Activated sludge - Knowledge

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to 10 mg/L. Operators should monitor the tank for low DO bacteria, such as S. natans, type 1701 and H. hydrossis, which indicate low DO conditions by elevated effluent turbidity and dark activated sludge with foul odours. Many plants have on-line monitoring equipment that continuously measures and records DO levels at specific points within the aeration tank. These on-line analysers send data to the SCADA system and allow automatic control of the aeration system to maintain a predetermined DO level. Whether generated automatically or taken manually, regular monitoring is necessary to favour organisms that settle well rather than filaments. However, operating the aeration system involves finding a balance between sufficient oxygen for proper treatment and the energy cost, which represents approximately 90% of the total treatment cost.

121: 20: 1128: 1157: 200:(aeration compartment). Facultative bacteria then reduce the nitrate to nitrogen gas in anoxic conditions (anoxic compartment). Moreover, the organisms used for the phosphorus uptake (Polyphosphate Accumulating Organisms) are more efficient under anoxic conditions. These microorganisms accumulate large amounts of phosphates in their cells and are settled in the secondary clarifier. The settled sludge is either disposed of as waste activated sludge or reused in the aeration tank as return activated sludge. Some sludge must always be returned to the aeration tanks to maintain an adequate population of organisms. 137: 954:

plants, a biotic floc is created which provides the required substrate. Package plants are designed and fabricated by specialty engineering firms in dimensions that allow for their transportation to the job site in public highways, typically width and height of 3.7 by 3.7 metres (12 ft × 12 ft). Length varies with capacity with larger plants being fabricated in pieces and welded on site. Steel is preferred over synthetic materials (e.g., plastic) for its durability. Package plants are commonly variants of

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in grams per liter. The MCRT is the total mass (in kilograms or pounds) of mixed liquor suspended solids in the aerator and clarifier divided by the mass flow rate (in kilograms/pounds per day) of mixed liquor suspended solids leaving as WAS and final effluent. The F/M is the ratio of food fed to the microorganisms each day to the mass of microorganisms held under aeration. Specifically, it is the amount of BOD fed to the aerator (in kilograms/pounds per day) divided by the amount (in kilograms or pounds) of

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activated sludge process produces about 70–100 grams per cubic metre (1.9–2.7 oz/cu yd) of waste activated sludge (that is grams of dry solids produced per cubic metre of wastewater treated). 80 grams per cubic metre (2.2 oz/cu yd) is regarded as being typical. In addition, about 110–170 grams per cubic metre (3.0–4.6 oz/cu yd) of primary sludge is produced in the primary sedimentation tanks which most - but not all - of the activated sludge process configurations use.

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the oxygen forced into solution by the pressure at the base of the shaft breaks out as molecular oxygen providing a highly efficient source of oxygen for the activated sludge biota. The rising oxygen and injected return sludge provide the physical mechanism for mixing of the sewage and sludge. Mixed sludge and sewage is decanted at the surface and separated into supernatant and sludge components. The efficiency of deep shaft treatment can be high.

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aeration tank. It usually includes a pump that draws the portion back. The RAS line is designed considering the potential for clogging, settling, and other relatable issues that manage to impact the flow of the activated sludge back to the aeration tank. This line must handle the required flow of the plant and has to be designed to minimize the risk of solids settling or accumulating.

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attached to the inner surface. When the tube is rotated, the vanes spin liquor up and out of the cones drawing new sewage liquor from the base of the tank. In many works, each cone is located in a separate cell that can be isolated from the remaining cells if required for maintenance. Some works may have two cones to a cell and some large works may have 4 cones per cell.

973:. This refers to the way the biological load is processed. In high charged systems, the biological stage is presented with a high organic load and the combined floc and organic material is then oxygenated for a few hours before being charged again with a new load. In the low charged system the biological stage contains a low organic load and is combined with 1110:(SBRs) treat wastewater in batches within the same vessel. This means that the bioreactor and final clarifier are not separated in space but in a timed sequence. The installation consists of at least two identically equipped tanks with a common inlet, which can be alternated between them. While one tank is in settle/decant mode the other is 276:, and other microorganisms - which produces a sludge that is difficult to settle and can result in the sludge blanket decanting over the weirs in the settlement tank to severely contaminate the final effluent quality. This material is often described as sewage fungus but true fungal communities are relatively uncommon. 1059: 1177:

Pure oxygen activated sludge aeration systems are sealed-tank reactor vessels with surface aerator type impellers mounted within the tanks at the oxygen carbon liquor surface interface. The amount of oxygen entrainment, or DO (Dissolved Oxygen), can be controlled by a weir adjusted level control, and

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process. In the UK it is found at three sites: Tilbury, Anglian water, treating a wastewater with a high industrial contribution; Southport, United Utilities, because of land space issues; and Billingham, ICI, again treating industrial effluent, and built (after the Tilbury shafts) by ICI to help the

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To use less space, treat difficult waste, and intermittent flows, a number of designs of hybrid treatment plants have been produced. Such plants often combine at least two stages of the three main treatment stages into one combined stage. In the UK, where a large number of wastewater treatment plants

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Ammonium can have toxic effort on aquatic organism. Nitrification also takes places in bodies of water, which leads to oxygen depletion. Furthermore, nitrate and ammonium are eutophying (fertilizing) nutrients that can impair water bodies. For these reasons, nitrification and, in many cases, nitrogen

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Activated sludge plants are wholly dependent on an electrical supply to power the aerators to transfer settled solids back to the aeration tank inlet, and in many cases to pump waste sludge and final effluent. In some works untreated sewage is lifted by pumps to the head-works to provide sufficient

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Where land is in short supply sewage may be treated by injection of oxygen into a pressured return sludge stream which is injected into the base of a deep columnar tank buried in the ground. Such shafts may be up to 100 metres (330 ft) deep and are filled with sewage liquor. As the sewage rises

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To ensure good bacterial settlement and to avoid sedimentation problems caused by filamentous bacteria, plants using atmospheric air as an oxygen source should maintain a dissolved oxygen (DO) level of about 2 mg/L in the aeration tank. In pure oxygen systems, DO levels are usually in the range of 4

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The SVI is the volume of settled sludge occupied by a given mass of dry sludge solids. It is calculated by dividing the volume of settled sludge in a mixed liquor sample, measured in milliliters per liter of sample (after 30 minutes of settling), by the MLSS (Mixed Liquor Suspended Solids), measured

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The yield of PAOs (Polyphosphate Accumulating Organisms) is reduced between 70 and 80% under aerobic conditions. Even though the phosphorus can be removed upstream of the aeration tank by chemical precipitation (adding metal ions such as: calcium, aluminum or iron), the biological phosphorus removal

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can occur which makes activated sludge difficult to settle and frequently has an adverse impact on final effluent quality. Treating sludge bulking and managing the plant to avoid a recurrence requires skilled management and may require full-time staffing of a works to allow immediate intervention. A

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The activated sludge process for removing carbonaceous pollution begins with an aeration tank where air (or oxygen) is injected into the waste water. This is followed by a settling tank to allow the biological flocs (the sludge blanket) to settle, thus separating the biological sludge from the clear

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process which produces a granular sludge that settles very well (the sludge volume index is reduced from 200–300 to 40 millilitres per gram (192–288 to 38 US fl oz/oz)). A new process reactor system is created to take advantage of this quick settling sludge and is integrated into the

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b) Denitrification: Reduction of nitrate nitrogen to molecular nitrogen, which escapes from the wastewater into the atmosphere. This step can be carried out by microorganism commonly found in sewage treatment plants. However, these only use the nitrate as an electron acceptor if no dissolved oxygen

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In order for denitrification to take place in the activated sludge process, an electron source, a reductant, must therefore also be present that can reduce sufficient nitrate to N2. If there is too little substrate in the raw wastewater, this can be added artificially. In addition, denitrification

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In an aerated basin system, the aerators provide two functions: they transfer air into the basins required by the biological oxidation reactions, and they provide the mixing required for dispersing the air and for contacting the reactants (that is, oxygen, wastewater and microbes). Typically, the

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There are a wide range of types of package plants, often serving small communities or industrial plants that may use hybrid treatment processes often involving the use of aerobic sludge to treat the incoming sewage. In such plants the primary settlement stage of treatment may be omitted. In these

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Treatment of nitrogenous or phosphorous matter comprises the addition of an anoxic compartment inside the aeration tank in order to perform the nitrification-denitrification process more efficiently. First, ammonia is oxidized to nitrite, which is then converted into nitrate in aerobic conditions

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Vertically mounted tubes of up to 1-metre (3.3 ft) diameter extending from just above the base of a deep concrete tank to just below the surface of the sewage liquor. A typical shaft might be 10 metres (33 ft) high. At the surface end, the tube is formed into a cone with helical vanes

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The amount of sewage sludge produced from the activated sludge process is directly proportional to the amount of wastewater treated. The total sludge production consists of the sum of primary sludge from the primary sedimentation tanks as well as waste activated sludge from the bioreactors. The

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Activated sludge is also the name given to the active biological material produced by activated sludge plants. Excess sludge is called "surplus activated sludge" or "waste activated sludge" and is removed from the treatment process to keep "food to biomass" (F/M) ratio in balance (where biomass

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Based on these control methods, the amount of settled solids in the mixed liquor can be varied by wasting activated sludge (WAS) or returning activated sludge (RAS). The returning activated sludge is designed to recycle a portion of the activated sludge from the secondary clarifier back t the

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tanks but on a much larger scale. Air is pumped through the blocks and the curtain of bubbles formed both oxygenates the liquor and also provides the necessary mixing action. Where capacity is limited or the sewage is unusually strong or difficult to treat, oxygen may be used instead of air.

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In some areas, where more land is available, sewage is treated in large round or oval ditches with one or more horizontal aerators typically called brush or disc aerators which drive the mixed liquor around the ditch and provide aeration. These are oxidation ditches, often referred to by

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Nitrification and denitrification are in considerable contradiction with regard to the required environmental conditions. Nitrification requires oxygen and CO2. Denitrification only takes place in the absence of dissolved oxygen and with a sufficient supply of oxidizable substances.

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Biological oxidation processes are sensitive to temperature and, between 0 and 40 °C (32 and 104 °F), the rate of biological reactions increase with temperature. Most surface aerated vessels operate at between 4 and 32 °C (39 and 90 °F).

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to transfer nitrified mixed liquor from the aeration zone to the anoxic zone for denitrification. These pumps are often referred to as internal mixed liquor recycle pumps (IMLR pumps). The raw sewage, the RAS, and the nitrified mixed liquor are mixed by

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manufacturer's trade names such as Pasveer, Orbal, or Carrousel. They have the advantage that they are relatively easy to maintain and are resilient to shock loads that often occur in smaller communities (i.e. at breakfast time and in the evening).

1302:, which produced a highly treated effluent. They aerated the waste-water continuously for about a month and were able to achieve a complete nitrification of the sample material. Believing that the sludge had been activated (in a similar manner to 553: 805: 376:). In the reactor/aerator and clarifier system, the sludge blanket is measured from the bottom of the clarifier to the level of settled solids in the clarifier's water column; this, in large plants, can be done up to three times a day. 1249:

The activated sludge process is an example for a more high-tech, energy intensive or "mechanized" process that is relatively expensive compared to some other wastewater treatment systems. It can provide a very high level of treatment.

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The general process control method is to monitor sludge blanket level, SVI (Sludge Volume Index), MCRT (Mean Cell Residence Time), F/M (Food to Microorganism), as well as the biota of the activated sludge and the major nutrients DO

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aeration tank instead of having a separate unit outside. About 30 Nereda wastewater treatment plants worldwide are operational, under construction or under design, varying in size from 5,000 up to 858,000 person equivalent.

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entrapping fine particulate matter as they do so. It thereby produces a liquid that is relatively free from suspended solids and organic material, and flocculated particles that will readily settle out and can be removed.

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serve small populations, package plants are a viable alternative to building a large structure for each process stage. In the US, package plants are typically used in rural areas, highway rest stops and trailer parks.

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Settling tank (usually referred to as "final clarifier" or "secondary settling tank") to allow the biological flocs (the sludge blanket) to settle, thus separating the biological sludge from the clear treated

1089:/kWh). However, they do not provide as good mixing as is normally achieved in activated sludge systems and therefore aerated basins do not achieve the same performance level as activated sludge units. 407:

a) Nitrification: Oxidation of ammonium nitrogen and organically bound nitrogen to nitrate. Nitrification is very sensitive to inhibitors and can lead to a pH value in poorly buffered water.

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with retention times of 1 to 10 days. The basins may range in depth from 1.5 to 5.0 metres (4.9 to 16.4 ft) and utilize motor-driven aerators floating on the surface of the wastewater.

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Most biological oxidation processes for treating industrial wastewaters have in common the use of oxygen (or air) and microbial action. Surface-aerated basins achieve 80 to 90% removal of

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to remove some wastewater from the mixed liquor prior to treatment. This results in a more concentrated waste product that can then be treated using the activated sludge process.

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Nitrification is associated with the production of acid (H+). This puts a strain on the buffering capacity of the water or a pH value shift may occur, which impairs the process.

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of 24 – 48 hours, and a sludge age of 12 – 20 days. This compares with nitrifying activated sludge plants having a retention time of 8 hours, and a sludge age of 8 – 12 days.

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involving the aeration of sewage in a bottle that had been coated with algae. Fowler's engineering colleagues, Ardern and Lockett, experimented on treating sewage in a

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treated water. Part of the waste sludge is recycled to the aeration tank and the remaining waste sludge is removed for further treatment and ultimate disposal.

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However, the costs of construction are high. Deep Shaft has seen the greatest uptake in Japan, because of the land area issues. Deep Shaft was developed by

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Saikaly PE, Oerther DB (2011). "Diversity of dominant bacterial taxa in activated sludge promotes functional resistance following toxic shock loading".

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corrects the change in H+ concentration (pH value shift) that occurs during nitrification. This is particularly important for poorly buffered water.

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DeepShaft is a patented, licensed, process. The licensee has changed several times and currently (2015) Noram Engineering sells it.

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by two engineers, Edward Ardern and W.T. Lockett, who were conducting research for the Manchester Corporation Rivers Department at

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Their results were published in their seminal 1914 paper, and the first full-scale continuous-flow system was installed at

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fall through the works to enable a satisfactory discharge head for the final effluent. Alternative technologies such as

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The general arrangement of an activated sludge process for removing carbonaceous pollution includes the following items:

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Plant types include package plants, oxidation ditch, deep shaft/vertical treatment, surface-aerated basins, and

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Oxidation ditches are installed commonly as 'fit & forget' technology, with typical design parameters of a

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a vent gas oxygen controlled oxygen feed valve. Oxygen is generated on site by cryogenic distillation of air,

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Surface aerator for aeration tank at activated sludge sewage treatment plant (at Morro Alto Treatment Plant,

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Fine bubble diffusers in aeration tank of activated sludge sewage treatment plant near Adelaide, Australia

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and a range of other filter-feeding species. Other important constituents include motile and sedentary

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floating surface aerators are rated to deliver the amount of air equivalent to 1.8 to 2.7 kilograms

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being introduced into a mixture of screened, and primary treated sewage or industrial wastewater (

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system to re-seed the new wastewater entering the tank. This fraction of the floc is called

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is run off to undergo further treatment before discharge. Part of the settled material, the

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Surface aerators are commonly quoted as having an aeration efficiency of 0.5–1.5 kg O

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is usually mixed with primary sludge from the primary clarifiers and undergoes further

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Activated sludge addition (seeding) to a pilot scale membrane bioreactor in Germany

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grid aeration systems that are attached to the floor. These are like the diffused

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micro-organisms that can digest organic matter in sewage, and clump together by

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The space required for a sewage treatment plant can be reduced by using a

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There are a variety of types of activated sludge plants. These include:

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A Typical Surface-Aerated Basing (using motor-driven floating aerators)

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The combination of wastewater and biological mass is commonly known as

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treatment requires much less power and can operate on gravity alone.

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Aeration tank where air (or oxygen) is injected in the mixed liquor.

27:, UK. The white bubbles are due to the diffused air aeration system. 2249: 2141: 2076: 1455:"Mark van Loosdrecht - Professor at Delft University of Technology" 1140: 1111: 361: 292: 261: 237: 160: 156: 59: 51: 1535: 2176: 1330: 1326: 257: 149: 104:

process which produces a granular sludge that settles very well.

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Wastewater treatment process using aeration and a biological floc

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Wastewater Technology Fact Sheet. Document no. EPA 832-F-00-016.

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A generalized, schematic diagram of an activated sludge process.

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Beychok, M.R. (1971). "Performance of surface-aerated basins".

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the new treatment method spread rapidly, especially to the US,

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The Culture of Flushing: A Social and Legal History of Sewage

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The activated sludge process is a biological process used to

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Typically, the air is generated by some type of air blower.

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Oerther DB, de los Reyes FL, Hernandez M, Raskin L (1999).

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The activated sludge process was discovered in 1913 in the

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to treatment plants designed primarily to treat domestic

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A new development of the activated sludge process is the

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in the anoxic zones in order to achieve denitrification.

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Aerial photo of Kuryanovo wastewater treatment plant in

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new development of the activated sludge process is the

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Aqueous Wastes from Petroleum and Petrochemical Plants

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Two special steps are required for nitrogen removal:

1953:"Wastewater Characteristics, Treatment and Disposal" 1444: 1239:

Sewage treatment § Types of treatment processes

395: 1096: 1991: 1720: 996: 922: 799: 658: 547: 220:) combined with organisms to develop a biological 1575:Wastewater engineering : treatment and reuse 260:. In poorly managed activated sludge, a range of 207: 204:is more economic due to the saving of chemicals. 78:organic pollutants, producing a waste sludge (or 2565: 1638: 1636: 1634: 1210:Secondary treatment § Design considerations 410:Nitrification takes places in following steps: 1899: 1873:Chemical Engineering Progress Symposium Series 1232: 2037: 1870: 1631: 1013:/kWh), diffused aeration as 1.5–2.5 kg O 264:filamentous bacteria can develop - including 1950: 1797: 1727:(1st ed.). John Wiley & Sons Ltd. 1649:. Archived from the original on 2012-09-07. 1151: 2044: 2030: 1716: 1714: 1712: 1710: 1135:Sewage liquor is run into deep tanks with 1968: 1553: 1505:"Explaining the Activated Sludge Process" 1385:List of wastewater treatment technologies 1321:two years later. In the aftermath of the 1245:Sewage treatment § Process selection 1047: 1866: 1864: 1862: 1860: 1775:Review of UK and international standards 1675:"Lesson 8: The Activated Sludge Process" 1265: 1155: 1126: 1057: 135: 127: 119: 111: 18: 1944: 1707: 1172: 155:, oxidising nitrogenous matter (mainly 2566: 1644:"Mathematics For Wastewater Operators" 1604: 1602: 1600: 1185: 1021:/kWh). Deep Shaft claims 5–8 kg O 382:Mixed Liquor Volatile Suspended Solids 339:, followed by thickening, dewatering, 327:refers to the activated sludge). This 170: 2025: 1857: 1840:"NORAM VERTREAT (VERtical TREATment)" 965:Package plants may be referred to as 163:) in biological matter, and removing 132:Activated sludge under the microscope 1567: 1565: 1474: 1472: 1422: 1420: 1122: 321: 82:) containing the oxidized material. 1597: 1117: 240:flora component mainly composed of 13: 2433:Ultraviolet germicidal irradiation 1698: 1614:Water/Wastewater Distance Learning 1555:10.1111/j.1574-6941.1999.tb00604.x 1221:The discharge of toxic industrial 980: 916: 907: 888: 878: 860: 836: 832: 793: 790: 787: 784: 781: 778: 772: 763: 750: 729: 725: 710: 686: 682: 652: 649: 646: 643: 640: 637: 620: 616: 601: 571: 567: 541: 538: 535: 532: 529: 526: 520: 511: 498: 477: 473: 458: 428: 424: 350: 14: 2595: 2303:Agricultural wastewater treatment 1882:Available at CSA Illumina website 1618:Mountain Empire Community College 1562: 1469: 1417: 1272:Davyhulme Sewage Works Laboratory 1203: 948: 396:Nitrification and Denitrification 309:Many sewage treatment plants use 291:, is returned to the head of the 23:Activated sludge tank at Beckton 2547: 2546: 1486:. Partners for Water. 2015-09-10 1097:Sequencing batch reactors (SBRs) 2363:Industrial wastewater treatment 2333:Decentralized wastewater system 1985: 1893: 1832: 1821: 1810: 1786: 1768: 1739: 1701:Nitrifikation-Ammoniakoxidation 1692: 1463:International Water Association 1380:Industrial wastewater treatment 997:Deep shaft / Vertical treatment 175:The process takes advantage of 2051: 1667: 1529: 1497: 940: 881: 719: 610: 467: 208:Bioreactor and final clarifier 153:carbonaceous biological matter 1: 2383:Rotating biological contactor 1793:British Standard BS 6297:1983 1410: 1395:Rotating biological contactor 1803:EPA. Washington, DC (2000). 1610:"Lesson 7: Activated Sludge" 212:The process involves air or 7: 1992:Benidickson, Jamie (2011). 1780:September 28, 2007, at the 1721:Beychok, Milton R. (1967). 1348: 1233:Costs and technology choice 1229:can create process upsets. 1036:, as a spin-off from their 167:(nitrogen and phosphorus). 10: 2600: 2448:Wastewater treatment plant 2215:Adsorbable organic halides 1428:"Activated Sludge Process" 1261: 1242: 1236: 1207: 1100: 1051: 236:but also has an important 107: 2579:Environmental engineering 2542: 2456: 2283: 2220:Biochemical oxygen demand 2205: 2059: 1957:Water Intelligence Online 1951:Von Sperling, M. (2015). 1922:10.1007/s00248-010-9783-6 1659:: CS1 maint: unfit URL ( 1542:FEMS Microbiology Ecology 1198: 1180:pressure swing adsorption 1108:Sequencing batch reactors 370:Biochemical oxygen demand 91:sequencing batch reactors 58:composed of bacteria and 1375:Aerobic treatment system 1370:Aerobic granular reactor 1306:) the process was named 1292:University of Manchester 1152:Surface aerators (cones) 1103:Sequencing batch reactor 991:hydraulic retention time 38:is a type of biological 2408:Sewage sludge treatment 2348:Fecal sludge management 2308:API oil–water separator 2275:Wastewater surveillance 1817:Vertical Shaft Projects 1343:sewage treatment plants 1017:/kWh (3.3–5.5 lb O 1009:/kWh (1.1–3.3 lb O 297:return activated sludge 2265:Total suspended solids 2260:Total dissolved solids 2225:Chemical oxygen demand 1355:Activated sludge model 1284:Davyhulme Sewage Works 1275: 1165: 1132: 1063: 1048:Surface-aerated basins 924: 801: 660: 549: 401:removal is necessary. 374:Chemical oxygen demand 343:and land application. 145: 133: 125: 117: 48:industrial wastewaters 28: 25:sewage treatment plant 2132:Industrial wastewater 1970:10.2166/9781780402086 1300:draw-and-fill reactor 1290:, a scientist at the 1269: 1243:Further information: 1237:Further information: 1208:Further information: 1159: 1130: 1085:(4.0 to 6.0 lb O 1061: 1052:Further information: 1025:/kWh (11–18 lb O 925: 802: 661: 550: 234:Saprotrophic bacteria 139: 131: 123: 115: 42:process for treating 22: 2584:Chemical engineering 2474:Groundwater recharge 1828:Tilbury construction 1173:Pure oxygen aeration 819: 675: 560: 417: 76:biologically oxidize 40:wastewater treatment 2388:Secondary treatment 2373:Membrane bioreactor 2328:Constructed wetland 2127:Infiltration/Inflow 1914:2011MicEc..61..557S 1747:"Code of Practice, 1390:Membrane bioreactor 1365:Aerobic granulation 1186:Recent developments 849: 742: 699: 633: 584: 490: 441: 337:anaerobic digestion 304:membrane bioreactor 267:Sphaerotilus natans 171:Process description 64:secondary treatment 2553:Category: Sewerage 2514:Septic drain field 2479:Infiltration basin 2423:Stabilization pond 2343:Facultative lagoon 2207:Quality indicators 2087:Blackwater (waste) 2067:Acid mine drainage 1887:2007-11-14 at the 1484:Dutch Water Sector 1405:Thermal hydrolysis 1276: 1166: 1133: 1064: 977:for longer times. 920: 835: 797: 728: 685: 656: 619: 570: 545: 476: 427: 316:submersible mixers 224:which reduces the 146: 134: 126: 118: 29: 2561: 2560: 2338:Extended aeration 2285:Treatment options 2235:Oxygen saturation 2082:Blackwater (coal) 2060:Sources and types 1963:: 9781780402086. 1902:Microbial Ecology 1805:"Package Plants." 1749:Flows and Loads-2 1699:Mohren, Andreas. 1517:on 17 August 2012 1123:Diffused aeration 1041:agent sell more. 956:extended aeration 905: 886: 877: 858: 831: 825: 724: 708: 681: 669:this results in: 615: 599: 566: 472: 456: 423: 322:Sludge production 54:and a biological 2591: 2550: 2549: 2469:Evaporation pond 2457:Disposal options 2428:Trickling filter 2413:Sewage treatment 2313:Carbon filtering 2293:Activated sludge 2046: 2039: 2032: 2023: 2022: 2016: 2015: 2013: 2012: 1989: 1983: 1982: 1972: 1948: 1942: 1941: 1897: 1891: 1880: 1868: 1855: 1854: 1852: 1851: 1842:. Archived from 1836: 1830: 1825: 1819: 1814: 1808: 1801: 1795: 1790: 1784: 1772: 1766: 1765: 1763: 1762: 1753:. Archived from 1751:, British Water" 1743: 1737: 1736: 1718: 1705: 1704: 1696: 1690: 1689: 1687: 1685: 1671: 1665: 1664: 1658: 1650: 1648: 1640: 1629: 1628: 1626: 1625: 1606: 1595: 1594: 1578: 1569: 1560: 1559: 1557: 1533: 1527: 1526: 1524: 1522: 1516: 1509: 1501: 1495: 1494: 1492: 1491: 1476: 1467: 1466: 1451: 1442: 1441: 1439: 1438: 1424: 1308:activated sludge 1304:activated carbon 1256:trickling filter 1118:Aeration methods 929: 927: 926: 921: 919: 915: 914: 903: 896: 895: 884: 875: 868: 867: 856: 848: 843: 829: 823: 806: 804: 803: 798: 796: 771: 770: 758: 757: 741: 736: 722: 718: 717: 706: 698: 693: 679: 665: 663: 662: 657: 655: 632: 627: 613: 609: 608: 597: 583: 578: 564: 554: 552: 551: 546: 544: 519: 518: 506: 505: 489: 484: 470: 466: 465: 454: 440: 435: 421: 358:Dissolved oxygen 333:sludge treatment 311:axial flow pumps 33:activated sludge 2599: 2598: 2594: 2593: 2592: 2590: 2589: 2588: 2564: 2563: 2562: 2557: 2538: 2504:Reclaimed water 2452: 2378:Reverse osmosis 2279: 2201: 2167:Reverse osmosis 2092:Boiler blowdown 2055: 2050: 2020: 2019: 2010: 2008: 2006: 1990: 1986: 1949: 1945: 1898: 1894: 1889:Wayback Machine 1879:(107): 322–339. 1869: 1858: 1849: 1847: 1838: 1837: 1833: 1826: 1822: 1815: 1811: 1802: 1798: 1791: 1787: 1782:Wayback Machine 1773: 1769: 1760: 1758: 1745: 1744: 1740: 1719: 1708: 1697: 1693: 1683: 1681: 1673: 1672: 1668: 1652: 1651: 1646: 1642: 1641: 1632: 1623: 1621: 1608: 1607: 1598: 1591: 1571: 1570: 1563: 1534: 1530: 1520: 1518: 1514: 1507: 1503: 1502: 1498: 1489: 1487: 1478: 1477: 1470: 1453: 1452: 1445: 1436: 1434: 1426: 1425: 1418: 1413: 1351: 1323:First World War 1313: 1264: 1247: 1241: 1235: 1212: 1206: 1201: 1188: 1175: 1154: 1125: 1120: 1105: 1099: 1088: 1079: 1056: 1050: 1028: 1024: 1020: 1016: 1012: 1008: 999: 983: 981:Oxidation ditch 951: 943: 910: 906: 891: 887: 863: 859: 844: 839: 822: 820: 817: 816: 766: 762: 753: 749: 737: 732: 713: 709: 694: 689: 678: 676: 673: 672: 628: 623: 604: 600: 579: 574: 563: 561: 558: 557: 514: 510: 501: 497: 485: 480: 461: 457: 436: 431: 420: 418: 415: 414: 398: 353: 351:Process control 335:for example by 324: 228:content of the 210: 173: 110: 17: 12: 11: 5: 2597: 2587: 2586: 2581: 2576: 2559: 2558: 2556: 2555: 2543: 2540: 2539: 2537: 2536: 2531: 2529:Surface runoff 2526: 2521: 2516: 2511: 2509:Sanitary sewer 2506: 2501: 2499:Marine outfall 2496: 2494:Marine dumping 2491: 2486: 2484:Injection well 2481: 2476: 2471: 2466: 2464:Combined sewer 2460: 2458: 2454: 2453: 2451: 2450: 2445: 2440: 2435: 2430: 2425: 2420: 2415: 2410: 2405: 2403:Settling basin 2400: 2395: 2390: 2385: 2380: 2375: 2370: 2365: 2360: 2355: 2350: 2345: 2340: 2335: 2330: 2325: 2320: 2315: 2310: 2305: 2300: 2298:Aerated lagoon 2295: 2289: 2287: 2281: 2280: 2278: 2277: 2272: 2267: 2262: 2257: 2252: 2247: 2242: 2237: 2232: 2230:Coliform index 2227: 2222: 2217: 2211: 2209: 2203: 2202: 2200: 2199: 2194: 2189: 2184: 2179: 2174: 2172:Sanitary sewer 2169: 2164: 2159: 2157:Produced water 2154: 2149: 2144: 2139: 2134: 2129: 2124: 2119: 2114: 2109: 2104: 2102:Combined sewer 2099: 2094: 2089: 2084: 2079: 2074: 2069: 2063: 2061: 2057: 2056: 2049: 2048: 2041: 2034: 2026: 2018: 2017: 2004: 1984: 1943: 1908:(3): 557–567. 1892: 1856: 1831: 1820: 1809: 1796: 1785: 1767: 1738: 1706: 1691: 1679:water.mecc.edu 1666: 1630: 1596: 1589: 1561: 1548:(2): 129–136. 1528: 1496: 1468: 1443: 1432:web.deu.edu.tr 1415: 1414: 1412: 1409: 1408: 1407: 1402: 1400:Sludge bulking 1397: 1392: 1387: 1382: 1377: 1372: 1367: 1362: 1360:Aerated lagoon 1357: 1350: 1347: 1314:and ammonia.) 1311: 1288:Gilbert Fowler 1280:United Kingdom 1263: 1260: 1234: 1231: 1215:Sludge bulking 1205: 1204:Process upsets 1202: 1200: 1197: 1187: 1184: 1174: 1171: 1153: 1150: 1124: 1121: 1119: 1116: 1101:Main article: 1098: 1095: 1086: 1077: 1054:Aerated lagoon 1049: 1046: 1026: 1022: 1018: 1014: 1010: 1006: 998: 995: 982: 979: 950: 949:Package plants 947: 942: 939: 918: 913: 909: 902: 899: 894: 890: 883: 880: 874: 871: 866: 862: 855: 852: 847: 842: 838: 834: 828: 795: 792: 789: 786: 783: 780: 777: 774: 769: 765: 761: 756: 752: 748: 745: 740: 735: 731: 727: 721: 716: 712: 705: 702: 697: 692: 688: 684: 667: 666: 654: 651: 648: 645: 642: 639: 636: 631: 626: 622: 618: 612: 607: 603: 596: 593: 590: 587: 582: 577: 573: 569: 555: 543: 540: 537: 534: 531: 528: 525: 522: 517: 513: 509: 504: 500: 496: 493: 488: 483: 479: 475: 469: 464: 460: 453: 450: 447: 444: 439: 434: 430: 426: 397: 394: 352: 349: 323: 320: 209: 206: 197: 196: 192: 172: 169: 109: 106: 97:Sludge bulking 72:microorganisms 15: 9: 6: 4: 3: 2: 2596: 2585: 2582: 2580: 2577: 2575: 2572: 2571: 2569: 2554: 2545: 2544: 2541: 2535: 2532: 2530: 2527: 2525: 2522: 2520: 2517: 2515: 2512: 2510: 2507: 2505: 2502: 2500: 2497: 2495: 2492: 2490: 2487: 2485: 2482: 2480: 2477: 2475: 2472: 2470: 2467: 2465: 2462: 2461: 2459: 2455: 2449: 2446: 2444: 2441: 2439: 2436: 2434: 2431: 2429: 2426: 2424: 2421: 2419: 2416: 2414: 2411: 2409: 2406: 2404: 2401: 2399: 2396: 2394: 2393:Sedimentation 2391: 2389: 2386: 2384: 2381: 2379: 2376: 2374: 2371: 2369: 2366: 2364: 2361: 2359: 2356: 2354: 2351: 2349: 2346: 2344: 2341: 2339: 2336: 2334: 2331: 2329: 2326: 2324: 2321: 2319: 2316: 2314: 2311: 2309: 2306: 2304: 2301: 2299: 2296: 2294: 2291: 2290: 2288: 2286: 2282: 2276: 2273: 2271: 2268: 2266: 2263: 2261: 2258: 2256: 2253: 2251: 2248: 2246: 2243: 2241: 2238: 2236: 2233: 2231: 2228: 2226: 2223: 2221: 2218: 2216: 2213: 2212: 2210: 2208: 2204: 2198: 2195: 2193: 2190: 2188: 2187:Sewage sludge 2185: 2183: 2180: 2178: 2175: 2173: 2170: 2168: 2165: 2163: 2160: 2158: 2155: 2153: 2150: 2148: 2145: 2143: 2140: 2138: 2135: 2133: 2130: 2128: 2125: 2123: 2120: 2118: 2115: 2113: 2112:Cooling water 2110: 2108: 2107:Cooling tower 2105: 2103: 2100: 2098: 2095: 2093: 2090: 2088: 2085: 2083: 2080: 2078: 2075: 2073: 2072:Ballast water 2070: 2068: 2065: 2064: 2062: 2058: 2054: 2047: 2042: 2040: 2035: 2033: 2028: 2027: 2024: 2007: 2005:9780774841382 2001: 1998:. UBC Press. 1997: 1996: 1988: 1980: 1976: 1971: 1966: 1962: 1958: 1954: 1947: 1939: 1935: 1931: 1927: 1923: 1919: 1915: 1911: 1907: 1903: 1896: 1890: 1886: 1883: 1878: 1874: 1867: 1865: 1863: 1861: 1846:on 2015-07-03 1845: 1841: 1835: 1829: 1824: 1818: 1813: 1806: 1800: 1794: 1789: 1783: 1779: 1776: 1771: 1757:on 2009-03-26 1756: 1752: 1750: 1742: 1734: 1730: 1726: 1725: 1717: 1715: 1713: 1711: 1702: 1695: 1680: 1676: 1670: 1662: 1656: 1645: 1639: 1637: 1635: 1619: 1615: 1611: 1605: 1603: 1601: 1592: 1590:0-07-112250-8 1586: 1582: 1577: 1576: 1568: 1566: 1556: 1551: 1547: 1543: 1539: 1532: 1513: 1506: 1500: 1485: 1481: 1475: 1473: 1465:. 2015-10-13. 1464: 1460: 1456: 1450: 1448: 1433: 1429: 1423: 1421: 1416: 1406: 1403: 1401: 1398: 1396: 1393: 1391: 1388: 1386: 1383: 1381: 1378: 1376: 1373: 1371: 1368: 1366: 1363: 1361: 1358: 1356: 1353: 1352: 1346: 1345:were common. 1344: 1340: 1339:sewer systems 1336: 1332: 1328: 1324: 1320: 1315: 1309: 1305: 1301: 1297: 1296:Massachusetts 1293: 1289: 1285: 1281: 1273: 1268: 1259: 1257: 1251: 1246: 1240: 1230: 1228: 1224: 1219: 1216: 1211: 1196: 1193: 1183: 1181: 1170: 1163: 1158: 1149: 1146: 1145:tropical fish 1142: 1138: 1129: 1115: 1114:and filling. 1113: 1109: 1104: 1094: 1090: 1084: 1080: 1071: 1069: 1060: 1055: 1045: 1042: 1039: 1035: 1030: 1003: 994: 992: 987: 978: 976: 972: 968: 963: 959: 957: 946: 938: 934: 930: 911: 900: 897: 892: 872: 869: 864: 853: 850: 845: 840: 826: 814: 810: 807: 775: 767: 759: 754: 746: 743: 738: 733: 714: 703: 700: 695: 690: 670: 634: 629: 624: 605: 594: 591: 588: 585: 580: 575: 556: 523: 515: 507: 502: 494: 491: 486: 481: 462: 451: 448: 445: 442: 437: 432: 413: 412: 411: 408: 405: 402: 393: 389: 385: 383: 377: 375: 371: 367: 363: 359: 348: 344: 342: 338: 334: 330: 329:sewage sludge 319: 317: 312: 307: 305: 300: 298: 294: 290: 286: 282: 277: 275: 274: 269: 268: 263: 259: 255: 251: 247: 243: 239: 235: 231: 227: 223: 219: 215: 205: 201: 193: 190: 189: 188: 185: 182: 178: 168: 166: 162: 158: 154: 151: 143: 138: 130: 122: 114: 105: 103: 98: 94: 92: 87: 83: 81: 77: 73: 69: 65: 61: 57: 53: 49: 45: 41: 37: 34: 26: 21: 2534:Vacuum sewer 2418:Sewer mining 2368:Ion exchange 2318:Chlorination 2292: 2240:Heavy metals 2197:Urban runoff 2137:Ion exchange 2117:Fecal sludge 2009:. Retrieved 1994: 1987: 1960: 1956: 1946: 1905: 1901: 1895: 1876: 1872: 1848:. Retrieved 1844:the original 1834: 1823: 1812: 1799: 1788: 1770: 1759:. Retrieved 1755:the original 1748: 1741: 1722: 1700: 1694: 1682:. Retrieved 1678: 1669: 1622:. Retrieved 1620:. 2013-03-19 1613: 1574: 1545: 1541: 1531: 1519:. Retrieved 1512:the original 1499: 1488:. Retrieved 1483: 1458: 1435:. Retrieved 1431: 1316: 1307: 1277: 1252: 1248: 1220: 1213: 1189: 1176: 1167: 1134: 1106: 1091: 1072: 1065: 1043: 1031: 1004: 1000: 988: 984: 970: 967:high charged 966: 964: 960: 952: 944: 935: 931: 815: 813:is present. 811: 808: 671: 668: 409: 406: 403: 399: 390: 386: 378: 372:), and COD ( 354: 345: 325: 308: 301: 296: 281:mixed liquor 280: 278: 271: 265: 262:mucilaginous 254:Vorticellids 211: 202: 198: 186: 181:flocculation 174: 147: 95: 88: 84: 35: 32: 30: 2524:Storm drain 2519:Sewage farm 2443:Vermifilter 2398:Septic tank 2358:Imhoff tank 2255:Temperature 2162:Return flow 2152:Papermaking 1286:. In 1912, 971:low charged 941:Plant types 285:supernatant 246:Spirotrichs 2568:Categories 2489:Irrigation 2353:Filtration 2053:Wastewater 2011:2013-02-07 1850:2015-08-13 1761:2007-09-08 1624:2022-02-19 1521:6 February 1490:2016-05-03 1459:The Source 1437:2019-12-27 1411:References 1162:Vespasiano 975:flocculate 341:composting 299:(R.A.S.). 252:including 250:Peritrichs 218:wastewater 2323:Clarifier 2270:Turbidity 2122:Greywater 1979:1476-1777 1684:19 August 1319:Worcester 1223:pollution 1164:, Brazil) 882:⟶ 846:− 739:− 720:⟶ 630:− 611:⟶ 581:− 487:− 468:⟶ 366:phosphate 238:protozoan 165:nutrients 2574:Sewerage 2250:Salinity 2142:Leachate 2077:Bathroom 1938:38062767 1930:21153808 1885:Archived 1778:Archived 1733:67019834 1655:cite web 1349:See also 1143:used in 1141:airstone 1137:diffuser 1112:aerating 362:nitrogen 293:aeration 273:Gordonia 258:Rotifers 161:nitrogen 157:ammonium 144:, Russia 60:protozoa 52:aeration 2177:Septage 1910:Bibcode 1331:Germany 1327:Denmark 1262:History 1038:Pruteen 1029:/kWh). 368:, BOD ( 242:amoebae 226:organic 177:aerobic 150:oxidise 108:Purpose 36:process 2551: 2192:Toilet 2182:Sewage 2147:Manure 2002: 1977: 1936: 1928: 1731: 1587: 1335:Canada 1227:sewage 1199:Issues 1192:Nereda 904: 885: 876: 857: 830: 824: 723: 707: 680: 614: 598: 565: 471: 455: 422: 289:sludge 230:sewage 214:oxygen 195:water. 142:Moscow 102:Nereda 70:) and 68:oxygen 50:using 44:sewage 2097:Brine 1934:S2CID 1647:(PDF) 1515:(PDF) 1508:(PDF) 2438:UASB 2000:ISBN 1975:ISSN 1926:PMID 1729:LCCN 1686:2024 1661:link 1585:ISBN 1581:1456 1523:2022 1341:and 1333:and 1270:The 222:floc 159:and 80:floc 56:floc 31:The 1965:doi 1918:doi 1550:doi 1083:kWh 1068:BOD 1034:ICI 969:or 360:), 74:to 46:or 2570:: 2245:pH 1973:. 1959:. 1955:. 1932:. 1924:. 1916:. 1906:61 1904:. 1877:67 1875:. 1859:^ 1709:^ 1677:. 1657:}} 1653:{{ 1633:^ 1616:. 1612:. 1599:^ 1583:. 1564:^ 1546:29 1544:. 1540:. 1482:. 1471:^ 1461:. 1457:. 1446:^ 1430:. 1419:^ 1329:, 873:10 364:, 270:, 248:, 244:, 2045:e 2038:t 2031:v 2014:. 1981:. 1967:: 1961:6 1940:. 1920:: 1912:: 1853:. 1764:. 1735:. 1703:. 1688:. 1663:) 1627:. 1593:. 1558:. 1552:: 1525:. 1493:. 1440:. 1312:5 1087:2 1081:/ 1078:2 1076:O 1027:2 1023:2 1019:2 1015:2 1011:2 1007:2 917:O 912:2 908:H 901:6 898:+ 893:2 889:N 879:H 870:+ 865:+ 861:H 854:2 851:+ 841:3 837:O 833:N 827:2 794:y 791:g 788:r 785:e 782:n 779:E 776:+ 773:O 768:2 764:H 760:+ 755:+ 751:H 747:2 744:+ 734:3 730:O 726:N 715:2 711:O 704:2 701:+ 696:+ 691:4 687:H 683:N 653:y 650:g 647:r 644:e 641:n 638:E 635:+ 625:3 621:O 617:N 606:2 602:O 595:5 592:, 589:0 586:+ 576:2 572:O 568:N 542:y 539:g 536:r 533:e 530:n 527:E 524:+ 521:O 516:2 512:H 508:+ 503:+ 499:H 495:2 492:+ 482:2 478:O 474:N 463:2 459:O 452:5 449:, 446:1 443:+ 438:+ 433:4 429:H 425:N 356:(

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