Adsorption of the fungicide carbendazim on activated carbon: analysis of isotherms, kinetics, rapid small-scale column tests, and impacts of the presence of organic matter

The adsorption of the fungicide carbendazim (CBZ) on granular activated carbon (GAC) made from bovine bone was investigated in deionized water (DW) and DW with the addition of natural organic matter (DWNOM). The study included tests of isotherms, kinetics, and rapid small-scale column tests (RSSCT). The Freundlich model represented better the adsorption of the fungicide in both matrices, while the pseudo-second-order model fitted better in DW. The isotherm and kinetic studies showed the interference of NOM in the adsorption of CBZ through changes in the parameters of the applied models. In RSSCT, the breakthrough time was faster in DWNOM than in DW. Nevertheless, the CBZ concentrations of both matrices were considered statistically similar for most contact times in RSSCT. In the fixed-bed experiments, the organic matter did not cause significant changes in the adsorption of CBZ in GAC. The NOM presence may have improved the efficiency of GAC in adsorbing CBZ in kinetic and RSSCT tests. There is no knowledge of a similar approach to studying the adsorption of CBZ on GAC in Brazil, mainly using fixed-bed studies. In this way, the present work contributes to a better understanding of the adsorption of carbendazim through the methods used. HIGHLIGHTS Bovine bone GAC removed carbendazim in deionized water (DW) and deionized water with the addition of natural organic matter (DWNOM).; Freundlich isotherm and pseudo-second-order equation fitted better the adsorption of CBZ in DW and DWNOM.; There was a 72% reduction in the Freundlich constant (Kf) of the isotherm with DWNOM compared to DW.; The interference of NOM was not significant in the adsorption of CBZ on RSSCT.;