Oil Shale of Rif region: natural adsorbents for environmental cleaning Larbi El Hammari, Souhayla Latifi, Asmae Gouza, Omar Boukra, Sanaa Saoiabi and Ahmed Saoiabi E3S Web Conf., 336 (2022) 00002 Published online: 17 January 2022 DOI: 10.1051/e3sconf/202233600002