Characteristics and Applications of Sewage Sludge Biochar Modified by Ferrous Sulfate for Remediating Cr(VI)-Contaminated Soils
Table 4
Sequential extraction procedure.
Step
Extraction procedure
Chemical phases
1
Extracted by 0.11 mol/L of HOAc at a liquid to solid (L/S) ratio of 40
Exchangeable fraction
2
Extracted by 0.5 mol/L of NH2OH·HCl (adjusted to pH = 1.5 with HNO3) at a liquid to solid (L/S) ratio of 40
Reducible fraction
3
Extracted by 8.8 mol/l of H2O2 at a liquid to solid (L/S) ratio of 10, and then extracted by 1 mol/l of NH4OAc (adjusted to pH = 2.0 with HNO3) at a liquid to solid (L/S) ratio of 50
