GREEN SYNTHESIS OF COPPER OXIDE NANOPARTICLES USING CARICA PAPAYA LEAF EXTRACT FOR ADSORPTIVE REMOVAL OF WATER HARDNESS. Impact International Journals and Publications, [S. l.], v. 2, n. issue 1, p. 854–866, 2026. Disponível em: https://impactinternationaljournals.com/publications/index.php/ojs/article/view/278. Acesso em: 14 mar. 2026.