Effect of magnetic field on scale removal in drinking water pipeline

Abstract

The presence of scale in drinking water pipeline causes economical and environmental problems. It caused the corrosion of water pipeline, affected the water pressure and distribution system. Magnetic field was proposed as a physical treatment method on scale prevention. However, there is minimal study regarding the removal of scale drinking water pipeline. This study also developed the magnetic devices with different magnetic flux orientation to determine the effect on scale removal, by determining the concentrations of Ca2+ and Mg2+ in the water. Several parameters were investigated for preliminary tests, which were pH, turbidity and total suspended solids. In preliminary test, three different of magnetic flux density were conducted in the experiment, which were 0.120 Tesla, 0.050 Tesla and 0.025 Tesla. The treatment system without magnetic field acted as control sample. After the preliminary test, two self-designed magnetic devices with the magnetic flux density of 0.4 Tesla, 0.3 Tesla and 0.1 Tesla were developed. Three different flow rates of 1.0 mL/s, 1.3 mL/s and 1.5 mL/s were studied throughout the experiments. The systems conducted in a circulation flow system. Magnetic field reduced turbidity and TSS of water sample around 50% and 20% respectively. In the outlet of water sample of the system with magnetic field, the concentration of Ca2+ and Mg2+ were 90% and 20% higher than the system without magnetic field. Besides, with flow rates of 1.5 mL/s, the self-designed inverted magnetic devices showed the concentration of Ca2+ and Mg2+ of 13.45 mg/L and 4.91 mg/L respectively in the outlet of water sample. Its concentration was 40% higher than non-inverted magnet devices. The non-inverted magnetic devices were detected the concentration of Ca2+ and Mg2+ of 9.51 mg/L and 2.57 mg/L respectively. Compared between different magnetic flux density, 0.4 Tesla inverted magnetic devices removed Ca2+ and Mg2+, which were 40% higher than 0.1 Tesla and 0.3 Tesla inverted magnetic devices with the flow rates of 1.5 mL/s. Investigation of the effect of flow rates, 1.5 mL/s showed higher concentration of Ca2+ and Mg2+ in effluent of water sample compared with 1.0 mL/s and 1.3 mL/s. It can be concluded that the presence of magnetic field reduced the turbidity and TSS of water sample. It also enhances the removal of scale in drinking water pipelines. With higher magnetic flux density and higher flow rates, the removal of scale from the drinking water pipeline is higher.