342
15 Polyesters
streams could minimize use of further acid/alkali for neutralization prior to further
wastewater treatment and then released into the environment. The use of sodium
hydroxide and hydrochloric acid replaces the use of chloroform and organic solvents
such as hexane and methanol. Since no volatile solvents are used in the patented
method, the acids and alkali used can be treated at the wastewater treatment.
15.6.3 Wastewater Generated
Most of the water used in the process eventually becomes wastewater since the final
extract is in the solid form. The rest is evaporated during the drying process. The acids
and bases used during the extraction are all dissolved in water. A liquid to solids ratio
of 100:1 is used in the first extraction stage using high-temperature alkali treatment.
For every gram of cuticle, 100 ml of water is required. Most of the water used here
can be recycled back into the feed stream or fed in with the next batch. More water is
used in the washing of the solid residue to obtain the final product. Additional water
used in washing the waste solid residues is also directed to the wastewater stream.
The water could either be treated on site or sent to the wastewater treatment plant.
Most industrial laws require the acidic and alkali wastewater to be neutralized and
not simply diluted. The level of treatment required will depend on the country of
operations and the local laws which exist there.
15.6.4 Solid Waste Generated
The cuticle is made up of 40–80% cutin, and the rest of the cuticle comprises of
the waxes and other components of the cuticular matrix such as cinnamic acid, but
mainly waxes. The wax is made up of mostly aliphatic molecules such as ketones,
long-chain fatty acids, primary alcohols, aldehydes and ketones. These are more
soluble in acidic conditions and hence can be filtered off following acidification
while the crude cutin precipitates as a gel-like solid form (Borisjuk et al. 2018;
Cigognini et al. 2015). The plant biomass also contains other valuable biopolymers
such as starch and protein. The cuticle can be first removed, and the rest of the plant
further processed for extraction of the other biopolymers.
15.6.5 Aquatic Plant Harvesting
Cultivation of aquatic plants such as duckweed has benefits for the environment.
They are utilized in the bioremediation of wastewater due to their ability to take
up nutrients such as nitrogen and phosphate compounds from the water. Beyond
acting as a feedstock for cutin, the process of extraction of cutin also yields waxes
15 Polyesters
streams could minimize use of further acid/alkali for neutralization prior to further
wastewater treatment and then released into the environment. The use of sodium
hydroxide and hydrochloric acid replaces the use of chloroform and organic solvents
such as hexane and methanol. Since no volatile solvents are used in the patented
method, the acids and alkali used can be treated at the wastewater treatment.
15.6.3 Wastewater Generated
Most of the water used in the process eventually becomes wastewater since the final
extract is in the solid form. The rest is evaporated during the drying process. The acids
and bases used during the extraction are all dissolved in water. A liquid to solids ratio
of 100:1 is used in the first extraction stage using high-temperature alkali treatment.
For every gram of cuticle, 100 ml of water is required. Most of the water used here
can be recycled back into the feed stream or fed in with the next batch. More water is
used in the washing of the solid residue to obtain the final product. Additional water
used in washing the waste solid residues is also directed to the wastewater stream.
The water could either be treated on site or sent to the wastewater treatment plant.
Most industrial laws require the acidic and alkali wastewater to be neutralized and
not simply diluted. The level of treatment required will depend on the country of
operations and the local laws which exist there.
15.6.4 Solid Waste Generated
The cuticle is made up of 40–80% cutin, and the rest of the cuticle comprises of
the waxes and other components of the cuticular matrix such as cinnamic acid, but
mainly waxes. The wax is made up of mostly aliphatic molecules such as ketones,
long-chain fatty acids, primary alcohols, aldehydes and ketones. These are more
soluble in acidic conditions and hence can be filtered off following acidification
while the crude cutin precipitates as a gel-like solid form (Borisjuk et al. 2018;
Cigognini et al. 2015). The plant biomass also contains other valuable biopolymers
such as starch and protein. The cuticle can be first removed, and the rest of the plant
further processed for extraction of the other biopolymers.
15.6.5 Aquatic Plant Harvesting
Cultivation of aquatic plants such as duckweed has benefits for the environment.
They are utilized in the bioremediation of wastewater due to their ability to take
up nutrients such as nitrogen and phosphate compounds from the water. Beyond
acting as a feedstock for cutin, the process of extraction of cutin also yields waxes