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 <i>Chlorella</i> sp. and <i>Allium sativum</i> 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.