Biosorption characterization of herbicides, 2,4-D and atrazine, and two chlorophenols on fungal mycelium

Biosorption of the 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4-dichlorophenol (2,4-DCP), 4-chlorophenol (4-CP) and 2-chloro-ethylamino-6-isopropylamino-1,3,5-triazine (atrazine) has been studied on the mycelium of Emericella nidulans and Penicillium miczynskii, isolated from composted wheat straw and a soil respectively. Results obtained with inactivated fungal biomass showed that a rapid adsorption on fungal cell walls surfaces was the main sorption phenomenon for the more hydrophobic molecules. This sorption was only partially reversible. With active living mycelia, additional phenomena were responsible for an increased sorption of all chemicals. This process was slow and depended on the chemical concentration. For 4-CP, it was attributed to biodegradation as demonstrated by the presence of degradation products in solution. Bioaccumulation inside the mycelium could also partially explained the results observed with living biomass for 4-CP, 2,4-DCP and 2,4-D.