Study on the ability to remove Cd2+ ions in water environment by using halloysite mixture from Thach Khoan area, Phu Tho - BUI, BAC; Hạnh, Võ; Duyên, Lê; Thảo, Nguyễn; Hùng, Khương; An, Đỗ; Lực, Trịnh (VNUHCM Journal of Environment and Earth Sciences, 2021)