Sub-Table of Contents
Artifactual Life is life created by intelligence and not based on natural life. This combines with the rapid pressure drop to throw things out of the airplane. For example, in the northeastern regions of Ethiopia and Kenya, which share a border with Somalia, the Somali people practise FGM at around the same rate as they do in Somalia. The present can affect a future event, but it cannot "change" a future event. In the living organism, energy is liberated, along with carbon dioxide, through the oxidation of molecules containing carbon.
Basic types of respiratory structures
Standing in front and taking hold of the clitoris with a broad-mouthed forceps in his left hand, the surgeon stretches it outward, while with the right hand, he cuts it off at the point next to the pincers of the forceps. It is proper to let a length remain from that cut off, about the size of the membrane that's between the nostrils, so as to take away the excess material only; as I have said, the part to be removed is at that point just above the pincers of the forceps.
Because the clitoris is a skinlike structure and stretches out excessively, do not cut off too much, as a urinary fistula may result from cutting such large growths too deeply. The genital area was then cleaned with a sponge, frankincense powder and wine or cold water, and wrapped in linen bandages dipped in vinegar, until the seventh day when calamine , rose petals, date pits or a "genital powder made from baked clay" might be applied.
Whatever the practice's origins, infibulation became linked to slavery. Thus, Mackie argues, a "practice associated with shameful female slavery came to stand for honor". Gynaecologists in 19th-century Europe and the United States removed the clitoris to treat insanity and masturbation.
Mary's Hospital , believed that masturbation, or "unnatural irritation" of the clitoris, caused hysteria , spinal irritation, fits, idiocy, mania and death. Marion Sims followed Brown's work and in slit the neck of a woman's uterus and amputated her clitoris, "for the relief of the nervous or hysterical condition as recommended by Baker Brown". Later in the 19th century, A.
Bloch, a surgeon in New Orleans, removed the clitoris of a two-year-old girl who was reportedly masturbating. From until , he performed "love surgery" by cutting women's pubococcygeus muscle , repositioning the vagina and urethra, and removing the clitoral hood, thereby making their genital area more appropriate, in his view, for intercourse in the missionary position.
Little knives in their sheaths That they may fight with the church, The time has come. Elders of the church When Kenyatta comes You will be given women's clothes And you will have to cook him his food. An important ethnic marker, the practice was known by the Kikuyu , the country's main ethnic group, as irua for both girls and boys.
It involved excision Type II for girls and removal of the foreskin for boys. Unexcised Kikuyu women irugu were outcasts. Jomo Kenyatta , general secretary of the Kikuyu Central Association and later Kenya's first prime minister, wrote in that, for the Kikuyu, the institution of FGM was the " conditio sine qua non of the whole teaching of tribal law, religion and morality".
No proper Kikuyu man or woman would marry or have sexual relations with someone who was not circumcised. A woman's responsibilities toward the tribe began with her initiation.
Her age and place within tribal history was traced to that day, and the group of girls with whom she was cut was named according to current events, an oral tradition that allowed the Kikuyu to track people and events going back hundreds of years. The CSM announced that Africans practising it would be excommunicated, which resulted in hundreds leaving or being expelled.
In the Kenya Missionary Council began referring to FGM as the "sexual mutilation of women", rather than circumcision, and a person's stance toward the practice became a test of loyalty, either to the Christian churches or to the Kikuyu Central Association.
Edward Grigg , the governor of Kenya , told the British Colonial Office that the killer, who was never identified, had tried to circumcise her. Over the next three years, thousands of girls cut each other's genitals with razor blades as a symbol of defiance. The movement came to be known as Ngaitana "I will circumcise myself" , because to avoid naming their friends the girls said they had cut themselves.
Historian Lynn Thomas described the episode as significant in the history of FGM because it made clear that its victims were also its perpetrators. Scottish missionaries require Kikuyu Christians to take an oath against FGM; most leave to form their own churches. Egypt bans infibulation in state-run hospitals; allows partial clitoridectomy if parents request it.
Saadawi's The Naked Face of Women describes her own circumcision. United Nations International Women's Year. Fran Hosken publishes The Hosken Report: Genital and Sexual Mutilation of Females , the first to estimate global figures.
Robin Morgan and Gloria Steinem call it "female genital mutilation" in Ms magazine. French Association of Anthropologists publishes statement that "a certain feminism resuscitates today the moralistic arrogance of yesterday's colonialism.
Circumcision and its Consequences. Circumcision and Infibulation of Women in Africa. Infibulation was banned there in , but the law was unpopular and barely enforced.
Women in the Arab World , which described her own clitoridectomy when she was six years old:. I did not know what they had cut off from my body, and I did not try to find out. I just wept, and called out to my mother for help. But the worst shock of all was when I looked around and found her standing by my side. Yes, it was her, I could not be mistaken, in flesh and blood, right in the midst of these strangers, talking to them and smiling at them, as though they had not participated in slaughtering her daughter just a few moments ago.
In , Rose Oldfield Hayes, an American social scientist, became the first female academic to publish a detailed account of FGM, aided by her ability to discuss it directly with women in Sudan. Her article in American Ethnologist called it "female genital mutilation", rather than female circumcision, and brought it to wider academic attention.
Genital and Sexual Mutilation of Females ,  the first to offer global figures. She estimated that ,, women in 20 African countries had experienced FGM. The conference listed FGM as a form of violence against women , marking it as a human-rights violation, rather than a medical issue. Immigration spread the practice to Australia, New Zealand, Europe and North America, all of which outlawed it entirely or restricted it to consenting adults. In the United States an estimated , women and girls had experienced FGM or were at risk as of In addition, 24 states have legislation banning FGM.
Canada recognized FGM as a form of persecution in July , when it granted refugee status to Khadra Hassan Farah, who had fled Somalia to avoid her daughter being cut. Canadian officials have expressed concern that a few thousand Canadian girls are at risk of "vacation cutting", whereby girls are taken overseas to undergo the procedure, but as of there were no firm figures. According to Colette Gallard, a family-planning counsellor, when FGM was first encountered in France, the reaction was that Westerners ought not to intervene.
It took the deaths of two girls in , one of them three months old, for that attitude to change. Around , women and girls living in England and Wales were born in countries where FGM is practised, as of Both men were acquitted in Anthropologists have accused FGM eradicationists of cultural colonialism , and have been criticized in turn for their moral relativism and failure to defend the idea of universal human rights.
Africans who object to the tone of FGM opposition risk appearing to defend the practice. The feminist theorist Obioma Nnaemeka , herself strongly opposed to FGM, argues that renaming it female genital mutilation introduced "a subtext of barbaric African and Muslim cultures and the West's relevance even indispensability in purging [it]".
The photographs were published by 12 American newspapers, without the girl consenting either to be photographed or to have the images published. The debate has highlighted a tension between anthropology and feminism, with the former's focus on tolerance and the latter's on equal rights for women.
According to the anthropologist Christine Walley, a common position within anti-FGM literature has been to present African women as victims of false consciousness participating in their own oppression, a position promoted by feminists in the s and s, including Fran Hosken, Mary Daly and Hanny Lightfoot-Klein. Nnaemeka argues that the crucial question, broader than FGM, is why the female body is subjected to so much "abuse and indignity", including in the West.
Carla Obermeyer has argued that FGM may be conducive to a subject's social well-being in the same way that rhinoplasty and male circumcision are. Cosmetic procedures such as labiaplasty and clitoral hood reduction do fall within the WHO's definition of FGM, which aims to avoid loopholes, but the WHO notes that these elective practices are generally not regarded as FGM.
Sweden, for example, has banned operations "on the outer female sexual organs with a view to mutilating them or bringing about some other permanent change in them, regardless of whether or not consent has been given for the operation". The philosopher Martha Nussbaum argues that a key concern with FGM is that it is mostly conducted on children using physical force. The distinction between social pressure and physical force is morally and legally salient, comparable to the distinction between seduction and rape.
She argues further that the literacy of women in practising countries is generally poorer than in developed nations, which reduces their ability to make informed choices. Arguments have been made that non-therapeutic male circumcision , practised by Muslims, Jews and some Christian groups, also violates children's rights. Globally about 30 percent of males over 15 are circumcised ; of these, about two-thirds are Muslim.
However, in some countries, medicalized female genital mutilation can include removal of the prepuce only Type Ia Thabet and Thabet, , but this form appears to be relatively rare Satti et al. Almost all known forms of female genital mutilation that remove tissue from the clitoris also cut all or part of the clitoral glans itself.
Book XVI, chapter 4 , Martínez 6 March The Guardian ; also see Anantnarayan, Lakshmi et al. A Contested Site" , wespeakout. Donaldson James, Susan 13 December Vintage Books, , ; for irugu being outcasts, Kenyatta, , and Zabus , 48— State University of New York Press, , ff. Also see Lynn M. Thomas, " 'Ngaitana I will circumcise myself ': From Wikipedia, the free encyclopedia. For other uses, see FGM disambiguation. Road sign near Kapchorwa , Uganda , Prevalence of female genital mutilation by country.
Religious views on female genital mutilation. Campaign against female genital mutilation in colonial Kenya. Egyptian Doctors' Society call for ban. Sudan, under Anglo-Egyptian control , bans infibulation; the law is barely enforced. Guinean gynaecologist Aja Tounkara Diallo Fatimata begins year practice of performing fake clitoridectomies to satisfy families.
Denniston, et al eds. Thomas, "'Ngaitana I will circumcise myself ': A Reader , Pambazuka Press, , p. Female genital mutilation in the United States. Female genital mutilation in the United Kingdom. The term 'female circumcision' has been rejected by international medical practitioners because it suggests the fallacious analogy to male circumcision In most countries, medical personnel, including doctors, nurses and certified midwives, are not widely involved in the practice.
Cut, no flesh removed describes a practice known as nicking or pricking, which currently is categorized as Type IV. And sewn closed corresponds to Type III, infibulation. For the years and country profiles: In Abusharaf, Rogaia Mustafa. University of Pennsylvania Press. Bagnol, Brigitte; Mariano, Esmeralda The Oxford Dictionary of the Jewish Religion. British Crusades in Colonial Sudan. Wombs and Alien Spirits: University of Wisconsin Press.
Why Aren't Jewish Women Circumcised? Gender and Covenant In Judaism. University of California Press. El Guindi, Fadwa El Dareer, Asma Woman, Why Do You Weep: The Female Circumcision Controversy: Hosken, Fran . The Missionary Movement in Colonial Kenya: The Foundation of Africa Inland Church.
Greek Papyri in the British Museum. The Beginning of the End". Female "Circumcision" in Africa: Archived from the original PDF on 29 October Mandara, Mairo Usman View of Nigerian Doctors on the Medicalization Debate". Culture Controversy and Change. Sex and Social Justice. New York and Oxford: In James, Stanlie M. Genital Cutting and Transnational Sisterhood. University of Illinois Press.
Female Circumcision and Clitoridectomy in the United States: A History of a Medical Treatment. University of Rochester Press. In Borch, Merete Falck.
Language and Translation in Postcolonial Literatures. Journal of Medical Ethics. WHO collaborative prospective study in six African countries". Berer, Marge 30 June It's female genital mutilation and should be prosecuted".
Health Care for Women International. Black, John July Journal of the Royal Society of Medicine. Elchalal, Uriel; Ben-Ami, B. Essén, Birgitta; Johnsdotter, Sara July Acta Obstetricia et Gynecologica Scandinavica. Archived from the original PDF on 14 April International Journal of Epidemiology.
BMJ Clinical research ed. Gallard, Colette 17 June Gruenbaum, Ellen September—October Research Findings, Gaps, and Directions". Hayes, Rose Oldfield 17 June Carey; Teklemariam, Mamae 19 January New England Journal of Medicine. Iavazzo, Christos; Sardi, Thalia A.
Archives of Gynecology and Obstetrics. Ismail, Edna Adan Edna Adan University Hospital. Studies in Family Planning. Johnsdotter, Sara; Essén, Birgitta May Archived from the original PDF on 21 September Who is at risk in the U.
Public Health Reports Washington, D. Kelly, Elizabeth; Hillard, Paula J. Current Opinion in Obstetrics and Gynecology. Khazan, Olga 8 April The Journal of Sex Research. Knight, Mary June Some remarks on the practice of female and male circumcision in Graeco-Roman Egypt". Kool, Renée; Wahedi, Sohail 15 April A Comparative Law Perspective".
Mandara, Mairo Usman March International Journal of Gynaecology and Obstetrics. Mackie, Gerry December Mackie, Gerry June Journal of Religion in Africa. Reviews in Obstetrics and Gynecology. Annals of Medical and Health Sciences Research. Zeitschrift für Ägyptische Sprache und Altertumskunde. Reisel, Dan; Creighton, Sarah M. Rodriguez, Sarah July American medicine and female sexuality in the late nineteenth century". An element, normally a gas, which is liquefied under pressure and stored in steel cylinders.
Used as a disinfectant and algaecide when it is introduced in water solution into a pool or spa. A very toxic biocide. A halogen element isolated as a heavy irritating greenish-yellow gas of pungent odor, used as a bleach, oxidizing agent, and a disinfectant in water purification.
A chemical which causes dispersed colloidal particles to become destabilized, thereby aiding in their removal during municipal water treatment. Aluminum and iron salts are commonly used for this purpose.
A practice common in municipal water treatment in which a chemical coagulant , most commonly alum, is added to water in order to destabilize colloidal particles by neutralization of their electrical charges.
Coagulation is used, together with flocculation, as a process for colloid removal. Un-dissolved, sub micron-sized, suspended particles which are well dispersed in a solution and will not readily settle out on standing. Many colloidal minerals claim to be organic due to the fact that they come from prehistoric mineral deposits such as humic shale and that some of the minerals are bound to carbon. The undesirable physical compression of a reverse osmosis or ultrafiltration membrane which results in reduced flux rates.
The phenomenon is accelerated at higher temperatures and pressures. The portion of a feed stream that retains the ions, organics and suspended particles that were rejected during the cross flow filtration or purification process. Associated with water cooled distillers and reverse osmosis systems. A measure of the ability of an aqueous substance to transmit an electric current. The conductivity imparted to water by dissolved solids is a function of both the amount and composition of the salts and the temperature of the water.
An unprotected connection between a domestic water system and any pool or other non-potable water whereby back flow to the domestic system could occur. Appropriate protection may be vacuum breakers, air gaps or other methods. Diatomaceous Earth, a type of filtration media. Can also stand for Dual Element when talking about electrical fusing.
Those areas surrounding a pool, spa or hot tub that are specifically constructed or installed for use by bathers. Removal of ions from water by exchange with other ions associated with fixed charges on a resin. First, positively charged ions are removed, by a cation exchange resin, in exchange for a chemically equivalent amount of hydrogen ions.
Second, negatively charged ions are removed, by an anion exchange resin for a chemically equivalent amount of hydroxide ions. The hydrogen and hydroxide ions introduced in this process unite to form water molecules. This process is also called demineralization by ion exchange. The process of removing minerals from water e. The removal of dissolved inorganic solids salts from a solution such as water to produce a liquid which is free of dissolved salts.
Desalination is typically accomplished by distillation, reverse osmosis or electrodialysis. A common source water may be seawater. The average rate of flow in a system which is used for design calculation usually the flow in gallons per minute divided by the effective filter area in square feet.
A severe, often fatal encephalopathy which has been attributed to accumulation in the brain of aluminum from dialysate prepared with inadequately purified water. May include consumption of tap water with high levels of alum used in most municipal water treatment processes. Porous silica from skeletal remains of one-celled plants, which when properly graded, acts as a precoat filter media for water filtration.
A piece, adjacent to the impeller exit, which has multiple passages of increasing area for converting velocity to pressure in a pump. An inlet fitting which provides adjustment in direction and flow rate to produce proper distribution of incoming water. A process for the destruction of bacteria. The process may be physical, as with heat or ultraviolet irradiation, or chemical, as with chlorination. Includes colloidal and suspended particles at sizes far less than one micron in diameter.
Associated with evaporation process such as distillation. Steam from boiling water is condensed on a cool surface, collected and stored. Most contaminants do not vaporize and therefore do not pass to the condensate. Removes nearly percent of salts and those organics that do not have a vaporizing temperature near or below that of water. Usually combined with carbon filtration to remove balance of remaining organics with vaporization temperatures below that of water.
Water which has been purified by passing through an evaporation, condensation cycle; it generally contains less than 5 ppm of dissolved solids. The device in a filter designed to divert the incoming water to prevent erosion of the filter media. That area of a pool designed for diving. A board especially designed to produce diver spring action when properly installed on an anchor base and fulcrum. The term diving board includes non-spring types.
The difference between the static water level and the pumping water level in a well. Also can refer to the per cycle capacity rating of a pressure tank at a given pressure range. A normal weatherproof fixture placed in an opening behind the pool wall which illuminates the pool through a watertight window in the pool wall. The effective filter area is the filter surface that is perpendicular to the flow direction.
The total effective filter area shall be the cartridge area that is exposed to the direct flow of water. This excludes cartridge ends, seals, supports and other areas where flow is impaired.
A device consisting of a body, nozzle, and venturi tube that increases the pressure output of a jet pump. The nozzle increases the velocity of the water then the venturi tube converts the velocity to pressure.
The vertical distance between the level where fluid enters a pipe and the level where it leaves. As a rule of good installation practice, however, pipes should slope continuously upward from the inlet to the outlet to prevent entrapment of air. A measurement of the duration of contact between water and the media through which it is flowing, typically used in reference to carbon beds. Bacterial lipopolysaccharide, a substance released from the cell walls of gram-negative bacteria when the organism is broken down.
A type of motor enclosure that will prevent sparks generated by the motor from reaching the atmosphere outside of the motor enclosure. As a general rule our company does not sell this kind of motor. The piping with all valves and fittings which is used to connect the filter system together as a unit.
This includes all valves and piping necessary for the filter plant to perform the functions of filtering or backwashing, either by the plant as a whole or any unit operating singly. The ultimate load divided by the safe load or the ultimate strength divided by the allowable stress. Water under pressure entering a purification system or an individual piece of purification equipment, such as an ultra filter, distiller or reverse osmosis system.
A basis for indicating the resistance in a hydraulic system, equivalent to the height of a column of water that would cause the same resistance feet of head equals 43 pounds per square inch. The total head is the sum of all resistances in a complete operating system.
The principal factors affecting a head are vertical distances and the resistance caused by friction between the fluid and pipe walls. Small solid iron particles containing trivalent iron, usually as gelatinous ferric hydroxide or ferric oxide, 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 which, when dissolved in water, produces a clear solution. It is usually removed by cation exchange water softening.
Also called "clear water" iron. A device that separates solid particles from water by recirculating the water through a porous substance a filter medium element. A filter that utilizes a medium that under normal use will not have to be replaced. A filter that utilizes a thin layer of diatomaceous earth as its filter medium that periodically must be replaced.
A filter that utilizes a porous cartridge as its filter medium. A type of finely divided media used to coat a septum type filter, usually diatomaceous earth or volcanic ash. Alum, as used on the bed of a sand filter, is also referred to as a filter aid. A filter which operates through a disposeable cartridge. These are of two general types: The surface or area type where the suspended matter is removed at the surface, and the depth type in which the interstices vary from large to small in depth.
One designed to filter water through a thin layer of filter aid such as diatomaceous earth or volcanic ash. Diatomite filters may be of the Pressure, Gravity, Suction or Vacuum type. A device within a filter tank designed to entrap solids and conduct water to a manifold, collection header, pipe or similar conduit. A filter element usually consists of a septum and septum support. The finely graded material which entraps suspended particles sand, anthracite, diatomaceous earth, etc. That part of the filter element consisting of cloth, wire screen or other porous material on which the filter cake is deposited.
A filter with a layer of filter media usually silica sand supported on graded gravel through which water flows by gravity. A type of filter media composed of hard sharp silica, quartz, or similar particles with proper grading for size and uniformity. The rate of filtration of water through a filter during the filter cycle expressed in US gallons per minute per square foot of effective filter area.
The Federation Internationale de Natation Amateur — The governing body for intercollegiate competition including the Olympic games. A compound, such as one of the alums, which forms minute flakes in water which attract or enmesh small suspended particles.
Chemical which, when added to water, causes particles to coagulate into larger, settleable groupings. Aluminum compounds are common catalysts in this process. The slope in the pool floor, usually expressed in feet or inches of vertical rise in feet or inches of horizontal distance. A quantitative expression of the rate of linear motion at which water passes through a pipe or conduit. A process by which particles are suspended by an upward flow of liquid, such as may occur during back washing of ion exchange resin or carbon media.
A salt of hydrofluoric acid which may occur naturally in water supplies or be added by municipal processes for the prevention of dental caries.
Fluoride is considered toxic in most medical settings and has been implicated with a wide range of physiological disorders including renal bone disease. The rate per unit of area at which water passes through a semi-permeable membrane, such as those used for ultrafiltration or reverse osmosis. A modified check valve that has a screen on the suction end to prevent debris from entering the pump or pipe. The deposition of insoluble materials, such as bacteria, colloids, oxides and water-borne debris, onto the surface of a media such as water softening resins, reverse osmosis or ultrafiltration membrane.
Fouling is associated with decreased flux rates and may also reduce the rejection rates of reverse osmosis membranes. The clear vertical distance between the top of the filter medium and the lowest outlet of the upper distribution system in a permanent medium filter. The loss of pressure or head due to the resistance to flow in the pipe and fittings. Friction loss is influenced by pipe size and fluid velocity, and is usually expressed in feet of head.
Acidic substances which are found in humic organic soils and which may become suspended in water. A component in the production of chloramines. A parasitic plant which produces no chlorophyll and is dependent on other life forms for its existence. Wastewater from household baths and washing machines that is sometimes recycled especially for use in gardening or for flushing toilets.
Is not limited to but may be located within or without the pool, spa or hot tub or as part of a set of steps or deck-installed equipment. The amount of calcium and magnesium in the water in grains per gallon, expressed as calcium carbonate.
This level is important to control during distillation or reverse osmosis processes to prevent scaling. Each grain is equal to What constitutes truly "hard" water is subject to much debate and controversy. Proponents of water softening systems tend to call water "hard" which contains between 3 and 10 grains of hardness.
This definition is supported by the American Society of Agricultural Engineers and the Water Quality Association, major supporters of the water softening industry.
Water with 10 grains of hardness, is regularly used by consumers, with little or no adverse affect on plumbing or other household functions. Water, which approaches 15 to 20 grains is more in line with situations which require water softening or conditioning. Water with 3 grains of hardness and is termed "moderately hard" by these organizations is typically found in surface and spring water sources, far removed from what one would consider hard water sources. A term used to define water pressure in vertical feet.
Or a term representing the energy content of a liquid, expressed as the height of an equivalent vertical column of water.
This is expressed in feet of head. This can apply to both sides of a pump; the suction side and discharge side. It is also used to express the total losses in a pumping system Total Dynamic Head.
Metals having a high density or specific gravity. A generic term used to classify contaminants such as cadmium, lead and mercury. These contaminants can damage living things even at low concentrations and tend to accumulate in the food chain. The horizontal distance between the point where fluid enters a pipe and the point at which it leaves. The fitting used to connect the hose to the vacuum wall fitting usually a combination hose sleeve and nut. A spa constructed of wood with sides and bottom formed separately; and the whole shapes to join together by pressure from the surrounding hoops, bands or rods; as distinct from spa units formed from plastic, concrete, metal or other materials.
A damaging condition that occurs when a column of liquid changes direction quickly and increases in velocity. Weakest point in system will break. Causes can be sudden loss of power to the driver, valve closing too quickly, valve closing too slowly allowing backflow.
A toxic gas that is detectable by a strong "rotten egg" odor. Associated with high levels of bacterial decay. Commonly found together with iron and manganese contaminants. A fitting that bleeds air and water creating a high velocity, turbulent stream of air enriched water.
The term used to describe how water travels through the environment by evaporation, condensation and precipitation. Identical process is observed in steam distillation systems. A chemical process resulting from reactions with water; frequently used in reference to the breakdown of polymers.
A unit that may have a therapeutic use which is not drained, cleaned or refilled for each individual. It may include, but not be limited to, hydrojet circulation, hot water and cold water mineral baths, air induction bubbles or any combination thereof. A device used to feed, control and measure a solution of sodium or calcium hypochlorite into a water being treated.
There are three general types: The positive displacement type which is usually a motor driven unit, the aspirator type actuated by a pressure differential created within the hydraulic system, and the metering type connected to the pump suction using an orifice which is opened and closed by a timing mechanism. A chemical compound commonly found in two forms for use with pools, spas and hot tubs: The bladed member of the rotating assembly of the pump which applies the principal force to the liquid being pumped.
The fitting through which the filtered water passes to the pool filtered water inlet , or the fitting through which raw water passes to the pool raw water inlet.
An element related to chlorine and bromine used as a disinfectant, both in its natural solid form and in iodide compounds. When iodides are used, chlorine is normally employed to free the elemental iodine. An atom or molecule having either a positive or negative electrical charge. Positively charged ions are referred to as cations and ions having a negative charge are termed anions. A process by which certain ionized chemicals present in water are replaced with other ionized chemicals temporarily attached to resin particles.
The exchange process is made only for ions having the same charge. A very common element often present in ground water in amounts ranging from 0. Iron may be found in three forms: Bacteria which thrive on iron and are able to actually use ferrous iron as found in water or steel pipes in their metabolic processes to incorporate ferric iron in their cell structure and to deposit gelatinous ferric hydroxide iron compounds in their life processes.
An accessory kit sold with jet pumps. Can consist of ejector, extra nozzles and venturis, bushings and reducers, pipe adapters and foot valves, and packing leathers. Also known as Ejector package or Injector package. A visual means of measuring water clarity based upon the amount of light passing through a tube of water. A mechanism that has a coil spring, leaf spring or comparable device located beneath the board which is activated by the force exerted in jumping on the board.
A ladder that straddles the pool wall of an aboveground pool and provides pool ingress and egress. Any ladder with provision for making entry inaccessible when a pool, spa or hot tube is not in use i.
Associated with fluid dynamics and designs of fluid tubing and pipelines. A calculated number used to predict the calcium carbonate CaCO3 stability of a water; whether a water will precipitate, dissolve, or be in equilibrium with, calcium carbonate. It is sometimes erroneously assumed that any water that tends to dissolve calcium carbonate is automatically corrosive. A polysaccharide found in the cell walls of plants; a breakdown product of decaying vegetation, which may be present in surface water supplies.
A liner that is constructed of a material that has the capability of stretching into a greater depth of irregular shape other than the original construction dimensions. The liner that is used to obtain greater depth by geometrical pattern construction on the liner bottom or floor to fit a predetermined size and shape.
Those devices used in the bottom of a permanent medium filter to collect the water during the filtering and to distribute the water during the backwashing. Thin films constructed of cellulosic or synthetic materials, which are designed to provide selective transport of solutes.
Widely used for hemodialysis, micro filtration, ultrafiltration and reverse osmosis, membranes may be either homogeneous or asymmetric. Homogeneous membranes have a uniform structure or cross-section while asymmetric membranes have a dense "skin" which overlays a porous substructure.
The presence in blood of methemoglobin, a substance related to normal oxyhemoglobin, but having no oxygen-carrying capabilities and induced by exposure of blood to certain toxic chemicals, such as nitrites. A measure of concentration of a dissolved substance in a liquid. For practical purposes, this unit is equal to parts per million ppm since one liter of water is equal in weight to one million milligrams.
Thus, a liter of water containing 10 milligrams of calcium has 10 parts of calcium per one million parts of water or 10 parts per million 10 ppm.
The separation or removal from a liquid of particulates and micro-organisms in the size range of 0. In the context of water purification, membranes having an average pore size, which is between 0. A measurement of capacitance electrical storage capability. Capacitors or condensers have a range listed on the casing MFD, example showing the capacity it can handle. They will also show the maximum voltage they can handle V, example. One millionth of an ohm.
The unit of measurement for testing the electrical resistance of water to determine its purity. The closer water comes to absolute purity, the greater its resistance to conduction of an electrical current. Absolute pure water has a specific resistance over 18 million ohms megohms across one centimeter of water at a temperature of 78 degrees Fahrenheit.
A unit of linear measure. It is one millionth of a meter, or one thousandth of a millimeter. The smallest particle than can be distinguished by the naked eye would be about 40 microns across. A measurement applied to filters or filter media to indicate the particle size at which a substantial percentage of suspended solids above that size will be removed.
As used in the water treatment industry standards, this may be an absolute rating or a nominal rating. A common measurement for the flow rate of small RO systems. Usually measured with a graduate cylinder. One thousandth of a liter per minute.
The intermixing of two or more filter or ion exchange products in the same vessel during a service run. In filtration, there may be an intermixing of two or more media in a single tank with each stratified into separate layers.
Short for Modular Media, a type of filtration system. Consists of filters within filters - interchangeable and replaceable. A volatile organic chemical VOC used as an octane-enhancing lead substitute and more recently as an oxygenating agent in gasoline to reduce carbon monoxide emissions from automobiles. MTBE is volatile, flammable and highly soluble in water. During refueling and gasoline production, MTBE is volatilized to the atmosphere where it dissolves into the atmospheric moisture and returns to earth as precipitation, polluting our water supplies.
Since MTBE does not adsorb well with organic matter in soils it is easily washed away. In surface water, MTBE volatilizes into the air. While in ground water, MTBE persists and moves freely. MTBE occurrences in ground water above 40 ppb have so far been attributed to point source contamination such as underground gasoline tank leaks, overflows, etc. A multi-port valve with at least four positions for varous filter operations, which combines in one unit the function of two or more single direct flow valves Dial Selector Valve.
The nanofiltration process can pass more water at lower pressure operations than reverse osmosis, can remove particles in the to 1, molecular weight range such as humic acid and organic color bodies present in water, and can reject selected typically polyvalent salts.
Nanofiltration may be used for selective removal of hardness ions in a process known as membrane softening. National Collegiate Athletic Association — The governing body for intercollegiate competition and the recording agent for college swimming records. The addition of either an acid to a base or a base to an acid to produce a more nearly neutral solution. The use of alkaline or basic materials to neutralize acidity of some water is common practice in water processing to prevent corrosion of metallic home plumbing.
An anion comprised of one nitrogen atom and three oxygen atoms. Nitrates are considered toxic in hemodialysis water and are also harmful to infants when consumed orally. Filter rating indicating the approximate size particle, the majority of which will not pass through the filter. It is generally interpreted as meaning 85 percent of the particles of the size equal to the nominal filter rating will be retained by the filter.
Any portion of a pool, spa or hot tub where water depth, offset ledges or similar irregularities would prevent normal swimming activities.
Atmospheric pressure causes the increase in velocity. NPS occurs mainly through stormwater runoff. Net Positive Suction Head. There are two types of NPSH. NPSHR is the amount of head required by the pump to keep the liquid being pumped in a liquid state. The only way NPSHR can be changed is by changing the pumps' rotational speed or its impeller diameter.
NPSHA is affected by atmospheric pressure changes, altitude, pipe and fitting sizes, and elevation to the liquid being pumped. An instrumental means of measuring water clarity based upon the intensity of light scattered by suspended particles.