Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure Awad, M.; Liu, Z.; Skalicky, M.; Dessoky, E.S.; Brestic, M.; Mbarki, S.; Rastogi, A.; El Sabagh, A. Biomolecules 11(3) 2021 10.3390/biom11030448 https://eurekamag.com/research/079/153/079153695.php