Copyright © Philip M. Parker, INSEAD. Terms of Use.
Definition: Sewerage |
SewerageNoun1. Waste matter carried away in sewers or drains. 2. A waste pipe that carries away sewage or surface water. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
Date "sewerage" was first used in popular English literature: sometime before 1883. (references) |
| Domain | Definition |
Building & Civil Engineering | The entire system of sewage collection, treatment and disposal. Source: European Union. (references) |
Tips from 1870 | Usage: Sewage, Sewerage. These words have distinct meanings. Sewage refers to the contents of the sewer; sewerage to the system of sewers. Source: Slips of Speech. |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
Sewage treatment or sewerage treatment cleans water containing human or industrial excreta and waste.This article essentially describes sewage treatment as practiced in the USA. Other countries practices might be quite different.
Historical sewage treatment
Originally, cities had no sewers. Waste water simply ran down the streets, which had stepping stones to keep pedestrians out of the muck, and eventually drained as runoff into the local watershed. The next significant development was to move to a single set of sewers that accepted both storm runoff as well as blackwater and industrial waste, which improved conditions on the streets significantly but which still usually just dumped the untreated waste water into the local watershed.
Modern sewage treatment
Common practice in the U.S. and Canada at this time (2002) is to have two systems: storm sewers, and sanitary sewers. Storm sewers in some wealthy areas (like southern California) might get some processing to remove waste such as automobile oil. Sanitary sewers are processed to clean up human waste. In some areas there is a clear movement advocating dedicated industrial sewers as well, to handle chemical wastes and solvents. In the ultimate case, perhaps automatic delivery vehicles should visit every waste point, and pick up pure wastes for precise forms of recycling.
In many other countries, including many quite-wealthy ones, untreated sewage is released directly to surface water. A rule of thumb is that if a city's tapwater is not considered potable, the country does not perform sewage treatment. In many such countries, the legislature would have to allocate money to such treatment were it to mandate outfall levels, and the legislators find other priorities more pressing.
Although there are many methods for coping with human excreta, generations of sewage engineers have refined the following processes, which are the least expensive known mass processes to separate people from pathogens in their excreta.
It consists of several stages:
Traditional plants use massive installations with large concrete tanks. Recent trends are to use plastic pool liners in dirt pools, or small mass-produced plastic or metal tanks in small systems that run themselves automatically. (See septic tanks.)
- primary treatment, which removes most of the solids from the sewage
- secondary treatment, which renders the outfall biologically safe,
- tertiary treatment, which removes salts and chemicals.
Primary treatment
This begins with a collection network of sewer pipes. Most sewers are arranged so that gravity moves the sewage. Pumps are problematic in a sewer system because people often flush foreign objects such as socks, tampons, condoms and disposable diapers down their toilets. Even so, in a very flat area, sewer pumps and regional sumps are a practical necessity.
The pipes can also be blocked by the growth of biofilms. The flow has to exceed 3/4 of a meter at least once per day to keep slime from building up and blocking the pipes. Even so, most systems have problem spots that have to be cleaned periodically. Sewage pipes are cleaned with pressurised water.
The first step in the plant is foreign-object protection: The incoming sewage pipes go up in a hump, usually about six feet high. This helps keep very large foreign objects in the pipes from damaging the bar grid. There are valves to divert the flow, and manholes to remove these objects. Every sewage plant has stories about objects found in the pipes: toilets, children's tricycles and toys, and the staple: very large round rocks.
The valves divert the sewage directly to the outfall. The hump hall's drain also leads directly to the outfall. If the plant goes off-line, this is where the spill occurs.
If the plant is for a single-pipe system that processes storm runoff as well as sewage, there will be provision for diverting storm flows to holding tanks. Often the first flush of a storm flow will be terribly dirty, and require treatment, while the rest will be more than 5/6 rain water and can be safely diverted to the outfall.
A treatment plant measures the incoming volume from major pipes in order to track and charge customers. The measurement area is usually at the top of the hump. Generally the sewage charge is actually paid as a surcharge on customers' water bills. The difference between incoming sewage and outgoing water is used to establish the sewage rate fees as a percentage of water use. The metering also gives administrators a means to measure water waste and irrigation of lawns and other diversions to the storm sewers.
The measurement area is also where chemists monitor the incoming sewage for industrial chemicals such as heavy metals and toxic solvents. If these become too high in concentration, the plant (in the U.S., anyway) becomes unable to sell its sludge, which must then be placed in toxic land-fills.
To keep the sludge salable, when toxic waste is detected, the sewage engineers begin tracing the toxic waste to its source. At this point, the polluter is at least notified. In some areas, he is charged with fines large enough to motivate him to change his ways.
The next step is a bar grid. A bar grid is supposed to remove foreign objects from the sewage. It generally has strap-shaped stainless-steel bars, edge to the flow, a half-inch apart. Every few minutes, a mechanical claw scrapes foreign objects up the bar grid, onto a conveyor, and out to a dumpster. The dumpster contents are usually placed in a landfill.
The next step is a grit settling tank, or in smaller systems, a series of finer grids. These take out things between a half inch and sand-sized. These also go to the landfill.
The next step is usually a sedimentation basin or an Imhoff tank. At this point, the sewage separates into sludge and waste water.
At this point, primary treatment is complete. In poor countries, the water goes to the outfall, and the sludge goes to the farms.
Secondary treatment
Secondary treatment removes bacteria and offensive smells from the sludge and water. It generally employs bacteria to consume the available nutrients and organic compounds. What remains are inorganic salts, carbon dioxide and water.
Sludge treatment
The basic treatment for the sludge is digestion. The sludge is pumped to concrete digesters where anaerobic bacteria eat the sludge and produce methane. The digesters usually run quite hot, near 100°F, just from the bacterial action. Sludge may also be processed and thickened in aerobic digesters kept oxygenated by the same power source that supplies the secondary treatment aeration.
The sludge is then run through another settling tank, or in some plants, pressed between mesh conveyor belts to wring out the water.
The result of the digester is reduced sludge, methane, and water.
The reduced-volume, bacterially-safe sludge can then be sold to farmers, gardeners and nurseries, who use it as an organic amendment for soil.
The plant doesn't make any money on sludge. The fee is usually just enough to keep the users from abandoning the sludge. Other organic amendments are cheap, so the chief cost advantage of sewage sludge is that it is local.
In some countries, sludge is incinerated. This is far too polluting for most locations in the U.S. Some of these plants use the heat to generate electricity. It's theoretically possible to scrub the stack gases if pure human waste were being processed, but in practice, the chemicals in sludge and human waste are too unpredictable to be safely burned in an urban area.
If the sludge has too many solvents or heavy metals to be sold, it has to be trucked, or hauled by railway to a toxic landfill. This is much more expensive than selling it.
The methane is usually burned in large internal combustion engines to generate power. These are usually diesel (compression ignited), although some plants have adapted natural gas turbines (natural gas is mostly methane). If the plant is efficient enough, it can generate enough electricity from the methane to run itself.
The heat from the engine exhaust is usually recycled as process heat. In some plants, it preheats sludge going into the digesters.
Wastewater treatment
The water drawn off the top of the sedimentation tank in primary treatment also has substantial amounts of bacteria and dissolved solids. The basic treatment is to mix "activated sludge" with the water, and bubble air through it so that aerobic bacteria can eat the dissolved solids.
The water from the aerator is moved to a settling tank. The activated sludge (actually mats of bacteria) settles, and is removed. At this point, some plants may use hydrogen peroxide or ozone-creating ultraviolet lamps to oxidize any remaining viruses and smelly organics that remain in the water. This is frequently done when the outfall water enters an ocean or river where swimming is permitted.
The water from the digester and aerator are usually mixed, partially disinfected with chlorine or chlorine compounds, ozone, ultraviolet light, or hydrogen peroxide and then discharged. In some areas, disinfection is delayed until after clarification (half tertiary) treatment.
After secondary treatment, the wastewater can safely water ornamental plants. In some areas it used for that purpose. See water (resource).
In most areas, the water is considered grossly unsafe, and is discharged to the outfall.
Tertiary treatment
Tertiary treatment removes minerals from the water, to restore it to a more natural state. The most damaging remaining minerals are usually nitrates and phosphates. These are especially damaging when the local economy depends on tourism drawn by a large beautiful lake. Nitrates from even a small human population can cause eutrophication of a lake. The general process of eutrophication is algal bloom, followed by rotting, followed by oxygen depletion followed by the stinking death of the lake's life. This is an ugly process that repulses tourists, and anyone else near the lake.
To prevent eutrophication, many plants use a sort of half tertiary treatment that removes some minerals and organics. Algae and rotifers are grown in a "clarifier" tank, or perhaps in a trickle fiter with a trickle of water over "biofilms" grown on limestone chips. After this, the water is sterilized and discharged. Such "half-tertiary" treatment is used in Orange County, California, to protect the swimming beaches of Southern California.
In some areas, all the minerals must be removed. Complete tertiary treatments are still experimental. Tertiary treatment that demineralizes waste water is rare and still costly.
The classical method is to adapt desalting techniques, which effectively, though expensively, remove minerals. The resulting water is safe to drink. These systems use techniques like reverse osmosis, pressure membrane purification and distillation. One of the earliest tertiary treatment plants is used by South Lake Tahoe, California and Stateline, Nevada to protect Lake Tahoe.
A promising method that began to be promoted about 1995 is to run the waste-water through a sort of artificial swamp called a "living machine" or constructed wetland. To the organisms in the swamp, the minerals and organic materials of secondary water are valuable nutrients. The resulting "effluent" water is indistinguishable from unpolluted natural runoff.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Sewage treatment."
Synonyms: SewerageSynonyms: cloaca (n), sewage (n), sewer (n). (additional references) |
| Context | Synonyms within Context (source: adapted from Roget's Thesaurus). |
Cleanness | Noun: cleanness, cleanliness; Adjective: purity; cleaning; Verb: purification, defecation; Verb: purgation, lustration; detersion, abstersion; epuration, mundation; ablution, lavation, colature; disinfection; Verb: drainage, sewerage. |
Uncleanness | Spawn, offal, gurry; lientery; garbage, carrion; excreta; slough, peccant humor, pus, matter, suppuration, lienteria; faeces, feces, excrement, ordure, dung, crap, sewage, sewerage; muck; coprolite; guano, manure, compost. |
| Source: adapted from Roget's Thesaurus. | |
Crosswords: Sewerage |
| Specialty definitions using "sewerage": INSPECTOR, INDUSTRIAL WASTE ♦ separate system. (references) |
| Domain | Title | ||
References | |||
Books |
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Periodicals |
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Source: compiled by the editor from various references; see credits. | |||
| Thumbnail | Description & Credit | Thumbnail | Description & Credit |
 | Miner's house at Scott's Run, West Virginia. Note sewerage system. Credit: Library of Congress. |  | Rock Gate Farm Dairy, Bedford Hills, New York. Sewerage plant I. Credit: Library of Congress. |
Source: pictures compiled by the editor from various references; see picture credits. | |||
| Subject | Topic | Quote |
Business | Only a few cities have sewerage systems, and nearly all provide collection only and do not treat collected sewage. (references) | |
Major civil engineering projects include another 450 km long of MRT lines, the southern arm of the deep tunnel sewerage system and the common services, in addition to expansion of surface roads. (references) | ||
JBIC has recently put an emphasis on environmental protection for recipient countries, including goods and services to reduce, air pollution, water pollution and water supply and sewerage development. (references) | ||
Economic History | Cyprus | Local municipalities are working on long-term plans for sewerage projects and plans for new highways. (references) |
Malaysia | The normal method of marketing to the sewerage industry is through appointed agents or by direct tender. (references) | |
Honduras | Total domestic water coverage and sanitary sewerage services in Honduras are 75.21% and 71.10%, respectively. (references) | |
Trade | Turkey | Turkey offers numerous major project opportunities in telecommunications, energy, transportation, and building of infrastructure projects such as dams, airports, harbors, roads, and water and sewerage systems. (references) |
Barbados | The Embassy submits notice of these projects to the National Trade Data Bank as soon as information is available.) In 2000, funds sourced on the capital market were augmented by project funds, mainly from the CDB and the IDB, amounting to US$35.8 million, more than doubling the amount received in 1999. The main projects benefiting from these funds were the school computerization and infrastructure improvement through the EDUTECH 2000 program (US$11.3 million), the expansion of the Grantley Adams International Airport (US$8.5 million), the South Coast Sewerage (US$8.5 million), and the Bridgetown rehabilitation project. (references) | |
Worker Rights | Zambia | In addition to the Zambia Defense Force, the judiciary, the police, the prison service, and the Intelligence Security Service, the law defines as essential services power, medical, water, sewerage, fire fighting, and certain mining occupations essential to safety. (references) |
Source: compiled by the editor from ICON Group International, Inc.; see credits. | ||
| "Sewerage" is generally used as a noun (singular) -- approximately 89.61% of the time. "Sewerage" is used about 77 times out of a sample of 100 million words spoken or written in English. Its rank is based on over 700,000 words used in the English language. Some parts-of-speech are not covered due to the samples used by the British National Corpus. (note: percents less than one-hundredth of one percent have been omitted) |
| Parts of Speech | Percent | Usage per 100 Million Words | Rank in English |
| Noun (singular) | 89.61% | 69 | 40,280 |
| Lexical Verb (infinitive) | 3.9% | 3 | 202,518 |
| Lexical Verb (base form) | 3.9% | 3 | 202,518 |
| Noun (proper) | 2.6% | 2 | 245,945 |
| Total | 100.00% | 77 | N/A |
Source: compiled by the editor from several corpora; see credits.
Expressions using "sewerage": combined sewerage system ♦ sewerage disposal ♦ sewerage system ♦ urban sewerage system. Additional references. | |
| Source: compiled by the editor from various references; see credits. |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Language | Translations for "sewerage"; alternative meanings/domain in parentheses. | |
Albanian | largim i ujërave të zeza, kanale shkarkimi të ujërave të zeza. (various references) | |
Arabic | مجاري (cesspit, drain, drainage). (various references) | |
Bulgarian | канални води (drainage, sewage, waste), канални нечистотии (sewage), канализация (drainage, drains, piping, sanitation, sewage). (various references) | |
Czech | kanalizace (canalization, drainage, sanitation). (various references) | |
Danish | kloaksystem (sewage network, sewer system, sewerage system, water-borne sewage system), kloaknet (sewage network, sewer system, sewerage system). (various references) | |
Dutch | rioolsysteem (sewage network, sewer system, sewerage system), rioolstelsel (sewage network, sewer system, sewerage system), riolering (buried sewer, sewage network, sewer system, sewerage system), riolenstelsel (sewage network, sewer system, sewerage system). (various references) | |
Farsi | فاضلاب (Sewage), مجموع مجرای فاضلاب , زهکشی (Drainage). (various references) | |
Finnish | viemärijärjestelmä (system of sewers), viemäröinti (system of sewers). (various references) | |
French | réseau d'assainissement (sewage network, sewer system, sewerage system), eaux d'égout (sewage). (various references) | |
German | Kanalisation (canalization, drainage, sanitation, sewers). (various references) | |
Greek | σύστημα υπονόμων πόλεωσ τίνοσ, σύστημα υπονόμων (sewage network, sewer system, sewerage system), ιλύσ υπονόμων, δίκτυο υπονόμων (sewage network, sewer system, sewerage system), δίκτυο αποχέτευσησ. (various references) | |
Hebrew | תעלת מעבר, תעול (canalization, drainage), ביוב (canalization, drain, drainage), רשת תעול. (various references) | |
Hungarian | szennyvíz (drainage, refuse water, sewage, slop, waste water), csatornahálózat (arterial drainage, drainage), csatornázás (canalization, channeling, channelling, conduit, drainage, guttering, irrigation). (various references) | |
Italian | sistema di smaltimento delle acque di scarico (sewage network, sewer system, sewerage system), rete fognaria, rete di fognature (sewage network, sewer system, sewerage system). (various references) | |
Japanese Kanji | '液 (drainage), 下水 (ditch, drainage, gutter, sewage). (various references) | |
Japanese Katakana | 'すい (ditch, drainage, gutter, sewage), はいえき (drainage, waste liquid). (various references) | |
Korean | 하수도. (various references) | |
Manx | sornaigys. (various references) | |
Pig Latin | eweragesay.(various references) | |
Portuguese | sistema de esgotos, rede de esgotos (water-borne sewage system), imundícies (sewage). (various references) | |
Romanian | sistem de canalizare, canalizare (canalization, drainage). (various references) | |
Russian | канализация (canalization, sewage). (various references) | |
Serbo-Croatian | kanlizacija. (various references) | |
Spanish | alcantarillado (sewage, sewage system). (various references) | |
Swedish | avloppsnät. (various references) | |
Turkish | lağım suyu (sewage), lağım pisliği (sewage, sewage sludge, soil), kanalizasyon (drain, drainage, gully drain, sewage). (various references) | |
Ukrainian | каналізація (canalization, drainage, sewage), нечистоти (night-soil, ordure, scum, sewage). (various references) | |
Vietnamese | hệ thống cống rãnh (drainage). (various references) | |
| Source: compiled by the editor from various translation references. | ||
Derivations | |
Words beginning with "sewerage": sewerages. (additional references) | |
| |
"Sewerage" is suggested in spellcheckers for the following: sawerage. (additional references) | |
| Source: compiled by the editor, based on several corpora (additional references). | |
| # of Phoneme Matches | Pronunciation | Word(s) rhyming with "sewerage" (pronounced suw"erij) |
| 3 | -er i j | amperage, average, beverage, brokerage, hemorrhage, leverage, pilferage, seigniorage, stockbrokerage, underage. |
Source: compiled by the editor (additional references); see credits. | ||
Scrabble® Enable2K-Verified Anagrams | |
| Words within the letters "a-e-e-e-g-r-s-w" | |
-2 letters: agrees, eagers, eagres, grease, ragees, sewage, swager, wagers. | |
-3 letters: agers, agree, eager, eagre, egers, erase, ewers, gears, geese, grees, ragee, rages, reges, resaw, resee, resew, sager, saree, sarge, sawer, serge, sewar, sewer, swage, sware, swear, sweer, wager, wages, wares, wears. | |
-4 letters: agee, ager, ages, ares, arse, awee, awes, ears, ease, eger, eras, ergs. | |
| Words containing the letters "a-e-e-e-g-r-s-w" | |
+1 letter: sewerages. | |
+2 letters: gearwheels. | |
+3 letters: beggarweeds, steerageway. | |
+4 letters: steerageways. | |
+5 letters: whigmaleeries. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
| 1. Definition 2. Synonyms 3. Crosswords 4. Usage: Commercial | 5. Images: Slideshow 6. Images: Photo Album 7. Quotations: Non-fiction 8. Usage Frequency | 9. Expressions 10. Expressions: Internet 11. Translations: Modern 12. Derivations | 13. Rhymes 14. Anagrams 15. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
