ASSESSING ANTIBACTERIAL EFFICACY OF NANOPARTICLES FROM THREE PLANT EXTRACTS AGAINST E.COLI AND STREPTOCOCCI IN URBAN WASTEWATER

<p>Silver nanoparticles (Ag-NPs) obtained through green syntheses are gaining remarkable interest<br />in water treatment due to their excellent chemical, physical, and biological properties. Ag-NPs were<br />synthesized using three plant extracts: Carica papaya, Vernonia amygdalina, and Perilla<br />frustescens var as reducing agent, and 6 mM of silver nitrate as precursor. The extracts<br />demonstrated a good potential to reduce Ag(+1) to Ag(0) for Ag-NPs synthesis. Characterization of<br />synthesized Ag-NPs was achieved through UV-Vis spectroscopy, Fourier Transform Infrared<br />analysis, X-ray diffraction, optical microscopy, and zeta potential. The Surface Plasmon Resonance<br />(SPR) was between 410 and 440 nm. The optical microscopy confirmed the presence of<br />nanoparticles (NP) and an aggregate of NP. The synthesized NPs had a crystalline structure,<br />confirmed by the XRD spectra. The average surface charge of NPs was negative (< -10 mV),<br />indicating a potential for aggregation of the three NPs, as confirmed by the particle size distribution.<br />Their antibacterial activities against E. coli and Streptococci were analyzed in urban wastewater.<br />They exhibited good antibacterial properties, with BNPs being most effective at inhibiting both<br />bacteria, followed by PNP and VNP. This reveals that NPs produced from different plants have<br />different yields, properties, and antibacterial activities, and, most especially, can be used in water<br />and wastewater treatment..</p>