Algae growth

[Tharindu]

Dear friends,

 

Do you know the range of ultrasonic frequency which has used to control algae growth?

[Tharindu]

Please help me

[Tharindu]

Help me guys

[CaptainPanic]

Tharindu,

Nobody has an answer. We all saw your threads. We saw this one, which you now bumped back up twice. Also, we saw the other thread, where you asked basically the same question.

 

I'm sure you're not the only one with algae growth in a cooling tower. So, ask some experts. Ask people who actually have a cooling tower (power stations, industry) or ask someone at a university. But stop asking the same question over and over again here, please.

 

We just do not have an answer.

 

You're welcome to our forum with a new question.

[Moontanman]

Dear friends,

 

Do you know the range of ultrasonic frequency which has used to control algae growth?

 

 

There are, to my knowledge, very few ways to control the growth of algae, restrict nutrients or energy input, or raise temps above which algae can grow or lower temps until algae cannot grow.

 

Exactly what type of algae are you having problems with? Some species can be controlled with poisons, copper sulfate will control some species.

 

I'd have to have some details on the environment your algae is growing in before I or anyone here could even start to suggest real world solutions...

[ewmon]

You're looking for the frequency for its efficient transfer energy into the object — the algae's "resonant frequency" or some other energy transfer maxima. The first method considers the media, the second method considers the object's resonant frequency.

 

 

I don't know how valid this method is (and I forget where I learned it), but one method is to determine the wavelength that's twice the width of the object you want to excite for the media through which the sound waves are traveling. For example, to break a wine glass with a diameter of 3 inches (¼ feet) in air would experience a energy transfer maxima at 1,126 ft/ sec / 2×¼ feet = 2,252 Hertz. I don't know if this works with "soft" objects, such as algae. I'm thinking that these algae are in water, so use the speed of sound in water. You may want to target the algae themselves or, say, its organelles such as mitochondria, etc. So, by this method, if the algae is, say, 5 micrometers in diameter, and the speed of sound in water is 1,500 meters/second, the resonant frequency would be 1,500 m/s / 2×0.000005 m = 150 MHz, which is the high-frequency band for ultrasound.

 

 

This video shows another method that uses the object's natural resonant frequency, but we can't easily tickle some algae and measure their resonant frequency (or can we?). This method determines that the glass's resonant frequency as 337.5 Hz (cycles/second). It's an answer much lower than the frequency found by the first method. If you divide 1,126 ft/sec (the speed of sound in air at room temp) by 337.5 Hertz (or cycles), you'll get 3.34 feet per cycle (meaning 3.34 feet between compressions). This wavelength equals 40 inches, half of which is 20 inches, which is obviously much greater than the diameter of the wine glass. So, this is a frequency different from the first method.

 

Also note that the video shows sound waves of about 1-inch wavelength, which corresponds to about 15,000 Hz, which is much different than the stated 337.5 Hz. In reality, the compressions are much farther apart and traveling much faster than shown.