Role of unsaturated soil above a heavily contaminated aquifer in the natural attenuation of arsenicNadia Martínez-Villegas, Andrea del Pilar Gómez, Armando Zamora-Morales, Jejanny Lucero Hernández Martínez, Diana Meza-Figueroa and Bhaskar SenGuptaE3S Web Conf., 98 (2019) 09017DOI: https://doi.org/10.1051/e3sconf/20199809017