Silicate Derived\nfrom Phaeodactylum\ntricornutum for Removal of Polystyrene: Interfacial\nEffects of Living Organism and Its Derivatives with Nanoplastics

The deposition of nanoplastics in the environment poses\na direct\nthreat to human health through the food chain. There is an urgent\nneed to investigate how they can be effectively removed from water.\nIn this work, the toxic effects of nanopolystyrene (PS) at different\nconcentrations on <i>Phaeodactylum tricornutum</i> (PT)\nwere investigated. The results show that PS affects the cell activity\nof PT through cell wall adhesion and shading effect and hinders the\ntransmission of light energy, thus inhibiting the growth of PT. Considering\nthat living PT is not suitable for the removal of heterogeneous aggregation\nof PS, magnesium silicate (MS) was obtained by calcination of PT biomass\nbased on retaining salt. The maximum adsorption capacity of PS by\nMS was 40.85 mg g<sup>–1</sup>, which was 10 times higher than\nthat of conventional adsorbents. The presence of competitive anions\nsignificantly affects the removal of PS. The application in real water\nbodies and the reusability of the adsorbents were also verified. By\ncharacterizing the materials before and after adsorption, it is found\nthat the adsorption mechanism mainly includes electrostatic attraction,\nhydrogen bonding, π–π interaction, and complexation\nbetween Si–O bond and PS. This study explains the toxic effect\nof nano-PS on PT and innovatively develops a biomass derivative from\ndiatoms, which provides a novel and feasible strategy for environmental\nremediation.