Fig. 13

Langmuir isotherm plots for the adsorption of heavy metals (Pb²⁺ (a), Cu²⁺ (b, c), and Cd²⁺(d, e)) onto limestone (CaCO₃) and calcined (CaO. According to the equation: \(\frac{{C}_{e}}{{q}_{e}}=\frac{1}{b {q}_{max}}+\frac{{C}_{e}}{{q}_{max}}\)⁹⁷. P indicate the number of corresponding points.