At appropriate dosage alum, ferric salts, chitosan..all will work .
I have worked with different strains and all these flocculants worked (>90% sedimented).
However, the main concern would be cost of these flocculants. Flocculation will consume about 200-400gm of flocculant to harvest 1kg of dry biomass, depending on the strains, pH and salinity.1 kg of flocculants may cost 20-50cents.
For energy consumption in different harvesting techniques you can refer the following document:
E. Molina Grima, E.-H. B., F.G Acien Fernandez, A. Robles Medina, Yusuf Chisti (2003). "Recovery of microalgal biomass and metabolites:process options and economics." Biotechnology Advances 20: 491-515.
Probir
From: Bobby Yates Emory <liberty1@...> To: oil_from_algae@yahoogroups.com Sent: Friday, 3 July 2009 10:37:58 Subject: Re: [oil_from_algae] Re: alum???
Alex,
Reading between the lines, there may be some info here that could help when trying to floc out algae.
Also, it says that alum can give a boost to sand filters.
I still like the idea of froth flotation, but who knows what is going to be cost effective?
See http://WWW.southsho regunitepools. Com/resources/ pdfs/how_ alum_works. pdf Alum works to remove suspended particles, not emulsions. Does algae stay in suspension when processed? I'd guess filtration (various options depending on porosity of the resulting cake and gunking) would remove most of it. If not I do not see how flocculants would do anything for algae sourced emulsions.
???Alum (pronounced /ˈæləm/) is both a specific chemical compound and a class of chemical compounds. The specific compound is the hydrated aluminum potassium sulfate with the formula KAl(SO4)2.12H2O. The wider class of compounds known as alums have the related stoichiometry, AB(SO4)2.12H2O. --- In oil_from_algae@ yahoogroups. com, Bobby Yates Emory <liberty1@...> wrote: > > Ron and Gianfranco, > > I think that is commonly called Alum and is easily available - this is > WalMart's listing: > > < > http://www.walmart. com/search/ search-ng. do?search_ constraint= 0&ic=48_0&search_query= alum&Find.x=11&Find.y=8&Find=Find > > > > Bobby > > 2009/7/1 Gian Roncolato alchemirg@.. . > > > > > > > Dear Ron, > > In the water treatment industries to clarify the water and flocculatind all > > te
suspended solids it is normally used "Aluminum Sulfate" (liquid form > > about 8% content), can be used fram 10 to 25 grams per cubic meters. > > It is not expensive and it work perfectly. It need a "pre-dilution" with > > water followed by a distribution and good mixture inside the tank. > > Regards > > Gianfranco Roncolato > > > > ------------ --------- --------- > > To: oil_from_algae@ yahoogroups. com > > From: potrzebie44@ ... > > Date: Tue, 30 Jun 2009 13:23:21 -0700 > > Subject: [oil_from_algae] Learning from Failure [1 Attachment] > > > > [Attachment( s)<http://co119w. col119.mail. live.com/ mail/EditMessage Light.aspx? ReadMessageId= fa6d5360- f2a2-4af6- 9a38-e81dcc47970 8&FolderID=00000000- 0000-0000- 0000-00000000000 1&CP=-1&n=1316965772&Action=Reply&AllowUnsafe= False#TopText>from Ron Brown included below] > > > > The attached photo shows an algae culture we grew from one slant of > > Chlorella vulgaris that we got from Carolina Biological Supply Company > > ($9.00 + $30.00 s&H) in one week. I count that part as a success. But we > > tried to flocculate it with lime, and that was a little disappointing. > > "Microalgae Harvesting and > >
Processing: A Literature Review" discusses the use of lime to flocculate > > algae. a quick search of the internet confirmed that lime has been used to > > control algae in ponds. Well, it was quick, cheap and easy, but it didn't > > work. We applied a pound or two of lime that was left over from a > > construction project to about 300 gallons of culture. I was hoping to be > > able to scoop up the floc with a household strainer. Although there was a > > fine white precipitate on the bottom, there was no sign of flocculation. > > > > > > ---rsb > > Ron Brown > > 30JUNE2009 > > > > > > > > ------------ --------- --------- > > What can you do with the new Windows Live? Find out<http://www.microsof t.com/windows/
windowslive/ default.aspx> > > > > > > > > -- > Toward freedom, > > Bobby Yates Emory >
The attached photo shows an algae culture we grew from one slant of Chlorella vulgaris that we got from Carolina Biological Supply Company ($9.00 + $30.00 s&H)...
That is the problem with "Googleing" things. While doing this can be a good source of information, if you are doing serious research. It would be best to look...
Dear Ron, In the water treatment industries to clarify the water and flocculatind all te suspended solids it is normally used "Aluminum Sulfate" (liquid form...
Bruce, Do you think it might work as a flocculant? I am also considering using it to remove gypsum from drinking water. Bobby ... -- Toward freedom, Bobby...
Bobby, I am not sure.. I will think about it over the fourth.. Sure would be quick to test..Have a great 4th.. See you on the other side .. Bruce and Eric ......
Bobby, for what i know it works only with the suspended solids. Cannot work with the dissolved elements. If alum (aluminum sulphate) has too much acidity, you...
See http://WWW.southshoregunitepools.Com/resources/pdfs/how_alum_works.pdf Alum works to remove suspended particles, not emulsions. Does algae stay in...
Alex, Reading between the lines, there may be some info here that could help when trying to floc out algae. Also, it says that alum can give a boost to sand...
BOBBY, WE TESTED THE ALUM ON A LARGE VOLUME OVER THE 4TH.. WORKED BUT TOOK A LOT OF ENERGY TO REMOVE THE MASS .. WATER WAS CLEAR IN THE END.. BRUCE ... when ...
Bruce, Good news. Now we know one way that works. Since we only have to remove about 25% of the algae, maybe a little alum would work. To make it easier to...
Hi Bobby: Let's get back to the objective of algae processing. Aren't we trying to
remove lipids/oils/organics from the mass and then recycle what is left?...
Alex, First we have to get the algae out of the culture. Removing lipids is second. I assume your point was that we should not use a treatment that prevents us...
... What do you guys think about the flocculants remaining in the dry biomass? Depending on the subsequent process one has in mind (extracting oil, fermenting,...
Hi Manfred, In 1 kg of dry biomass you can expect 100-120mg of metal (either Fe or Al). These metals donot affect much in producing FAME from the dry biomass....
Bobby: I can see your point that removing algae first makes it easier to then
separate lipids from the aqueous phase. But what if we are satisfied with
say...
Alex, I feel we should not have any arbitrary standards. We need to be flexible in the solutions we consider. If there is a good reason to only remove 80% of...
'But what if we are satisfied with say 80% removal of lipids from a mixed media and then recycle that media back to the algae growing units?' You will then end...
Thanks Brian: So basically what you are saying is recycle makes no sense because it
becomes uncontrollable for the effective and consistent generation of lipid...
This discussion is stimulating. Brian and Bobby, thanks for getting these
issues out in the open. Other comments from others? I sense there is a
wealth of...
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