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{{wikipedia p|Sewage treatment}}
== What is Wasterwater?==
{{wikipedia p|Industrial wastewater treatment}}
 
[[Wastewater]] is more commonly known as sewage treatment. Wastewater treatment is a vital part of making sure that we live in a pleasant and healthy environment. [[Wastewater]] typically contains [[pathogens]], and usually '''organic matter''' which allows the pathogens to multiply, and absorbs oxygen from the water. It also contains [[nutrients]], which in the right context are good, but in a natural water body can be very damaging, in a process known as [[eutrophication]].
 
 
{{WP|wastewater}}
 




== What is Wasterwater?==
== Wastewater Treatment and Technology==
  '''Wastewater treatment''' is also known as sewage treatment. an essential part of creating a healthy and pleasant environment.
[[Wastewater]] typically contains [[pathogens]], and usually '''organic matter''' which allows the pathogens to multiply, and absorbs oxygen from the water. It also contains [[nutrients]], which in the right context are good, but in a natural water body can be very damaging, in a process known as [[eutrophication]].


== Effects of Wasterwater==
Appropriate technologies for wastewater treatment may be capable of reducing the health and environmental impact of wastewater. This may include any of the following: lowering the amount of water that people use, which would lower the amount of waste, treating the wastewater anaerobically with a [[biogas digester]], which would extract energy from the waste and reduce the volume, or [[nutrient removal]], for nitrogen and phosphorus.




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Most of the time, [[Physical/Chemical plants]] are used to treat industrial wastewater. This is because they normally contain chemical pollutants that would not be removed completely in a Biological plant. The physical plant process, usually treats [[suspended pollutants]], rather than [[dissolved pollutants]].
Most of the time, [[Physical/Chemical plants]] are used to treat industrial wastewater. This is because they normally contain chemical pollutants that would not be removed completely in a Biological plant. The physical plant process, usually treats [[suspended pollutants]], rather than [[dissolved pollutants]].




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The first stages is a physical processes that takes out the easily removable [[pollutants]]. The pollutants left over are then treated with a more advanced biological or chemical process. The biological and chemcial processes will then do one of the following: 1) convert dissolved or colloidal impurities into a solid or gaseous form, so that they can be easily removed physically, 2) convert them into dissolved materials which remain in the water, but are not considered as bad as the pollutants that started out in the beggining. The solids, more commonly known as sludge or residuals, formed from the previous process also have to be treated, in order to be disposed of.  
The first stages is a physical processes that takes out the easily removable [[pollutants]]. The pollutants left over are then treated with a more advanced biological or chemical process. The biological and chemcial processes will then do one of the following: 1) convert dissolved or colloidal impurities into a solid or gaseous form, so that they can be easily removed physically, 2) convert them into dissolved materials which remain in the water, but are not considered as bad as the pollutants that started out in the beggining. The solids, more commonly known as sludge or residuals, formed from the previous process also have to be treated, in order to be disposed of.  


Another type of wastewater treatment plant would be a Municipal Treatment Plant. These plants, have 3 main..... The first would be a preliminary treatment. The preliminary treatment removes the larger solids, which could clogger or damage the equipment.The equipment generally is along the lines of the following, grinders (comminuters), bar screens, or grit channels. The grinders chop up things like rags and trash. While the bar screens catches the larger objects, the ones that can be raked off of the screen. The grit channels help the heavier materials to settle out, this is to prevent heavy wear on the equipment used farther down in the process. The grit channels also help to remove the larger food particles that remain.  
Another type of wastewater treatment plant would be a Municipal Treatment Plant. These plants, have a three step process. The first part of the process would be a preliminary treatment. The preliminary treatment removes the larger solids, which could clogger or damage the equipment.The equipment generally is along the lines of the following, grinders (comminuters), bar screens, or grit channels. The grinders chop up things like rags and trash. While the bar screens catches the larger objects, the ones that can be raked off of the screen. The grit channels help the heavier materials to settle out, this is to prevent heavy wear on the equipment used farther down in the process. The grit channels also help to remove the larger food particles that remain.
 
The second part is the Primary settling basins. This is where the water flows slowly for several hours, so that the organic matter can settle out. The primary settling basins are either circular or rectangular. Either type of settling basin has to have some type of scraper at the bottom, so that it can collect the settled sludge and direct it to a pit from which it can be pumped to get more treatment. The basin also needs skimmers at the surface, so that is can collect the material that floats to the top.
 
[[Image:psb.gif]]
 
 
The third part of this process is called Secondary treatment. The secondary treatment is usually a biological process, which tries to remove the remaining dissolved or colloidal organic matter. The process is the [[biodegradation]], which takes place in a location where plenty of air can be supplied to the microorganisms. This promotes formation of the less offensive, oxidized products. The design and capacity of this treatment unit is established so that enough of the impurities will be removed to prevent significant oxygen demand in the receiving water after discharge.
 
There are two major types of biological treatment. These two types are: attached growth and suspended growth. During the attached growth process, microorganisms grow on a surface. The more common type of growth process is suspended growth. The suspended growth process is also known as activated sludge system. This system has two parts, an aeration tank and a setteling tank. The aeration tank has a "sludge", which is best described as a mixed microbial culture. This contains mostly bacteria, as well as protozoa, fungi, algae, etc. This sludge is constantly mixed and aerated either by compressed air bubblers located along the bottom, or by mechanical aerators on the surface. The wastewater to be treated enters the tank and mixes with the culture, which uses the organic compounds for growth-- producing more microorganisms--and for respiration, which results mostly in the formation of carbon dioxide and water. 
 
After the sludge has had the proper amount of aeration time, it is carried into the settleing tank.The sludge collected at the bottom is then recycled to the aeration tank to consume more organic material. The term activated sludge is used, because by the time the sludge is returned to the aeration tank, the microorganisms have been in an environment depleted of food for some time, and are in a hungry, or activated condition, eager to start biodegrading some more wastes. Since the amount of [[microorganisms]], or [[biomass]], increases as a result of this process, some must be removed on a regular basis for further treatment and disposal, adding to the solids produced in primary treatment.  


The second is the Primary settling basins. This is where the water flows slowly for several hours, so that the organic matter can settle out. The primary settling basins are either circular or rectangular. Either type of settling basin has to have some type of scraper at the bottom, so that it can collect the settled sludge and direct it to a pit from which it can be pumped to get more treatment. The basin also needs skimmers at the surface, so that is can collect the material that floats to the top.  
[[Image:asp.gif]]






== Equipment Used to Treat wastewater==




{{wikipedia p|Industrial wastewater treatment}}
{{wikipedia p|Sewage treatment}}
{{Wikipedia p|Wastewater}}








Appropriate technologies for wastewater treatment may reduce the health and environmental impact of wastewater ( domestic or in industry by various measures which may include some or all of these steps:
* minimizing the amount of water used, (thus reducing the volume of waste)
* treating the wastewater anaerobically with a [[biogas digester]] (to extract energy from the waste, as well as reducing the volume).
* treating the wastewater aerobically - this .
* [[nutrient removal]] - particularly of nitrogen and phosphorus.


{{stub}}
Ohio State University's fact sheet on wastewater treatment. [http://ohioline.osu.edu/aex-fact/0768.html]
[[Category:Waste management]]
The Siemens, a water treatment facility, page. [http://www.water.siemens.com/en/Pages/default.aspx]
The U.S. Geological Services page. [http://ga.water.usgs.gov/edu/wuww.html]
 
 
[[Category:Wastewater]]
[[Category:Wastewater]]
[[Category:Clean water]]


{{PH261 Page}}
{{PH261 Page}}

Revision as of 16:59, 7 December 2007

What is Wasterwater?

Wastewater is more commonly known as sewage treatment. Wastewater treatment is a vital part of making sure that we live in a pleasant and healthy environment. Wastewater typically contains pathogens, and usually organic matter which allows the pathogens to multiply, and absorbs oxygen from the water. It also contains nutrients, which in the right context are good, but in a natural water body can be very damaging, in a process known as eutrophication.


W


Wastewater Treatment and Technology

Appropriate technologies for wastewater treatment may be capable of reducing the health and environmental impact of wastewater. This may include any of the following: lowering the amount of water that people use, which would lower the amount of waste, treating the wastewater anaerobically with a biogas digester, which would extract energy from the waste and reduce the volume, or nutrient removal, for nitrogen and phosphorus.


How Wastewater is Treated

Wastewater is treated in Wastewater Treatment plants. There are two major types of wastewater treatment plants, biological plants, and physcial/chemical.

Biological plants are mainly used to treat combined domestic and industrial wastewater from municipalities. The biological plants use almost the same process that occurs naturally, during the rceiveing of water. However at the biological treatment plants, the wastewater is being treated under controlled conditions. This is to ensure that the water is fully cleansed before it is placed back into the environment.

Most of the time, Physical/Chemical plants are used to treat industrial wastewater. This is because they normally contain chemical pollutants that would not be removed completely in a Biological plant. The physical plant process, usually treats suspended pollutants, rather than dissolved pollutants.


Wastewater Treatment Plants

A typical Wastewater Treatment Plant has trains with individual unit processes set up. The unit processes include the output or effluent and the input or influent. With the unit process, the effluent of one becomes the influent of another.

The first stages is a physical processes that takes out the easily removable pollutants. The pollutants left over are then treated with a more advanced biological or chemical process. The biological and chemcial processes will then do one of the following: 1) convert dissolved or colloidal impurities into a solid or gaseous form, so that they can be easily removed physically, 2) convert them into dissolved materials which remain in the water, but are not considered as bad as the pollutants that started out in the beggining. The solids, more commonly known as sludge or residuals, formed from the previous process also have to be treated, in order to be disposed of.

Another type of wastewater treatment plant would be a Municipal Treatment Plant. These plants, have a three step process. The first part of the process would be a preliminary treatment. The preliminary treatment removes the larger solids, which could clogger or damage the equipment.The equipment generally is along the lines of the following, grinders (comminuters), bar screens, or grit channels. The grinders chop up things like rags and trash. While the bar screens catches the larger objects, the ones that can be raked off of the screen. The grit channels help the heavier materials to settle out, this is to prevent heavy wear on the equipment used farther down in the process. The grit channels also help to remove the larger food particles that remain.

The second part is the Primary settling basins. This is where the water flows slowly for several hours, so that the organic matter can settle out. The primary settling basins are either circular or rectangular. Either type of settling basin has to have some type of scraper at the bottom, so that it can collect the settled sludge and direct it to a pit from which it can be pumped to get more treatment. The basin also needs skimmers at the surface, so that is can collect the material that floats to the top.

Psb.gif


The third part of this process is called Secondary treatment. The secondary treatment is usually a biological process, which tries to remove the remaining dissolved or colloidal organic matter. The process is the biodegradation, which takes place in a location where plenty of air can be supplied to the microorganisms. This promotes formation of the less offensive, oxidized products. The design and capacity of this treatment unit is established so that enough of the impurities will be removed to prevent significant oxygen demand in the receiving water after discharge.

There are two major types of biological treatment. These two types are: attached growth and suspended growth. During the attached growth process, microorganisms grow on a surface. The more common type of growth process is suspended growth. The suspended growth process is also known as activated sludge system. This system has two parts, an aeration tank and a setteling tank. The aeration tank has a "sludge", which is best described as a mixed microbial culture. This contains mostly bacteria, as well as protozoa, fungi, algae, etc. This sludge is constantly mixed and aerated either by compressed air bubblers located along the bottom, or by mechanical aerators on the surface. The wastewater to be treated enters the tank and mixes with the culture, which uses the organic compounds for growth-- producing more microorganisms--and for respiration, which results mostly in the formation of carbon dioxide and water.

After the sludge has had the proper amount of aeration time, it is carried into the settleing tank.The sludge collected at the bottom is then recycled to the aeration tank to consume more organic material. The term activated sludge is used, because by the time the sludge is returned to the aeration tank, the microorganisms have been in an environment depleted of food for some time, and are in a hungry, or activated condition, eager to start biodegrading some more wastes. Since the amount of microorganisms, or biomass, increases as a result of this process, some must be removed on a regular basis for further treatment and disposal, adding to the solids produced in primary treatment.

Asp.gif



Template:Wikipedia p Template:Wikipedia p Template:Wikipedia p



Ohio State University's fact sheet on wastewater treatment. [1] The Siemens, a water treatment facility, page. [2] The U.S. Geological Services page. [3]


Template:PH261 Page

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