Algae growth in cooling towers

[Tharindu]

Dear Friends,

 

We are facing difficulties while maintaining cooling towers by rapid growth of Algae. This spoils water content in it. I am really not sure but it may tend to increase hardness of water.

Blowing down process is not effective due to this case. We can not add any acid forms because the thin copper valves are located inside the tower. Once I tried coppersulphate but it increased the hardness value. So I am seeking permanent chemical, physical or biological solution which does not have any side effect to other parts of this.

[Moontanman]

Dear Friends,

 

We are facing difficulties while maintaining cooling towers by rapid growth of Algae. This spoils water content in it. I am really not sure but it may tend to increase hardness of water.

Blowing down process is not effective due to this case. We can not add any acid forms because the thin copper valves are located inside the tower. Once I tried coppersulphate but it increased the hardness value. So I am seeking permanent chemical, physical or biological solution which does not have any side effect to other parts of this.

 

 

Does the algae have to eliminated completely or is simply restricting it's growth acceptable? If the it is later then you could employ snails to eat the algae and keep it trimmed back somewhat.

[CaptainPanic]

Mod comment: I've turned down the volume (font size and colors) a bit on the post of Tharindu.

[Tharindu]

Does the algae have to eliminated completely or is simply restricting it's growth acceptable? If the it is later then you could employ snails to eat the algae and keep it trimmed back somewhat.

 

Thanks for your comment.

 

Algae have to eliminate completely but I cant agree with your solution about snails.

It will directly effect to the quality of water and process of cooling tower.

 

I need to know the range of effective ultrasonic frequency which can use against algae. Anybody is here to solve this?

[Harry Potterish]

Hello Friends,

 

Industrial cooling towers are essential to maintaining controlled temperatures in many operations. Since these systems often use water or fluids, algae problems are common.

 

Historically, algae, along with biofilm formation can be a problem inside the cooling tower basin and on nearby grids. These types of growth can have a negative influence on the efficiency of the cooling tower and there is an ongoing concern for guarding against the formation of Legionella bacteria, which can contribute to Legionnaires disease in humans.

 

Interestingly, this bacteria, as well as many forms of algae grow better with the help of biofilm that forms in the cooling tower. Studies have shown that ultrasound in particular works very well to control this biofilm formation, and in doing so, it's also provided a way to safely limit algae and unwanted bacteria from forming.

 

Thanks with Best Regards,

Harry Potterish

[alpha2cen]

Thanks for your comment.

 

Algae have to eliminate completely but I cant agree with your solution about snails.

It will directly effect to the quality of water and process of cooling tower.

 

I need to know the range of effective ultrasonic frequency which can use against algae. Anybody is here to solve this?

 

How about using U.V. light? U.V. gives a damage to DNA in the cell. But, handle it very carefully, the instrument must operate in sealed to prevent light leaking.

[Essay]

Dear Friends,

 

We are facing difficulties while maintaining cooling towers by rapid growth of Algae. This spoils water content in it. I am really not sure but it may tend to increase hardness of water.

Blowing down process is not effective due to this case. We can not add any acid forms because the thin copper valves are located inside the tower. Once I tried coppersulphate but it increased the hardness value. So I am seeking permanent chemical, physical or biological solution which does not have any side effect to other parts of this.

...I did some web surfing on this topic:

 

There might be some botanical remedies....

 

 

http://www.sciencedi...568988306001089

 

"Effect of five chinese traditional medicines on the biological activity of a red-tide causing alga"

 

"...with aloe (Aloe vera L. var. chinensis (Haw.) Berg.); followed by areca seed with aloe, and golden thread and areca seed with kelp (Laminaria japonica). In general, the zeolite based algal inhibitors were less effective. The inhibitory rates of the algal inhibitors LA, LI, KG, KA and KG were all above 90%, and remained high for 72 h."

 

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http://www.aseanbiot...ct/21015467.pdf

 

Growth Inhibition of Cyanobacteria by Ultrasonic Radiation:

Environ. Sci. Technol. 2003, 37, 3031-3037

 

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http://onlinelibrary...06.01951.x/full

 

"Growth inhibition of bloom-forming cyanobacterium Microcystis aeruginosa by rice straw extract"

 

Letters in Applied Microbiology; Volume 43, Issue 3, pages 307–312, September 2006

 

"Allelopathy is defined as the direct or indirectly harmful or beneficial effects of one plant (including a micro-organism) on another through the production of chemical compounds that are released into the environment (Rice 1984). The allelopathic activity of plants, such as rice straw, has already been documented, and phenolic compounds invariably identified as the allelopathic or phytotoxic substances."

 

Conclusions: The growth of M. aeruginosa was inhibited by rice straw extract concentrations ranging from 0·01 to 10 mg l−1. This activity was due to the synergistic effects of various phenolic compounds in the rice straw.

 

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http://onlinelibrary...ial+maintenance

 

INHIBITION OF UNICELLULAR ALGAE BY SYNTHETIC SURFACE-ACTIVE AGENTS

Journal of Phycology; Volume 1, Issue 3, pages 102–110, September 1965

 

SUMMARY

The effects of non-ionic, anionic and cationic detergents on 12 species of marine phytoplankton lucre observed. Although individual species varied widely in response, growth inhibition in non-ionic surfactants became more pronounced as the surface-active properties of the agents tested increased. The tolerances of species belonging to the same family were generally similar, and each family had a specific inhibition pattern. Anionic detergents inhibited growth in concentration ranges that depended on the species and the surfactant. All species were more sensitive to the cationic agent than to anionic or non-ionic agents

 

 

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http://www.waterbugd...ths/barley.html

 

Barley Straw Clears Ponds - Myth based on fact.

 

A couple of studies have shown that barley straw does inhibit algae growth in water. If that's all the info you need in order to buy and add barley straw to your pond then your next step is: The study that started it all is Newman, JR & Raven, 1993 at The Centre for Aquatic Plant Management in the UK. Another study that basically confirms what Newman found is Brownlee, 2003.

 

The most important point is that these studies show barley straw can inhibit the rate of algae growth. Most people seem to read inhibit as kill or stop. The studies only show growth slowing. As the scientists say; "it's algistatic (prevents new growth of algae) rather than algicidal (kills already existing algae)".

 

It is likely that a combination of factors results in the anti-algal activity generated from decomposing straw.

He then describes a complex process where the end result is hydrogen peroxide a known inhibitor of algae growth.

 

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http://www.bbe.or.kr...ile/article.pdf

 

Biotechnol. Bioprocess Eng. 2002, 7: 231-233

 

"Effect of Calcium Peroxide on the Growth and Proliferation of

Microcystis aerusinosa, a Water-blooming Cyanobacterium"

One possible explanation for this growth inhibition is the removal of the available phosphate by calcium peroxide.

 

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Search:

algal inhibition by peroxide

...or, by humic substances

[StringJunky]

Instead of looking to control the algae directly why not look into controlling the cooling-water's dissolved and suspended components ie create and maintain an inhospitable environment for the algae...look at reducing ambient-light levels as well.

 

I found this article on Best Management Practice: Cooling Tower Management by the US DoE that you might get something useful from.

Edited October 28, 2012 by StringJunky

[vampares]

I'd use Borax. To reduce the hardness, NaCl. To reduce acidity sodium bicarbonate.

Edited October 29, 2012 by vampares