Effect of magnetic field on calcium carbonate precipitated in natural waters with prevalent temporary hardness

[Display omitted] •MWT determines different characteristics of the CaCO3 precipitates obtained at different temperatures.•Increasing water hardness values require the optimization of a series of parameters to make the MWT effective.•The magnetization memory of the water has been also detected. This work evaluates the magnetic treatment efficacy of natural water classifiable between middle hard to very hard water. For this purpose, the effects of the magnetic water treatment (MWT) were studied on the characteristics of the calcium carbonate precipitates, detected in the bulk of the water and on the surfaces in contact with water. In particular MWT leads to an increase of the mass of the bulk precipitate and to a reduction of the mass of surface deposits (of the order of 60 and 40 % for water with medium and high hardness) compared to those detected for non-magnetized water. In addition, the positive effect of MWT was also verified after 14 days. From the set of experimental results it is evident that each water with certain chemical-physical characteristics requires the optimization of a series of parameters designed to reduce the mass of the deposited carbonate and to increase the size of the calcite crystals, characteristics that allow easy removal of calcite from surfaces.