There is provided a method for treating a fluid with an anti-microbial agent comprising the steps of: (a) contacting the fluid with a solid material containing an anti-microbial agent； and (b) abrading an interface of the solid material and removing particles therefrom and exposing an underlying surface of the solid material to the fluid thereby facilitating release of the antimicrobial agent of the underlying surface of the solid material and/or the removed particles into the fluid. The solid material comprises an anti-microbial agent dispersed and/or embedded in a solid carrier. Typically the anti-microbial agent is one or more of a metal metal oxide metal compound metal salt metal-ligand complex or derivatives thereof based on silver copper and zinc.
