Both refers to the measurement of analyte over time. but what is the actual difference between the two or are they synonymous? And could anyone elaborate how they are connected with isotherm determination in adsorption? with equilibrium concentration how can we determine the fitness of isotherm in particular!!
Sir, Actually when is break through curves are studied and when is equilibrium concentration of an analyte is done in adsorption? What is the difference in studying both with reference to adsorption?
Breakthrough curve refers to the variation of the solution (or effluent) concentration at the outlet of the sorption bed over time. This plot is useful to determine the saturation time of your material, as well as the mass transfer zone within your bed . It is conducted in column experiments.
While isotherm curve is a plot of equilibrium concentration in solid phase qe (concentration of the solute/ pollutant over your adsorbant) versus the solution concentration Ce in equilibrium with solid phase. It is obtained from batch experiment conducted at constant temperature (usually CSTP ), and fixed agitation. The variation is usually fitted to adsorption models (isotherms) such Freundlish, Langmuir...., qe= f(Ce).
For instance, if langmuir was applicable, it allows you to determine the theoritical maximum adsorption capacity of your material, qm.
In summary, equilibrium concentration Ce, is the concentration of your solute remaining in the medium after equilibrium is reached; in batch experiment, contact time is usually set to 24h or 42h . Qe is calculated from Ce, by assuming that the difference between initial and final concentration has been adsorbed over the material (Sorbant), qe= (Ci-Cf)*V/m where V is the volume of your solution and m the mass of your sorbant.
Noting that breakthrough time is the time at which your material is totally consumed/saturated and can no longer retain the pollutant. Knowing this parameter, you can determine the mass of adsorbant needed to ensure good retention in real application, in other word the lifespan of you material before you will to replace it.
To conclude, isotherms and Breakthrough are both important characterization of the material in question. The first one allows to determine the sorption capacity of the material, the second one its lifespan.
Hope it answers your question!
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