal of Membrane Science. 2019; 591:117317. DOI: 10.1016/j.memsci.2019.117317

14. Mohammad A.W., Hilal N., Al-Zoubi H., Darwish N.A. Prediction of permeate fluxes and rejections of highly concentrated salts in nanofiltration membranes. Journal of Membrane Science. 2007; 289(1-2):40-50. DOI: 10/1016/j.memsci.2006.11.035

15. Pervov A.G. Removal of calcium carbonate from antiscalant-containing reverse osmosis concentrates. Membranes and Membrane Technologies. 2017; 7(3):192-205. DOI: 10.1134/S2218117217030063. EDN YTFQTL. (rus.).

16. Hedayatipour M., Jaafarzadeh N., Ahmadmoazzam M. Removal optimization of heavy metals from effluent of sludge dewatering process in oil and gas well drilling by nanofiltration. Journal of Environmental Management. 2017; 203:151-156. DOI: 10.1016/j.jenvman.2017.07.070

17. Ahmed S.F., Mehejabin F., Momtahin A., Tasannum N., Faria N.T., Mofijur M. Strategies to improve membrane performance in wastewater treatment. Chemosphere. 2022; 306:135527. DOI: 10.1016/j.chemosphere.2022.135527

18. Voutchkov N. Overview of seawater concentrate disposal alternatives. Desalination. 2011; 273(1):205-219. DOI: 10.1016/j.desal.2010.10.018

19. Al-Ghamdi A.A. Recycling of Reverse Osmosis (RO) reject streams in brackish water desalination plants using fixed bed column softener. Energy Procedia. 2017; 107:205-211. DOI: 10.1016/j.egypro.2016.12.174

20. Najid N., Fellaou S., Kouzbour S., Gourich B., Ruiz-García A. Energy and environmental issues of seawater reverse osmosis desalination considering boron rejection : a comprehensive review and a case study of exergy analysis. Process Safety and Environmental Protection. 2021; 156:373-390. DOI: 10.1016/j.psep.2021.10.014

21. Koyuncu I., Yalcin F., Ozturk I. Color removal of high strength paper and fermentation industry effluents with membrane technology. Water Science and Technology. 1999; 40(11-12):241-248. DOI: 10.2166/wst.1999.0718

22. Collivignarelli M.C., Abbà A., Miino M.C., Damiani S. Treatments for color removal from wastewater: State of the art. Journal of Environmental Management. 2019; 236:727-745. DOI: 10.1016/j.jenvman.2018.11.094

23. Zheng Y., Yu S., Shuai S., Zhou Q., Cheng Q., Liu M. et al. Color removal and COD reduction of biologically treated textile effluent through submerged filtration using hollow fiber nanofiltration membrane. Desalination. 2013; 314:89-95. DOI: 10.1016/j.desal.2013.01.004

24. Jafarinejad S., Esfahani M.R. A review on the nanofiltration process for treating wastewaters from the petroleum industry. Separations. 2021; 8(11):206. DOI: 10.3390/separations8110206

25. Turek M., Mitko K., Piotrowski K., Dydo P., Laskowska E., Jakóbik-Kolon A. Prospects for high water recovery membrane desalination. Desalination. 2017; 401:180-189. DOI: 10.1016/j.desal.2016.07.047

26. Bunani S., Yörükoğlu E., Sert G., Yüksel Ü., Yüksel M., Kabay N. Application of nanofiltration for reuse of municipal wastewater and quality analysis of product water. Desalination. 2013; 315:33-36. DOI: 10.1016/j.desal.2012.11.015

27. Pervov A.G., Shirkova T.N., Tikhonov V.A. Design of reverse osmosis and nanofiltration membrane facilities to treat landfill leachates and increase recoveries. Membranes and Membrane Technologies. 2020; 2:296-309.