Do, T.-T., H.-T. Van, and T.-M.-T. Nguyen. “Ammonium Adsorption from Aqueous Solutions Using MnFe2O4-Functionalized Coffee Husk Biochar Nanocomposites: An Evaluation of HNO3 and NaOH Activation”. Applied Environmental Research, vol. 48, no. 3, Feb. 2026, doi:10.35762/AER.2026021.