A critical review of the application of electromagnetic fields for scaling control in water systems: mechanisms, characterization, and operation

Abstract

Scale deposits in water systems often result in ample technical and economic problems. Conventional chemical treatments for scale control are expensive and may cause health concerns and ecological implications. Non-chemical water treatment technologies such as electromagnetic field (EMF) are attractive options so the use of scale inhibitors, anti-scalants, or other chemical involved processes can be avoided or minimized. Although there are demonstrated beneficial effects of EMF on scale control, the scientific basis for its purported effectiveness is not clear in the available literature, especially lack of quantitative assessment and systematic evaluation of the effectiveness of EMF technologies. This review aims to elucidate the factors pertaining to EMF water treatment and their anti-scaling effects. We have critically reviewed relevant literature on EMF scale control, in particular recent studies, in various water systems, including desalination membranes, heat exchangers (e.g., cooling towers), water pipes, and bulk solutions. We systematically studied the impacts of operational conditions on EMF efficacy, and quantitatively evaluated the EMF improvement on scaling control. The scaling prevention mechanisms, conventional and cutting-edge characterization methods, and potential real-time monitoring techniques are summarized and discussed. The economic benefits of EMF treatment in terms of chemicals, operation and maintenance costs are highlighted. This review provides guidelines for future EMF system design and points out the research needed to further enhance EMF treatment performance.