Ecofriendly algal extracellular polymeric substance-based nanobiocomposite for photodegradation of bisphenol A

Bisphenol A (BPA), a common plasticizer and an emerging pollutant is found in the water bodies due to the degradation of microplastics. The present work studies the efficiency of algal extracellular polymeric substance (EPS)-based zeolite/nanoceria nanobiocomposite for the degradation of BPA. Zeolite was heat/acid activated for deposition of photoactive CeO₂ nanoparticles. The nanobiocomposite was characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDX) analysis. The removal of BPA was studied with different parameters, i.e., BPA concentration (20-60 mg/L) and pH (6-10). 31% BPA got adsorbed under dark conditions. Nanobiocomposite under ultraviolet A irradiation increased the BPA removal to 81% after 120 min of the photocatalytic reaction. The BPA removal mechanism was elucidated using liquid chromatography-mass spectrometry analysis. Biosafety assessment revealed 96% and 89% cell viability in Chlorella sp. and Allium sativum with the degraded solution. Furthermore, the biosafety evaluation for the nanobiocomposite also revealed that EPS enables synergism as both green and efficient approach for BPA breakdown.