humic acid graft copolymer (PSt-g-HA) was prepared by graft copolymerization of Humic acid (HA) with styrene and the sorption of three selected organic pesticides, parathion-methyl, carbaryl and carbofuran by PSt-g-HA acid and untreated humic were also examined, respectively. The PSt-g-HA had relatively high aromatic carbons content because the grafted copolymerization of polystyrene entered into condensed domains in HA, whereas the removal of the polar function groups, such as carboxyl and phenolic hydroxyl group, was performed. For above reasons, the sorption capacity of three organic pestic...