Unraveling the potential of Chlorella vulgaris in sustainable bioplastic production, carbon sequestration, and wastewater treatment using integrated approaches.

Abstract

With rising concerns over plastic pollution and climate change, microalgae-based bioplastics offer a promising alternative to petroleum-derived plastics. This study explores the dual role of Chlorella vulgaris in bioplastic synthesis and environmental remediation through its cultivation in a wastewater-fed bioreactor. By leveraging wastewater as a nutrient source, C. vulgaris achieved a biomass yield of 3.472 g/L, with 20 mg/L of polyhydroxyalkanoate (PHA) extracted. Fourier Transform Infrared (FTIR) spectroscopy validated the presence of PHA-specific ester functional groups, confirming its suitability for bioplastic applications. Additionally, the cultivation process resulted in a complete reduction of free CO₂ within three days, demonstrating efficient carbon sequestration. Significant declines in wastewater contaminants, including COD, BOD, nitrogen, and phosphorus, highlight the microalga's bioremediation capabilities, making it a promising candidate for sustainable wastewater treatment. This study introduces a cost-efficient, self-sustaining microalgal bioprocess that eliminates the need for synthetic nutrients while achieving high-yield PHA production, complete CO₂ sequestration, and efficient wastewater detoxification. By integrating three essential sustainability goals- bioplastic production, carbon capture, and water purification- this work bridges the gap between bio-based materials and environmental conservation. The results affirm C. vulgaris as a multifunctional bioresource that supports both biopolymer synthesis and climate change mitigation. This work advances microalgal biotechnology by demonstrating its potential for large-scale, closed-loop biomanufacturing, providing an eco-friendly, scalable solution for reducing plastic waste and greenhouse gas emissions while promoting sustainable industrial practices.