Sorption behaviors of the modified biochar were varying under different H2O2 levels.
Sorption property of the modified HLG by 20% H2O2 (mHLG2) was the most desirable.
H2O2 modification availably advanced sorption capacity of hydrothermal biochars.
The functional groups changed non-uniformly with the increase of H2O2 levels.
Carboxylic group had a significant relationship with H2O2 modification.