Green-Synthesized Silver Nanoparticles of Nannochloropsis sp. for Phthalate Esters Remediation: Surface Characterization and Interaction Analysis

Phthalate esters (PAEs) are persistent plastic pollutants known for their endocrine-disrupting characteristics, driving the need for sustainable remediation strategies. The biosynthesis of silver nanoparticles (AgNPs) utilizing Nannochloropsis sp. extract was explored, and their interactions with dibutyl phthalate (DBP) and diethyl phthalate (DEP) were evaluated. Nannochloropsis sp. was cultivated on blue-green algae medium (BG۱۱). AgNPs of Nannochloropsis sp. (NNAgNPs) were synthesized at a ratio of ۱:۴ and characterized. A concentration of ۱ g/L of NNAgNPs was applied in the biotreatment of the standard PAE solutions and water sample for ۲۴, ۴۸, and ۷۲ h. The samples were filtered and analyzed using various analytical techniques. UV-Vis spectra revealed a distinct surface plasmon resonance peak at ۴۲۲ nm, which is characteristic of AgNP formation. FTIR spectroscopy identified the functional groups present in the synthesized nanoparticles. TEM analysis revealed an average nanoparticle size of ۵۱.۹۳ nm, and EDX validated the dominant silver composition with a purity of ۸۴.۸۷%. From the controlled biotreatment of DEP and DBP, NNAgNPs showed the highest removal efficiency of ۹۷.۸% for DBP and ۷۴.۲% at ۲۴ and ۴۸ h, respectively. Biotreatment with NNAgNPs displayed a biphasic and paradoxical behaviour, which rebounded at ۷۲ h. SEM micrographs revealed significant ultrastructural alterations on the cell surfaces. However, quantitative analysis using GC–MS produced contradictory removal efficiencies ranging from −۱۰۳.۹۶ to +۷۴.۲۲%, signifying major analytical interference from leached biological matrix compounds associated with the nanoparticles. This provides a novel analytical framework that identifies biological interference as a critical methodological challenge in green nano-remediation research.

کلیدواژه ها:

Green synthesis ، Silver nanoparticles ، Nannochloropsis sp ، Phthalate esters ، Biosorption