1.3.5 Membrane Separation
To a vacuum flask funnel is connected in the laboratory. The contents on the funnel
are poured out onto the filter and allowed to dry some on the pipe as the vacuum is
pulled on. This method could be targeted for collecting low-density microalgae but is
generally performed on a minor scale. Yet there is membrane fouling that is the
biggest downside. There are three reforms: (1) reverse-flow vacuum, (2) direct
vacuum above the filter along with stirring blade, and (3) belt compression.
1.3.6 Flocculation
It is a process in which some chemical substance is added to a water alga mix which
results in aggregation of clumping of algae together with colloid formation. Chemical flocculants contain chloride in the alum along with ferric. Chitosan is an organic
flocculant but it costs quite high. In autoflocculation, injection of CO 2 into system
causes algae to flocculate alone. Flocculation is sometimes used in conjunction with
a compressor filter, as mentioned in the last paragraph, that can be caused in various
ways. First, where a charged particle attracts a particle charged in the opposite
direction forming a layer. Second, connecting the surface of two different particles
forming a connection between them. Major factors such as cell concentration,
surface properties, flocculant concentration, pH, ionic strength, and microalgal
growth step play chief roles in the flocculation cycle. Coagulants distort the loads
and physical characteristics of the suspended cells, so that agglomeration is not
tolerated. Flocculants focus on promoting the production of larger, destabilized
masses from algal biomass. Chemical flocculation, autoflocculation,
electroflocculation, and bioflocculation are all instances of practices which rely on
cumulative and rapid flocculation. All these flocculation processes, on a large scale,
requires vast space and are costly due to the expenses of coagulants, flocculants, and
operators (Bosma et al. 2003) and various chemical modifications (e.g.,
autoflocculation pH adjustments).
1.3.6.1 Chemical Flocculation
Chemical flocculation adds to the culture medium flocculating along with coagulating agents to accelerate cell aggregation. This method acts as a pretreatment with
microalgae in conjunction with other methods, for instance, dissolved flotation of air
(DAF). While this enhances pace of cells collection, to achieve this rate there is the
additional dosage of chemicals complication at the desired concentration. They are
typically used to neutralize particle charges within the solution, and flocculants are
the chemicals utilized in collection of the particles. Such chemical coagulants and
flocculants exacerbate the overall cycle by introducing extra costs, often
20
A. Shrivastava et al.
To a vacuum flask funnel is connected in the laboratory. The contents on the funnel
are poured out onto the filter and allowed to dry some on the pipe as the vacuum is
pulled on. This method could be targeted for collecting low-density microalgae but is
generally performed on a minor scale. Yet there is membrane fouling that is the
biggest downside. There are three reforms: (1) reverse-flow vacuum, (2) direct
vacuum above the filter along with stirring blade, and (3) belt compression.
1.3.6 Flocculation
It is a process in which some chemical substance is added to a water alga mix which
results in aggregation of clumping of algae together with colloid formation. Chemical flocculants contain chloride in the alum along with ferric. Chitosan is an organic
flocculant but it costs quite high. In autoflocculation, injection of CO 2 into system
causes algae to flocculate alone. Flocculation is sometimes used in conjunction with
a compressor filter, as mentioned in the last paragraph, that can be caused in various
ways. First, where a charged particle attracts a particle charged in the opposite
direction forming a layer. Second, connecting the surface of two different particles
forming a connection between them. Major factors such as cell concentration,
surface properties, flocculant concentration, pH, ionic strength, and microalgal
growth step play chief roles in the flocculation cycle. Coagulants distort the loads
and physical characteristics of the suspended cells, so that agglomeration is not
tolerated. Flocculants focus on promoting the production of larger, destabilized
masses from algal biomass. Chemical flocculation, autoflocculation,
electroflocculation, and bioflocculation are all instances of practices which rely on
cumulative and rapid flocculation. All these flocculation processes, on a large scale,
requires vast space and are costly due to the expenses of coagulants, flocculants, and
operators (Bosma et al. 2003) and various chemical modifications (e.g.,
autoflocculation pH adjustments).
1.3.6.1 Chemical Flocculation
Chemical flocculation adds to the culture medium flocculating along with coagulating agents to accelerate cell aggregation. This method acts as a pretreatment with
microalgae in conjunction with other methods, for instance, dissolved flotation of air
(DAF). While this enhances pace of cells collection, to achieve this rate there is the
additional dosage of chemicals complication at the desired concentration. They are
typically used to neutralize particle charges within the solution, and flocculants are
the chemicals utilized in collection of the particles. Such chemical coagulants and
flocculants exacerbate the overall cycle by introducing extra costs, often
20
A. Shrivastava et al.