Reverse osmosis water purification and brine valorization in a Tunisian hemodialysis center

ABSTRACT

The technical–economic analysis of the hemodialysis water purification process, which uses reverse osmosis with sand, softeners, and granular-activated carbon as pretreatment steps, shows that the permeate conductivity exceeds 25 µS cm⁻¹ at 25°C due to softeners failure and that the cost of cubic meter of water produced is 2.4 €. The purification unit generated brine with a conductivity above 5 mS.cm⁻¹ and it is discharged into the sewer. Several brine valorizations are proposed; brine recycling and simulation with IMS design software reveal that it is possible to recycle 0.2 m³.h⁻¹ of brine and achieve 83% conversion rate with a good quality of permeate. The residual of the first reverse osmosis brine is diluted by the second reverse osmosis permeate and is to be used for toilet flushing, landscape irrigation, and sterilization steam production.

KEYWORDS:

• HD water
• desalination
• tap water
• reverse osmosis
• brine valorization

Acknowledgments

The authors would like to thank the reviewer for their pertinent contribution in the correction of manuscript.

The authors are also grateful to the HD water production unit manager at Soliman HD center and Mr Karim for their help throughout the research project.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contribution

Hajer Chaaben is a PhD student. She carried out the experiment and wrote the main part of the paper and analyzed literature research works. Dr Hayet Cherif is a co-supervisor of the PhD student and contributed to the process simulation by IMS design, wrote a part of the paper, and reviewed the paper. Pr. Hamza Elfil is the main supervisor of the phD student. All authors read and approved the final manuscript.

Additional information

Funding

The authors certify that no funding has been received to carry out this study.