Figure 5
An environmental feasibility of the sample for the removal of Pb(II) metals. (a) Percentage removal and equilibrium adsorption capacity of Pb(II) onto the ZOCF adsorbent as a function of contact time at the initial Pb(II) ion concentrations of 50, 100, and 150 mg L−1, at pH 5.5, in the contact time range of 10 to 180 min at room temperature (25 ± 1°C) with a fixed adsorbent dose, and (b) the equilibrium adsorption capacity of Pb(II) ions onto the ZOCF adsorbent as a function of equilibrium Pb(II) ion concentration with nonlinear curve fits of the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models.