The Influence of Activated Carbon Produced from Duck Eggshells as an Adsorbent for Free Fatty Acid Content of Used Cooking Oilc. JURNAL FARMASIMED (JFM), [S. l.], v. 8, n. 2, p. 1018–1024, 2026. DOI: 10.35451/r6vzyw08. Disponível em: https://ejournal.medistra.ac.id/index.php/JFM/article/view/3544. Acesso em: 6 may. 2026.