Glossary of Terms - G
A :B :C :D :E :F :G :H :I :J :K :L :M :N :O :P :Q :R :S :T :U :V :W :X :Y :Z :
A very coarse grainy salt of "Ground Alum" size, which was formerly used for regenerating zeolite water softeners, sometimes used coincidentally with alum as a coagulant.
A genus of stalked, ribbon-like bacteria which utilize iron in their metabolism and cause staining, plugging, and odor problems in water systems. (See Iron Bacteria)
A common unit of liquid volume; the U.S. gallon has a volume of 231 cubic inches or 3.78533 liters; the British (Imperial) gallon has a volume of 277.418 cubic inches or 4.54596 liters.
A cell, consisting of dissimilar metals in contact with each other and with an electrolyte, which generates an electrical current.
A form of corrosion which occurs in a galvanic cell in which one of the metals dissolves and goes into solution. This form of corrosion is accelerated by high concentrations of dissolved minerals in water that increase electrical conductivity. Galvanic corrosion may occur if two pipes of dissimilar metals are joined directly--without the use of a pipe fitting designed to insulate different metals from one another and prevent such corrosion of the pipes. See Also: Reverse Osmosis
A list of metals and alloys presented in the order of their tendency to corrode (or go into solution). Also called the electromotive series. This is a practical application of the theoretical electrochemical series.
To coat a metal (especially iron or steel) with zinc. Galvanization is the process of coating a metal with zinc.
A group of hard, reddish, glassy, mineral sands made up of silicates of base metals (calcium, magnesium, iron, and manganese).
Garnet has a higher density than sand.
A chemical analytical instrument used to separate a sample into components during gas chromatography.
See Also: Chromatography Gas Chromatography (GC) Mass Spectrometry (MS) Chromatography Liquid Chromatography Gas Chromatography (GC) High Performance Liquid Chromatography (HPLC) Mass Spectrometry (MS)
Chromatography in which the sample mixture is vaporized and injected into a stream of carrier gas such as helium or nitrogen (mobile phase) which is moving through a column containing solid medium or medium coated with a relatively nonvolatile liquid (stationary phase).
The mobile phase sample is, thereby, separated into its component compounds according to the unique affinity of each compound for the stationary phase.
The components appear separately at the effluent end of the column where they can be detected and measured by density differences, thermal conductivity changes, or ionization detectors.
The detector gives a signal (in peak form) for each separated component compound; the intensity of the signal is proportional to the quantity of the compound injected, making it possible to provide a quantitative analysis by calibration.
See Also: Chromatography Liquid Chromatography Gas Chromatograph (GC) High Performance Liquid Chromatography (HPLC) Mass Spectrometry (MS) Chromatography Gas Chromatograph (GC) Mass Spectrometry (MS) Chromatography Liquid Chromatography Gas Chromatograph (GC) High Performance Liquid Chromatography (HPLC) Mass Spectrometry (MS) Contactor
An inflammation of the stomach and intestine resulting in diarrhea, with vomiting and cramps when irritation is excessive.
When caused by an infectious agent, it is often associated with fever.
A type of valve in which the closing element (the gate) is a disc that moves across the stream in a groove or slot for support against pressure.
A gate valve has relatively large full ports and a straight line flow pattern.
A gate valve creates very little pressure drop; this valve is, however, subject to leakage if the sealing surfaces are scored or marred or if debris becomes lodged in the groove.
A number that defines the thickness of the sheet used to make steel pipe.
The larger the number, the thinner the pipe wall.
The pressure within a closed container or pipe as measured with a gauge.
In contrast, absolute pressure is the sum of atmospheric pressure (14.7 lbs/sq in) PLUS pressure within a vessel (as measured by a gauge).
Most pressure gauges read in gauge pressure or psig (pounds per square inch gauge pressure).
See Also: Chlorination Liquid Chromatography Intermittent Flow Manganese Dioxide- Renalin Saturated Solution
Type of exposure in which a substance is administered to an animal through a stomach tube.
A "gellular resin" form of ion exchanger as opposed to macroporous exchangers.
Gel resin is typically cross-linked with eight percent divinylbenzene.
A synthetic sodium alumina silicate cation exchange product that was very widely used in residential water softeners prior to the development of DVB/styrene cation resin.
Also called siliceous gel zeolite.
A detailed description of all underground features discovered during the drilling of a well (depth, thickness, and type of formations).
A record of the structure and composition of the earth encountered when drilling a well or similar type of test hole or boring.
An ultraviolet light that peaks at a 2,537-angstrom wavelength and is in a wavelength that lies between 200 and 300 nanometers.
This is known as the germicidal or short-wave ultraviolet band.
A common waterborne protozoan that forms cysts and is resistant to disinfectants such as chlorine and ultraviolet light.
Giardia can be removed by filters that capture all particles of four microns and greater in size.
See Also: Cyst Beaver Fever Giardia Lamblia Oocyst Cyst Beaver Fever
Flagellate protozoan which is shed during its cyst stage into the feces of man and animals.
When water containing these cysts is ingested, the protozoan causes a severe gastrointestinal disease called giardiasis.
See Also: Cyst Beaver Fever Giardia Oocyst
Intestinal disease caused by an infestation of Giardia flagellates.
An anhydrous sodium sulfate (Na2SO4 10H2O) salt compound.
A natural dull-green iron potassium silicate mineral occurring abundantly in greensand.
The approximate formula for glauconite is K15(Fe, Mg, Al)4-6(Si,Al)3O20(OH)4.
A type of valve in which the closing element is a segment of a sphere or a flat or rounded gasket which is moved into or onto a round port.
The globe valve usually has small ports, an "S" flow pattern and relatively high pressure drop.
Globe valves provide tight dependable seals with minimum maintenance.
[OCH(CH2)3CHO] A general disinfectant for drinking water treatment equipment, including reverse osmosis membranes. Available as sporicidin and cidex, for example; requires full strength use for disinfection.
A general disinfectant for drinking water treatment equipment, including reverse osmosis membranes. Available as sporicidin and cidex, for example; requires full strength use for disinfection.
A trihydroxy alcohol with sweet tast and syrup-like consistency; the "gylcerine" spelling has come into general use, but it is chemically incorrect.
A portion of a service connection between the distribution system water main and a meter.
Sometimes called a pigtail.
A single sample of material collected at one place and one time; represents only the specific material at the time and place of sampling.
The elevation of the invert of the bottom of a pipeline, canal, culvert, or similar conduit. The inclination or slope of a pipeline, conduit, stream channel, or natural ground surface usually expressed in terms of the ratio or percentage of number of units of vertical rise or fall per unit of horizontal distance. A 0.5 percent grade would be a drop of one-half foot per hundred feet of pipe.
A unit of weight equal to 0.0648 grams or 0.000143 pounds or 1/7000th of a pound.
A common method of reporting water analysis results in the United States and Canada.
One grain per gallon equals 17.1 parts per million (ppm) or 17.1 milligrams per liter. Grains per Imperial gallon equals 14.3 mg/L (or ppm).
The basic unit of weight measurement in the metric system.
One gram equals 0.0022 pounds or 15.432 grains. The gram was originally devised as the weight of one cubic centimeter or one milliliter of water at 4 degrees Centigrade.
The equivalent weight (in grams) divided by 1,000.
Designation for materials listed by the U.S. Food and Drug Administration (FDA) as "generally regarded as safe."
Various layers of different sized gravel and coarse sand placed above the underdrain network to support filter or ion exchange media beds.
The gravel support bed contributes greatly to the distribution and collection of product water and the even dispersal of the backwash water flow.
A means of measuring unknown concentrations of water quality indicators in a sample by weighing a precipitate or residue of the sample.
Measurement on the basis of weight.
The SI unit of absorbed dose of ionizing radiation.
One gray (Gy) equals 100 rads.
See Also: Biodegradable Biodegradation Hydraulic Grade Line Energy Grade Line (EGL) United States Pharmacopeia (USP) WFI Slope
A natural mineral, primarily composed of complex silicates, which possess ion exchange properties.
Waste water other than sewage, such as sink drainage or washing machine discharge.
The total radioactivity due to beta particle emission as inferred from measurements on a dry sample.
The total radioactivity due to beta particle emission as inferred from measurements on a dry sample.
Water found beneath the surface of the ground.
Groundwater is primarily water which has seeped down from the surface by migrating through the interstitial spaces in soils and geologic formations.
Cement-like fluid which is poured or injected into the bore hole during well drilling to seal crevices and to prevent contamination or loss of drilling mud.
Grouting provides protection around the metal well casing and helps prevent corrosion and infiltration into the well bore hole from surface water and shallow groundwater.
Grouting can sometimes improve the strength and elasticity of the rock formation itself.
The screw which holds the swivel part of a yoke connector for a portable exchange tank in place.
(CaSO4 2H2O) A moderately insoluable calcium sulfate, containing 20.9 percent water, which is often used as a soil amendment to aid in building soil structure and permeability.
A moderately insoluble calcium sulfate, containing 20.9 percent water, which is often used as a soil amendment to aid in building soil structure and permeability.