The invention provides compositions for purification of fluids such as water and air. In particular the invention provides a mixture of a chlorhexidine substance, a calcium phosphate compound, a carbon material and sand. The mixed compositions may be provided in the form of loose particles that optionally contain a binder that swells in the presence of a fluid to be filtered. The compositions avoid the need for pre-formation of filter cartridges and may be used in a variety of water purification devices without further adaptation. The compositions also enable rapid, economical generation of purified fluids that are essentially free of chlorhexidine. The invention can be used for either high volume applications or disposable single-use applications.
