Plasma technology for disinfection of sea water

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Discussion Overview

The discussion revolves around the use of plasma technology for the disinfection of seawater, specifically in the context of ballast water treatment systems mandated by marine regulations. Participants are seeking to understand the mechanisms behind plasma shockwaves and their effectiveness in killing microorganisms.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes a Korean system that combines filtering, UV radiation, and plasma shockwaves for ballast water disinfection but expresses a lack of understanding of the plasma mechanism.
  • Another participant questions the feasibility of generating high-energy plasma from a low-power discharge and expresses skepticism about the claim that shockwaves can effectively rupture microbial cell walls.
  • A later reply acknowledges the initial misunderstanding regarding the purpose of the ballast water treatment, clarifying that the goal is to prevent cross-contamination of invasive species.
  • One participant suggests a more traditional method of water purification, such as distillation combined with chlorine and ozone, as an alternative to the plasma system.
  • Another participant seeks clarification on how the "plasma shockwave" is generated and its specific action on microorganisms, noting that brochures provide limited scientific detail.
  • One participant speculates on the nature of plasma and discusses the generation of plasma using RF signal generators in a vacuum, while drawing parallels to ultrasonic cleaning methods that can rupture cellular membranes.

Areas of Agreement / Disagreement

Participants express various levels of skepticism and curiosity regarding the plasma technology, with no consensus on its effectiveness or the scientific principles behind it. Multiple competing views and uncertainties remain in the discussion.

Contextual Notes

Participants highlight limitations in the provided information, noting that the descriptions in brochures lack scientific rigor and clarity. There are also unresolved questions about the generation of plasma and its operational principles in the context of water disinfection.

ChemengMarine
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Hello,

I'm a chemical engineer working in the shipping industry.

In a few words,there are many technologies emerging lately due to a new Marine convention that forces all vessels to treat ballast water (disinfection) before discharging it in order to minimize consequences from the mix of different sea ecosystems.

One Korean system uses a combination of filtering, UV radiation and Plasma shockwaves to achieve the necessary levels of disinfection.

My problem is i don't have the necessary knowledge to understand how this Plasma system works. I would like someone to take a few mins to read through the subject and explain to me how this system works. Here is a link describing this system : http://mykomec.blogspot.gr/2012/04/ara-plasma-ballast-water-treatment.html

I'm looking forward to your replies.

Thank you in advance.

PS.Excuse my flawed English, i am Greek
PS1. Feel free to move this thread to a more suited section, if there is one. I understand this is not a ''typical'' engineering question.
 
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Welcome to PF.
I have no education in anything, let alone this subject, so take what I say with a grain of salt. The link that you posted leaves a lot of questions to me, although a physicist or engineer might not have the same issues.
First off, I can't figure out how they can generate high-energy plasma from a "low-power discharge". Secondly, I'm not sure that I trust the statement that the shockwave will kill all of the bad guys by rupturing their sidewalls. It seems to me that you'd have to run the whole sample through a microscope to determine whether or not that happens.
I'm not outright denying it, and am not qualified to do so, but I am a tad suspicious.
(They don't pay me enough to be certain of anything.)
 
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Well, my first thought is that I hope they mean "rudder" operation. As it is written, I don't even want to guess what "rubber" operation might entail. (I know what it means to my life, but I can't see that being extrapolated to the bottom of a ship.)
I must point out, though, that I misunderstood the purpose the first time around. Your second link makes it clear that the ballast water is to be expelled in a somewhat purified form. I have to assume that the purpose is to avoid cross-contamination of invasive species into a different body of water than that in which they were ingested. My initial thought, after your first post, was that you wanted to extract potable water from the ballast. I realize now that you did specify the goal, but I was somehow thinking of human usage being between the intake and outlet. I have no idea why I thought that. My bad.
Anyhow, for either purpose I'd be a lot more comfortable just distilling the stuff with a good old fashioned boiler and some tubing. Throw in a bit of chlorine and ozone for flavour, and you're golden. :biggrin:
 
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I stand corrected. :redface:
 
Anyone else want to give a try? To be more specific my goal is to understand how the ''plasma shockwave'' aspect of this system works. All i read in the brochures is ''a plasma shockwave kills all micro-organisms''. I want to understand how this shockwave is generated and ow it acts to kill.
 
ChemengMarine said:
Anyone else want to give a try? To be more specific my goal is to understand how the ''plasma shockwave'' aspect of this system works. All i read in the brochures is ''a plasma shockwave kills all micro-organisms''. I want to understand how this shockwave is generated and ow it acts to kill.

Since you referred back to the brochures it means you did not read ther links I provided. How unfortunate.
There is sufficient information there to be able to deduce the nature of the subject. Afteral you say you are a chemical engineer and engineers are supposed to be pretty smart at taking a subject and being able to understand it with minimal information.
 
Um, i could be wrong but i bet its just called plasma. From what I under stand Plasma is plasma its not liquid its not gas. The only way i know how to make plasma with a low energy signal source is under vacuum backfilling with your gas of choice and use an RF signal generator like a microwave to apply the frequency to the system.

I aint never heard of liquids being made to plasma in no boat but maybe it happens
What you desrcibe sounds like a good old fashioned sonicator. We use them to clean, samples, parts, and glassware in the lab. It just pulses ultrasonic frequency through the water and it breaks down all kinds of stuff. I have heard that it ruptures the cellular membranes of most eukaryotes. buy a cheap ultrasonic humidifier and stick your finger down in the water inside the machine and you'll see what Its all about.
 

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