I had carried out the batch experiment using different types of resins on adsorption of flavanoids at different initial concentrations. Based on the results I found that when I decreased the initial concentration, the percentage of adsorption increases. So should I choose the lowest concentration for bulk adsorption?
It is a good idea to perform sorption isotherm experiments and from Langmuir modeling, optimum concentration can be easily estimated from the plot. Good luck!
In the case of the equilibrium adsorption alone in batch system, there is no optimal Co value. There is an upper limit (it's not the same as the optimum) determined by the maximum adsorption capacity. If the adsorption is accompanied by mass transport phenomena , which resistances increase as the adsorbate concentration increases (due to eg increase in viscosity), then the optimum is possible. It should also be remembered that the closer to the maximum adsorption capacity, the longer the time needed to reach equilibrium. Thus, only a compromise between the adsorption time and the adsorbed mass related to the adsorbent mass is possible here.
In addition, you should know that with the decrease in Co, (Co-C)/Co will increse until it reaches the value 1 (C = 0). Regards,
I don't know what you have found but mostly select the one with the highest adsorption capacity