Effect of contact time
To know the kinetics of the adsorption process and equili- bration time on pomegranate peel carbon, the effect of contact time on Fe(II) biosorption was studied, and the results were shown in Figure 2. According to Figure 2, the adsorption quantity of Fe(II) ion increases as the contact time increases. The equilibration was nearly reached after 40 min. Therefore, equilibration period of 40 min was selected for all further experiments. The time profiles are single, smooth, and continuous curves leading to satur- ation, suggesting the possible monolayer coverage of Fe(II) on the surface of the adsorbent.