Biochar application to detoxification of the heavy metal-contaminated fluvisols Tatiana Bauer, Tatiana Minkina, Saglara Mandzhieva, Marina Burachevskaya and Maria Zharkova E3S Web Conf., 175 (2020) 09009 Published online: 29 June 2020 DOI: 10.1051/e3sconf/202017509009