sunlight, and other requirements such as electricity supply. Significant cost reduction
is attainable (up to 50%) with good co-location facilities and CO 2 sources [42].
6 Factors Affecting Microalgae Growth Rate
To obtain maximum yield of biodiesel and bioproducts, the microalgae culture
conditions should be optimized to provide excellent growth conditions. The following are the key factors that determine rate of microalgal growth:
• Properties of growing medium: water is one of the vital growth medium for algae
production. Therefore, the water composition along with key parameters like
temperature, salinity, and pH value are main factors. The temperature of the
growth medium must be maintained in the optimum range, and for most algal
species, the most favorable temperature range usually remains within 16–27
C.
• Properties of light: light is one important factor required for the photosynthesis
process. The proposition of lipids and other microalgal products differs with the
light intensity used and light exposure duration. The cells shading and equal
exposure of all cells to light can be accomplished by doing proper mixing. To cut
down the biofuel production costs, algal growth should depend on sunlight
available throughout the day, though there are seasonal changes in intensity of
natural light [3, 43].
• CO 2 : CO 2 is one of the crucial necessities for algal growth. Therefore, an
adequate supply of CO 2 must be ensured for its proper growth. Proper aeration
should be given to boost the rate of algal growth and for proper mixing.
• Nutrients: essential nutrients like phosphorus (P), iron (Fe), nitrogen (N), and in
some cases silicon (Si) are essential for the nourishment of algal cells to grow and
mature. To make cells absorb maximum nutrients, ample supply of nutrient
should be dispersed in the growth medium.
7 Harvesting Techniques
The microalgae are very small in cell size and are submerged into water. The harvest
of fully matured microalgae happens by filtering and drying them toward the
production of microalgal biomass which act as a feedstock for future applications.
The different techniques like biological, chemical, electrical, and mechanicalbased systems can be utilized for harvesting the algal biomass. Some of the broadly
used methods are centrifugation, filtration, sedimentation, flocculation, etc. Some
method might be used as preliminary technique to enhance coagulation, aggregation,
and easy removal, and chemical flocculation is one such technique normally used to
boost the molecular dimension of microalgae before utilizing another technique. In
centrifugation method (mechanical system), most of solid biomass can be recovered
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B. Srinivasan and G. Kulshreshtha
is attainable (up to 50%) with good co-location facilities and CO 2 sources [42].
6 Factors Affecting Microalgae Growth Rate
To obtain maximum yield of biodiesel and bioproducts, the microalgae culture
conditions should be optimized to provide excellent growth conditions. The following are the key factors that determine rate of microalgal growth:
• Properties of growing medium: water is one of the vital growth medium for algae
production. Therefore, the water composition along with key parameters like
temperature, salinity, and pH value are main factors. The temperature of the
growth medium must be maintained in the optimum range, and for most algal
species, the most favorable temperature range usually remains within 16–27
C.
• Properties of light: light is one important factor required for the photosynthesis
process. The proposition of lipids and other microalgal products differs with the
light intensity used and light exposure duration. The cells shading and equal
exposure of all cells to light can be accomplished by doing proper mixing. To cut
down the biofuel production costs, algal growth should depend on sunlight
available throughout the day, though there are seasonal changes in intensity of
natural light [3, 43].
• CO 2 : CO 2 is one of the crucial necessities for algal growth. Therefore, an
adequate supply of CO 2 must be ensured for its proper growth. Proper aeration
should be given to boost the rate of algal growth and for proper mixing.
• Nutrients: essential nutrients like phosphorus (P), iron (Fe), nitrogen (N), and in
some cases silicon (Si) are essential for the nourishment of algal cells to grow and
mature. To make cells absorb maximum nutrients, ample supply of nutrient
should be dispersed in the growth medium.
7 Harvesting Techniques
The microalgae are very small in cell size and are submerged into water. The harvest
of fully matured microalgae happens by filtering and drying them toward the
production of microalgal biomass which act as a feedstock for future applications.
The different techniques like biological, chemical, electrical, and mechanicalbased systems can be utilized for harvesting the algal biomass. Some of the broadly
used methods are centrifugation, filtration, sedimentation, flocculation, etc. Some
method might be used as preliminary technique to enhance coagulation, aggregation,
and easy removal, and chemical flocculation is one such technique normally used to
boost the molecular dimension of microalgae before utilizing another technique. In
centrifugation method (mechanical system), most of solid biomass can be recovered
148
B. Srinivasan and G. Kulshreshtha