Table 2 Isotherm models used to describe the uptake of Cr(VI) onto SBCH and BMOJ.

From: Preparation and characterization of Allium cepa extract coated biochar and adsorption performance for hexavalent chromium

Isotherm model

Equation

Parameters

References

Langmuir

\({q}_{e}=\frac{{q}_{max}{bC}_{e}}{1+b{C}_{e}}\)

\({q}_{max},\) b

74

Freundlich

\({q}_{e}={K}_{F}{C}_{e}^{1/n}\)

\({k}_{F}, n\)

75

  1. qeq adsorption capacity (mg g−1) of SBCH or BMOJ, Ceq equilibrium concentration of Cr(VI) in solution (mg dm−3), qmax maximum monolayer capacity (mg g−1) of SBCH and BMOJ, b Langmuir isotherm constant (dm3 mg−1), KF Freundlich isotherm constant (mg g−1) (dm−3 mg−1), n adsorption intensity.
Back to article page