Removal of Escherichia coli via low frequency electromagnetic field in riverbank filtration system.

Abstract

The removal of Escherichia coli (E. coli) via low frequency of electromagnetic field (LF-EMF) with different magnetic field was studied. LF-EMF is known as a high magnetic susceptibility method, which could affect E. coli growth without the usage of chemicals. The aim of this study was to investigate the removal of E. coli by using LF-EMF in water abstraction for the riverbank filtration (RBF) application. The effect of LF-EMF with the intensity of 2 to 10mT and 50Hz on coiled column of 1mm copper wire at 1 to 6 hours was assessed. The removal of E. coli after exposing to LF-EMF on the column model was measured using most probable number (MPN/100mL) and colonies forming unit (CFU/100mL) methods. Water flows into the column were varied up to 6 hours and with flowrate of 100 mL/min. Experimental results demonstrate that 100% of E. coli was removed at 8mT after 6 hours exposure. The magnetic field at 10mT removed 100% of E. coli after 4 hours exposure. The results obtained in this study proved that the LF-EMF was efficient in E. coli removal from RBF system. These finding indicated that the LF-EMF intensities and time of exposure can affect the removal of E. coli.