Powdered phosphate can be added to help with scale control. Powdered activated carbon consists of fine mesh activated carbon. Because it is a fine powder, it must be bound in place by paper or plastic binders to be used. With its large surface area to mass ratio, it can be effective in reducing a wide variety of organic impurities, including solvents, pesticides, and herbicides. It can be combined with metals scavengers such as sodium aluminosilicate to reduce lead, cadmium, mercury, copper, and other heavy metals.
Some filters combine mechanical and chemical methods to reduce impurities.
Carbon block filters consist of finely powdered activated carbon combined with a plastic binder material and heated to form a hollow cylinder. The blocks may be further wrapped with various papers and netting to improve performance and reduce clogging. Cation exchange resin is sometimes used to give these filters metals reduction capabilities. Ceramic filters can be combined with granular activated carbon or even carbon blocks, by encasing the media inside the ceramic outer shell. Filter Styles Filters can be configured in many ways, depending on their specific application.