Table 2 Isotherm parameters for Carbamazepine (CBZ) adsorption by graphene oxide nanoplatelet (GONP)

Langmuir

\( \frac{C_e}{q_e}=\frac{1}{Q^0b}+\frac{C_e}{Q^0} \)

Equilibrium CBZ concentration in solution

mg L^− 1

0.065

Theoretical maximum adsorption capacity

mg g^− 1

2.47

Maximum monolayer coverage capacity calculated from slope of C_e/q_e vs. C_e plot.

mg g^− 1

0.80

Langmuir coefficient of energy of adsorption calculated from intercept of C_e/q_e vs. C_e plot.

L mg⁻¹

0.50

Correlation coefficient

0.914

Freundlich

\( \ln {q}_e=\frac{1}{n_f}\ln {C}_e+\ln {K}_f \)

Adsorption intensity calculated from slope of ln q_e vs. ln C_e plot

4.02

Freundlich coefficient of adsorption capacity calculated from intercept of ln q_e vs. ln C_e plot

mg g⁻¹

1.49

Correlation coefficient

0.709

Temkin

q_e = B_T ln C_e + B_T ln K_T

Coefficients of heat of adsorption calculated from slope of q_e vs. ln C_e plot at operational temperature T (308 K)

J mol⁻¹

0.39

Temkin equilibrium binding constant calculated from intercept of q_e vs. ln C_e plot at operational temperature T (308 K)

L g⁻¹

64

Correlation coefficient

0.815

Dubinin-Radushkevich

lnq_e = ln Q_s − Bε²

Dubinin–Radushkevich constant calculated from slope of ln q_e vs. ε² plot.

mol² kJ⁻²

1.0E-08

Theoretical isotherm saturation capacity calculated from intercept of ln q_e vs. ε² plot.

mg g⁻¹

0.30

Polanyi potential

7071

Correlation coefficient

0.402