Synthesis of hydrochloric acid-assisted coconut trunk biochar and evaluation of its adsorption capacity for methyl red and copper ions. Vietnam Journal of Catalysis and Adsorption, [S. l.], v. 15, n. 3, p. 77–82, 2026. DOI: 10.62239/jca.2026.050. Disponível em: https://jca.edu.vn/index.php/jca/article/view/2026.050.. Acesso em: 14 oct. 2026.