Applied Chemical Engineering

Multi-cycle regeneration of cation and anion exchange resins in a continuous-flow water treatment system

Thulfuqar A. Jawad

Chemical engineering department, Collage of engineering, Babylon university, Babylon City, 51002, Iraq

Sata K. Ahmed Ajjam

Chemical engineering department, Collage of engineering, Babylon university, Babylon City, 51002, Iraq

DOI: https://doi.org/10.59429/ace.v8i3.5707

Keywords: regeneration of resin; ion exchange; lead removal; nitrate removal; purelite C100 resin regeneration; resinex™️ NR-1 resin regeneration; water purification; continuous flow

---

Abstract

This study evaluates the regeneration performance and long-term operability of a continuous-flow, dual fixed-bed ion-exchange system for the simultaneous removal of lead (Pb²⁺) and nitrate (NO₃⁻) from water. Two acrylic columns (total height 45 cm; internal diameter 3.0 cm), each packed with 40 g of resin, were operated in series at pH 7.0 ± 0.1: a strong-acid cation exchanger (Purelite C100) for Pb²⁺ and a strong-base anion exchanger (Resinex™ NR-1) for NO₃⁻. Packed-bed heights were 8.0 cm (≈56.6 mL) for the cation column and 9.0 cm (≈63.6 mL) for the anion column. A 12-run Box–Behnken design investigated inlet concentration (40–80 mg L⁻¹), temperature (25–60 °C), and flow rate (40–100 mL min⁻¹) before and after regeneration with 10% (w/w) NaCl. Under optimized conditions (≈43 °C; 60 mL min⁻¹; 40 mg L⁻¹), Cycle 1 removals were 82.5% (Pb²⁺) and 92.3% (NO₃⁻). After six regeneration cycles, removals declined moderately to 70.2% and 83.6%, respectively, indicating good reusability with a slower efficiency decay for the anion resin. Quadratic response-surface models fit the data well (adjusted R² = 0.973 for Pb²⁺; 0.999 for NO₃⁻); concentration and flow were dominant negative factors, while elevated temperature mitigated mass-transfer limitations. A 10% NaCl protocol is therefore an effective baseline for routine regeneration, with scope for further capacity retention via longer brine contact, occasional deep-clean steps, or tailored regenerant dosing.

---

References

[1]. A. Q. Jasim and S. K. Ajjam, “Removal of heavy metal ions from wastewater using ion exchange resin in a batch process with kinetic isotherm,” South African J. Chem. Eng., vol. 49, no. March, pp. 43–54, 2024, doi: 10.1016/j.sajce.2024.04.002.

[2]. N. M. Marin, M. Nita Lazar, M. Popa, T. Galaon, and L. F. Pascu, “Current Trends in Development and Use of Polymeric Ion-Exchange Resins in Wastewater Treatment,” Materials (Basel)., vol. 17, no. 23, pp. 1–19, 2024, doi: 10.3390/ma17235994.

[3]. M. S. Ummah, No 主観的健康感を中心とした在宅高齢者における 健康関連指標に関する共分散構造分析Title, vol. 11, no. 1. 2019. [Online]. Available: http://scioteca.caf.com/bitstream/handle/123456789/1091/RED2017-Eng-8ene.pdf?sequence=12&isAllowed=y%0Ahttp://dx.doi.org/10.1016/j.regsciurbeco.2008.06.005%0Ahttps://www.researchgate.net/publication/305320484_SISTEM_PEMBETUNGAN_TERPUSAT_STRATEGI_MELESTARI

[4]. R. Adolph, “済無No Title No Title No Title,” pp. 1–23, 2016.

[5]. S. K. Sharma and R. Sanghi, Advances in water treatment and pollution prevention, vol. 9789400742. 2012. doi: 10.1007/978-94-007-4204-8.

[6]. C. Charcosset, “Classical and Recent Developments of Membrane Processes for Desalination and Natural Water Treatment,” Membranes (Basel)., vol. 12, no. 3, pp. 1–28, 2022, doi: 10.3390/membranes12030267.

[7]. J. B. de Heredia, J. R. Domínguez, Y. Cano, and I. Jiménez, “Nitrate removal from groundwater using Amberlite IRN-78: Modelling the system,” Appl. Surf. Sci., vol. 252, no. 17, pp. 6031–6035, 2006, doi: 10.1016/j.apsusc.2005.11.030.

[8]. M. J. McCoy, “Ion exchange,” Ultrapure Water, vol. 13, no. 1, pp. 20–31, 1996, doi: 10.1201/noe0824727857.ch185.

[9]. S. Kumar and S. Jain, “History, introduction, and kinetics of ion exchange materials,” J. Chem., vol. 2013, 2013, doi: 10.1155/2013/957647.

[10]. G. P. Ponnaiah, S. Lakshmi, A. B. L. S. Sivalingam, and S. Sivalingam, “A review of current practices on lead ions removal from different aqueous streams,” Brazilian J. Dev., vol. 10, no. 3, p. e68334, 2024, doi: 10.34117/bjdv10n3-062.

[11]. T. E. Bulletin, “Purolite C100 Sodium Cycle”.

[12]. P. D. Sheet, P. Applications, R. Approvals, T. Packaging, and T. Physical, “Purolite TM C100,” pp. 3–5, 2025.

[13]. T. Properties, T. Applications, S. D. Conditions, S. Packaging, and K. Features, “Resinex-RX-AP-Strong-base-anion-exchange-resin-Lenntech”.

[14]. LENNTECH, “Resinex NR-1,” 2014.

[15]. S. Al-Asheh and A. Aidan, “A Comprehensive Method of Ion Exchange Resins Regeneration and Its Optimization for Water Treatment,” Promis. Tech. Wastewater Treat. Water Qual. Assess., 2021, doi: 10.5772/intechopen.93429.

[16]. A. A. Hekmatzadeh, A. Karimi-Jashani, N. Talebbeydokhti, and B. Kløve, “Modeling of nitrate removal for ion exchange resin in batch and fixed bed experiments,” Desalination, vol. 284, pp. 22–31, 2012, doi: 10.1016/j.desal.2011.08.033.

[17]. K. J. H. and G. T. John C. Crittenden, R. Rhodes Trussell, David W. Hand, “Ion Exchange: MWH’s Water Treatment: Principles and Design, Third Edition John,” John Wiley Sons, Inc, 2012.

[18]. S. L. Gromov and A. A. Panteleev, “Counterflow ionite regeneration technologies for water treatment: Part 1,” Therm. Eng., vol. 53, no. 8, pp. 620–625, 2006, doi: 10.1134/S0040601506080076.

[19]. A. M. Wachinski, Environmental Ion Exchange: Principles and Design, Second Edition. 2016. doi: 10.1201/9781315368542.

[20]. R. B. Gauntlett, “Nitrate removal from water by ion exchange,” Water Treatm.Exam., vol. 24, no. 3 pt 3, pp. 172–193, 1AD, doi: 10.17508/cjfst.2017.9.2.15.

[21]. R. R. Yaragal and S. Mutnuri, “Nitrates removal using ion exchange resin: batch, continuous column and pilot-scale studies,” Int. J. Environ. Sci. Technol., vol. 20, no. 1, pp. 739–754, 2023, doi: 10.1007/s13762-021-03836-8.

[22]. A. Lalmi, K. E. Bouhidel, B. Sahraoui, and C. el H. Anfif, “Removal of lead from polluted waters using ion exchange resin with Ca(NO3)2 for elution,” Hydrometallurgy, vol. 178, no. 2017, pp. 287–293, 2018, doi: 10.1016/j.hydromet.2018.05.009.

[23]. Purolite, “Ion Exchange Resin Regeneration and Cleaning,” Purolite, [Online]. Available: https://www.purolite.com/index/core-technologies/industry/food-and-beverage/sugar-refining-applications/cane-sugar-production/ion-exchange-resin-regeneration-and-cleaning. [Accessed: 17-Aug-2025].

[24]. Veolia Water Technologies, “Chapter 08 – Ion Exchange,” Ion Exchange Handbook, [Online]. Available: https://www.watertechnologies.com/handbook/chapter-08-ion-exchange. [Accessed: 17-Aug-2025].

[25]. D. Carlson, “Resin Regeneration Fundamentals,” WaterWorld Magazine, 2018. [Online]. Available: https://www.waterworld.com/residential-commercial/article/14307808/resin-regeneration-fundamentals. [Accessed: 17-Aug-2025].

[26]. Wikipedia, “Ion Exchange,” Wikipedia, 2025. [Online]. Available: https://en.wikipedia.org/wiki/Ion_exchange. [Accessed: 17-Aug-2025].