A method of delivering a treatment substance to a target substance in a treatment zone is disclosed. The method comprises providing a treatment substance responsive to an electric or magnetic field such that the treatment substance experiences a kinetic force when disposed in said field, providing an electric or magnetic field extending through a treatment zone, and disposing the treatment substance in the electric or magnetic field such that the treatment substance moves towards the treatment zone and contributes to a reaction with the target substance. A corresponding system is also disclosed.