An apparatus for treating a mixture of fossil fuel and water includes a treatment unit for treating the mixture and including an inlet for the mixture, an outlet for discharging a treated mixture of fossil fuel and water, and an assembly of tubes of a non-magnetic material, the tubes having a circular cross-section, and the assembly arranged between the inlet and the outlet, the tubes have different diameters, have substantially equal lengths, are arranged in length alignment, and are arranged concentrically with the tubes defining intermediary spaces, thus providing flow paths for the mixture between the inlet to the outlet, an innermost and outermost tube being electrically connected to an electrical current generator, for supplying a pulsed current with the innermost tube connected to a positive pole and the outermost tube connected to a negative pole to expose the mixture flowing through the intermediary spaces to an electromagnetic field.