Glossary of Terms

Activated Carbon: A granular material normally produced by heating wood or coconut shells in the absence of air. Used to remove taste, odours & many chemicals from water.
Deionation: Removal of both in-organic & organic ionized minerals & salts from water by a two-phase ion exchange method.
Demineralization: Removal of in-organic ionized minerals & salts by process similar to deionation.
Disinfection: A process in which pathogens (bacteria) are killed by chlorination, UV light, boiling, etc.
EPCB: Extended Pass Carbon Block. This filter is made from a porous carbon block and provides microfiltration (0.5 microns) for cyst removal as well as many chemicals.
Hardness: A characteristic of natural water due to the presence of dissolved calcium & magnesium; hard water gives rise to scale formation & reacts with soap.
Litre: Basic metric unit of volume; one litre of water weighs 1000 grams.
Micron: A linear measure equal to one millionth of a meter.
Ozone: An unstable form of oxygen (O3). It is a strong oxidizing agent and used as a water disinfectant.
PPM: Parts Per Million. Indicates the number of parts by weight of a dissolved or suspended contaminant per million parts by weight of water.
Permanent Hardness: Water hardness due to presence of chlorides and sulphates of calcium & magnesium which will not be precipitated by boiling.
Reverse Osmosis: A process that reverses by application of pressure the flow of water through a semi-permeable membrane, so that it passes from the more concentrated side to the more dilute side.
SD: This term refers to a sediment removal cartridge filter for removal of suspended solids like sand, dirt, and rust.
Soft Water: Water, which contains less than 17.1 mg/L of hardness minerals.
Sterilization: A process in which all living organisms are destroyed.
Turbidity: A measure of finely divided suspended matter in water that causes the scattering and adsorption of the light rays, making the water look cloudy.
Ultraviolet Light: That band of the electromagnetic spectrum where disinfection takes place. Usually the 254nm band output given by the UV lamp.
UV Lamp: A low-pressure Mercury vapour lamp giving 254nm wavelength suitable for UV disinfection.