BACKGROUNDThree-dimensional ordered honeycomb-like structured biomass carbon foams (BCFs) were prepared from eucalyptus sawdust using polyethylene glycol 2000 (PEG), Pluronic (R) P-123 and Pluronic (R) F-127 as structure-directing agents. The effect of different surfactants on the morphology and pore structure of BCFs, and the adsorption performance and mechanisms of metronidazole onto BCFs was clarified. RESULTSThe physicochemical characteristics of BCFs depend on the surfactant molecular structure. The adsorption process of metronidazole was spontaneous and endothermic in nature and followed a pseudo-second-order kinetic model. Metronidazole adsorption onto BCF-PEG and BCF-F127 followed the Langmuir isotherm, whereas that onto BCF-P123 followed the Freundlich isotherm. The maximum adsorption capacities for BCF-PEG, BCF-P123 and BCF-F127 were 56.40, 67.52 and 42.92mgg(-1), respectively. The adsorption mechanisms of metronidazole onto BCF-PEG and BCF-P123 were mainly hydrogen bonding, - interactions and pore filling. Hydrogen bonding and - interactions were mainly responsible for adsorption of metronidazole onto BCF-F127. CONCLUSIONAll results demonstrated that types of surfactant significantly affected the BCFs' physicochemical properties, and played an important role in controlling the adsorption characteristics of metronidazole onto BCFs. In addition, shaped BCF can be utilized as an effective, easily recovered and promising adsorbent for the removal of pollutants in wastewater. (c) 2018 Society of Chemical Industry