Growing algae - Revision history

Jmdonev: 1 revision imported

2019-01-04T18:15:22Z

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2dev>Rudi.Meyer at 20:19, 17 December 2018

2018-12-17T20:19:59Z

← Older revision		Revision as of 20:19, 17 December 2018
Line 1:		Line 1:
	[[Category: Done ~~2015~~-09-06]]		[[Category:Done 2018-12-10]] [[Category: Ashley edit]]
	[[~~File~~:AlgaePondRaceway.jpg\|400px\|thumbnail\|right\|<center>Figure 1. Open Pond / Raceway<ref name=web1>Y. Chisti, 2007 Biodiesel from microalgae, Biotechnology Advances, (May-June 2007), pp. 294-306</ref></center>]]		<onlyinclude>'''Growing algae''' is important as [[algae]] are used as a food supplement, a [[biofuel]] resource, a [[chemical]] [[resource]], and a [[waste management system]].</onlyinclude> The growth of algae generally takes place in one of three different forms:
	<onlyinclude>'''Growing algae''' is important as [[algae]] is used as a food supplement, a [[biofuel]] resource, a [[chemical]] [[resource]] and a [[waste management system]].</onlyinclude> The growth of algae generally takes place in one of three different forms:

	1) Open Pond / Raceway		1) Open Pond / Raceway
Line 10:		Line 9:

	== Open Pond / Raceway ==		== Open Pond / Raceway ==
	A raceway pond (~~figure~~ 1) grows algae as it moves along a [[water]] channel circuit that is usually about 30 [[cm]] deep. The base of the winding channel is usually constructed out of compacted dirt and/or cement and lined with white reflective material (usually plastic). Flow through the channel is provided by a paddle-wheel that is located between the extractor of mature algae and the feeder of new algae, while the flow is directed around the bends by baffles, as shown in the figure below.<ref name=web1/>		[[File:AlgaePondRaceway.jpg\|400px\|thumbnail\|right\|Figure 1. Open Pond / Raceway<ref name=web1>Y. Chisti, 2007 Biodiesel from microalgae, Biotechnology Advances, (May-June 2007), pp. 294-306</ref>]]
	Raceway ponds are desirable for their large scalability and low set-up costs but experience significant water loss through evaporation. The raceway pond also experiences [[temperature]] fluctuations and [[carbon dioxide]] losses to the surrounding environment. Productivity is affected by contamination with unwanted algae and microorganisms that feed on algae~~, while~~ concentration of algae ~~remains~~ low ~~because~~ raceways ~~are~~ poorly mixed.		A raceway pond (Figure 1) grows algae as it moves along a [[water]] channel circuit that is usually about 30 [[cm]] deep. The base of the winding channel is usually constructed out of compacted dirt and/or cement and lined with a white reflective material (usually plastic). Flow through the channel is provided by a paddle-wheel that is located between the extractor of mature algae and the feeder of new algae, while the flow is directed around the bends by baffles, as shown in the figure below.<ref name=web1/>
			Raceway ponds are desirable for their large scalability and low set-up costs but experience significant water loss through [[evaporation]]. The raceway pond also experiences [[temperature]] fluctuations and [[carbon dioxide]] losses to the surrounding environment. Productivity is affected by contamination with unwanted algae types and microorganisms that feed on algae. The concentration of algae can remain low due to raceways being poorly mixed.

	== Tubular Bioreactor ==		== Tubular Bioreactor ==
	[[File:TubularBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 2. Tubular bioreactor<ref name=web1/></center>]]		[[File:TubularBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 2. Tubular bioreactor<ref name=web1/></center>]]
	A tubular bioreactor (~~figure~~ 2) grows algae in an array of plastic or glass tubes that have CO<sub>2</sub> ~~being~~ constantly fed through the closed system along with the necessary nutrients, such as nitrogen, phosphorus and iron.<ref>J.U. Grobbelaar, Algal nutrition, A. Richmond (Ed.), Handbook of microalgal culture: biotechnology and applied phycology, Blackwell (2004), pp. 97–115</ref> The tubes are generally less than 10cm in diameter to allow for [[light]] to penetrate ~~through~~ to all of the algae. The array of ~~clear~~ tubes is arranged horizontally, vertically or on a slant but always oriented running north to south. This arrangement allows for semi-continuous growth of algae, as the fresh algae culture is being fed into the bioreactor at the same rate at which the mature algae is being drawn out. ~~algae~~ production is stopped periodically in order to clean the tubes.<ref name=web1/>		A tubular bioreactor (Figure 2) grows algae in an array of clear plastic or glass tubes that have CO<sub>2</sub> constantly fed through the closed system along with the necessary nutrients, such as [[nitrogen]], [[phosphorus]], and [[iron]].<ref>J.U. Grobbelaar, Algal nutrition, A. Richmond (Ed.), Handbook of microalgal culture: biotechnology and applied phycology, Blackwell (2004), pp. 97–115</ref> The tubes are generally less than 10cm in diameter to allow for [[light]] to penetrate to all of the algae. The array of tubes is arranged horizontally, vertically, or on a slant but always oriented running north to south. This arrangement allows for the semi-continuous growth of algae, as the fresh algae culture is being fed into the bioreactor at the same rate at which the mature algae is being drawn out. Algae production is stopped periodically in order to clean the tubes.<ref name=web1/>
	The recycled growth medium and fresh young culture in a new medium are degassed to remove the oxygen and bubbles from the new culture before being fed into the tubular bioreactor. Excess [[oxygen]] needs to be removed from the system because oxygen concentrations above 4 times that of air will prevent algae growth.<ref name=book1>E. Molina Grima, J. Fernández, F.G. Acién Fernández, Y. Chisti, Tubular photobioreactor design for algal cultures, J Biotechnol, 92 (2001), pp. 113–131</ref> The feeding of [[carbon dioxide\|CO<sub>2</sub>]] and other inorganic supplements mentioned ~~earlier~~ happens at the entrance to the tubes and at locations along the length of the tube as required. Testing sites are necessary along the length of the tubular bioreactor to control the [[pH]] and inorganic salt concentrations at different stages of the algae growth. The best photosynthetic conversion rates are achieved at tubular diameters of 2-5 cm.<ref name=web2>M.A. Borowitzka, 1999, Commercial production of algae: ponds, tanks, tubes and [[ferment]]ers, Journal of Biotechnology, 70 (1999), pp. 313-321</ref>		The recycled growth medium and fresh young culture in a new medium are degassed to remove the oxygen and bubbles from the new culture before being fed into the tubular bioreactor. Excess [[oxygen]] needs to be removed from the system because oxygen concentrations above 4 times that of air will prevent algae growth.<ref name=book1>E. Molina Grima, J. Fernández, F.G. Acién Fernández, Y. Chisti, Tubular photobioreactor design for algal cultures, J Biotechnol, 92 (2001), pp. 113–131</ref> The feeding of [[carbon dioxide\|CO<sub>2</sub>]] and other inorganic supplements mentioned above happens at the entrance to the tubes and at locations along the length of the tube as required. Testing sites are necessary along the length of the tubular bioreactor to control the [[pH]] and inorganic salt concentrations at different stages of the algae growth. The best photosynthetic conversion rates are achieved at tubular diameters of 2-5 cm.<ref name=web2>M.A. Borowitzka, 1999, Commercial production of algae: ponds, tanks, tubes and [[ferment]]ers, Journal of Biotechnology, 70 (1999), pp. 313-321</ref>

	== Vertical Bag Bioreactor ==		== Vertical Bag Bioreactor ==
	[[File:VerticalBagBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 3. Vertical bag bioreactor<ref>C. Gramling, "As Green As It Gets: Algae Biofuels", Earth Magazine. [Online] 2009. Available: http://www.earthmagazine.org/article/green-it-gets-algae-biofuels</ref></center>]]		[[File:VerticalBagBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 3. Vertical bag bioreactor<ref>C. Gramling, "As Green As It Gets: Algae Biofuels", Earth Magazine. [Online] 2009. Available: http://www.earthmagazine.org/article/green-it-gets-algae-biofuels</ref></center>]]
	A vertical bag system (~~figure~~ 3) grows algae in an aqueous solution within a closed bag usually 2-4 cm thick for optimum photosynthetic [[efficiency]].<ref name=web2/> The CO<sub>2</sub> and other inorganic nutrients are fed through the system from the top, bottom or sides of the bag and bubbled through the algae. Exhaust gases rich in oxygen are siphoned off of the top of the vertical bags to reduce the oxygen in the growth medium, as too much oxygen inhibits algae growth.<ref name=book1/> The vertical bag system was derived from the tubular bioreactor system in order to reduce material start-up costs and allow for easier modification of the system (adding and removing testing and feeding points is much easier with a vertical bag).		A vertical bag system (Figure 3) grows algae in an aqueous solution within a closed bag usually 2-4 cm thick for optimum photosynthetic [[efficiency]].<ref name=web2/> The CO<sub>2</sub> and other inorganic nutrients are fed through the system from the top, bottom, or sides of the bag and bubbled through the algae. Exhaust gases rich in oxygen are siphoned off of the top of the vertical bags to reduce the oxygen in the growth medium, as too much oxygen inhibits algae growth.<ref name=book1/> The vertical bag system was derived from the tubular bioreactor system in order to reduce material start-up costs and allow for easier modification of the system (adding and removing testing and feeding points is much easier with a vertical bag).

	The vertical bag system is very good for a laboratory setting as any size ~~of algae batches~~ can be made with it. Lab trials have found that the bags needed to be replaced every 60-90 days as contaminants build up in the system and prevent effective algae growth.<ref>Long-term outdoor growth and lipid productivity of Tetraselmis suecica, Dunaliella tertiolecta and Chlorella sp (Chlorophyta) in bag photobioreactors, Navid Reza Moheimani Received: 19 January 2012 / Revised and accepted: 19 April 2012 / Published online: 12 May 2012# Springer Science+Business Media B.V. 2012</ref>		The vertical bag system is very good for a laboratory setting because algal batches of any size can be made with it. Lab trials have found that the bags needed to be replaced every 60-90 days as contaminants build up in the system and prevent effective algae growth.<ref>Long-term outdoor growth and lipid productivity of Tetraselmis suecica, Dunaliella tertiolecta and Chlorella sp (Chlorophyta) in bag photobioreactors, Navid Reza Moheimani Received: 19 January 2012 / Revised and accepted: 19 April 2012 / Published online: 12 May 2012# Springer Science+Business Media B.V. 2012</ref>

			==For Further Reading==
			*[[Algae]]
			*[[Photosynthesis]]
			*[[Oxygen]]
			*[[Water]]
			*[[Carbon dioxide]]
			*Or explore a [[Special:Random\|random page]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

J.williams: 1 revision imported

2015-09-18T16:51:39Z

1 revision imported

← Older revision	Revision as of 16:51, 18 September 2015
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Kjstenho at 20:59, 3 September 2015

2015-09-03T20:59:31Z

← Older revision		Revision as of 20:59, 3 September 2015
Line 1:		Line 1:
	[[Category:Done 2015-06~~-01~~]]		[[Category: Done 2015-09-06]]
	[[File:AlgaePondRaceway.jpg\|400px\|thumbnail\|right\|<center>Figure 1. Open Pond / Raceway<ref name=web1>Y. Chisti, 2007 Biodiesel from microalgae, Biotechnology Advances, (May-June 2007), pp. 294-306</ref></center>]]		[[File:AlgaePondRaceway.jpg\|400px\|thumbnail\|right\|<center>Figure 1. Open Pond / Raceway<ref name=web1>Y. Chisti, 2007 Biodiesel from microalgae, Biotechnology Advances, (May-June 2007), pp. 294-306</ref></center>]]
	<onlyinclude>'''Growing algae''' is important as [[algae]] is used as a food supplement, a [[biofuel]] resource, a chemical resource and a [[waste management system]].</onlyinclude> The growth of algae generally takes place in one of three different forms:		<onlyinclude>'''Growing algae''' is important as [[algae]] is used as a food supplement, a [[biofuel]] resource, a [[chemical]] [[resource]] and a [[waste management system]].</onlyinclude> The growth of algae generally takes place in one of three different forms:

	1) Open Pond / Raceway		1) Open Pond / Raceway
Line 10:		Line 10:

	== Open Pond / Raceway ==		== Open Pond / Raceway ==
	A raceway pond (figure 1) grows algae as it moves along a water channel circuit that is usually about 30 [[cm]] deep. The base of the winding channel is usually constructed out of compacted dirt and/or cement and lined with white reflective material (usually plastic). Flow through the channel is provided by a paddle-wheel that is located between the extractor of mature algae and the feeder of new algae, while the flow is directed around the bends by baffles, as shown in the figure below.<ref name=web1/>		A raceway pond (figure 1) grows algae as it moves along a [[water]] channel circuit that is usually about 30 [[cm]] deep. The base of the winding channel is usually constructed out of compacted dirt and/or cement and lined with white reflective material (usually plastic). Flow through the channel is provided by a paddle-wheel that is located between the extractor of mature algae and the feeder of new algae, while the flow is directed around the bends by baffles, as shown in the figure below.<ref name=web1/>
	Raceway ponds are desirable for their large scalability and low set-up costs but experience significant water loss through evaporation. The raceway pond also experiences [[temperature]] fluctuations and [[carbon dioxide]] losses to the surrounding environment. Productivity is affected by contamination with unwanted algae and microorganisms that feed on algae, while concentration of algae remains low because raceways are poorly mixed.		Raceway ponds are desirable for their large scalability and low set-up costs but experience significant water loss through evaporation. The raceway pond also experiences [[temperature]] fluctuations and [[carbon dioxide]] losses to the surrounding environment. Productivity is affected by contamination with unwanted algae and microorganisms that feed on algae, while concentration of algae remains low because raceways are poorly mixed.

	== Tubular Bioreactor ==		== Tubular Bioreactor ==
	[[File:TubularBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 2. Tubular bioreactor<ref name=web1/></center>]]		[[File:TubularBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 2. Tubular bioreactor<ref name=web1/></center>]]
	A tubular bioreactor (figure 2) grows algae in an array of plastic or glass tubes that have CO<sub>2</sub> being constantly fed through the closed system along with the necessary nutrients, such as nitrogen, phosphorus and iron.<ref>J.U. Grobbelaar, Algal nutrition, A. Richmond (Ed.), Handbook of microalgal culture: biotechnology and applied phycology, Blackwell (2004), pp. 97–115</ref> The tubes are generally less than 10cm in diameter to allow for light to penetrate through to all of the algae. The array of clear tubes is arranged horizontally, vertically or on a slant but always oriented running north to south. This arrangement allows for semi-continuous growth of algae, as the fresh algae culture is being fed into the bioreactor at the same rate at which the mature algae is being drawn out. algae production is stopped periodically in order to clean the tubes.<ref name=web1/>		A tubular bioreactor (figure 2) grows algae in an array of plastic or glass tubes that have CO<sub>2</sub> being constantly fed through the closed system along with the necessary nutrients, such as nitrogen, phosphorus and iron.<ref>J.U. Grobbelaar, Algal nutrition, A. Richmond (Ed.), Handbook of microalgal culture: biotechnology and applied phycology, Blackwell (2004), pp. 97–115</ref> The tubes are generally less than 10cm in diameter to allow for [[light]] to penetrate through to all of the algae. The array of clear tubes is arranged horizontally, vertically or on a slant but always oriented running north to south. This arrangement allows for semi-continuous growth of algae, as the fresh algae culture is being fed into the bioreactor at the same rate at which the mature algae is being drawn out. algae production is stopped periodically in order to clean the tubes.<ref name=web1/>
	The recycled growth medium and fresh young culture in a new medium are degassed to remove the oxygen and bubbles from the new culture before being fed into the tubular bioreactor. Excess [[oxygen]] needs to be removed from the system because oxygen concentrations above 4 times that of air will prevent algae growth.<ref name=book1>E. Molina Grima, J. Fernández, F.G. Acién Fernández, Y. Chisti, Tubular photobioreactor design for algal cultures, J Biotechnol, 92 (2001), pp. 113–131</ref> The feeding of [[carbon dioxide\|CO<sub>2</sub>]] and other inorganic supplements mentioned earlier happens at the entrance to the tubes and at locations along the length of the tube as required. Testing sites are necessary along the length of the tubular bioreactor to control the [[pH]] and inorganic salt concentrations at different stages of the algae growth. The best photosynthetic conversion rates are achieved at tubular diameters of 2-5 cm.<ref name=web2>M.A. Borowitzka, 1999, Commercial production of algae: ponds, tanks, tubes and [[ferment]]ers, Journal of Biotechnology, 70 (1999), pp. 313-321</ref>		The recycled growth medium and fresh young culture in a new medium are degassed to remove the oxygen and bubbles from the new culture before being fed into the tubular bioreactor. Excess [[oxygen]] needs to be removed from the system because oxygen concentrations above 4 times that of air will prevent algae growth.<ref name=book1>E. Molina Grima, J. Fernández, F.G. Acién Fernández, Y. Chisti, Tubular photobioreactor design for algal cultures, J Biotechnol, 92 (2001), pp. 113–131</ref> The feeding of [[carbon dioxide\|CO<sub>2</sub>]] and other inorganic supplements mentioned earlier happens at the entrance to the tubes and at locations along the length of the tube as required. Testing sites are necessary along the length of the tubular bioreactor to control the [[pH]] and inorganic salt concentrations at different stages of the algae growth. The best photosynthetic conversion rates are achieved at tubular diameters of 2-5 cm.<ref name=web2>M.A. Borowitzka, 1999, Commercial production of algae: ponds, tanks, tubes and [[ferment]]ers, Journal of Biotechnology, 70 (1999), pp. 313-321</ref>

	== Vertical Bag Bioreactor ==		== Vertical Bag Bioreactor ==
	[[File:VerticalBagBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 3. Vertical bag bioreactor<ref>C. Gramling, "As Green As It Gets: Algae Biofuels", Earth Magazine. [Online] 2009. Available: http://www.earthmagazine.org/article/green-it-gets-algae-biofuels</ref></center>]]		[[File:VerticalBagBioreactor.jpg\|300px\|thumbnail\|right\|<center>Figure 3. Vertical bag bioreactor<ref>C. Gramling, "As Green As It Gets: Algae Biofuels", Earth Magazine. [Online] 2009. Available: http://www.earthmagazine.org/article/green-it-gets-algae-biofuels</ref></center>]]
	A vertical bag system (figure 3) grows algae in an aqueous solution within a closed bag usually 2-4 cm thick for optimum photosynthetic efficiency.<ref name=web2/> The CO<sub>2</sub> and other inorganic nutrients are fed through the system from the top, bottom or sides of the bag and bubbled through the algae. Exhaust gases rich in oxygen are siphoned off of the top of the vertical bags to reduce the oxygen in the growth medium, as too much oxygen inhibits algae growth.<ref name=book1/> The vertical bag system was derived from the tubular bioreactor system in order to reduce material start-up costs and allow for easier modification of the system (adding and removing testing and feeding points is much easier with a vertical bag).		A vertical bag system (figure 3) grows algae in an aqueous solution within a closed bag usually 2-4 cm thick for optimum photosynthetic [[efficiency]].<ref name=web2/> The CO<sub>2</sub> and other inorganic nutrients are fed through the system from the top, bottom or sides of the bag and bubbled through the algae. Exhaust gases rich in oxygen are siphoned off of the top of the vertical bags to reduce the oxygen in the growth medium, as too much oxygen inhibits algae growth.<ref name=book1/> The vertical bag system was derived from the tubular bioreactor system in order to reduce material start-up costs and allow for easier modification of the system (adding and removing testing and feeding points is much easier with a vertical bag).

	The vertical bag system is very good for a laboratory setting as any size of algae batches can be made with it. Lab trials have found that the bags needed to be replaced every 60-90 days as contaminants build up in the system and prevent effective algae growth.<ref>Long-term outdoor growth and lipid productivity of Tetraselmis suecica, Dunaliella tertiolecta and Chlorella sp (Chlorophyta) in bag photobioreactors, Navid Reza Moheimani Received: 19 January 2012 / Revised and accepted: 19 April 2012 / Published online: 12 May 2012# Springer Science+Business Media B.V. 2012</ref>		The vertical bag system is very good for a laboratory setting as any size of algae batches can be made with it. Lab trials have found that the bags needed to be replaced every 60-90 days as contaminants build up in the system and prevent effective algae growth.<ref>Long-term outdoor growth and lipid productivity of Tetraselmis suecica, Dunaliella tertiolecta and Chlorella sp (Chlorophyta) in bag photobioreactors, Navid Reza Moheimani Received: 19 January 2012 / Revised and accepted: 19 April 2012 / Published online: 12 May 2012# Springer Science+Business Media B.V. 2012</ref>

J.williams: 1 revision imported

2015-08-26T21:30:48Z

1 revision imported

← Older revision	Revision as of 21:30, 26 August 2015
(No difference)

J.williams at 16:42, 12 August 2015

2015-08-12T16:42:58Z

New page

[[Category:Done 2015-06-01]]
[[File:AlgaePondRaceway.jpg|400px|thumbnail|right|<center>Figure 1. Open Pond / Raceway<ref name=web1>Y. Chisti, 2007 Biodiesel from microalgae, Biotechnology Advances, (May-June 2007), pp. 294-306</ref></center>]]
<onlyinclude>'''Growing algae''' is important as [[algae]] is used as a food supplement, a [[biofuel]] resource, a chemical resource and a [[waste management system]].</onlyinclude> The growth of algae generally takes place in one of three different forms:

1) Open Pond / Raceway

2) Tubular Bioreactor

3) Vertical Bag Bioreactor

== Open Pond / Raceway ==
A raceway pond (figure 1) grows algae as it moves along a water channel circuit that is usually about 30 [[cm]] deep. The base of the winding channel is usually constructed out of compacted dirt and/or cement and lined with white reflective material (usually plastic). Flow through the channel is provided by a paddle-wheel that is located between the extractor of mature algae and the feeder of new algae, while the flow is directed around the bends by baffles, as shown in the figure below.<ref name=web1/>
Raceway ponds are desirable for their large scalability and low set-up costs but experience significant water loss through evaporation. The raceway pond also experiences [[temperature]] fluctuations and [[carbon dioxide]] losses to the surrounding environment. Productivity is affected by contamination with unwanted algae and microorganisms that feed on algae, while concentration of algae remains low because raceways are poorly mixed.

== Tubular Bioreactor ==
[[File:TubularBioreactor.jpg|300px|thumbnail|right|<center>Figure 2. Tubular bioreactor<ref name=web1/></center>]]
A tubular bioreactor (figure 2) grows algae in an array of plastic or glass tubes that have CO2 being constantly fed through the closed system along with the necessary nutrients, such as nitrogen, phosphorus and iron.<ref>J.U. Grobbelaar, Algal nutrition, A. Richmond (Ed.), Handbook of microalgal culture: biotechnology and applied phycology, Blackwell (2004), pp. 97–115</ref> The tubes are generally less than 10cm in diameter to allow for light to penetrate through to all of the algae. The array of clear tubes is arranged horizontally, vertically or on a slant but always oriented running north to south. This arrangement allows for semi-continuous growth of algae, as the fresh algae culture is being fed into the bioreactor at the same rate at which the mature algae is being drawn out. algae production is stopped periodically in order to clean the tubes.<ref name=web1/>
The recycled growth medium and fresh young culture in a new medium are degassed to remove the oxygen and bubbles from the new culture before being fed into the tubular bioreactor. Excess [[oxygen]] needs to be removed from the system because oxygen concentrations above 4 times that of air will prevent algae growth.<ref name=book1>E. Molina Grima, J. Fernández, F.G. Acién Fernández, Y. Chisti, Tubular photobioreactor design for algal cultures, J Biotechnol, 92 (2001), pp. 113–131</ref> The feeding of [[carbon dioxide|CO2]] and other inorganic supplements mentioned earlier happens at the entrance to the tubes and at locations along the length of the tube as required. Testing sites are necessary along the length of the tubular bioreactor to control the [[pH]] and inorganic salt concentrations at different stages of the algae growth. The best photosynthetic conversion rates are achieved at tubular diameters of 2-5 cm.<ref name=web2>M.A. Borowitzka, 1999, Commercial production of algae: ponds, tanks, tubes and [[ferment]]ers, Journal of Biotechnology, 70 (1999), pp. 313-321</ref>

== Vertical Bag Bioreactor ==
[[File:VerticalBagBioreactor.jpg|300px|thumbnail|right|<center>Figure 3. Vertical bag bioreactor<ref>C. Gramling, "As Green As It Gets: Algae Biofuels", Earth Magazine. [Online] 2009. Available: http://www.earthmagazine.org/article/green-it-gets-algae-biofuels</ref></center>]]
A vertical bag system (figure 3) grows algae in an aqueous solution within a closed bag usually 2-4 cm thick for optimum photosynthetic efficiency.<ref name=web2/> The CO2 and other inorganic nutrients are fed through the system from the top, bottom or sides of the bag and bubbled through the algae. Exhaust gases rich in oxygen are siphoned off of the top of the vertical bags to reduce the oxygen in the growth medium, as too much oxygen inhibits algae growth.<ref name=book1/> The vertical bag system was derived from the tubular bioreactor system in order to reduce material start-up costs and allow for easier modification of the system (adding and removing testing and feeding points is much easier with a vertical bag).

The vertical bag system is very good for a laboratory setting as any size of algae batches can be made with it. Lab trials have found that the bags needed to be replaced every 60-90 days as contaminants build up in the system and prevent effective algae growth.<ref>Long-term outdoor growth and lipid productivity of Tetraselmis suecica, Dunaliella tertiolecta and Chlorella sp (Chlorophyta) in bag photobioreactors, Navid Reza Moheimani Received: 19 January 2012 / Revised and accepted: 19 April 2012 / Published online: 12 May 2012# Springer Science+Business Media B.V. 2012</ref>

==References==
{{reflist}}
[[Category:Uploaded]]