Recovering Na2SO4 from Simulated Industrial Brine by Membrane Crystallization
Source abstract
Abstract
Solutions with NaCl and Na2SO4 mixture simulating three real industrial RO waste brines were treated by membrane crystallization (MCr) with the aim of recovering the ions as crystals. In particular, the three different solutions have NaCl and Na2SO4 molar ratios of 1:2, 2:1 and 1:1, respectively. Experiments at two different feed temperatures were performed and analyzed. Results showed that the separation of the NaCl and Na2SO4 mixture can be realized by the MCr process and the Na2SO4 salts were successfully recovered from the mixture. Different morphologies of Na2SO4 crystals were obtained by selecting an appropriate feed temperature. Crystal size distribution (CSD) and cumulative fraction of the crystals were calculated to determine the distribution of the crystals’ size and their variation around the average size. The Na2SO4 salts obtained from all experiments were of high purity, indicating promising salt separation, recovery, and reuse from RO brine from a sustainable perspective.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Freezing and Crystallization Processes
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Institute on Membrane Technology “Enrico Drioli” (CNR-ITM), Via Pietro Bucci 17/C, 87036 Rende, Italy
Department of Chemical Science, University of Padova, Via F. Marzolo 1, 35131 Padova, Italy
Institute on Membrane Technology “Enrico Drioli” (CNR-ITM), UoS of Padova, Via F. Marzolo 1, 35131 Padova, Italy
References (33)
Show source-provided references
1. Li, X., Pan, J., Macedonio, F., Ursino, C., Carraro, M., Bonchio, M., Drioli, E., Figoli, A., Wang, Z., and Cui, Z. (2022). Fluoropolymer Membranes for Membrane Distillation and Membrane Crystallization. Polymers, 14.10.3390/polym14245439 ↗
2. Evaluation of sodium chloride crystallization in membrane distillation crystallization applied to water desalination10.1590/0104-6632.20160333s20150133 ↗
3. A study of membrane distillation and crystallization for lithium recovery from high-concentrated aqueous solutions10.1016/j.memsci.2016.01.033 ↗
4. Membrane crystallization for mineral recovery from saline solution: Study case Na2SO4 crystals10.1016/j.desal.2017.02.021 ↗
5. Waste salt separation by antisolvent crystallization process: Mechanism study of Na2SO4-NaCl-solvent ternary phase diagrams and its life cycle assessment10.1016/j.desal.2025.118985 ↗
6. A full-scale study of nanofiltration: Separation and recovery of NaCl and Na2SO4 from coal chemical industry wastewater10.1016/j.desal.2021.115239 ↗
7. Reclamation of sodium sulfate from industrial wastewater by using membrane distillation and membrane crystallization10.1016/j.desal.2016.05.007 ↗
8. Wang, C., Huang, X., Wang, H., Chen, R., and Ruan, X. (2025). Combined Frozen Crystallization and Stepwise Decompression Evaporation for Na2SO4/NaCl Separation from Mixed Salts. Recycling, 10.10.3390/recycling10030106 ↗
9. Experimental study of the crystallization of sodium sulfate hydrates through temperature monitoring10.1007/s12665-014-3379-2 ↗
10. Thermodynamic modelling of a membrane distillation crystallisation process for the treatment of mining wastewater10.2166/wst.2015.515 ↗
11. Electrodialysis of concentrated brine from RO plant to produce coarse salt and freshwater10.1016/j.memsci.2013.09.020 ↗
12. Enhanced anti-wetted PVDF membrane for pulping RO brine treatment by vacuum membrane distillation10.1016/j.desal.2021.115533 ↗
13. Recovery of water and contaminants from cooling tower plume10.4491/eer.2018.192 ↗
14. Pavuluri, S. (2026, July 09). Kinetic Approach for Modeling Salt Precipitation in Porous-Media. Available online: https://www.researchgate.net/publication/262495450_Kinetic_approach_for_modeling_salt_precipitation_in_porous-media.
15. Research on the Solubilities of Sodium Chloride and Sodium Sulfate Under Hydrothermal Conditions10.1007/s10953-020-01020-z ↗
16. Na+/Mg2+ interactions on membrane distillation permeation flux and crystallization performance during high saline solution treatment10.1016/j.seppur.2020.118191 ↗
17. Studies on solution crystallization of Na2SO4·10H2O embedded in porous polyurethane foam for thermal energy storage application10.1016/j.tca.2018.08.005 ↗
18. Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress10.1016/j.gca.2008.05.053 ↗
19. Integration of reverse osmosis and membrane crystallization for sodium sulphate recovery10.1016/j.cep.2014.08.003 ↗
20. Thermodynamics of crystallization of sodium sulfate decahydrate in H2O–NaCl–Na2SO4: Application to Na2SO4·10H2O-based latent heat storage materials10.1016/S0040-6031(99)00331-7 ↗
21. Temperature-dependent solubility transition of Na2SO4 in water and the effect of NaCl therein: Solution structures and salt water dynamics10.1021/jp507949h ↗
22. Tsai, J.-H., Perrotta, M.L., Gugliuzza, A., Macedonio, F., Giorno, L., Drioli, E., Tung, K.-L., and Tocci, E. (2018). Membrane-Assisted Crystallization: A Molecular View of NaCl Nucleation and Growth. Appl. Sci., 8.10.3390/app8112145 ↗
23. Influence of Feed Composition on Distillate Flux and Membrane Fouling in Direct Contact Membrane Distillation10.1080/01496391003666908 ↗
24. Concentration polarization and fouling10.1016/S0011-9164(00)88604-X ↗
25. Study of polarization phenomena in membrane distillation of aqueous salt solutions10.1081/SS-100100237 ↗
26. Crystallization Behavior and Damage Potential of Na2SO4–NaCl Mixtures in Porous Building Materials10.1021/acs.cgd.0c00671 ↗
27. Experimental and theoretical evaluation of temperature polarization phenomenon in direct contact membrane distillation10.1016/j.cherd.2013.06.030 ↗
28. How does sodium sulfate crystallize? Implications for the decay and testing of building materials10.1016/S0008-8846(00)00381-1 ↗
29. In situ Raman observation of the crystallization in NaNO3-Na2SO4-H2O solution droplets10.1007/s12665-012-1997-0 ↗
30. Bergaya, F., Theng, B.K.G., and Lagaly, G. (2006). Surface and interface chemistry of clay minerals. Developments in Clay Science, Elsevier.
31. Worsfold, P., Townshend, A., Poole, C.F., and Miró, M. (2019). Encyclopedia of Analytical Science, Elsevier. [3rd ed.].
32. FTIR Spectroscopy of the Atmosphere. I. Principles and Methods10.1081/ASR-200030192 ↗
33. Chemical interaction between PVDF and Li cations during LiCl crystallization in VMCr10.1016/j.memsci.2022.120733 ↗