Table 4 Isotherm constants and correlation coefficients obtained for the removal of Cd²⁺ ions by CuS nanorods.

Langmuir

\(\:{q}_{e}=\frac{{Q}_{m}{K}_{L}{C}_{e}}{1+\:{K}_{L}{C}_{e}}\)

Q_m (mg g^− 1)

K_L (L^− 1 mg)

R²

Freundlich

\(\:{q}_{e}=\:{K}_{F}{C}_{e}^{\raisebox{1ex}{$1$}\!\left/\:\!\raisebox{-1ex}{$n$}\right.}\)

K_F (mg g^− 1. L mg^− 1)

n

R²

D-R

\(\:{q}_{e}=\:{q}_{s}\text{e}\text{x}\text{p}(-{K}_{DR}{\left[RT\text{ln}(1+\:\frac{1}{{C}_{e}}\right]}^{2})\)

Q_s (mg g^− 1)

K_DR (mol² kJ²)

E (kJ mol^− 1)

R²

Temkin

\(\:{q}_{e}=\frac{RT}{{b}_{T}}\text{l}\text{n}\left({A}_{T}{C}_{e}\right)\)

A_T (L mg^− 1)

b_T (J mol^− 1)

R²