Development of a Method for Quantitative Evaluation of Protein Skimmer Performance
- Thread starter Gary Majchrzak
- Start date
thriceanangel
New member
Which is why I was suggesting a fish only design. Corals and Algae are going to be able to turn light into organic compounds. Probably in a fairly large quantity. SO, if you start with a completely inorganic medium (IE Reverse Osmosis salt water which would be relatively sterile at least for these purposes) don't add light. Add some fish. And the only TOC that you will have will be what you add as no or very little algae will grow on the surfaces due to lack of light, there will be only fish and other creatures (bacterium protozoans etc.) that will only be able to feed on the sole energy source (Carbohydrate from the food you add and the wastes from processing and metabolizing this).
Gary Majchrzak
Team RC
nobody that reads the article carefully should come to the conclusion that this is a good idea.
SkiFletch
New member
Another of my own musings. It doesn't seem all that surprising to me that total TOC removal is only on the order of 25-30%. Proteins are VERY complex molecules when you start getting down to the level of structure and polarization. Not all proteins and other organics are hydrophobic and hydrophyllic and if they are not, they will not be attracted to the bubble and therefore will not be removed by foam fractionation. While 25-30% does seem like it might be a little low as a representation of those proteins which have the appropraite polar characteristics, it shouldn't be all that surprising.
Exactly, Mike,
I'm not surprised either . In fact the untested assumptions about skimmer efficiency enhancements is one of the concerns that led me to stop vodka dosing a couple of years ago.
As you may know the carbon dosing methods rely on increased skimmer efficiency to remove the dosed carbon along with N and P taken up by bacteria which are part of the TOC web. I am not real clear on the hydrophilic,hydrophobic characteristics of these organisms. In deciding wether or not to dose a carbon source to help with N and P which many do with reports of success it would be good to know wether the bacteria involved in the process would be easily attracted to the air water interface and enhance TOC export or not.
I've always been a granulated activated carbon fan but I'd also like to know more about what % of TOC and what types of organics gac will export at what levels of use. Seems like the researchers have had good results with gac in a general sense.It has been my understanding,however, that some of the larger more complex organic molecules have a very limited affinity for activated carbon. Perhaps water changes gac and ozone(to break down some of them ) will emerge as preferred methods along with wet skimming.
I'm not surprised either . In fact the untested assumptions about skimmer efficiency enhancements is one of the concerns that led me to stop vodka dosing a couple of years ago.
As you may know the carbon dosing methods rely on increased skimmer efficiency to remove the dosed carbon along with N and P taken up by bacteria which are part of the TOC web. I am not real clear on the hydrophilic,hydrophobic characteristics of these organisms. In deciding wether or not to dose a carbon source to help with N and P which many do with reports of success it would be good to know wether the bacteria involved in the process would be easily attracted to the air water interface and enhance TOC export or not.
I've always been a granulated activated carbon fan but I'd also like to know more about what % of TOC and what types of organics gac will export at what levels of use. Seems like the researchers have had good results with gac in a general sense.It has been my understanding,however, that some of the larger more complex organic molecules have a very limited affinity for activated carbon. Perhaps water changes gac and ozone(to break down some of them ) will emerge as preferred methods along with wet skimming.
it would be an interesting study to perform to add a carbon source to these tests to then retest skimmer performance however with the high variability of the studies. As evidenced here:
The rather large scatter in the data as indicated by the error bars (from 16 - 44% of the mean value) does not permit any statistically significant distinction to be made between any two skimmers in their overall capacity to remove TOC.
Would make the results difficult to determine. I don't believe that the results would be completely useless however. Simply for the fact that the data is testable and a few lose conclusions can be drawn from it.
In regards to the empirical ramifications of carbon dosing if this skimmer study holds true for carbon dosing. It seems to provide a sever limiting factor for carbon dossers, as you are only exporting around 20-30% of the new bacteria and only temporally binding around 70-80% percent of the new bacteria (that is not exported by the skimmer). Perhaps for that reason alone the maintenance dose is required for the continued performance and the potential fallout if that dose is stopped. Unless there was a way to culture strictly hydrophobic bacteria and still receive the desire result then you would have a solution to the potential pitfalls of carbon dosing. Because as it seems now you are not exporting any large amounts of undesirables you are simply binding without any means of exporting them and that is simply not a long term solution.
I hope that made sense.
Rob
The rather large scatter in the data as indicated by the error bars (from 16 - 44% of the mean value) does not permit any statistically significant distinction to be made between any two skimmers in their overall capacity to remove TOC.
Would make the results difficult to determine. I don't believe that the results would be completely useless however. Simply for the fact that the data is testable and a few lose conclusions can be drawn from it.
In regards to the empirical ramifications of carbon dosing if this skimmer study holds true for carbon dosing. It seems to provide a sever limiting factor for carbon dossers, as you are only exporting around 20-30% of the new bacteria and only temporally binding around 70-80% percent of the new bacteria (that is not exported by the skimmer). Perhaps for that reason alone the maintenance dose is required for the continued performance and the potential fallout if that dose is stopped. Unless there was a way to culture strictly hydrophobic bacteria and still receive the desire result then you would have a solution to the potential pitfalls of carbon dosing. Because as it seems now you are not exporting any large amounts of undesirables you are simply binding without any means of exporting them and that is simply not a long term solution.
I hope that made sense.
Rob
I don't use ozone but I am giving it some thought because it may increase the effciency of granulated activated carbon(GAC).
In addition to it's potential to make some organics once oxidized more bioavailable to bacteria for example..In one of his articles on it Randy Farely cites a study of ozone's effects on TOC removal. In the study while ozone did not remove TOC, it enhanced GACs performance from a 37% removal rate to 72%. it is thought this occured as a result of ozone breaking down organic molecules into smaller varieties with greater affinity for the gac or posibly from enhanced bacterial growth on the GAC.
In addition to it's potential to make some organics once oxidized more bioavailable to bacteria for example..In one of his articles on it Randy Farely cites a study of ozone's effects on TOC removal. In the study while ozone did not remove TOC, it enhanced GACs performance from a 37% removal rate to 72%. it is thought this occured as a result of ozone breaking down organic molecules into smaller varieties with greater affinity for the gac or posibly from enhanced bacterial growth on the GAC.
reefnready
New member
Great research and article Ken!
I was hoping to ask a few questions if this topic is still at large!
Why did you choose a larger frit size than Brown et al. in reference to Figure 2?
Have you done any research on expanding surface area if faster gas rates and smaller bubbles increase R with surface area being the limiting factor?
Has any research now been done on the chemical structures of the TOC components.
Once again fantastic research and artcle
I was hoping to ask a few questions if this topic is still at large!
Why did you choose a larger frit size than Brown et al. in reference to Figure 2?
Have you done any research on expanding surface area if faster gas rates and smaller bubbles increase R with surface area being the limiting factor?
Has any research now been done on the chemical structures of the TOC components.
Once again fantastic research and artcle
Similar threads
