Adsorption on a fixed - bed column of Mn(II) from aqueous solutions by nano bentonite prepared from ultrasonic – assited activation. Vietnam j. catal. adsorp. [Internet]. 2019 Jul. 30 [cited 2025 Jul. 4];8(2):23-8. Available from: https://jca.edu.vn/index.php/jca/article/view/571