Bac, Bui, Thao, Nguyen, Hanh, Vo, Duyen, Le, Dung, Nguyen, Son, Phan, AND An, Do. " Removal of Pb2+ from Aqueous Solution using Thach Khoan Kaolin from Phu Tho Province" VNU Journal of Science: Earth and Environmental Sciences [Online], Volume 38 Number 2 (27 June 2022)