The potential of semi-permeable bentonite and zeolite composite on the reduction of Pb (II) concentration in landfillMochamad Arief Budihardjo, Badrus Zaman, Ika Bagus Priyambada, Dona Ramadani and Alfian Rizky RizaldiantoE3S Web Conf., 148 (2020) 01005DOI: https://doi.org/10.1051/e3sconf/202014801005