Recent Advances in Understanding the Role of Wastewater …
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the exhaustion rate of petroleum reserves. Therefore, it becomes mandatory to search
for alternate and renewable natural recourses for the plastic production in future.
Biodegradable polymers are now recognised as a better substitute to the conventional petroleum-based plastics [71, 72]. In this context, several research and developments are being widely carried-out for the synthesis of sustainable plastics.
Synthetic polyester-based biodegradable plastics which are produced by using few
process modifications in polyethylene polymerization and blending agents have been
commercialized in food packaging industry, paper industry and garbage carry-bags.
Studies have reported that polylactic acid (PLA) and thermoplastic starch-based
polyesters polymers are easily degraded into non-toxic end products i.e. water and
carbon dioxide, upon the microbial environment. The agricultural products such as
potato, corn and wheat starch are the natural resource for starch-based plastic polymers. Another type of biodegradable polymers are produced by bacteria includes
polyhydroxyalkanoates (PHAs) [73]. Because of the mechanical property, biodegradability and biocompatibility of PLA polymers, they were greatly used for insurgical
implants, drug delivery support materials since 1980s. Inspite of its advantages,
the production cost and the rate of biodegrdation of PLA is the major drawback in
extensive usage [74].
Starch-based polymers are considered as comparatively low-cost polymers that
are produced from agricultural resources. However, the consumption of water in
the manufacturing process is high and also influences the strength of the polymeric products. Cellulosic polymers is the another biodegradable material but cannot
afford thermal stability. Attempts are made to improve the thermostability and thermoplasticity of cellulosic polymers which in-turn reduces the rate of biodegradability. Henceforth, technical problems are to be resolved to balance the stability
and biodegradability of agricultural based polymeric materials. In which, molecular
mass and water percentage are the crucial factor for balancing the material property
[71, 75]. The synthetic hydrophobic polymers are manufactured and made available since 1990s. Unfortunately the commercially available synthetic hydrophobic
polymers are expensive than the petroleum based polymers. Hence, the blending of
starch with these polymers has recently become the focus of researchers to reduce the
production cost and improves bioaccessibility [71, 76]. The plastic waste obtained
from wastewater treatment units can be recycled by using these strategies in order to
reduce waste generations and to provide product value in the market [77].
5 Conclusion
Till date, immense resources have been used for the facility development and establishment of wastewater treatment sectors. Deplorably, none have met the standard
discharge permits level and operational efficiency. Process modifications in the treatment approaches are needed to provide more reliable performance. Operation and
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the exhaustion rate of petroleum reserves. Therefore, it becomes mandatory to search
for alternate and renewable natural recourses for the plastic production in future.
Biodegradable polymers are now recognised as a better substitute to the conventional petroleum-based plastics [71, 72]. In this context, several research and developments are being widely carried-out for the synthesis of sustainable plastics.
Synthetic polyester-based biodegradable plastics which are produced by using few
process modifications in polyethylene polymerization and blending agents have been
commercialized in food packaging industry, paper industry and garbage carry-bags.
Studies have reported that polylactic acid (PLA) and thermoplastic starch-based
polyesters polymers are easily degraded into non-toxic end products i.e. water and
carbon dioxide, upon the microbial environment. The agricultural products such as
potato, corn and wheat starch are the natural resource for starch-based plastic polymers. Another type of biodegradable polymers are produced by bacteria includes
polyhydroxyalkanoates (PHAs) [73]. Because of the mechanical property, biodegradability and biocompatibility of PLA polymers, they were greatly used for insurgical
implants, drug delivery support materials since 1980s. Inspite of its advantages,
the production cost and the rate of biodegrdation of PLA is the major drawback in
extensive usage [74].
Starch-based polymers are considered as comparatively low-cost polymers that
are produced from agricultural resources. However, the consumption of water in
the manufacturing process is high and also influences the strength of the polymeric products. Cellulosic polymers is the another biodegradable material but cannot
afford thermal stability. Attempts are made to improve the thermostability and thermoplasticity of cellulosic polymers which in-turn reduces the rate of biodegradability. Henceforth, technical problems are to be resolved to balance the stability
and biodegradability of agricultural based polymeric materials. In which, molecular
mass and water percentage are the crucial factor for balancing the material property
[71, 75]. The synthetic hydrophobic polymers are manufactured and made available since 1990s. Unfortunately the commercially available synthetic hydrophobic
polymers are expensive than the petroleum based polymers. Hence, the blending of
starch with these polymers has recently become the focus of researchers to reduce the
production cost and improves bioaccessibility [71, 76]. The plastic waste obtained
from wastewater treatment units can be recycled by using these strategies in order to
reduce waste generations and to provide product value in the market [77].
5 Conclusion
Till date, immense resources have been used for the facility development and establishment of wastewater treatment sectors. Deplorably, none have met the standard
discharge permits level and operational efficiency. Process modifications in the treatment approaches are needed to provide more reliable performance. Operation and