Glossary of Terms

Glossary of Terms - F

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A laundry additive that gives fabrics a soft feel and smooth surface, reduces static electricity and wrinkling, and makes ironing easier. Most fabric softeners are designed for addition to the wash, rinse, or drying cycles. Wash- and rinse-added types are liquids; dryer-added fabric softeners come as sprays, impregnated tear-off sheets, and impregnated foam (porous) sheets, or as a slow-dispensing solid bar that attaches to the fin of a dryer. The softening agent most commonly used is a cationic quaternary ammonium compound. A fluorescent whitening agent or bluing is frequently included, as well as fragrance. Infrequently, antimicrobial ingredients are added. Fabric softening ingredients also are incorporated in some laundry detergent products.
Free Available (residual) Chlorine
Facultative microbes can use either molecular (dissolved) oxygen or oxygen obtained from food material such as sulfate or nitrate ions. In other words, facultative organisms can live under aerobic or anaerobic conditions.
A temperature scale in which water freezes at 32 degrees and boils at 212 degrees at atmospheric pressure. See Also: Atomic Absorption Spectroscopy Induced Infiltration Spectroscopy
A rinse process in which the rinse water is applied to the softener bed at the end of brine regeneration at a faster rate of flow than that for which the brine was applied. Because of the greater density of the brine, it moves down through the bed in a piston-like fashion. If rinsing were to continue at this rate until the chlorides had dropped to the acceptable level at which the unit could be returned to service, the time required would be excessive. After the higher concentrations of brine have passed from the unit, little is gained by prolonging the rinse time. The rinse rate during the last few minutes is increased approximately fivefold to complete the rinse cycle. This fast rinse quickly removes the last traces of chlorides and significantly reduces the regeneration time.
The principal components in the molecular structure of natural fats, vegetable oils, fish oils, waxes, rosin, and essential oils, where they are bound chemically with glycerin; this combination is termed a glyceride.
Primary alcohols from C6 to C22, usually straight chain, which is the type used by the detergent industry.
Bacteria found in the intestinal tracts of mammals and, therefore in, fecal matter. Their presence in water or sludge is an indicator of pollution and possible contamination by pathogens.
Matter (feces) containing or derived from animal or human bodily wastes that are discharged through the anus.
Streptococcus bacteria found in fecal matter
The pressure at which water is supplied to a water treatment device.
An ultrafiltration term borrowed from old-fashioned boiler operators. When applied to an ultrafilter design, it means multiple stages of ultrafilter units where the feedwater is controlled at a rate equal to the permeate plus concentrate flow rates and the reject water from the initial ultrafiltration stages is recirculated to subsequent stages.
The circulating action between a sensor measuring a process variable and the controller which controls or adjusts the process variable.
The water to be treated that is fed into a given water treatment system.
The conversion/breakdown of organic matter by anaerobic bacteria into carbon dioxide, methane, and similar compounds of low-molecular weight.
Small solid iron particles containing trivalent iron, usually as gelatinous ferric hydroxide [Fe(OH)3] or ferric oxide (Fe2O3), which are suspended in water and visible as "rusty water." Ferric iron can normally be removed by filtration. Also called precipitated iron.
A divalent iron ion, usually as ferrous bicarbonate [Fe(HCO3)2] which, when dissolved in water, produces a clear solution. It is usually removed by cation exchange water softening. Also called clear water iron.
A law of chemistry and physics: the rate of diffusion of one substance in another is proportional to the negative gradient of the concentration of the first substance.
See Water Spotting
Specifically, a device or system for the removal of solid particles (suspended solids); in general, includes mechanical, adsorptive, oxidizing and neutralizing filters. (Nonhealth related.)
An agent (such as diatomite) that improves filtering effectiveness in some way, such as enhancing the retention of particles or increasing the permeability of the filter to water flow. A filter aid is either added to the suspensions to be filtered or placed on the filter as a layer through which the liquid must pass.
The effective area through which water approaches the filter media often expressed in square feet. Also referred to as surface area.
1. Solids deposited on top of a filter media bed, often by use of chemically feeding a coagulant or filter aid. 2. The dewatered residue from a filter, centrifuge, or other dewatering device.
(See Media)
(See Micron Rating)
The trade name for an aluminum silicate (pumicite) granular product used as a general purpose filter medium.
The effluent liquid which has passed through any style filter.
The process of separating solids from a liquid by means of a porous substance such as a permeable fabric or membrane or layers of inert media.
Extremely small particles of filter media or ion exchange material formed either in the manufacturing process or as a result of breakdown: undesireable in most systems because of high pressure drop.
Product water as it leaves the municipal treatment plant for delivery to consumers. When it arrives at the point-of-use, it has become delivered water. Also called product water.
The water that immediately comes out when a tap is first opened. This water is likely to have the highest level of lead contamination from plumbing materials.
A one-liter sample of tap water, collected in accordance with CFR Section 141.86(b)(2), that has been standing in plumbing pipes at least six hours and is collected without flushing the tap.
As relates to biology, reproduction by cell division.
A sample is fixed in the field by adding chemicals that prevent the water quality indicators of interest in the sample from changing before final measurements are performed later in the lab.
1. The filter or ion exchange medium retained in a vessel. 2. Also refers to media beds which are "contained". That is, filled to the top or to the restraining barrier with filter media and not capable of being expanded during backwashing.
The residue (particulate and/or dissolved material) that remains behind (immovable or fixed) despite action to expel it, such as the residue remaining after heating or burning a substance to drive off the volatile solids. See Also: Fixed Solids Volatile Solids Dissolved Solids Residue Fixed Solids Volatile Solids
The term used in the laboratory analysis of the solid's content of water to define the residue of total suspended and/or dissolved solids after ignition (burning) or heating for a specified time at a specified temperature. See Also: Fixed Matter Volatile Solids Dissolved Solids Residue Fixed Matter Volatile Solids
As relates to plumbing, any permanently-installed receptacle that will hold water, such as a sink, lavatory, or water closet (toilet).
A count of the total number of plumbing fixtures (or water outlets) in a building. A fixture count is determined for the purpose of estimated peak flow rates and sizing equipment, especially for commercial or institutional buildings.
Microorganisms that move by the action of tail-like projections.
Melted by a flame to smooth out irregularities. Sharp or broken edges of glass (such as the end of a glass tube) are rotated in a flame until the edge melts slightly and becomes smooth.
The portion of a superheated fluid that is converted to vapor when its pressure is reduced as in flash distillation.
A distillation process in which hot incoming water flows into a chamber in which pressure is low, causing some of the water to flash (turn quickly into steam.)
As relates to water treatment, avery fine, fluffy-type mass formed by the coming together of a number of fine suspended particles. A floc can occur naturally, but most frequently it is induced by the addition of a coagulant/flocculent to raw water which contains undesirable turbidity or color. In wastewater treatment, a clump of solids formed in sewage by biological or chemical action.
A clump of solids formed in sewage by biological or chemical action.
The agglomeration of finely divided, suspended solids into larger, usually gelatinous, particles; the development of a "floc" after treatment with a coagulant by gentle stirring or mixing.
Materials which when added to water cause suspended particles to coagulate into larger groupings and form gelatinous clouds of precipitate which enclose additional fine particles of suspended dirt. The precipitate and the dirt can then be settled or filtered out of the water being treated.
The edge of a receptacle (such as a plumbing fixture) from which water will overflow.
A device designed to limit the flow of water or regenerant to a predetermined value over a broad range of inlet water pressures.
A cylindrical pressure-compensating valve installed to regulate the flow of water. Rated in gpm or gpd.
An in-line device or orifice fitting which will regulate and control flow of water or regenerant over a broad range of inlet water pressures. Some types are manually adjustable.
An instrument, mechanical or electronic, used for recording (in gallons, cubic feet, or cubic meters) the quantity of water passing through a particular pipe line or outlet. In water processing systems, meters may initiate certain functions such as automatically starting the regeneration cycle in an ion exchange system.
The quantity of water or regenerant which passes a given point in a specified unit of time, often expressed in gallons per minute.
A device that measures flow rate and can control or measure an action (such as chemical feed) in proportion to the flow rate of the fluid.
A device which, according to a preset flow rate condition, causes an action when the actual flow rate falls outside the preset limit(s).
A mass of solid particles that is made to flow like a liquid by injection of water or gas is said to have been fluidized. In water treatment, a bed of filter media is fluidized by backwashing water through the filter.
A medium bed which has become expanded during the backwash step or during "upflow" regeneration of an ion exchanger.
A raceway or channel constructed to carry water or to permit the measuring of its flow.
An orange-red compound that exhibits intense fluorescence in alkaline solutions and is used to dye water in order to trace its course and movement.
The addition of a fluoride compound to a potable water supply to produce the concentration desired for the reduction in incidence of dental caries.
A naturally-occurring constituent of some water supplies, an excess of which (over 2.0 ppm) can cause discolored teeth (mottling). Skeletal fluorosis, a serious crippling bone disorder resembling osteoporosis, can develop from many years of exposure to drinking water with more than 4.0 ppm of fluoride.
An abnormal condition caused by excessive intake of fluorine, characterized chiefly by mottling of the teeth.
1. To open a cold-water tap to clear out all the water which may have been sitting for a long time in the pipes. In new homes, to flush a system means to send large volumes of water gushing through the unused pipes to remove loose particles of solder and flux. 2. To force a cleansing liquid rapidly through piping, tubing, storage vessels, process tanks, or other plumbing items to clean them out.
The chamber of the toilet in which the water is stored for rapid release to flush the toilet. The size of the flush tank is to be accounted for in proper sizing of any plumbing system or water treatment system.
A self-closing valve used for flushing urinals and toilets in public buildings. This type of valve allows very high flow rates (15-20 gpm) for a few seconds.
In municipal water systems, a method used to clean water distribution lines. Hydrants are opened and water with a high velocity flows through the pipes, removes deposits from pipes, and flows out the hydrants.
In cross flow filtration, the flow rate of product water through a reverse osmosis, electrodialysis, or ultrafiltration membrane. The flow rate is usually given in terms of volume unit per time per membrane area, such as gallons per day per square foot or liters per hour per square meter.
See Lime (CaO)
The trade name for a patented medium composed of high purity copper and zinc granules. KDF is capable of removing chlorine, soluble heavy metals, and other inorganic contaminants from water through the chemical reduction/oxidation (redox) process.
Free mineral acidity
A mass of bubbles formed on liquids by agitation.
A water softener valve, controlled by a float, which controls the amount of water entering or brine solution leaving the brine tank. A special type of check valve located at the bottom end of the suction pipe on a pump. This valve opens when the pump operates to allow water to enter the suction pipe but closes when the pump shuts off to prevent water from flowing out of the suction pipe.
A tall column wherein water is sprayed downward through an upward flow of air for the purpose of removing gases such as carbon dioxide after the decationization unit in a deionization plant.
Formic aldehyde methanol, HCHO3, made by oxidation of synthetic methanol or low-boiling petroleum gases such as propane or butane. Available commercially as a 37-50 percent aqueous solution which may contain up to 15 percent methanol to inhibit polymerization. Commercial grades are called formalin. An effective preservative, disinfectant, and sanitizing agent, although it is not a sterilizer, because formaldehyde does not kill completely all microorganisms. Is not typically used to sanitize drinking water treatment equipment because of personal hazards associated with it i.e., toxic by inhalation, strong irritant, and a carcinogen.
Commercial grades of formaldehyde.
A group of similar consolidation (that is, relatively solid) rocks of unconsolidated (that is, relatively loose) minerals.
The process in which undesirable foreign matter accumulates in a bed of filter media or ion exchanger, clogging pores and coating surfaces and thus inhibiting or retarding the proper operation of the bed.
Feet (foot) per second
To separate into fractions or parts.
The regenerated form of a weak acid cation exchanger. See Also: Free Base Form Chelation Chelating Agent Organic Iron Humic Substances Weak Acid Cation Exchangers Total Acidity Strong Acid Cation Exchanger Ion Exchange Hot Process Softening Hydraulic Classification Validation Thermal Stratification Stratification Stratified Bed Cation Exchange Resin Cation Exchange Resin Resin Free Base Form
The concentration of residual chlorine present as dissolved gas, hypochlorous acid, or hypochlorite not combined with ammonia or in other less readily available form.
The regenerated form of a weak basic anion exchanger. See Also: Free Acid Form Alkali Noble Metal Weak Base Anion Exchangers Ion Exchange Cation Exchange Resin Cation Exchange Resin Resin Free Acid Form
Carbon dioxide (CO2) present in water as the gas or as carbonic acid, but not that combined in carbonates or bicarbonates.
(See Free Available Chlorine)
The application of chlorine to water to produce a free available chlorine residual equal to at least 80 percent of the total residual chlorine (sum of free and combined available chlorine residual).
The vertical distance between a bed of filter media or ion exchange material and the overflow or collector for backwash water; the height above the bed of granular media available for bed expansion during backwashing: may be expressed either as a linear distance or a percentage of bed depth.
Water having less than approximately 1,000 mg/L (ppm) of total dissolved solids (TDS).
An expression of the ability of ion exchange beads to resist cracking under hydrostatic operation.
The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, and restrictions caused by fittings. Water flowing in a pipe loses pressure or energy as a result of friction losses. See Also: Pressure Drop Static Pressure Pressure Drop
A clayish substance of hydrous aluminum silicate used as a filter aid in coagulation.
A water-soluble, natural organic substance of low molecular weight which is derived from humus often found in surface water. Fulvic acid contributes to the formation of trihalomethanes in chlorinated water supplies and can contribute to organic fouling of ion exchange resin beds. Fulvic acids are chelating agents that can bind and hold metal ions in solution, and are particularily involved in the solubilization and transport of iron in water. Fulvic acid compounds are associated with color in water. These yellow-brown materials frequently are encountered along with soluble iron. See Also: Chelation Chelating Agent Organic Iron Trihalomethanes (THMs) Humic Acid Humic Substances Humin Tannin Chelation Chelating Agent Organic Iron Trihalomethanes (THMs) Humic Acid Humin Tannin Humic Substances
See Exchange Sites
(singular = fungus) Mushrooms, molds, mildews, rusts, and smuts that are small nonchlorophyll-bearing plantlike organisms lacking roots, stems, and leaves. They have distinct nuclei surrounded by nuclear membranes as well as other specialized functional cell parts but cannot carry on photosynthesis. They occur in natural waters and grow best in the absence of light. Their decomposition may cause objectionable tastes and odors in water.