Unveiling the potential of microalgae for bioplastic production from wastewater – current trends, innovations, and future prospects

Bioplastics derived from polyhydroxyalkanoates (PHAs) are among the promising substitutes for unsustainable petroleum-based polymers. PHA-based polymers demonstrate superior chemical and physical properties, such as hydrophobicity, insolubility in water, iso-tacticity, UV resistance, hydrolysis resistance, and absolute biodegradability. Compared with conventional plastics, bioplastics are more beneficial due to their reduced carbon footprint, energy efficiency, biodegradability, and biocompatibility, and have hence revolutionized the polymer industry. However, further research is needed to explore novel strategies to overcome their limitations, such as decreasing water absorption and brittleness, while increasing the crystallization ability and increasing the thermal degradation temperature. These constraints can be addressed by supplementing the bioplastic synthesis process with reinforcements and plasticizers. The development and adoption of biopolymers as an environmentally friendly and economically viable substitutes for synthetic plastics is imperative, considering the degree of the subsequent exhaustion of petrochemical supplies and the worldwide environmental contamination instigated by the industrial production of synthetic plastics. The goal of this appraisal is to provide an in-depth account of the most recent advancements in the generation of bioplastics derived from various wastewater streams via the use of microalgae, and subsequent harvesting technologies. Bioplastics from microalgae are of higher quality and are made of polymeric biomolecules and include polymers based on cellulose, starch, proteins, PHA, polyhydroxybutyrate (PHB), polyethylene (PE), polylactic acid (PLA), and poly vinyl chloride (PVC). Various types of bioplastic manufacturing methodologies have also been highlighted for researchers and capitalists alike to investigate ways to harness these renewable resources for the development of sustainable bioplastics. Additionally, various innovations, challenges, potential possibilities for the future, and life cycle evaluations of bioplastics are addressed.