Bioadsorption of crude petroleum oil from seawater using the marine alga Hormophysa triquetra mediated silver nanoparticles.

The biosynthesis of silver nanoparticles, both economically and environmentally advantageous, uses algae extracts. In the current work, we extracted the marine brown alga Hormophysa triquetra (C. Agardh) kützing and used it to make silver nanoparticles (HAgNPs) which are characterized via UV-visible spectrophotometers, Transmission Electron Microscopy (TEM), Zeta potential, and FTIR then used them in the bio adsorption of crude petroleum oil from seawater, comparing them with H. triquetra aqueous extract. UV scan of the phycosynthesized silver nanoparticles achieved the highest absorption at 369 nm. TEM showed that the synthesized HAgNPs occur with smooth, spherical, and semispherical forms with sizes ranging from 12.04 to 20.67 nm, zeta potential illustrated that HAgNPs were charged with -22.1, The H. triquetra aqueous extract's FTIR examination identified several active groups like - OH, -C=C-, NO, -CH, CCl, -C ≡ C-H: CH which are responsible for the bioadsorption of crude petroleum oil. When extracting crude petroleum oil from seawater, HAgNPs worked better than its aqueous extract. The maximum removal % for light n-alkanes (Ln-alk), heavy n-alkanes (Hn-alk), and PAHs were 70.4 %, 71.63 %, and 75.38 % respectively for H. triquetra aqueous extract with adsorption capacity 889, 511, 273 μg/g at salinity 36 % and pH 5, while in case of HAgNPs the results were 75.81 %, 77.15 %, and 80.56 %, respectively with adsorption capacity 957, 550, 292 μg/g at the same salinity and pH.