Impact of Electromagnetic Fields on Gypsum and Silica Scaling in Reverse Osmosis

Journal Article · Sun Jun 01 00:00:00 EDT 2025 · Environmental Science & Technology

DOI:https://doi.org/10.1021/acs.est.4c14658· OSTI ID:2572172

Du, Xuewei ^[1]; Ahasan, Tarek ^[2]; Perera, Helani ^[2]; Jianga, Wenbin ^[1]; Wang, Yanxing ^[1]; Shu, Fangjun ^[1]; Wang, Huiyao ^[1]; Yuan, Ke ^[3]; Anovitz, Lawrence {Larry} M ^[3]; Ishai, Paul ben ^[4]; Xu, Pei ^[1]

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1. New Mexico State University, Las Cruces
2. New Mexico State University, Civil Engineering Department
3. ORNL
4. Hebrew University of Jerusalem, Israel

Electromagnetic field (EMF) is a cost-effective, simple, and energy-efficient method for scale control in reverse osmosis (RO) systems. However, its effects on gypsum and silica scaling, as well as the underlying mechanisms, remain poorly understood. This study systematically investigates the effects of EMF treatment on gypsum and silica scaling in RO systems, utilizing synthetic brackish water and natural RO concentrate (ROC) from a desalination facility. For gypsum, EMF changes the crystal morphology, resulting in the formation of a porous, less compact scaling layer. It is more readily removed through hydraulic flushing (HF), enhancing scaling reversibility and water recovery. In the case of silica scaling, EMF promotes homogeneous polymerization in the bulk solution, producing larger silica particles that inhibit the formation of a dense, cross-linked gel layer on the membrane surface, mitigating flux decline. This study thus demonstrates EMF’s effectiveness in controlling gypsum scaling in undersaturated feedwaters when combined with HF and in mitigating silica scaling under both HF and non-HF conditions for supersaturated feedwaters. These findings underscore EMF’s versatility as a nonchemical approach for scale control in RO desalination and show its substantial potential to enhance membrane performance and operational efficiency in real-world water treatment applications.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 2572172
• Journal Information: Environmental Science & Technology, Journal Name: Environmental Science & Technology Journal Issue: 23 Vol. 59
• Country of Publication: United States
• Language: English