Mitigation of biofouling using electromagnetic fields in tubular heat exchangers–condensers cooled by seawater

Abstract

Electromagnetic field (EMF) treatment is presented as an alternative physical treatment for the mitigation of biofouling adhered to the tubes of a heat exchanger-condenser cooled by seawater. During an experimental phase, a fouling biofilm was allowed to grow until experimental variables indicated that its growth had stabilised. Subsequently, EMF treatment was applied to seawater to eliminate the biofilm and to maintain the achieved cleanliness. The results showed that EMFs precipitated ions dissolved in the seawater. As a consequence of the application of EMFs, erosion altered the intermolecular bonding of extracellular polymers, causing the destruction of the biofilm matrix and its detachment from the inner surface of the heat exchanger-condenser tubes. This detachment led to the partial removal of a mature biofilm and a partial recovery of the efficiency lost in the heat transfer process by using a physical treatment that is harmless to the marine environment.

Hydraulic continuity and biological effects of low strength very low frequency electromagnetic waves: Case of microbial biofilm growth in water treatment

“…Changing from classical to corpuscular quantum physics does not alter this interpretation because the electromagnetic field in the first quantization is treated according to Maxwell's equations, implying continuous waves and not as quantized photons. Previous literature (Trueba et al, 2014;Cellini et al, 2008;Chua and Yea, 2005;Del re et al, 2004) reveals a sensitivity of living organisms to very weak electromagnetic fields. One has to consider how liquid water would react to a quantized virtual electromagnetic field known to be present in the vacuum generated through H-bonding between water molecules Del Guidice et al, 2010).…”

“…These cations mediate the formation and/or stabilization of the exopolymeric substances matrix network (Tsuneda et al, 2003). In water treated with electromagnetic fields Ca 2þ and Mg 2þ concentrations decrease due to nucleation of ionic calcium or magnesium and their precipitation into calcium or magnesium carbonates (Shahryari and Pakshir, 2008) could influence biofilm growth by acting on the exopolymeric matrix (Trueba et al, 2014). However, no conductivity change was observed between treated and untreated lines in this experiment and ionic strength was approximately 6.2 mM, with 2.4 mM for Ca 2þ and Mg 2þ .…”

“…To the best of our knowledge excluding the work of Trueba et al (2014), the only studies published on the effects of EMFs on biofilms concern extremely low frequency EMF. Although VLF electromagnetic waves are slightly more energetic than extremely low frequencies (ELF) electromagnetic waves, the nature of observed non-thermal effects could be similar to ELF electromagnetic waves.…”

“…A decrease in biofilm has been empirically noted after electromagnetic treatment of limescale formation in water supply lines of poultry farms and irrigation systems using VLF electromagnetic commercial systems. Treatment of seawater with the same electromagnetic system enabled the partial removal of a mature biofilm adhering to the inner surfaces of the tubes of a heat exchanger-condenser (Trueba et al, 2014). Therefore, it is interesting to investigate the effect of VLF-EMF on biofilm formation in water, through a multidisciplinary approach, under controlled conditions.…”

The effect of electromagnetic fields on biofouling in a heat exchange system using seawater

“…Trueba et al (2014) reported the mitigation of a mature biofilm formed on the internal surfaces of tubes in a heat exchanger-condenser that used seawater as the refrigerant fluid.…”