Open systems for the mass production of photoautotrophic microalgae outdoors: physiological principles
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The major physiological principles involved in mass production of photoautotrophic microalgae outdoors relate to sustained trapping of solar energy in as high an efficiency as possible throughout the year.
The tactics that should be employed for this goal include the improvement of suitable species, as well as developing culturing devices and proper management protocol aimed to facilitate efficient exploitation of the supper saturating photon flux densities existing outdoors.
The most common system used today in industry for outdoor production of microalgae is the open raceway, in which stirring is provided by a paddle wheel. This mode of production suffers usually from many weaknesses, since it does not permit a satisfactory response to the two major variables that limit productivity outdoors — i.e.- solar irradiance and ambient temperature. Sustained production of algal mass the year round requires constant monitoring of the state of the culture and adjusting imputs accordingly. The readily controllable variables relate to mineral nutrients and carbon balance as well as to turbulent streaming in the culture and to the population density.
The drawbacks of the open system relate in essence to the lack of temperature control and the long light-path which dictates maintenance of disadvantageously low cell concentrations. The open raceway thus falls short of the requirements necessary to insure sustained, year round high productivity outdoors.
It is thus proposed that in the future, closed reactors may become the major production mode of microalgae outdoors.
KeywordsMicroalgae Mass Production Mineral Nutrient Solar Irradiance Carbon Balance
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- Dodd JC (1986) Elements of pond design and construction. In Richmond A (ed.), CRC Handbook of Microalgal Mass Culture. CRC Press, Boca Raton, 265–283.Google Scholar
- Goldman JC (1979) Outdoor algal mass cultures. II. Photosynthesis yield limitations. Wat. Res. 13: 119–160.Google Scholar
- Gudin C, Chaumont D (1983) Solar biotechnology study and development of tubular solar receptors for controlled production of photosynthetic cellular biomass. In Palz W, Pirrwitz D (eds), Proceedings of the Workshop and E.C. Contractors' Meeting in Capri. Reidel Publ. Co., Dordrecht, 184–193.Google Scholar
- Hall DO, Coombs J, Scurlock JMO (1987) Biomass production and data. In Coombs J, Hall DO, Long SP, Scurlock JMO (eds), Techniques in Productivity and Photosynthesis. Pergamon Press, Oxford, 274–287.Google Scholar
- Pirt SJ, Lee YK, Walach MR, Pirt MW, Balyuzi HHM, Bazin MJ (1983) A tubular bioreactor for photosynthetic production of biomass from carbon dioxide: design and performance. J. Chem. Tech. Biotechnol. 33B: 35–58.Google Scholar
- Richmond A (ed.)(1986) CRC Handbook of Microalgal Mass Culture. CRC Press, Boca Raton, 528 pp.Google Scholar
- Richmond A (1990) Large scale microalgal culture and applications. Progr. Phycol. Res. 7: 269–330.Google Scholar
- Richmond A, Grobbelaar JU (1986) Factors affecting the output rate ofSpirulina platensis with reference to mass cultivation. Biomass 10: 253–264.Google Scholar
- Richmond A, Vonshak A (1978)Spirulina culture in Israel. Arch. Hydrobiol. 11: 274–280.Google Scholar
- Setlík I, Veladimir S, Malek I (1970) Dual purpose open circulation units for large scale culture of algae in temperate zones. I. Basic design consideration and scheme of pilot plant. Algol. Stud. (Trebon) 1: 11.Google Scholar
- Sorokin C, Krauss RW (1965) The dependence of cell division inChlorella on temperature and light intensity. Am. J. Bot. 52: 331.Google Scholar
- Torzillo G, Pushparaj B, Bocci F, Balloni W, Materassi R, Florenzano G (1986) Production ofSpirulina biomass in closed photobioreactors. Biomass 11: 61–64.Google Scholar
- Torzillo G, Sacchi A, Materassi R (1991) Temperature as an important factor affecting productivity and night biomass loss inSpirulina platensis grown outdoors in tubular photobioreactors. Bioresource Technol. 38: 95–100.Google Scholar
- Vonshak A, Abeliovich A, Boussiba Z, Arad S, Richmond A (1982) Production ofSpirulina biomass: effects of environmental factors and population density. Biomass 2: 175–185.Google Scholar