The removal of hydrophobic and hydrophilic pesticides (simazine and asulum) by granular activated carbon (GAC) adsorbers preloaded with natural organic matter (NOM) was studied through experiments using pilot scale columns and microcolumns. The pesticide concentration increased with time after the pesticide application, and it reached a pseudo-steady-state plateau. Less than 8% of the adsorbed simazine desorbed back into the column effluent by 15 days after the influent was switched to simazine-free water. The simazine desorbed from the upper part of the bed was re-adsorbed in the lower part, keeping the effluent concentration at a low level. In the pseudo-steady-state, the removal rate was described by a first order kinetic reaction for the pesticide concentration. The evaluation of removal rate modulus value revealed the profile of loaded pesticide-competitive NOM with depth. The pesticide-competitive NOMs were different for each pesticide. The percentage of the simazine-competitive NOM to the whole NOM increased after UF membrane filtration (molecular weight cutoff 1K), but not for the asulum-competitive NOM.
Research Article|January 01 2002
Pesticide removal by GAC preloaded with natural organic matter
Water Science and Technology: Water Supply (2002) 2 (1): 147-154.
Y. Matsui, K. Iwaki, M. Uematsu, A. Yuasa; Pesticide removal by GAC preloaded with natural organic matter. Water Science and Technology: Water Supply 1 January 2002; 2 (1): 147–154. doi: https://doi.org/10.2166/ws.2002.0019
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