Dear Abinubli,

Attached please find some publications that cover the answer to your question. I have copied titles and abstracts for some of these publications for quick view:

1-Flocculation as a low-cost method for harvesting microalgae for bulk biomass production

Dries Vandamme, Imogen Foubert, Koenraad Muylaertemail

KU Leuven Kulak, Laboratory Aquatic Biology, E. Sabbelaan 53, 8500 Kortrijk, Belgium

DOI: http://dx.doi.org/10.1016/j.tibtech.2012.12.005

showArticle Info

http://www.sciencedirect.com/science/article/pii/S0167779912002247

The global demand for biomass for food, feed, biofuels, and chemical production is expected to increase in the coming decades. Microalgae are a promising new source of biomass that may complement agricultural crops. Production of microalgae has so far been limited to high-value applications. In order to realize large-scale production of microalgae biomass for low-value applications, new low-cost technologies are needed to produce and process microalgae. A major challenge lies in the harvesting of the microalgae, which requires the separation of a low amount of biomass consisting of small individual cells from a large volume of culture medium. Flocculation is seen as a promising low-cost harvesting method. Here, we overview the challenges and possible solutions for flocculating microalgae.

Highlights

Microalgae are a promising new source of biomass for production of food, feed, fuel, or chemicals, but the cost and energy demand of large-scale production is still too high.

An efficient low-cost method for harvesting microalgae is essential for large-scale and low-cost production of microalgal biomass.

In this paper, we give an overview of different approaches for achieving flocculation of microalgae, each with their advantages and disadvantages.

Flocculation of microalgae can be achieved through chemical, biological, and physical methods and by genetic modification.

The global demand for biomass for food, feed, biofuels, and chemical production is expected to increase in the coming decades. Microalgae are a promising new source of biomass that may complement agricultural crops. Production of microalgae has so far been limited to high-value applications. In order to realize large-scale production of microalgae biomass for low-value applications, new low-cost technologies are needed to produce and process microalgae. A major challenge lies in the harvesting of the microalgae, which requires the separation of a low amount of biomass consisting of small individual cells from a large volume of culture medium. Flocculation is seen as a promising low-cost harvesting method. Here, we overview the challenges and possible solutions for flocculating microalgae.

 Keywords:

microalgae, biomass, biofuels, flocculation, coagulation, separation, harvesting

2-A Comprehensive Overview on Various Method of Harvesting Microalgae According to Indian Perspective

Jigar H Shah*, Abhijeet Deokar*, Kushal Patel*, Keyur Panchal*, Alpesh V. Mehta

Abstract--

The global demand of fossil fuel is increasing day by day due to urbanization, industrialization and increasing global population. Moreover, worldwide reserve of fossil fuel is vanishing at an alarming rate. Concentrating on the limited stock of fossil fuel, several effort have been started to search for sustainable renewable bio fuels like bio ethanol and biodiesel. Biodiesel extracted from the microalgae is an most promising source to cope up the global demand of fossil fuels. One of the major problems associated with the conversion of algae into biodiesel is the harvesting of algae. Harvesting of algae can be carried out by number of methods such as; sedimentation, flocculation, flotation, centrifugation and filtration or a combination of any of these. This paper discloses various method of harvesting microalgae from a aqueous solution for the production of biodiesel. Among the various method of harvesting, floatation is the most promising method for harvesting microalgae.

Keyword- Microalgae, Biodiesel, Harvesting, Flocculation, Centrifugation, Flotation, Filtration

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Hoping this will be helpful,

Rafik

Dear Abinubli,

You may work with this idea. Raise the salinity of the culture slowly but steadily to such a level ( though for a small amount of time) as to shrivel the cells. Once the cells shrivels a bit, apply CO2 or O2 or even air through minute bubbles slowly, which will get trapped ( at least some of them) from the bottom of the container, which will lift the cells to the surface. As the media is not agitated, the collected cells may be skimmed with suitable plankton net. 

Dear Abinubli,

I think that for laboratory scale harvesting, the best choice is centrifugation. You can use a small centrifuge (50 mL tubes) or a medium on (200 mL steel tubes). It is very fast and effective.

Best regards,

Davide

Thank you for all of your answers

I will take my time to read publication from Mr. Karaman

With the centrifuge you will have a much faster harvesting.

Best regards, Cihelio Alves Amorim

Continuous filtration with ultrafiltration will be best from economic and operational point of view. You can set the cross flow velocity as high as possible to prevent irreversible fouling.

Abinubli Tariswafi Mawarid

Hi

please see the attachment.

Please see the papers for your reference

https://www.researchgate.net/publication/327381747_Microalgae_Cultivation_Using_Various_Sources_of_Organic_Substrate_for_High_Lipid_Content

Article Evaluation of Lipid Content in Microalgae Biomass Using Palm...

//www.researchgate.net/publication/316675390_Evaluation_of_Lemna_minor_and_Chlamydomonas_to_treat_palm_oil_mill_effluent_and_fertilizer_production