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Best Tropical Algae Strains For Oil Production

Thirty microalgal strains were screened in the laboratory for their biomass productivity and lipid content. Four strains (two marine and two freshwater), selected because robust, highly productive and with a relatively high lipid content, were cultivated under nitrogen deprivation in 0.6-L bubbled tubes. Only the two marine microalgae accumulated lipid under such conditions. One of them, the eustigmatophyte Nannochloropsis sp. F&M-M24, which attained 60% lipid content after nitrogen starvation, was grown in a 20-L Flat Alveolar Panel photobioreactor to study the influence of irradiance and nutrient (nitrogen or phosphorus) deprivation on fatty acid accumulation. Fatty acid content increased with high irradiances (up to 32.5% of dry biomass) and following both nitrogen and phosphorus deprivation (up to about 50%).

Sat September 24 2011 04:29:55 AM by Kavi 4

Is Algae Based Treatment of Leather Industry Waste a Viable Option?

Some algae have proved highly effective in removing chromium from tannery effluent. Treatment of tannery effluent can be achieved through a custom-designed high rate algal ponding process to generate and precipitate metal sulphides. Aerobic lagoons are also used for the treatment of tannery effluent. Aerobic lagoons are large, shallow earthen basins used for treatment of wastewater by natural processes involving both algae and bacteria.


The algal species which is pointed out above should be Spirogyra condensata and Rhizoclonium hieroglyphicum which have been employed to remove chromium from tannery effluent. S. condensata to exhibits maximum uptake of about 14 mg Cr (III)/g of algae at optimum pH of 5.0 and R. hieroglyphicum had 11.81 mg of Cr (III)/g of algae at pH of 4.0.


Read more at -  

Thu September 22 2011 11:23:52 AM by Kavi 7

Which Algae Grows Best In Sewage Water, Has Good Doubling Time?

When I came across this question on CleanTick,I happened to recollect the different strains which produced a good yield of oil when grown in the presence of sewage water, carbon dioxide and sunlight. But one of the answers posted by an expert from Indian Agricultural Research Institute was interesting. 


Here's the answer I am talking about: 


"The best way will be to isolate algae growing in sewage and domesticate them. Natural acclimatisation is the advantage with these autochthonous algae.


Lift samples from natural sewage ponds/oxidation ponds and if needed raise enrichment cultures or directly plate appropriate dilutions on agar plates containing suitable nutrient medium. Pick isolated algal colonies and make them unialgal by repeated subculturing. The algal isolates can than be tested for growth in medium containing increasing levels of sewage water and ones growing happily at highest levels selected, ideal growth conditions are defined and maintained in the lab on agar slants as well as in broth to serve as mother culture. The culture of the so 'domesticated' alga is scaled up in the laboratory and inoculated in the outdoor seeding ponds and then to the oxidation ponds. " 


Check out more strain suggested at the link - 

Thu September 22 2011 10:59:36 AM by Kavi 2

Are there any fast growing benthic algae with high oil content?

Most benthic freshwater habitats are blue-green algae (Cyanophyta), green algae (Chlorophyta), diatoms (Bacillariophyta), or red algae (Rhodophyta). However, most other divisions of algae can occur in freshwater benthic habitats. The Chrysophyta, Xanthophyta, Cryptophyta,and Pyrrophyta have many species that usually occur in the phytoplankton,but they may also occur in physiologically active forms in some benthic habitats. 

In addition, resting cells of many algae can be found in the benthos, which may have originated there or may have settled from the water column (Sicko-Goad et al., 1989). The latter divisions seldom constitute more algal biomass in a benthic habitat than blue-green algae, green algae, diatoms, or red algae.


This is just one suggestion among others available at this link-


http://www.cleantick.com/questions/q/are-there-any-benthic-algae-which-contains-high-oil



Thu September 22 2011 10:05:00 AM by Kavi

Which is the Best Method For Algae Oil - Hexane Solvent Extraction Or Expellers?

"Solvent extraction by hexane is the most common choice for extraction of oil/lipids from algae. However, hexane is not the best choice of solvent for algae oil extraction because of the need to market byproducts for human and animal consumption. Oil and hexane from the solvent extraction process are separated by distillation/evaporation which is an energy intensive operation. Presence of explosive hexane vapors in the oil processing plant is also a serious safety concern. Extraction of algae oil with alcohols (e.g. ethanol) will eliminate the emission and toxicity issues. However, energy consumption for alcohol recovery/separation is significantly high because alcohols boil at higher temperature and latent heat of alcohols is 2-2.5 times higher than hexane."

http://www.sbir.gov/sbirsearch/detail/3221 


Is there any other alternative method to extract oil from Algae?


Suggest at http://www.cleantick.com/questions/q/is-hexane-solvent-extraction-the-best-method-for-algae-oil

Thu September 22 2011 10:00:40 AM by Kavi 3

How Effective Are Filters For Microalgae Harvesting?

Are drum, disc and belt filters effective for algae harvesting? 


"Belt-press seems to be comparatively cheaper than other harvesting methods. The costs of the belt-filters range from between between $150,000 to $180,000 each. Capital costs for belt filter presses vary with the size of the equipment. Vendor estimates vary from $47,500 (0.5 m belt, approximate capacity of 500 dry pounds per hour (~0.22679618499999998 tons)) to $115,000 (1.5 meter belt with approx capacity of 1,625 dry pounds per hour)" 


Read more at - 

Thu September 22 2011 07:13:34 AM by Kavi 27