– Any of the compounds whose chemical structure is based on carbon (e.g. carbon dioxide, wood, sugar, protein, plastics, methane, THM, TCE, etc.).
– The pressure created by the tendency of water to flow in osmosis. Every 100 ppm of TDS generates about 1 pound per square inch (psi) of osmotic pressure. This osmotic pressure must first be overcome by the water pressure for the reverse osmosis membrane to be effective.
– An unstable form of oxygen occurring naturally in the upper atmosphere or artificially produced because of its strong oxidizing or disinfection characteristics.
– As used in industry standards, the size of a particle suspended in water as determined by its smallest dimension, usually expressed in microns.
Parts per Million (ppm)
– A common basis for reporting the results of water waste water analysis, indicating the number of parts by weight of water or other solvent. In dilute water solutions, on part per million is practically equal to one milligram per liter, which is the preferred unit. 17.12 ppm equals one grain per U.S. gallon.
– An organism which may cause disease.
PCB (Polychlorinated Biphenyls)
– A highly toxic organic contaminant found in water supplies which is suspected of causing cancer in humans.
– or the potential of hydrogen ion activity or concentration. pH is a measure of the intensity of the acidity or alkalinity of water on a scale from 0 to 14, with 7 being neutral. When acidity is increased, the hydrogen ion concentration increases, resulting in a lower pH value. Similarly, when alkalinity is increased, the hydrogen ion concentration decreases, resulting in higher pH. The pH value is an exponential function so that pH 10 is 10 times as alkaline as pH 9 and 100 times as alkaline as pH 8. Similarly, a pH 4 is 100 times as acid as pH 6 and 1000 times as acid as pH 7.
Potassium Chloride (KCI)
– a compound consisting of potassium and chloride, becoming increasingly popular as a substitute for sodium chloride in regenerating water softeners.
Potassium Permanganate (KMnO4)
– A powerful oxidizing agent consisting of dark purple crystals with blue metallic sheen. Explosive in contact with sulfuric acid or hydrogen peroxide. Increases flammability of combustible materials. Used to renew the black manganese oxide coating on greensand media.
– To cause a dissolved substance to form a solid particle which can be removed by settling or filtering such as in the removal of dissolved iron by oxidation, precipitation and filtration. The term is also used to refer to the solid formed and the condensation of water in the atmosphere to form rain or snow.
– Whatever alterations of the raw feed water are required to prevent damage to the reverse osmosis membrane.
– The pure water that has been separated from the feed water stream by the reverse osmosis membrane.
– The amount of actual water that can be drawn from a pressure system expressed in gallons per minute (gpm) obtained by dividing the drawdown (gallons) by the cycle time (seconds) and multiplying the result by 60 (seconds).
– A high grade of glass made using quartz sand.
– Untreated water or any water before it reaches a specific water treatment device or process.
– The amount of product water as compared with the total amount of feed water. This will give a measure of the efficiency of operation. For example, starting with 10 gallons of feed water, if 6 gallons is product water and 4 gallons reject water, the recovery is 60%.
– A solution of a chemical used to restore the capacity of an ion exchange or oxidation system.
– In general, includes the backwash, brine and fresh water rinse steps necessary to prepare a water softener exchange bed for service after exhaustion. Specifically, the term may be applied to the “brine” step in which the sodium chloride solution is passed through the exchanger bed. The term may also be used for similar operations relating to demineralizers and certain filters.
– The percentage of TDS removed from the feed water. Typically greater than 90% rejection is achieved with reverse osmosis.
Reject Water (same as Brine)
– That portion of the feed water that does not pass through the R.O. membrane and which carries the remaining impurities to the drain.
– Chlorine remaining in a treated water after a specified period of contact time to provide protection throughout a distribution system. The difference between the total chlorine added and that consumed by oxidizable matter.
– Synthetic organic ion exchange material such as the high capacity cation exchange resin widely use in water softeners.
Reverse Osmosis (R.O.)
– A process that reverses, by the application of pressure, the flow of water in the natural process of osmosis so that the water passes from the more concentrated to the more dilute solution through a semi-permeable membrane.
– The sum of particles of dirt, clay, silt and vegetation which float or are suspended in water and can be removed by mechanical filtration. See Turbidity.
– A term which applies to special materials, both natural and synthetic, which allow certain substances such as water to pass through (to permeate) while blocking or rejecting the passage of other substances such as dissolved solids and organics.
Service (Peak) Flow Rate
– The greatest amount of water (expressed in gallons per minute) that a particular filter can effectively process based on short pump runs of less than 10 to 15 minutes maximum.
– A chemical reaction in which certain ions are bound into a stable, water soluble compound, thus preventing undesirable action the ions.
– One of a class of chemical compounds which possesses cleaning properties, formed by the reaction of a fatty acid with a base of alkali. Sodium and potassium soaps are soluble and useful but can be converted to insoluble calcium and magnesium soaps (curd) by the presence of these hardness ions in water.
– The common name for sodium carbonate, a chemical compound used as an alkaline builder in some soap and detergent formulations to neutralize acid water and in the lime soda ash water conditioning process.
– The sum of all hardness constituents in a water, expressed as their equivalent concentration of calcium carbonate. Primarily due to calcium and magnesium in solution but may include small amounts of metals, such as iron, which can act like calcium and magnesium in certain reactions (see Hardness).
– Having an adverse physiological effect on man.
– Elemental metals that find their way into water supplies from natural and industrial sources and which are detrimental to human health (e.g. lead, cadmium, mercury, arsenic).
– Carbon-based chemicals which are frequently found in our water supplies and are harmful to human health. They are usually from agricultural and industrial effluents and hazardous waste dumps (e.g. TCE, PCB, DCBP, pesticides, etc.).
– Suspended biological, inorganic and organic particles in water which may be in sufficient amount to make the water seem cloudy (see Sediment).
– The smallest form of life know to be capable of producing disease of infection, usually considered to be of large molecular size. They multiply by assembly of component fragments in living cells, rather than by cell division as do most bacteria.
Volatile Organic Chemical (VOC)
– Chemicals or compounds with boiling points below 212ºF, facilitating their evaporation before water.
– The removal of calcium and magnesium, the ions which are the principal cause of hardness, from water.