Chinh, N.T., Mai, T.T., Thu Trang, N.T., Thanh Huong, N.T. and Hoang, T. 2017. Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption. Vietnam Journal of Chemistry. 55, 2 (Apr. 2017), 196. DOI:https://doi.org/10.15625/2525-2321.2017-00443.