TY - JOUR
T1 - Organic micropollutant desorption in various water matrices - Activated carbon pore characteristics determine the reversibility of adsorption
AU - Aschermann, G.
AU - Schröder, Corinna
AU - Zietzschmann, Frederik
AU - Jekel, Martin
PY - 2019
Y1 - 2019
N2 - The adsorption of organic micropollutants (OMP) onto activated carbon (AC) in real waters is strongly affected by dissolved organic matter (DOM). This study examines the impact of DOM quantity and composition in terms of OMP desorption from different AC, by using four different water samples. In batch tests, an OMP concentration drop in the influent of an AC treatment system was simulated. These tests were conducted with six AC products with different internal pore structures. The tests were evaluated with respect to the extent of OMP desorption by interpreting corresponding OMP adsorption and desorption isotherms. For each tested AC and each evaluated OMP the isotherms in the different water samples were qualitatively very similar. Thus, despite different DOM composition very similar OMP desorption extents can be expected in different waters. Among the AC products a clear trend can be seen in all waters, namely that increasing pore size results in increasing desorption. The OMP desorption extent was quantified by a simple Freundlich equation-based approach, expressing the relative position of corresponding adsorption and desorption isotherms via the ratio KF, Des/KF, Ads. Plotting KF, Des/KF, Ads of any given substance for the different tested AC in one water over the average AC pore size shows a linear correlation. This confirms that the OMP desorption extent in real waters is strongly impacted by the AC pore structure. Furthermore, it indicates that the average AC pore size might be a good tool to assess the vulnerability of treatment systems towards desorption.
AB - The adsorption of organic micropollutants (OMP) onto activated carbon (AC) in real waters is strongly affected by dissolved organic matter (DOM). This study examines the impact of DOM quantity and composition in terms of OMP desorption from different AC, by using four different water samples. In batch tests, an OMP concentration drop in the influent of an AC treatment system was simulated. These tests were conducted with six AC products with different internal pore structures. The tests were evaluated with respect to the extent of OMP desorption by interpreting corresponding OMP adsorption and desorption isotherms. For each tested AC and each evaluated OMP the isotherms in the different water samples were qualitatively very similar. Thus, despite different DOM composition very similar OMP desorption extents can be expected in different waters. Among the AC products a clear trend can be seen in all waters, namely that increasing pore size results in increasing desorption. The OMP desorption extent was quantified by a simple Freundlich equation-based approach, expressing the relative position of corresponding adsorption and desorption isotherms via the ratio KF, Des/KF, Ads. Plotting KF, Des/KF, Ads of any given substance for the different tested AC in one water over the average AC pore size shows a linear correlation. This confirms that the OMP desorption extent in real waters is strongly impacted by the AC pore structure. Furthermore, it indicates that the average AC pore size might be a good tool to assess the vulnerability of treatment systems towards desorption.
KW - Activated carbon
KW - Adsorption
KW - Desorption
KW - Dissolved organic matter
KW - Organic micropollutants
KW - Water treatment
UR - http://www.scopus.com/inward/record.url?scp=85073705875&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2019.124415
DO - 10.1016/j.chemosphere.2019.124415
M3 - Article
C2 - 31398607
SN - 0045-6535
VL - 237
JO - Chemosphere
JF - Chemosphere
M1 - 124415
ER -